"probe holder and aircraft"

Abstract

In a probe holder (17, 17.1, 17.2) for holding a temperature probe (28), wherein the probe holder (17, 17.1, 17.2) comprises a leading edge (21), the leading edge (21) at least partially has an at least essentially sharp form.

Description

[0001] INTERNATIONAL (PCT) PATENT APPLICATION

[0002] Applicant:

[0003] Pilatus Flugzeugwerke AG Pilatusstrasse 1 CH-6370 Stans SWITZERLAND

[0004] Title: “Probe Holder and Aircraft”

[0005] Technical field

[0006] The invention relates to a temperature probe holder according to the preamble of claim 1 . The invention further relates to a temperature measurement system according to claim 19, an aircraft according to claim 20 and a method according to claim 24.

[0007] Background art

[0008] Modern aircraft are typically equipped with many technical instruments, for example sensors. Such sensors are typically configured for connecting data that helps to properly operate the aircraft in a safe, reliable and comfortable manner.

[0009] One type of sensors that are typically used in airplanes are sensors which make it possible to measure the outside air temperature of an aircraft while the aircraft is traveling. Knowing the temperature of the outside air while an aircraft is traveling for example makes it possible to more precisely operate various heating systems of the aircraft. However, when sensors are placed outside the aircraft, there is often a problem with ice that accumulates on such sensors. The formation of such ice on sensors can falsify temperature measurements or even make them impossible. Existing deicing solutions for airplanes have the disadvantage that they are not able to avoid the formation of ice on outside sensors of aircraft in all configurations and all situations.

[0010] Disclosure of the invention

[0011] It is the object of the invention to overcome or to at least diminish the above-mentioned disadvantages.

[0012] This problem is solved by a probe holder for holding a temperature probe, wherein the probe holder comprises a leading edge, wherein the leading edge at least partially has an at least essentially sharp form.

[0013] The temperature probe is typically a temperature probe for measuring an outside air temperature of an aircraft, in particular an aircraft that is traveling. The probe holder is typically configured to be fixed to an exterior of an aircraft, for example to a fuselage of an aircraft or to a wing of an aircraft. When the probe holder is fixed to an aircraft, the leading edge is typically pointing in a direction of travel of the aircraft, or in other words: in a forward direction, which can also be referred to as flying direction. Stated differently, the leading edge is typically an edge of the probe holder that is pointing in the direction of travel of the aircraft when the probe holder is fixed to the aircraft. The probe holder is typically configured to receive the temperature probe and for holding it.

[0014] The expression “leading edge” is to be understood as follows: the probe holder is typically an elongated body with a certain height and a cross-section that has the form of an airfoil. Such an elongated body with a cross-section in the form of an airfoil typically has a leading edge and typically also has a trailing edge. The expression “sharp form” is to be understood in such a way that the probe holder comprises, in an area of vicinity of the leading edge, lateral segments - namely one lateral segment on each side of the leading edge - which run at least along a part of the height of the probe holder, wherein these lateral segments are formed in such a way that they create the leading edge in the area where they hit each other. For example, these lateral segments can in preferred embodiments be or comprise rounded surfaces that hit each other in such a way at the leading edge that the leading edge has a sharp form - or in other words: a pointed form. This can for example be achieved by means of two lateral segments that have the same curvature radius but for which imaginary center points of their respective curvatures do not coincide but are apart from one another. When only looking at the cross-section of a probe holder with such rounded lateral segments, a perimeter line of this cross-section would then comprise two circular arcs hitting each other at the leading edge such that a sharp leading edge along at least a part of the height of the probe holder is formed. In preferred embodiments, the circular arcs hitting each other preferably have equal radii but their center points do not coincide. In preferred embodiments, the two circular arcs have equal lengths. In other typical embodiments, the lateral segments can be or comprise straight surfaces which are formed such that they create a sharp internal angle, typically an internal angle of less than 90 degrees, preferably less than 60 degrees, more preferably less than 30 degrees or less than 20 degrees or less than 10 degrees, at the location where thy hit each other, namely at the leading edge. The expression “essentially sharp” is to be understood such that it also comprises embodiments in which the leading edge is not exactly sharp in the sense of the above definitions but can also have a very small radius of curvature, for example a radius of curvature of less than 10 mm or less than 5 mm or less than 2 mm, or can have a bluntness. The above expression “at least partially” is to be understood in such a way that the leading edge does not necessarily have to have the described essentially sharp form along the entire height of the probe holder. For example, it might in certain embodiments be sufficient if the leading edge only has a sharp form along at least 70% of the height of the probe holder or along at least 80% of the height of the probe holder or along at least 90% of the height of the probe holder. For example, in certain embodiments of the probe holder, the leading edge might not have a sharp form in respective vicinities of a foot portion and / or a head portion of the probe holder.

[0015] The inventors have found by means of analysis and experiments that when probe holders with such at least essentially sharp leading edges are exposed in icing conditions, in particular when mounted to aircraft flying at altitudes, then ice shape is kept small and not around other parts of the probe holder. This has the effect that a temperature probe installed in the probe holder, which is typically installed towards a center of the probe holder and / or at a certain distance from the leading edge, is not by accumulating ice. Therefore, aerodynamic conditions around such a probe holder are not affected by the accumulating ice and are therefore able to provide more reliable measurement results even at high travelling altitudes and / or in low temperatures.

[0016] At least in certain embodiments, the probe holder can also be described as cylinder, with the cross-section forming the base of the cylinder.

[0017] In typical embodiments, the probe holder has a height, wherein a cross-section of the probe holder is oriented orthogonally to a direction of the height, wherein the crosssection is limited by a perimeter line, wherein the perimeter line preferably comprises a first kink area and a second kink area. The expression “height” is to be understood such that it relates to a dimension of the probe holder, which typically extends between a foot portion and a head portion of the probe holder. The foot portion of the probe holder is typically configured to be attached to the aircraft, whereas the head portion is typically located away from the aircraft when the probe holder is mounted to the aircraft. The expression “cross-section” is to be understood such that it relates to an area that is obtained when the probe holder is cut in a direction perpendicular to the direction of the height. Depending on at which distance from the foot portion the probe holder is cut perpendicular to the direction of the height, different cross-sections can in principle be obtained. The perimeter line of the cross-section can also be referred to as boundary line or limitation line. The expression “kink” is to be understood broadly, for example referring to a change of direction of the perimeter line. A “kink” can also be referred to as “bend”. Accordingly, a “kink area” is a part of the perimeter line that comprises a kink. In typical embodiments, the expression “kink” is to be understood in such a way that it refers to a part of the perimeter line, where a curvature of the perimeter line changes, for example an area in which a curvature of the perimeter line changes its mathematical sign. In certain embodiments, a kink area can also be an area in which the perimeter line comprises an angle. In typical embodiments, the perimeter line moves away from a chord line of the cross-section in the kink area. In a particular embodiment, the first kink area and / or the second kink area at least partly comprise(s) three circular arcs, wherein one of the arcs is curved clockwise and merges into another circular arc which is curved anticlockwise, and which then merges into yet another circular arc which is again curved clockwise. In other embodiments, the three circular arcs are curved in the opposite directions, namely anticlockwise - clockwise - anticlockwise. In typical embodiments, the first kink area and / or the second kink area comprise(s) two segments which touch each other at an angle, in particular at an angle between 120 degrees and 180 degrees.

[0018] The inventors have found that arranging two kink areas in the perimeter line of the cross-section of the probe holder, and thereby typically creating two elongated kink lines along the probe holder, can lead to a probe holder that is sufficiently thick at a center part such that a temperature probe can be hosted there and that on the other hand tapers off in such a way towards the leading edge that a sharp leading edge is formed. Such a design of the probe holder then makes it possible to make sure that any accumulating ice on the probe holder has a shape that does not negatively impact the temperature measurements of the temperature probe.

[0019] In typical embodiments, the cross-section is essentially identical over the entire height and / or the perimeter line is essentially identical over the entire height. This typically means that the cross-section of the probe holder is unchanged over essentially the entire height of the probe holder. Like that, two elongated kink lines or kink areas are obtained which run along the height of the temperature probe. In such cases, the probe holder typically has the form of an elongated body with a constant cross-section. In this regard, the expression “essentially” is to be understood such that small variations of the cross-section and / or the perimeter line are acceptable, for example towards the two ends of the probe holder, namely towards the foot portion or the head portion. For example, a probe holder in which the cross-section is identical over at least 90% or at least 93% or at least 95% or at least 97% of the height for example and is different in at most 10% or at most 7% or at most 5% or at most 3% of the height for example, wherein the area(s) where the cross-section is different is / are typically located at the foot portion and / or at the head portion of the probe holder, could in certain embodiments be a probe holder in which the cross-section is essentially identical over the entire height. Accordingly, a perimeter line which at certain distances from the foot portion of the probe holder (or in other words: at certain fractions of the height) is for example locally perforated due to for example through holes in the probe holder would also be considered a probe holder in which the perimeter line is essentially identical over the entire height. One could also say that a probe holder in which the perimeter line of the cross-section is identical over at least 90% or at least 93% or at least 95% or at least 97% of the height for example and is different in at most 10% or at most 7% or at most 5% or at most 3% of the height for example, wherein the area(s) where the perimeter line of the cross-section is different is / are typically located at fractions of the height of the probe holder, where the probe holder comprises one or more through holes, could in certain embodiments be a probe holder in which the perimeter line of the cross-section is essentially identical over the entire height. In other words, a perimeter line that comprises one or more perforations, especially perforations due to through holes in the probe holder, is to be considered a perimeter line that is essentially identical to a perimeter line that does not comprise such through holes but that is otherwise identical to the perimeter line with the perforation(s).

[0020] In typical embodiments, the cross-section has a chord line and is symmetrical with respect to the chord line. It is to be understood such that the cross-section of the probe holder can have the form of an airfoil, in particular a symmetrical airfoil which is symmetrical with respect to the chord line. The inventors have found that such a form of the probe holder is advantageous, for example because good ice accumulation control capacities can be obtained by such a probe holder and at the same time such a probe holder is not too difficult to manufacture.

[0021] In typical embodiments, the fist kink area comprises at least a part of a first segment, in particular a first circular arc, wherein, preferably, a concavity formed by the first circular arc is facing away from the chord line. One could also say, that in such a case, the concavity formed by the first circular arc is facing away from the cross-section. In typical embodiments, an imaginary center point of an imaginary circle of which the first circular arc would form part is located on a side of the first circular arc that is opposite to the side of the first circular arc where the chord line is located. The expression “facing away” can be understood such that an imaginary centerline of the concavity form by the first circular arc that is pointing upwards from a bottom of the concavity formed by the first circular arc is pointing away from the chord line at an angle between the 0 degrees and 90 degrees. The inventors have found that such a first circular arc as part of the perimeter line is a comparably simple and yet very efficient way of creating a kink in the first kink area. In certain embodiments, the first segment is or comprises the first circular arc.

[0022] In typical embodiments, the second kink area comprises at least a part of a second segment, in particular a second circular arc, wherein, preferably, a concavity formed by the second circular arc is facing away from the chord line. One could also say that, in such a case, the concavity formed by the second circular arc is facing away from the cross-section. In typical embodiments, an imaginary center point of an imaginary circle of which the second circular arc would form part is located on a side of the second circular arc that is opposite to the side of the second circular arc where the chord line is located. Also here, the expression “facing away” can be understood such that an imaginary centerline of the concavity formed by the second circular arc that is pointing upwards from a bottom of the concavity formed by the second circular arc is typically pointing away from the chord line at an angle between 0 degrees and 90 degrees. The inventors have found that especially a combination of a first kink area with a first circular arc as described above and a second kink area with such a second circular arc can lead to a probe holder that is able to control the formation of ice efficiently, in particular because any accumulating ice, which at least mainly accumulated along the at least essentially sharp leading edge, cannot negatively impact the measurements of the temperature probe. In certain embodiments, the second segment is or comprises the second circular arc.

[0023] In typical embodiments, the first circular arc has a radius of approximately 20 mm, and / or the second circular arc has a radius of approximately 20 mm, and / or the first segment, in particular the first circular arc, and second segment, in particular the second circular arc, are symmetrical with respect to the chord line. In general, throughout the claims and throughout the specification, the expression “approximately” shall be understood as referring to an acceptable tolerance of up to + / - 20 %, preferably up to + / - 15 %, more preferably up to + / - 10 % or up to + / - 5 % or up to + / - 1 %. The inventors have found that such a radius is particularly advantageous for obtaining a tapering towards the leading edge of the probe holder which controls the formation of ice on the probe holder in such a way that it does not negatively affect temperature measurements carried out by a temperature probe arranged in the probe holder, in particular arranged at or around the center of the probe holder. In typical embodiments, the perimeter line comprises a third segment, preferably a third circular arc, wherein the third circular arc preferably has a radius of approximately 50 mm. In typical embodiments, the perimeter line comprises a fourth segment, preferably a fourth circular arc, wherein the fourth circular arc preferably has a radius of approximately 50 mm. In typical embodiments, the perimeter line comprises a fifth segment, preferably a fifth circular arc, wherein the fifth circular arc preferably has a radius of approximately 2 mm. In typical embodiments, the perimeter line comprises a sixth segment, preferably a sixth circular arc, wherein the sixth circular arc preferably has a radius of approximately 2 mm. In typical embodiments, the perimeter line comprises a seventh segment, preferably a seventh circular arc, wherein the seventh circular arc preferably has a radius of approximately 35 mm. In typical embodiments, the perimeter line comprises an eighth segment, preferably an eighth circular arc, wherein the eighth circular arc preferably has a radius of approximately 35 mm. In typical embodiments, the perimeter line comprises a ninth segment, preferably a ninth circular arc, wherein the ninth circular arc preferably has a radius of approximately 25 mm. In typical embodiments, the perimeter line comprises a tenth segment, preferably a tenth circular arc, wherein the tenth circular arc preferably has a radius of approximately 25 mm. In typical embodiments, the perimeter line comprises an eleventh segment, preferably an eleventh circular arc, wherein the eleventh circular arc preferably has a radius of approximately 60 mm. In typical embodiments, the perimeter line comprises a twelfth segment, preferably a twelfth circular arc, wherein the twelfth circular arc preferably has a radius of approximately 60 mm.

[0024] In preferred embodiments, the first segment, in particular the first circular arc, has a length projected on the chord line of approximately 4.9 mm. In preferred embodiments, the second segment, in particular the second circular arc, has a length projected on the chord line of approximately 4.9 mm. In preferred embodiments, the third segment, in particular the third circular arc, has a length projected on the chord line of approximately 11.4 mm. In preferred embodiments, the fourth segment, in particular the fourth circular arc, has a length projected on the chord line of approximately 11 .4 mm. In preferred embodiments, the fifth segment, in particular the fifth circular arc, has a length projected on the chord line of approximately 1.1 mm. In preferred embodiments, the sixth segment, in particular the sixth circular arc, has a length projected on the chord line of approximately 1.1 mm. In preferred embodiments, the seventh segment, in particular the seventh circular arc, has a length projected on the chord line of approximately 3.9 mm. In preferred embodiments, the eighth segment, in particular the eighth circular arc, has a length projected on the chord line of approximately 3.9 mm. In preferred embodiments, the ninth segment, in particular the ninth circular arc, has a length projected on the chord line of approximately 13.5 mm. In preferred embodiments, the tenth segment, in particular the tenth circular arc, has a length projected on the chord line of approximately 13.5 mm. In preferred embodiments, the eleventh segment, in particular the eleventh circular arc, has a length projected on the chord line of approximately 15.2 mm. In preferred embodiments, the twelfth segment, in particular the twelfth circular arc, has a length projected on the chord line of approximately 15.2 mm. The expression “length projected on the chord line” is to be understood such that it describes a spatial extension of the respective segment, in particular the respective circular arc, along the direction of the chord line.

[0025] The inventors have found that such radii and dimensions are particularly advantageous for controlling the formation of ice on the probe holder in such a way that any accumulating ice does not negatively impact the measurements of a temperature probe located inside the probe holder.

[0026] In typical embodiments, the third and the fourth segment are symmetrical with respect to the chord line and / or the fifth segment and the sixth segment are symmetrical with respect to the chord line, and / or the seventh segment and the eighth segment are symmetrical with respect to the chord line, and / or the ninth segment and the tenth segment are symmetrical with respect to the chord line, and / or the eleventh segment and the twelfth segment are symmetrical with respect to the chord line. In each of these pairs of segments the two segments can of course have the form of circular arcs, in particular. It is then the respective circular arcs that are symmetrical with respect to the chord line.

[0027] In preferred embodiments, the probe holder comprises a trailing edge, wherein the leading edge is preferably more pointed than the trailing edge. In typical embodiments, the leading edge is more pointed than the trailing edge over the entire length of the leading edge. In preferred embodiments, the trailing edge is flat. In other words, the trailing edge is typically of rectangular shape over the entire height of the probe holder and is not pointed. In general, in the cross-section, the leading edge is preferably the point where the fifth segment and the sixth segment touch each other. Furthermore, in the perimeter line of the cross-section, the trailing edge is typically a straight line that is perpendicular to the chord line, wherein the length of this straight line is typically approximately 3 mm. The straight line that corresponds to the trailing edge in the perimeter line of the cross-section is typically symmetrical with respect to the chord line. In typical embodiments, in the perimeter line, the straight line that corresponds to the trailing edge connects the eleventh segment to the twelfth segment.

[0028] In preferred embodiments, the probe holder comprises two kink lines, wherein the leading edge and / or the trailing edge and / or both kink lines preferably each have the length of the height, at least approximately, and / or wherein the leading edge and the trailing edge and both kink lines preferably run along the height of the probe holder in parallel, at least essentially. Such a configuration of the probe holder has the advantage of efficiently controlling the formation of ice over essentially the entire height of the probe holder, in particular by making at least a large part of any accumulating ice accumulate around the leading edge, and thereby minimize any negative impact of accumulating ice on the measurements of a temperature probe carried by the probe holder at a location at sufficient distance from the leading edge.

[0029] In typical embodiments, the probe holder comprises a probe bore for receiving the temperature probe, wherein the probe bore preferably runs along the height of the probe holder, preferably in parallel with the leading edge and / or the trailing edge and / or both kink lines. In typical embodiments, the probe bore comprises two areas, in particular, two symmetrical areas, wherein the first area has a larger diameter than second area and wherein the first area is typically located on top of the second area when the probe holder is placed on its foot portion with the head portion sticking out to the top. In typical embodiments, the first area and the second area are hollow cylinders which are superimposed in the direction of the height of the probe holder. The second area typically has a height of approximately 1 .5 mm. The first area typically has a height of approximately 20.5 mm. The first area typically has a diameter of approximately 9 mm. The second area preferably has a diameter of approximately 5.2 mm. In typical embodiments, the diameter of the first area is 68% to 78%, preferably 70% to 76%, larger than the diameter of the second area. In typical embodiments, the diameter of the first area is approximately 73% larger than the diameter of the second area. The fact of making the first area larger than the second area has the advantage of enabling a sufficient airflow around a temperature probe inserted into the probe bore in the first area and at the same time assuring a tight fit of the temperature probe inside the second area. In typical embodiments, the probe bore is at least approximately in an area of the probe holder where the cross-section of probe holder has its largest thickness. In this regard, it shall be pointed out that the thickness of the cross-section of the probe holder is measured in a direction perpendicular to the height of the probe holder and also perpendicular to the chord line of the crosssection.

[0030] In preferred embodiments, the probe holder comprises a multitude of through holes, preferably eight through holes, preferably four through holes on a first side of the probe holder and four through holes on a second side of the probe holder, wherein the through holes are preferably of cylindrical shape and / or wherein the through holes are preferably all arranged with parallel longitudinal axes, wherein all these parallel longitudinal axes are preferably perpendicular to the direction of the height of the probe holder, and / or wherein all through holes preferably link an exterior of the probe holder to the probe bore. The trough holes can also be referred to as lateral openings. In particular embodiments, these lateral openings lead from an outside of the probe holder into the first area of the probe bore. In particular embodiments, four lateral openings are aligned with the ninth circular arc, in particular with the center of the ninth circular arc, and four lateral openings are aligned with the tenth circular arc, in particular with the center of the tenth circular arc. The expression “aligned with” is to be understood in such a way that it means that the lateral openings are in contact with an exterior of the probe holder in areas where the ninth circular arc or the tenth circular arc have their position in the perimeter line, but wherein the lateral openings are of course only present at certain distances along the height of the probe holder. Due to the comparably thick body form of the probe holder around the probe bore, the air pressure drops at an outside of the probe holder at the location of the through holes when the probe holder is exposed to an airflow, in particular during the flight of an airplane to which the probe holder is attached. This drop in air pressure is due to the Bernoulli effect. This lower pressure outside of the body of the probe holder at the location of the through holes will suck air through the probe bore and thus lead to an appropriate airflow inside the probe bore where a temperature probe can be installed. In particular, such a design will create an air flow between an opening of the probe bore located at the head portion of the probe holder and the outer openings of the trough holes, where the above-mentioned pressure drop occurs due to the Bernoulli effect.

[0031] In typical embodiments, the probe holder comprises a first fixation hole and a second fixation hole, wherein the fixation holes are preferably both arranged in parallel with the probe bore, wherein the first fixation hole is preferably arranged between the probe bore and the trailing edge, wherein the second fixation hole is preferably arranged between the probe bore and the leading edge, wherein a distance between a longitudinal axis of the first fixation hole and a longitudinal axis of the probe bore preferably equals a distance between a longitudinal axis of the second fixation hole and the longitudinal axis of the probe bore. In typical embodiments, each fixation hole comprises a countersink wherein the countersinks are typically arranged on the head portion of the probe holder.

[0032] In preferred embodiments, in the perimeter line, the first segment is connected to the third segment and the third segment is connected to the fifth segment, and the fifth segment is connected to the sixth segment, and the sixth segment is connected to the fourth segment, and the fourth segment is connected to the second segment, and the second segment is connected to the eighth segment, and the eighth segment is connected to the tenth segment, and the tenth segment is connected to the twelfth segment, and the eleventh segment is connected to the ninth segment, and the ninth segment is connected to the seventh segment, and the seventh segment is connected to the first segment. The expression “connected” is to be understood in the sense of “directly connected". One could for example also say that the first segment merges into the third segment, and the third segment merges into the fifth segment, and so on. One could also say that the first segment touches the third segment, and the third segment touches the fifth segment, and so on. In typical embodiments, the first segment and the second segment are convex when seen from the chord line and / or from probe bore. In typical embodiments, the third segment and / or the fourth segment and / or the fifth segment and / or the sixth segment and / or the seventh segment and / or the eighth segment and / or the ninth segment and / or the tenth segment and / or the eleventh segment and / or the twelfth segment is / are concave when seen from the chord line and / or from the probe bore.

[0033] In preferred embodiments, the twelve segments mentioned above are preferably all circular arcs. In preferred embodiments, in the perimeter line, the eleventh segment is preferably connected to a straight line corresponding to the trailing edge, and the twelfth segment is also connected to this straight line in the perimeter line. This straight line can also be referred to as thirteenth segment of the perimeter line. Once again, “connected” in this regard means “directly connected” and is to be understood in the sense of “merges” or “touches”. One could also say that the eleventh element and the twelfth element are both connected to the trailing edge, because the straight line is of course a specific part of the trailing edge, namely the specific portion of the trailing edge at the fraction of the height to which the cross-section corresponds.

[0034] In typical embodiments, the first kink area and the second kink area are located between the leading edge and the probe bore. The expression “between the leading edge and the probe bore” means that when the shortest possible connection line is drawn between the two kink areas - which are typically arranged symmetrically with respect to the chord line of the cross-section of the probe holder - then this connection line intersects with the chord line in a perpendicular manner at an intersection point. This intersection point is then located between the leading edge and the probe bore. This intersection point is then not located between the trailing edge and the probe bore.

[0035] In particular embodiments, one, some or all of the segments mentioned above are numbered differently.

[0036] A temperature measurement system according to the invention comprises a probe holder according to any of the previously described embodiments and a temperature probe, wherein the temperature probe is at least partly, preferably completely, arranged inside the probe holder. In typical embodiments, the temperature probe has a cylindrical form and is arranged inside the probe bore. An aircraft according to the invention comprises a probe holder according to any of the embodiments described above and / or a temperature measurement system as described above. In typical embodiments, the aircraft is an airplane, in particular a turbo-prop airplane, wherein the airplane typically comprises a single propeller engine arranged at the nose of the airplane. The probe holder is typically installed on the aircraft in such a way that the leading edge of the probe holder is pointing in the flying direction of the aircraft.

[0037] In typical embodiments, the probe holder is attached to a wing of the aircraft, in particular to an underside of the wing of the aircraft. Arranging the probe holder in such a way is particularly advantageous in the case where the aircraft is a turbo-prop airplane with a single engine arranged at its nose, for example because in such a case it has proven advantageous to leave a certain distance between the engine and the position of the probe holder where a temperature of an outside of the airplane is to be detected.

[0038] In typical embodiments, the probe holder is mounted in such a way at the underside of the wing that a distance between the probe holder and a wing root of the wing, preferably a distance between the longitudinal axis of the probe bore and the wing root of the wing, equals between 90% and 40%, preferably between 85% and 55%, more preferably between 80% and 70%, even more preferably approximately 75% of a length of the wing. In this regard, the expression “length of the wing” is to be understood such that it corresponds to a distance between the wing root and the wing tip, wherein its distance is preferably measured in a direction perpendicular to a longitudinal axis of the aircraft.

[0039] It shall be pointed out that it is not absolutely necessary to install the probe holder and / or the temperature measurement system on the wing of the aircraft. It is rather also possible to for example install the probe holder and / or the temperature measurement system on a fuselage of the aircraft, for example near the nose of the aircraft.

[0040] In preferred embodiments, the aircraft comprises a second probe holder according to any of the embodiments described above or a second temperature measurement system as described above, such that the aircraft preferably comprises either two identical probe holders or two identical temperature measurement systems, wherein the second probe holder or the second temperature measurement system is preferably arranged in a manner corresponding to the probe holder or the temperature measurement system on another side of the aircraft. In this regard the expression “another side” is to be understood as referring to either the starboard side or the port side of the aircraft, depending on whether the first probe holder or the first temperature measurement system is installed on starboard or on port of the aircraft. Such an aircraft with two identical probe holders or with two identical temperature measurement systems will therefore then have one of these probe holders or one of the temperature measurement systems on its starboard side and the respective other one on its port side. The expression “corresponding” means for example a same position on the wing of the other side or a same position on the fuselage, but on the other side of the aircraft. One can imagine that the two probe holders or the two temperature measurement systems are in such cases arranged as if they were mirrored through a vertical plane that passes through the longitudinal axis of the airplane. In typical embodiments, the second probe holder is attached to a wing of the aircraft to which the first probe holder is not attached, in particular to an underside of that wing of the aircraft. In typical embodiments, the second probe holder is mounted in such a way at the underside of the wing that a distance between the probe holder and a wing root of the wing to which it is mounted, preferably a distance between the longitudinal axis of the probe bore and the wing root of that wing, equals between 90% and 40%, preferably between 85% and 55%, more preferably between 80% and 70%, even more preferably approximately 75% of a length of that wing. In typical embodiments, the distances between the longitudinal axes of the probe bores of the two probe holders and the wing roots of the respective wings to which the probe holders are attached are equal.

[0041] In a method for heating propeller blades in an aircraft according to any of the embodiments described above, the method uses an outside air temperature measured by a first temperature measurement system according to the invention for determining a heating mode for heating the propeller blades, wherein the method preferably uses an outside air temperature measured by a second temperature measurement system according to the invention to validate the outside air temperature measured by the first temperature measurement system. Like this, it becomes possible to choose a most appropriate heating mode for heating the propeller blades for each outside air temperature, and it becomes furthermore possible to double-check the temperature measurements acquired by the first temperature measurement system by determining the outside air temperature also by measurements carried out by the second temperature measurement system and by then comparing the measurements of both temperature measurement systems.

[0042] Short description of figures

[0043] In the following, the invention is described in detail by means of drawings, wherein show:

[0044] Figure 1 : a perspective view of a probe holder according to one preferred embodiment,

[0045] Figure 2: a zoom-in view of a particular area of the probe holder shown in Figure 1 ,

[0046] Figure 3: a top view of the probe holder shown in Figure 1 ,

[0047] Figure 4: a side view of the probe holder shown in Figure 1 ,

[0048] Figure 5: a first cross-sectional view of the probe holder shown in Figure 1 ,

[0049] Figure 6: a second cross-sectional view of the probe holder shown in Figure 1 ,

[0050] Figure 7: a bottom view of the probe holder shown in Figure 1,

[0051] Figure 8: a view of a cut through probe holder shown in Figure 1 in the direction of its height,

[0052] Figure 9: the cut-view of Figure 8 turned upside down, with a temperature probe mounted inside the probe holder, and Figure 10: an aircraft according to one preferred embodiment.

[0053] Description of preferred embodiments

[0054] Figure 1 shows a perspective view of a probe holder according to one preferred embodiment of the invention. In particular, Figure 1 shows a probe holder 17. The probe holder 17 has a height 35. The probe holder 17 comprises a first fixation hole 19.1 and a second fixation hole 19.2. The first fixation hole 19.1 comprises a first countersink 20.1 and the second fixation hole 19.2 comprises a second countersink 20.2. The fixation holes 19.1 , 19.2 run through the probe holder 17 in the direction of the height 35 of the probe holder 17. By means of e.g. screws (not shown in Figure 1), which can be inserted into the fixation holes 19.1 , 19.2, and which will then run through the fixation holes 19.1 , 19.2, the probe holder 17 can be attached to an aircraft (also not shown in Figure 1), for example to an underside of a wing of such an aircraft. If the probe holder 17 shown in Figure 1 is screwed to the underside of a wing of an aircraft as described, the portion of the probe holder 17 that is shown on top of the probe holder 17 in Figure 1 will of course point downwards from the wing. Nevertheless, the portion that is on top of the probe holder 17 in Figure 1 is referred to as head portion of the probe holder 17. The probe holder 17 furthermore comprises a probe bore 16 which also runs through the probe holder 17 in the direction of the height 35 of the probe holder 17. A temperature probe (not shown in Figure 1) can be inserted into the probe bore 16, namely from the bottom side of the probe holder 17 as shown in Figure 1. The probe holder 17 furthermore comprises eight through holes of which only five through holes 18.1 , 18.2, 18.4, 18.3, 18.5 are visible in Figure 1. The through holes 18.1 , 18.2, 18.4, 18.3, 18.5 each run through a part of the probe holder 17 in a direction perpendicular to the direction of the height 35 of the probe holder 17. The four through holes 18.1 , 18.2, 18.3, 18.4 run from a right side of the probe holder 17 (this is the side that is visible to the viewer in Figure 1) into the probe bore 16. They thereby each create a channel between the outside of the probe holder 17 and the probe bore 16. In perfect analogy, the through hole 18.5 (and three more through holes which are not visible in Figure 1) run through a left side of the probe holder 17 and connect the left outside of the probe holder 17 with the probe bore 16. The through holes 18.1 , 18.2, 18.3, 18.4, 18.5 and the three through holes not visible in Figure 1 make it possible to create a pressure drop that sucks outside air (of which the temperature is supposed to be measured) into and through the probe bore 16, where said temperature probe can be arranged. The probe holder 17 in Figure 1 can be described as a cylindrical body with a base 14.1. Such a cylindrical body does therefore not have a round base but rather the more complex base 14.1 . The base 14.1 can also be referred to as cross-section 14.1 (and will be called so in the following). As can be understood from Figure 1, the cross-section 14.1 is an area perpendicular to the direction of the height 35 of the probe holder 17.

[0055] If one imagines that the probe holder 17 is cut in a direction parallel to the cross-section 14.1 , one will obtain another cross-section which shall be referred to as being identical (or at least essentially identical) to the cross-section 14.1 . In this regard, it shall be pointed out that the presence of the probe bore 16, the two fixation holes

[0056] 19.1 , 19.2 and the countersinks 20.1 , 20.2 shall be considered to not have any influence on the cross-section 14.1 and / or any other cross-section of the probe holder 17. In other words, a cross-section that is arranged at a fraction of e.g. 50 % of the height 35 of the probe holder 17 and that this is parallel with the cross-section 14.1 will be considered essentially identical to the cross-section 14.1, even though it will not comprise the countersinks 20.1 , 20.2. The cross-section 14.1 is limited by a perimeter line

[0057] 13.1 , In analogy to what has been said concerning the cross-section 14.1 and any other cross-section of the probe holder 17, an infinite number of such perimeter lines are in principle present along the height 35 of the probe holder 17. In Figure 1, a second perimeter line 13.2 and a fifth perimeter line 13.5 are explicitly visible and equipped with reference signs. In other words, the perimeter lines 13.1 , 13.2, 13.5 are identical along the entire length 35 of the probe holder 17, at least essentially. “At least essentially” for example means that a slanted edge (see Figure 2 for details) that is present between the first perimeter line 13.1 and the fifth perimeter line 13.5 is neglectable when it comes to comparing the forms of the three perimeter lines 13.1 ,

[0058] 13.2, 13.5: these perimeter lines 13.1 , 13.2, 13.5 will rather still be considered essentially identical. One can therefore say that the probe holder 17 shown in Figure 1 has a cross-section that is essentially identical over the entire height 35 and also that the cross-section is limited by a perimeter line that is essentially identical over the entire height 35. This identical perimeter line comprises a multitude of segments. In particular, the perimeter line of the probe holder 17 shown in Figure 1 comprises thirteen segments. Of these thirteen segments, eight segments are equipped with reference signs in Figure 1. In particular, the second perimeter line 13.2 comprises a first segment 1 , a third segment 3, fifth segment 5, a sixth segment 6, a seventh segment 7, a ninth segment 9 and an eleventh segment 11. The segments 1, 3, 5, 7, 9, 11 are arranged on the right side of the probe holder 17. The sixth segment 6, which is only partially visible in Figure 1 is part of the left side of the probe holder 17 and therefore only partially visible in Figure 1 . The segments 1 , 3, 5, 6, 7, 9, 11 are all circular arcs with certain radii, wherein the radii of the fifth segment 5 and the sixth segment 6 are identical. From Figure 1 it also becomes clear that the perimeter line comprises a thirteenth segment forming a straight line 15 in the perimeter line. This straight line 15 is part of a trailing edge 15 of the probe holder 17 and is visible only in the first perimeter line 13.1. In other words: the straight line 15, visible as part of the perimeter line 13.1 in the probe holder 17 in Figure 1, is part of a trailing edge 15 of the probe holder 17. The probe holder 17 furthermore comprises a leading edge 21 which is a line running in the direction of the height 35 along the height 35 of the probe holder 17 and which is formed at the intersection of the fifth segment 5 and the sixth segment 6. The probe holder 17 also comprises two rounded lateral segments 39.1 , 39.2. It can be observed that the leading edge 21 has a sharp form along the entire height 35 of the probe holder 17. This sharp form is created where the two rounded lateral segments 39.1 , 39.2 of the probe holder 17 hit each other. Figure 1 furthermore shows a zoom-in area Z which is a zoom-in of one part of the perimeter lines 13.1 , 13.5. The zoom-in Z is shown in more detail in Figure 2. The inventors have found that the sharp form of the leading edge 21 makes it possible to make is predominantly accumulate in the area of the leading edge 21 , whereby the negative effect of the accumulating ice on the measurements of a temperature probe (not shown in Figure 1) insertable into the probe bore 16 can be avoided.

[0059] Figure 2 shows a magnified view of the zoom-in view Z marked by a dashed circle in Figure 1 . It can be seen in this zoom-in view Z that the perimeter line 13.1 and the perimeter line 13.5 run in parallel, wherein a miniscule slanted edge 38 is present between the perimeter line 13.1 and the perimeter line 13.5. This slanted edge 38 is supposed to be neglectable as far as the form of the perimeter lines 13.1 , 13.5 is concerned so that one can say that the probe holder 17 as shown in Figure 1 and in the subsequent Figures has a cross-section with a perimeter line that is essentially identical over the entire height 35 of the probe holder 17.

[0060] Figure 3 is a top view of the probe holder shown in Figure 1 . In particular, Figure 3 shows the probe holder 17 with the perimeter line 13.5, wherein the perimeter line 13.5 comprises the first segment 1 , the second segment 2, the third segment 3, the fourth segment 4, the fifth segment 5, the sixth segment 6, the seventh segment 7, the eighth segment 8, the ninth segment 9, the tenth segment 10, the eleventh segment 11 and the twelfth segment 12. Furthermore, the straight line 15 of the perimeter line 13.5, which is part of the trailing edge 15 of the probe holder 17, is shown in Figure 3. The straight line 15 can be referred to as thirteenth segment. It becomes clear from Figure 3, that all segments 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12 are circular arcs and only the thirteenth segment 15 (also referred to as straight line 15 or trailing edge 15) is straight. The cross-section of the probe holder 17 shown in Figure 3 can be described as an airfoil, in particular an airfoil which is symmetrical to a chord line 23. Throughout this description, the chord line 23 is also referred to as chord line 23 of the cross-section of the probe holder 17. The cord line 23 is the shortest connection between the trailing edge 15 and the leading edge 21 of the cross-section of the probe holder 17. The first segment 1 and the second segment 2, when seen from the chord line 23, each form a convexity. The segments 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, however, form concavities when seen from the chord line 23. An effect of this is, that two kink areas 22.1 , 22.2 are formed in the perimeter line 13.5 of the cross-section of the probe holder 17. As a matter of fact, a change of direction is formed in the first kink area 22.1 that can be referred to as kink or bend. One reason for the occurrence of this kink in the first kink area 22.1 is the fact that, in the view shown in Figure 3, the seventh segment 7 is a circular arc curved towards the chord line 23, the first segment 1 is a circular arc curved away from the chord line 23 and the third segment 3 is again a circular arc curved towards the chord line 23. One can also say that the first kink area 22.1 comprises a kink that is at least partly formed by a circular arc curved away from the chord line 23. One can also say that the first kink area 22.1 comprises a circular arc 1 which is drawn around an imaginary center point, wherein the imaginary center point lies on a side of the perimeter line 13.5 which is opposite to the side of the perimeter line 13.5 on which the chord line 23 is located. Since the perimeter line 13.5 is perfectly symmetrical with respect to the chord line 23, everything that has been said concerning the first kink area 22.1 in principle also holds true for the second kink area 22.2 which comprises the second segment 2 and which also comprises a part of the fourth segment 4 and a part of the eighth segment 8. In particular, the first segment 1 and the second segment 2 are symmetrical with respect to the chord line 23, the third segment 3 and the fourth segment 4 are symmetrical with respect to the chord line 23 and the seventh segment 7 and the eighth segment 8 are also symmetrical with respect to the chord line 23. In general, each segment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12 has a correspondingly formed segment on the opposite side of the chord line 23. For the sake of completeness, the probe bore 16 and the two fixation holes 19.1, 19.2 are also equipped with reference sings in Figure 3.

[0061] Figure 4 shows a side view of the probe holder shown in Figure 1 . In particular, Figure 4 shows the probe holder 17 with the height 35, the trailing edge 15, the leading edge 21 , the perimeter lines 13.1 , 13.2, 13.5 as well as the four through holes 18.1, 18.2, 18.3, 18.4. Furthermore, the segments 1 , 3, 5, 7, 9, 11 of the perimeter line 13.2 are once more equipped with reference signs in Figure 4. Figure 4 furthermore shows a cut B - B and a cut C - C. Both cuts are cross-sectional views of the probe holder 17 in a direction perpendicular to the direction of the height 35. The cross-sectional view B - B is shown in Figure 5 and the cross-sectional view C - C is shown in Figure 6.

[0062] Figure 5 now shows a first cross-sectional view of the probe holder shown in the previous Figures, namely the view B - B. The probe holder 17 in Figure 5 once more shows the probe bore 16 and the two fixation holes 19.1 , 19.2. Also, the chord line 23 is shown in Figure 5. The cross-section 14.3 visible in Figure 5 is obviously a crosssection at the location of the cut line B - B in Figure 4 and is therefore located at another fraction of the height 35 of the probe holder 17 than the cross-section 14.1 that was for example shown in Figure 1 . However, as explained before, the probe holder 17 has an essentially identical cross-section of its entire height and therefore the cross-section 14.3 is essentially identical to the cross-section 14.1 indicated in Figure 1 . The cross-section 14.3 is limited by the perimeter line 13.3. which is, in turn, essentially identical to the cross-sections 13.1 , 13.2, 13.5 shown in the previous Figures. It can be seen in Figure 5 that the cross-section 13.3 is symmetrical with respect to the chord line 23 and that also the perimeter line 13.3 is symmetrical with respect to the chord line 23. The cross-section 14.3 (and the cross-section of the probe holder 17 in general) can therefore be referred to as a symmetrical airfoil.

[0063] Figure 6 shows a second cross-sectional view of the probe holder 17. As already mentioned, it is the cross-sectional view C - C indicated in Figure 4. The cross-sectional view in Figure 6 is of course very similar to the cross-sectional view B - B in Figure 5. The only difference between the cross-sectional views in Figure 6 and in Figure 5 is that in the cross-sectional view C - C in Figure 6, the two through holes 18.4, 18.8 are visible, because the cut line C - C runs through the respective middle of these through holes 18.4, 18.8. It can be seen in Figure 6, that the through holes 18.4, 18.8 each link the probe bore 16 to the exterior of the probe holder 17. Figure 6 furthermore shows the cross-section 14.4. that is limited by the perimeter line 13.4. Reference is made to what has been said regarding cross-section 14.3 and perimeter line 13.3 with respect to Figure 5. In particular, the perimeter line 13.4 is identical to the perimeter lines 13.1 , 13.2, 13.3, 13.5 shown in the previous Figures. Also, the cross-section 14.4 is identical to the previously shown cross-sections 14.1, 14.3. The fixation holes 19.1 , 19.2 as well as the chord line 23 are also visible in Figure 6.

[0064] Figure 7 shows a bottom view of the probe holder 17 shown in the previous Figures. The bottom side of the probe holder 17 shown in Figure 7 is referred to as foot portion of the probe holder 17. This foot portion comprises a cross-section 14.2 which is limited by a perimeter line 13.2. Once more, the cross-section 14.2 is at least essentially identical with the previously shown cross-sections 14.1 , 14.3, 14.4. Accordingly, the perimeter line 13.2 is also at least essentially identical with the perimeter lines 13.1 , 13.3, 13.4, 13.5 as previously shown and with all other perimeter lines along the height 35 of the probe holder 17. The bottom view in Figure 7 furthermore also shows the fixation holes 19.1 , 19.2. In order to fix the probe holder 17 to an aircraft, screws for fixing the probe holder 17 to the aircraft will stick out of the foot portion shown in Figure 7 through the fixation holes 19.1 , 19.2 and can be screwed to corresponding screw holes on the aircraft, for example on an underside of a wing of the aircraft (screws and aircraft not shown in Figure 7). Also, the probe bore 16 is shown in Figure 7. The visible diameter of the probe bore 16 in Figure 7 is smaller than the visible diameter of the probe bore 16 in the previous Figures. The reason for that is that in an area around the bottom of the probe holder 17, namely in the area of the foot portion of the probe holder 17 shown in Figure 7, the probe bore 16 is narrower than further towards the head portion of the probe holder 17. Also, the cross-section 14.2 and the perimeter line 13.2 are symmetrical with respect to a chord line of the cross-section 14.2 in Figure 7. However, this chord line is not visible in Figure 7 because a cut line A - A has been placed of top of it. The cut line A - A is therefore a cut in the direction of the height of the probe holder 17 that cuts the probe holder 17 into two symmetrical parts, namely a left part and a right part. In Figure 7 is furthermore indicated (by means of two dotted lines) an area of largest thickness 40 of the cross-section 14.2 of the probe holder 17. The probe bore 16 is located in this area of largest thickness 40.

[0065] Figure 8 is a view of this cut through the probe holder 17 in the direction of its height. In particular, in Figure 8 the cut A - A indicated in Figure 7 is shown. In the cut view in Figure 8, the two fixation holes 19.1 , 19.2 with the respective countersinks 20.1 , 20.2 are visible. The fixation hole 19.1 has a longitudinal axis 24.1 and the fixation hole 19.2 has a longitudinal axis 24.2. Figure 8 also shows a cut through the entire probe bore 16. The probe bore 16 has a longitudinal axis 25. Furthermore, the probe bore 16 comprises a first area 26 and a second area 27, wherein the first area 26 is arranged on top of the second area 27 in the view shown in Figure 8. A diameter of the first area 26 is larger than a diameter of the second area 27. The longitudinal axes 24.1 , 24.2 of the fixation holes 19.1 , 19.2 and the longitudinal axis 25 of the probe bore 16 all run in parallel in a direction of the height of the probe bore 17. A distance between the longitudinal axis 24.1 of the first fixation hole 19.1 and the longitudinal axis 25 of the probe bore 16 equals a distance between the longitudinal axis 24.2 of the second fixation hole 19.2 and the longitudinal axis 25 of the probe bore 16. Also visible in Figure 8 are the four through holes 18.5, 18.6, 18.7, 18.8.

[0066] Figure 9 now shows the cut-view of Figure 8 turned upside down, with a temperature probe 28 mounted inside the probe holder 17. One can see that the temperature probe 28 runs through the second area 27 of the probe bore 16 and also runs at least partly through the first area 26 of the probe bore 16. The temperature probe 28 comprises a temperature probe connection means 29 which can for example comprise a cable. The combination of the probe holder 17, the temperature probe 28 and the temperature probe connection means 29 can be regarded as a particular embodiment of a temperature measurement system according to one embodiment of the invention.

[0067] Figure 10 now shows a schematic view of an aircraft according to one preferred embodiment of the invention. In particular, Figure 10 shows an aircraft 30 which is in particular a single engine propeller airplane with a propeller 34 mounted at the nose of the airplane. The aircraft 30 comprises a first wing 31 .1 and a second wing 31 .2. In typical embodiments, the wings 31 .1 , 31.2 are straight wings, meaning that they both extend in a perpendicular direction away from a fuselage of the aircraft 30. The first wing 31 .1 comprises a wing root 32.1 and a wing tip 33.1. Mounted to an underside of the wing

[0068] 31 .1 is a first probe holder 17.1 . The first probe holder 17.1 can for example correspond to the probe holder 17 described by means of Figures 1 to 9. Figure 10 indicates also a distance 36 between the wing root 32.1 and the first probe holder 17.1 , as well as a distance 37 between the wing root 32.1 and the wing tip 33.1. In the embodiment shown in Figure 10, the distance 36 between the wing root 32.1 and the probe holder

[0069] 17.1 corresponds to approximately 75 % of the distance 37 between the wing root 32.1 and the wing tip 33.1 . The distance 36 between the wing root 32.1 and the first probe holder 17.1 is in particular the distance between the wing root 32.1 and a center of the first probe holder 17.1 (the center is of course located on the longitudinal axis of the probe bore of the probe holder 17.1) wherein this distance 36 is measured in a direction perpendicular to a propeller axis of the aircraft 30. The propeller axis is the rotation axis of the propeller 34 and is not explicitly indicated in Figure 10 for reasons of clarity. The described position of the first probe holder 17.1 on the underside of the first wing

[0070] 31.1 shall be referred to as “75%-position”. The second wing 31.2 is arranged on the aircraft 30 in a manner corresponding to the first wing 31.1. Accordingly, the second wing 31 .2 comprises a second wing root 32.2 and a second wing tip 33.2. Furthermore, on the underside of the second wing 31.2, a second probe holder 17.2 is arranged. This second probe holder 17.2 is also arranged at a 75%-position corresponding to the 75%-position as explained with respect to first wing 31.1. In typical embodiments, the first probe holder 17.1 and the second probe holder 17.2 are identical probe holders and hold identical temperature probes. In typical embodiments, these two temperature probes are used in a method for heating the blades of the propeller 34, wherein one of the probe holders 17.1 , 17.2 is used for measuring an outside air temperature of the aircraft 30 and to then use this measured temperature for determining a heating mode for heating the propeller blades of the propeller 34, and the second probe holder 17.2 and in particular a second temperature probe arranged inside it is used for validating the outside air temperature measurement carried out by the first temperature probe arranged inside the first probe holder 17.1. The probe holders 17.1 , 17.2 are arranged such that the respective leading edges are oriented towards the flying direction of the aircraft (this is not observable in Figure 10 because the leading edges are not indicated in Figure 10 for reasons of simplicity).

[0071] The invention is not limited to the preferred embodiments described here. The scope of protection is defined by the claims.

[0072] Furthermore, the following claims are hereby incorporated into the Description of Preferred Embodiments, where each claim may stand on its own as a separate embodiment. While each claim may stand on its own as a separate embodiment, it is to be noted that - although a dependent claim may refer in the claims to a specific combination with one or more other claims - other embodiments may also include a combination of the dependent claim with the subject matter of each other dependent or independent claim. Such combinations are proposed herein unless it is stated that a specific combination is not intended. Furthermore, it is intended to include also features of a claim to any other independent claim even if this claim is not directly made dependent to the independent claim.

[0073] It is further to be noted that methods disclosed in the specification or in the claims may be implemented by a device having means for performing each of the respective acts of these methods.

[0074] List of reference signs first segment second segment third segment fourth segment fifth segment sixth segment seventh segment eighth segment ninth segment tenth segment eleventh segment twelfth segment .1...13.5 perimeter line .1...14.4 cross-section (of probe holder) trailing edge (forming a straight line in the perimeter line) probe bore , 17.1 , 17.2 probe holder .1...18.8 through holes .1 , 19.2 fixation holes .1 , 20.2 countersinks leading edge .1 , 22.2 kink areas (first kink area and second kink area) chord line .1 , 24.2 longitudinal axes of first fixation hole and of second fixation hole longitudinal axis of probe bore first area of probe bore second area of probe bore temperature probe temperature probe connection means aircraft, in particular single-engine propeller airplane .1 , 31.2 wings 32.1 , 32.2 wing roots

[0075] 33.1 , 33.2 wing tips

[0076] 34 propeller

[0077] 35 height of probe holder

[0078] 36 distance between wing root and probe holder

[0079] 37 distance between wing root and wing tip

[0080] 38 slanted edge

[0081] 39.1 , 39.2 rounded lateral segments

[0082] 40 area of largest thickness (of the cross-section)

[0083] A - A cut through probe holder in the direction of its height

[0084] B - B first cross-sectional cut through probe holder

[0085] C - C second cross-sectional cut through probe holder

[0086] Z zoom-in view

Claims

Patent claims1. Probe holder (17, 17.1 , 17.2) for holding a temperature probe (28),- wherein the probe holder (17, 17.1 , 17.2) comprises a leading edge (21 ), characterized in that the leading edge (21 ) at least partially has an at least essentially sharp form.

2. Probe holder (17, 17.1 , 17.2) according to claim 1 , characterized in that- the probe holder (17, 17.1 , 17.2) has a height (35),- wherein a cross-section (14.1 , 14.2, 14.3, 14.4) of the probe holder (17, 17.1 , 17.2) is oriented orthogonally to a direction of the height (35),- wherein the cross-section (14.1 , 14.2, 14.3, 14.4) is limited by a perimeter line (13.1 , 13.2, 13.3, 13.4, 13.5),- wherein the perimeter line (13.1 , 13.2, 13.3, 13.4, 13.5) preferably comprises a first kink area (22.1 ) and a second kink area (22.2).

3. Probe holder (17, 17.1 , 17.2) according to claim 2s, characterized in that the cross-section (14.1 , 14.2, 14.3, 14.4) is essentially identical over the entire height (35) and / or in that the perimeter line (13.1 , 13.2, 13.3, 13.4, 13.5) is essentially identical over the entire height (35).

4. Probe holder (17, 17.1 , 17.2) according to any of the claims 2 to 3, characterized in that the cross-section (14.1 , 14.2, 14.3, 14.4) has a chord line (23) and is symmetrical with respect to the chord line (23).

5. Probe holder (17, 17.1 , 17.2) according to any of the claims 2 to 4, characterized in that the first kink area (22.1) comprises at least a part of a first segment (1), in particular a first circular arc (1), wherein, preferably, a concavity formed by the first circular arc (1) is facing away from the chord line (23).

6. Probe holder (17, 17.1 , 17.2) according to any of the claims 2 to 5, characterized in that the second kink area (22.2) comprises at least a part of a second segment (2), in particular a second circular arc (2), wherein, preferably, a concavity formed by the second circular arc (2) is facing away from the chord line (23).

7. Probe holder (17, 17.1 , 17.2) according to any of the claims 5 or 6, characterized in that- the first circular arc (1 ) has a radius of approximately 20 mm, and / or- the second circular arc (2) has a radius of approximately 20 mm, and / or- the first segment (1), in particular the first circular arc (1), and second segment (2), in particular the second circular arc (2), are symmetrical with respect to the chord line (23).

8. Probe holder (17, 17.1 , 17.2) according to any of the claims 2 to 7, characterized in that the perimeter line (13.1 , 13.2, 13.3, 13.4, 13.5) comprises:- a third segment (3), preferably a third circular arc (3), wherein the third circular arc (3) preferably has a radius of approximately 50 mm, and / or- a fourth segment (4), preferably a fourth circular arc (4), wherein the fourth circular arc (4) preferably has a radius of approximately 50 mm, and / or- a fifth segment (5), preferably a fifth circular arc (5), wherein the fifth circular arc (5) preferably has a radius of approximately 2 mm, and / or- a sixth segment (6), preferably a sixth circular arc (6), wherein the sixth circular arc (6) preferably has a radius of approximately 2 mm, and / or- a seventh segment (7), preferably a seventh circular arc (7), wherein the seventh circular arc (7) preferably has a radius of approximately 35 mm, and / or- an eighth segment (8), preferably an eighth circular arc (8), wherein the eighth circular arc (8) preferably has a radius of approximately 35 mm, and / or- a ninth segment (9), preferably a ninth circular arc (9), wherein the ninth circular arc (9) preferably has a radius of approximately 25 mm, and / or- a tenth segment (10), preferably a tenth circular arc (10), wherein the tenth circular arc (10) preferably has a radius of approximately 25 mm, and / or- an eleventh segment (11 ), preferably an eleventh circular arc (11 ), wherein the eleventh circular arc (11 ) preferably has a radius of approximately 60 mm, and / or- a twelfth segment (12), preferably a twelfth circular arc (12), wherein the twelfth circular arc (12) preferably has a radius of approximately 60 mm.

9. Probe holder (17, 17.1 , 17.2) according to any of the claims 5 to 8, characterized in that- the first segment (1 ), in particular the first circular arc (1), has a length projected on the chord line (23) of approximately 4.9 mm, and / or- the second segment (2), in particular the second circular arc (2), has a length projected on the chord line (23) of approximately 4.9 mm, and / or- the third segment (3), in particular the third circular arc (3), has a length projected on the chord line (23) of approximately 11.4 mm, and / or- the fourth segment (4), in particular the fourth circular arc (4), has a length projected on the chord line (23) of approximately 11 .4 mm, and / or- the fifth segment (5), in particular the fifth circular arc (5), has a length projected on the chord line (23) of approximately 1.1 mm, and / or- the sixth segment (6), in particular the sixth circular arc (6), has a length projected on the chord line (23) of approximately 1 .1 mm, and / or- the seventh segment (7), in particular the seventh circular arc (7), has a length projected on the chord line (23) of approximately 3.9 mm, and / or- the eighth segment (8), in particular the eighth circular arc (8), has a length projected on the chord line (23) of approximately 3.9 mm, and / or- the ninth segment (9), in particular the ninth circular arc (9), has a length projected on the chord line (23) of approximately 13.5 mm, and / or- the tenth segment (10), in particular the tenth circular arc (10), has a length projected on the chord line (23) of approximately 13.5 mm, and / or- the eleventh segment (11 ), in particular the eleventh circular arc (11 ), has a length projected on the chord line (23) of approximately 15.2 mm, and / or- the twelfth segment (12), in particular the twelfth circular arc (12), has a length projected on the chord line (23) of approximately 15.2 mm.

10. Probe holder (17, 17.1 , 17.2) according to any of the claims 8 to 9, characterized in that- the third segment (3) and the fourth segment (4) are symmetrical with respect to the chord line (23), and / or- the fifth segment (5) and the sixth segment (6) are symmetrical with respect to the chord line (23), and / or- the seventh segment (7) and the eighth segment (8) are symmetrical with respect to the chord line (23), and / or- the ninth segment (9) and the tenth segment (10) are symmetrical with respect to the chord line (23), and / or- the eleventh segment (11) and the twelfth segment (12) are symmetrical with respect to the chord line (23).

11. Probe holder (17, 17.1 , 17.2) according to any of the previous claims, characterized in that the probe holder (17, 17.1 , 17.2) comprises a trailing edge (15), wherein the leading edge (21) is preferably more pointed than the trailing edge (15).

12. Probe holder (17, 17.1 , 17.2) according to any of the previous claims, characterized in that the probe holder (17, 17.1 , 17.2) comprises two kink lines,- wherein the leading edge (21 ) and / or the trailing edge (15) and / or both kink lines preferably each have the length of the height (35), at least approximately, and / or- wherein the leading edge (21) and the trailing edge (15) and both kink lines preferably run along the height (35) of the probe holder (17, 17.1 , 17.2) in parallel, at least essentially.

13. Probe holder (17, 17.1 , 17.2) according to any of the previous claims, characterized in that the probe holder (17, 17.1 , 17.2) comprises a probe bore (16) forreceiving the temperature probe (28), wherein the probe bore (16) preferably runs along the height (35) of the probe holder (17, 17.1 , 17.2), preferably in parallel with the leading edge (21) and / or the trailing edge (15) and / or both kink lines.

14. Probe holder (17, 17.1 , 17.2) according to any of the previous claims, characterized in that the probe holder (17, 17.1 , 17.2) comprises a multitude of through holes (18.1 , ..., 18.8), preferably eight through holes (18.1 , ..., 18.8), preferably four through holes (18.1 , ..., 18.8) on a first side of the probe holder (17, 17.1 , 17.2) and four through holes (18.1 , ..., 18.8) on a second side of the probe holder (17, 17.1 , 17.2), wherein the through holes (18.1 , ..., 18.8) are preferably of cylindrical shape and / or wherein the through holes (18.1 , ..., 18.8) are preferably all arranged with parallel longitudinal axes, wherein all these parallel longitudinal axes are preferably perpendicular to the direction of the height (35) of the probe holder (17, 17.1 , 17.2), and / or wherein all through holes (18.1 , ..., 18.8) preferably link an exterior of the probe holder (17, 17.1 , 17.2) to the probe bore (16).

15. Probe holder (17, 17.1 , 17.2) according to any of the previous claims, characterized in that the probe holder (17, 17.1 , 17.2) comprises a first fixation hole (19.1) and a second fixation hole (19.2), wherein the fixation holes (19.1 , 19.2) are preferably both arranged in parallel with the probe bore (16), wherein the first fixation hole(19.1) is preferably arranged between the probe bore (16) and the trailing edge (15), wherein the second fixation hole (19.2) is preferably arranged between the probe bore (16) and the leading edge (21), wherein a distance between a longitudinal axis(24.1) of the first fixation hole (19.1) and a longitudinal axis (25) of the probe bore (16) preferably equals a distance between a longitudinal axis (24.2) of the second fixation hole (19.2) and the longitudinal axis (25) of the probe bore (16).

16. Probe holder (17, 17.1 , 17.2) according to any of the claims 8 to 15, characterized in that, in the perimeter line (13.1 , 13.2, 13.3, 13.4, 13.5),- the first segment (1) is connected to the third segment (3), and- the third segment (3) is connected to the fifth segment (5), and- the fifth segment (5) is connected to the sixth segment (6), and- the sixth segment (6) is connected to the fourth segment (4), and- the fourth segment (4) is connected to the second segment (2), and- the second segment (2) is connected to the eighth segment (8), and- the eighth segment (8) is connected to the tenth segment (10), and- the tenth segment (10) is connected to the twelfth segment (12), and- the eleventh segment (11 ) is connected to the ninth segment (9), and- the ninth segment (9) is connected to the seventh segment (7), and- the seventh segment (7) is connected to the first segment (1 ).

17. Probe holder (17, 17.1 , 17.2) according to any of the previous claims, characterized in that the twelve segments (1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12) are preferably all circular arcs, and / or, in the perimeter line (13.1 , 13.2, 13.3, 13.4, 13.5), the eleventh segment (11) is preferably connected to a straight line (15) corresponding to the trailing edge (15) and the twelfth segment (12) is also connected to this straight line (15).

18. Probe holder (17, 17.1 , 17.2) according to any the claims 2 to 17, characterized in that the first kink area (22.1) and the second kink area (22.2) are located between the leading edge (21) and the probe bore (16).

19. Temperature measurement system, comprising a probe holder (17, 17.1 , 17.2) according to any of the previous claims and a temperature probe (28), wherein the temperature probe (28) is at least partly, preferably completely, arranged inside the probe holder (17, 17.1 , 17.2).

20. Aircraft (30), comprising a probe holder (17, 17.1, 17.2) according to any of the claims 1 to 18 and / or a temperature measurement system according to claim 19.

21. Aircraft (30) according to claim 20, characterized in that the probe holder (17,17.1 , 17.2) is attached to a wing (31.1 , 31 .2) of the aircraft (30), in particular to an underside of the wing (31 .1 , 31 .2) of the aircraft (30).

22. Aircraft (30) according to claim 21 , characterized in that the probe holder (17,17.1 , 17.2) is mounted in such a way at the underside of the wing (31 .1 , 31 .2) that a distance (36) between the probe holder (17, 17.1 , 17.2) and a wing root (33.1 , 32.2) of the wing (31.1 , 31.2), preferably a distance (36) between the longitudinal axis of the probe bore (16) and the wing root (33.1 , 32.2) of the wing (31 .1 , 31 .2), equals between 90% and 40%, preferably between 85% and 55%, more preferably between 80% and 70%, even more preferably approximately 75% of a length (37) of the wing (31.1 , 31.2).

23. Aircraft (30) according to any of the claims 20 to 22, characterized in that the aircraft (30) comprises a second probe holder (17, 17.1 , 17.2) according to any of the claims 1 to 18 or a second temperature measurement system according to claim 19, such that the aircraft (30) preferably comprises either two identical probe holders (17,17.1 , 17.2) or two identical temperature measurement systems, wherein the second probe holder (17, 17.1 , 17.2) or the second temperature measurement system is preferably arranged in a manner corresponding to the probe holder (17, 17.1 , 17.2) or the temperature measurement system on another side of the aircraft (30).

24. Method for heating propeller blades in an aircraft (30) according to any of the claims 20 to 23, characterized in that the method uses an outside air temperature measured by a first temperature measurement system according to claim 19 for determining a heating mode for heating the propeller blades, wherein the method preferably uses an outside air temperature measured by a second temperature measurement system according to claim 19 to validate the outside air temperature measured by the first temperature measurement system.

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