A flight test method for tcas system function and performance

Abstract

The present application belongs to the field of aircraft flight test technology, and relates to a flight test method for TCAS system function and performance. The technical difficulty of two-aircraft collision avoidance in TCAS system flight verification is solved, a flight test method for TCAS system function and performance is designed, and the flight path and data collection time point are controllable, and high-credibility and high-precision TCAS system alarm function and alarm performance parameters are obtained.

Description

Technical Field

[0001] This invention belongs to the field of aircraft flight test technology within the field of aircraft testing and flight testing technology, and relates to a flight test method for the function and performance of a TCAS system. Background Technology

[0002] The airborne collision avoidance system on an aircraft is called the Traffic Alert and Collision Avoidance System (TCAS) in the U.S. aviation system.

[0003] The TCAS system is one of the important airborne devices for improving aircraft flight safety. However, CCAR-23R3 and CCAR-25R4 do not contain relevant provisions regarding the airworthiness requirements of the TCAS system, and AC-25-7C does not contain any guidelines for airworthiness compliance flight testing related to the TCAS system. In order to promote the TCAS system, the United States issued the "Airworthiness Advisory Circular for TCAS Systems and Related Mode S Transponders" (AC-20-151C). This advisory circular details the various technical requirements for obtaining airworthiness certification for the TCAS system, but it rarely mentions flight testing methods for the TCAS system.

[0004] The current challenge is to overcome the technical difficulties of dual-aircraft collision avoidance in TCAS system flight verification, design a safe flight test method for TCAS system functions and performance with controllable flight path and data acquisition time, and obtain highly reliable and accurate TCAS system alarm functions and alarm performance parameters. Summary of the Invention

[0005] Purpose of the invention

[0006] The purpose of this invention is to solve the technical difficulties in flight testing of the functions and performance of the TCAS system mentioned above, and to propose a flight testing method for the functions and performance of the TCAS system.

[0007] Technical solution

[0008] A flight test method for the functionality and performance of a TCAS system includes the following steps:

[0009] (1) Two helicopters, A and B, equipped with TCAS system and testing equipment;

[0010] (2) Helicopter A hovers at a fixed height H1. Helicopter B rises from a height position of H1-900m directly below helicopter A at a constant vertical upward speed V1 to a position of H1-150m and hovers there. It then disengages according to the instructions of the TCAS system. During the process, the types of alarms that appear on the TCAS system on helicopter A and the time of occurrence are recorded. The alarm functions and performance of the TCAS system in the vertical direction are calculated by using the parameters of the test equipment.

[0011] Based on the performance design parameters of the TCAS system, its maximum vertical alarm distance is approximately 1200ft to 1500ft (approximately 365m to 457m). Selecting 900m can completely cover its maximum alarm distance.

[0012] Based on the performance design parameters of the TCAS system, its minimum vertical alarm distance is about 850ft (about 259m). Selecting 150m can completely cover its minimum alarm distance, and maintaining a distance of 150m (half an altitude level) from the test aircraft A can maximize the protection of flight spacing and ensure flight safety.

[0013] This patent is not limited to the application of current actual models. The values ​​of H1, H2, H1-900, etc., in this document are universal and are based on two considerations: 1) ensuring flight safety and leaving sufficient clearance; 2) meeting the performance testing requirements of the TCAS system. Detailed parameter definitions are provided below. These parameters cannot be modified to describe the altitude they guarantee based on their function or purpose; otherwise, the test cannot be completed based on these parameters.

[0014] (3) Helicopter A hovers at a fixed height H2. Helicopter B descends from a height of H2+900m directly above helicopter A at a constant vertical descent speed V2 to a position of H2+150m and hovers there. It then disengages according to the instructions of the TCAS system. During the process, the types of alarms that appear on the TCAS system on helicopter A and the time of occurrence are recorded. The alarm functions and performance of the TCAS system in the vertical direction are calculated by using the parameters of the test equipment.

[0015] (4) Both helicopters A and B hovered at a fixed height H2. Helicopter B was located 900m to the left of helicopter A and moved at a constant speed of V3 to hover 150m to the left of helicopter A. It then disengaged according to the instructions of the TCAS system. The alarm types and times of occurrence of the TCAS system on helicopter A were recorded during the process. The alarm function and performance of the left side of the TCAS system were calculated by testing the parameters of the test equipment.

[0016] (5) Both helicopters A and B hovered at a fixed height H2. Helicopter B was located 900m to the right of helicopter A and moved at a constant speed of V3 to hover 150m to the right of helicopter A and disengaged according to the instructions of the TCAS system. The alarm types and times of occurrence of the TCAS system on helicopter A were recorded during the process. The alarm function and performance of the right side of the TCAS system were calculated by testing the parameters of the test equipment.

[0017] (6) Both helicopters A and B hovered at a fixed altitude H2. Helicopter B was located 40km ahead of helicopter A in the longitudinal direction. During the first flight, helicopter B moved at a constant speed of V4 to hover 10km ahead of helicopter A in the longitudinal direction. During the second flight, helicopter B moved at a constant speed of V5 to hover 2km ahead of helicopter A in the longitudinal direction and disengaged according to the instructions of the TCAS system. The alarm types and times of occurrence of the TCAS system on helicopter A were recorded during the process. The alarm function and performance of the longitudinal front end of the TCAS system were calculated by testing the parameters of the equipment.

[0018] The 40km, 10km, and 2km ranges are all designed based on the performance requirements of the TCASⅡ system.

[0019] (7) Both helicopters A and B hovered at a fixed altitude H2. Helicopter B was located 40km behind the longitudinal rear of helicopter A. During the first flight, helicopter B moved at a constant speed of V4 to hover 10km behind the longitudinal rear of helicopter A. During the second flight, helicopter B moved at a constant speed of V5 to hover 2km behind the longitudinal rear of helicopter A and disengaged according to the instructions of the TCAS system. The alarm types and times of occurrence of the TCAS system on helicopter A were recorded during the process. The alarm function and performance of the longitudinal rear of the TCAS system were calculated by testing the parameters of the equipment.

[0020] Furthermore, in step (1),

[0021] 1) The TCAS system is a valid TCAS system for flight testing, and its standard is no lower than TCAS II.

[0022] 2) The test equipment installed on helicopters A and B should be able to acquire, at least in time, the aircraft's climb rate, descent rate, level flight speed, flight altitude, GPS coordinate parameters, and TCAS display video.

[0023] Furthermore, in step (2):

[0024] 1) The fixed altitude H1 is the radio altitude, H1≥1200m, and the calculated corrected sea pressure altitude is less than the service ceiling of helicopter A;

[0025] 2) Climbing velocity V1 ≤ 10 m / s;

[0026] The movement distance is 750m, and the aircraft data sampling rate is generally 16 times / second. If the speed is high, then: 1) the time history is short, the aircraft kinetic energy is high, and it is not easy to recover from the dangerous approach state after approaching aircraft A; 2) the interval between each sampling is close to 1m (3ft), which affects the accuracy of the alarm distance. The same applies to V2 and V3 in the text.

[0027] 3) The alarm types for vertical downward verification in the TCAS system are TA and RA.

[0028] Furthermore, in step (3):

[0029] 1) The fixed altitude H2 is the radio altitude, H2≥300m, and the calculated corrected sea pressure altitude is less than the service ceiling of helicopter A;

[0030] During flight, each altitude level is 300 meters to ensure that the aircraft has sufficient clearance from the ground and to guarantee flight safety.

[0031] 2) The corrected sea level altitude calculated from H2+900m is less than the service ceiling of helicopter B;

[0032] 3) Descent speed V2 ≤ 10 m / s;

[0033] 4) The alarm types verified in the vertical direction of the TCAS system are TA and RA.

[0034] Furthermore, in step (4):

[0035] 1) The fixed altitude H2 is the radio altitude, H2≥300m, and the calculated corrected sea pressure altitude is less than the service ceiling of helicopter A and helicopter B;

[0036] 2) Level flight speed V3 ≤ 10m / s;

[0037] 3) The alarm types for horizontal left-side verification in the TCAS system are TA and RA.

[0038] Furthermore, in step (5):

[0039] 1) The fixed altitude H2 is the radio altitude, H2≥300m, and the calculated corrected sea pressure altitude is less than the service ceiling of helicopter A and helicopter B;

[0040] 2) Level flight speed V3 ≤ 10m / s;

[0041] 3) The alarm types for the horizontal right-side verification of the TCAS system are TA and RA.

[0042] Furthermore, in step (6):

[0043] 1) The fixed altitude H2 is the radio altitude, H2≥300m, and the calculated corrected sea pressure altitude is less than the service ceiling of helicopter A and helicopter B;

[0044] 2) Level flight speed V4 ≤ 50m / s;

[0045] The travel distance is 30km, and the travel time is about 10 minutes. The general cruising speed of civilian helicopters is around 150-200km / h, and 50m / s is equivalent to 180km / h, which is a suitable cruising speed.

[0046] 3) Level flight speed V5 ≤ 20m / s;

[0047] The closest distance to test aircraft A is 2km. The aircraft flies at a low and constant speed, with low kinetic energy and low inertia, making it easy to decelerate and recover from the dangerous close proximity of the two aircraft after the test, avoid the risk of collision, and ensure flight safety.

[0048] 4) The alarm types for longitudinal front-end verification of the TCAS system are NA, PA, TA, and RA.

[0049] Furthermore, in step (7):

[0050] 1) The fixed altitude H2 is the radio altitude, H2≥300m, and the calculated corrected sea pressure altitude is less than the service ceiling of helicopter A and helicopter B;

[0051] 2) Level flight speed V4 ≤ 50m / s;

[0052] 3) Level flight speed V5 ≤ 20m / s;

[0053] 4) The alarm type for longitudinal back-end verification of the TCAS system is TA-Behind.

[0054] The beneficial effects of this application are as follows:

[0055] The beneficial effects of this invention are as follows: This invention is a flight test method for the function and performance of a TCAS system, which solves the technical difficulties of dual-aircraft collision avoidance in the flight verification of TCAS system. It designs a safe flight test method for the function and performance of a TCAS system with controllable flight path and data acquisition time, and obtains highly reliable and accurate alarm functions and alarm performance parameters of the TCAS system. Detailed Implementation

[0056] The present invention will be further described below with reference to embodiments. The following description represents only a portion of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0057] This invention provides a flight test method for the function and performance of a TCAS system, which is used to obtain highly reliable and accurate alarm functions and alarm performance parameters of a TCAS system through flight testing. The invention will be further described below with reference to embodiments.

[0058] In one embodiment of the present invention, a novel domestically produced TCAS system mounted on a certain type of amphibious aircraft is tested and verified using the flight test method for the TCAS system functions and performance proposed in this invention. The steps are as follows:

[0059] (1) Two helicopters, A and B, equipped with the domestically produced new TCAS system (not lower than TCASⅡ standard) and corresponding testing equipment, can at least obtain the aircraft's climb rate, descent rate, level flight speed, flight altitude, GPS coordinate parameters and TCAS display video corresponding to the time.

[0060] (2) A civil airport with an altitude of 6m was selected as the test site. Helicopter A hovered at a fixed altitude of 1200m. Helicopter B rose from a position 300m directly below Helicopter A at a constant vertical speed of 5m / s to a position of 1050m and hovered. Helicopter B disengaged according to the TCAS system instructions. The alarm types and times of occurrence of the TCAS system on Helicopter A were recorded. The alarm function and disengagement instruction function of the TCAS system in the vertical direction were calculated to be normal through the test equipment parameters. The alarm performance in the vertical direction was: 259m≤TA≤365m, RA<259m.

[0061] (3) Helicopter A hovers at a fixed height of 300m. Helicopter B descends from a height of 1200m directly above Helicopter A at a constant vertical descent speed of 5m / s to a position of 450m and hovers there. It then disengages according to the TCAS system instructions. During the process, the types of alarms that appear on the TCAS system on Helicopter A and the time of occurrence are recorded. The alarm function and disengagement instruction function of the TCAS system in the vertical direction are calculated to be normal through the test equipment parameters. The alarm performance in the vertical direction is: 259m≤TA≤365m, RA<259m.

[0062] (4) Both helicopters A and B hovered at a fixed height of 300m. Helicopter B was located 900m to the left of helicopter A and moved at a constant speed of 10m / s to hover 150m to the left of helicopter A. It then disengaged according to the TCAS system instructions. The alarm types and timestamps of the TCAS system on helicopter A were recorded during the process. The alarm function and disengagement instruction function of the TCAS system on the left side were calculated to be normal through the test equipment parameters. The alarm performance on the left side was: 259m≤TA≤365m, RA<259m.

[0063] (5) Both helicopters A and B hovered at a fixed height of 300m. Helicopter B was located 900m to the right of helicopter A and moved at a constant speed of 10m / s to hover 150m to the right of helicopter A. It then disengaged according to the TCAS system instructions. The alarm types and timestamps of the TCAS system on helicopter A were recorded during the process. The alarm function and disengagement instruction function of the TCAS system on the right side were calculated to be normal through the test equipment parameters. The alarm performance on the right side was: 259m≤TA≤365m, RA<259m.

[0064] (6) Both helicopters A and B hovered at a fixed height of 300m. Helicopter B was located 40km ahead of helicopter A in the longitudinal direction. During the first flight, helicopter B moved at a constant speed of 30m / s in level flight to hover 10km ahead of helicopter A in the longitudinal direction. During the second flight, helicopter B moved at a constant speed of 10m / s in level flight to hover 2km ahead of helicopter A in the longitudinal direction and disengaged according to the TCAS system instructions. The alarm types and timestamps of the TCAS system on helicopter A during the process were recorded. The alarm function and disengagement instruction function of the longitudinal front end of the TCAS system were calculated to be normal through the test equipment parameters. The alarm performance of the longitudinal front end was: 37km < NA, 6km ≤ PA ≤ 37km, 3.8km < TA < 6km, RA ≤ 3.8km.

[0065] (7) Both helicopters A and B hovered at a fixed height of 300m. Helicopter B was located 40km behind helicopter A. During the first flight, it moved at a constant speed of 30m / s to hover 10km behind helicopter A. During the second flight, it moved at a constant speed of 10m / s to hover 2km behind helicopter A and disengaged according to the TCAS system instructions. The alarm types and times of occurrence of the TCAS system on helicopter A were recorded during the process. The alarm function and disengagement instruction function of the longitudinal rear end of the TCAS system were calculated to be normal through the test equipment parameters. The alarm performance of the longitudinal rear end was: TA-Behind≤6km.

[0066] Defined as 1200m, H1-900m is 300m. During flight, 300m is considered a flight altitude layer. This invention provides a flight test method for the functionality and performance of a TCAS system, used to obtain highly reliable and accurate alarm functions and performance parameters of the TCAS system through flight testing. The invention is further illustrated below with reference to embodiments. This ensures the aircraft has sufficient ground clearance to guarantee flight safety.

[0067] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein. The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A flight test method for the function and performance of a TCAS system, characterized in that, Includes the following steps: (1) Two helicopters, A and B, equipped with TCAS system and testing equipment; (2) Helicopter A hovers at a fixed height H1. Helicopter B rises from a height position of H1-900m directly below helicopter A at a constant vertical upward speed V1 to a position of H1-150m and hovers there. It then disengages according to the instructions of the TCAS system. During the process, the types of alarms that appear on the TCAS system on helicopter A and the time of occurrence are recorded. The alarm functions and performance of the TCAS system in the vertical direction are calculated by using the parameters of the test equipment. (3) Helicopter A hovers at a fixed height H2. Helicopter B descends from a height of H2+900m directly above helicopter A at a constant vertical descent speed V2 to a position of H2+150m and hovers there. It then disengages according to the instructions of the TCAS system. During the process, the types of alarms that appear on the TCAS system on helicopter A and the time of occurrence are recorded. The alarm functions and performance of the TCAS system in the vertical direction are calculated by using the parameters of the test equipment. (4) Both helicopters A and B hovered at a fixed height H2. Helicopter B was located 900m to the left of helicopter A and moved at a constant speed of V3 to hover 150m to the left of helicopter A. It then disengaged according to the instructions of the TCAS system. The alarm types and times of occurrence of the TCAS system on helicopter A were recorded during the process. The alarm function and performance of the left side of the TCAS system were calculated by testing the parameters of the test equipment. (5) Both helicopters A and B hovered at a fixed height H2. Helicopter B was located 900m to the right of helicopter A and moved at a constant speed of V3 to hover 150m to the right of helicopter A and disengaged according to the instructions of the TCAS system. The alarm types and times of occurrence of the TCAS system on helicopter A were recorded during the process. The alarm function and performance of the right side of the TCAS system were calculated by testing the parameters of the test equipment. (6) Both helicopters A and B hovered at a fixed altitude H2. Helicopter B was located 40km ahead of helicopter A in the longitudinal direction. During the first flight, helicopter B moved at a constant speed of V4 to hover 10km ahead of helicopter A in the longitudinal direction. During the second flight, helicopter B moved at a constant speed of V5 to hover 2km ahead of helicopter A in the longitudinal direction and disengaged according to the instructions of the TCAS system. The alarm types and times of occurrence of the TCAS system on helicopter A were recorded during the process. The alarm function and performance of the longitudinal front end of the TCAS system were calculated by testing the parameters of the equipment. (7) Both helicopters A and B hovered at a fixed altitude H2. Helicopter B was located 40km behind the longitudinal rear of helicopter A. During the first flight, helicopter B moved at a constant speed of V4 to hover 10km behind the longitudinal rear of helicopter A. During the second flight, helicopter B moved at a constant speed of V5 to hover 2km behind the longitudinal rear of helicopter A and disengaged according to the instructions of the TCAS system. The alarm types and times of occurrence of the TCAS system on helicopter A were recorded during the process. The alarm function and performance of the longitudinal rear of the TCAS system were calculated by testing the parameters of the equipment.

2. The method as described in claim 1, characterized in that, In step (1), 1) The TCAS system is a valid TCAS system for flight testing, and its standard is no lower than TCAS II. 2) The test equipment installed on helicopters A and B should be able to acquire, at least in time, the aircraft's climb rate, descent rate, level flight speed, flight altitude, GPS coordinate parameters, and TCAS display video.

3. The method as described in claim 2, characterized in that, In step (2): 1) The fixed altitude H1 is the radio altitude, H1≥1200m, and the calculated corrected sea pressure altitude is less than the service ceiling of helicopter A; 2) Climbing velocity V1 ≤ 10 m / s; 3) The alarm types for vertical downward verification in the TCAS system are TA and RA.

4. The method as described in claim 3, characterized in that, In step (3): 1) The fixed altitude H2 is the radio altitude, H2≥300m, and the calculated corrected sea pressure altitude is less than the service ceiling of helicopter A; 2) The corrected sea level altitude calculated from H2+900m is less than the service ceiling of helicopter B; 3) Descent speed V2 ≤ 10 m / s; 4) The alarm types verified in the vertical direction of the TCAS system are TA and RA.

5. The method as described in claim 4, characterized in that, In step (4): 1) The fixed altitude H2 is the radio altitude, H2≥300m, and the calculated corrected sea pressure altitude is less than the service ceiling of helicopter A and helicopter B; 2) Level flight speed V3 ≤ 10m / s; 3) The alarm types for horizontal left-side verification in the TCAS system are TA and RA.

6. The method as described in claim 5, characterized in that, In step (5): 1) The fixed altitude H2 is the radio altitude, H2≥300m, and the calculated corrected sea pressure altitude is less than the service ceiling of helicopter A and helicopter B; 2) Level flight speed V3 ≤ 10m / s; 3) The alarm types for the horizontal right-side verification of the TCAS system are TA and RA.

7. The method as described in claim 6, characterized in that, In step (6): 1) The fixed altitude H2 is the radio altitude, H2≥300m, and the calculated corrected sea pressure altitude is less than the service ceiling of helicopter A and helicopter B; 2) Level flight speed V4 ≤ 50m / s; 3) Level flight speed V5 ≤ 20m / s; 4) The alarm types for longitudinal front-end verification of the TCAS system are NA, PA, TA, and RA.

8. The method as described in claim 7, characterized in that, In step (7): 1) The fixed altitude H2 is the radio altitude, H2≥300m, and the calculated corrected sea pressure altitude is less than the service ceiling of helicopter A and helicopter B; 2) Level flight speed V4 ≤ 50m / s; 3) Level flight speed V5 ≤ 20m / s; 4) The alarm type for longitudinal back-end verification of the TCAS system is TA-Behind.