A method for verifying the airworthiness compliance of a helicopter near-ground handling characteristic
Patent Information
- Application Number
- CN202511842169.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-10-20
- Estimated Expiration
- 2045-12-09
AI Technical Summary
但目前适航规章及相关咨询通告并未直接提供具体的符合性验证方法
[0041]1、近地面操纵特性试飞的基本原理是通过直升机的侧飞和后飞来模拟风速和风向，为了排除环境风的干扰，一般需要在近似无风条件(环境风速≤1.5m/s)下进行。使用本发明时，通过伴随车可以获得稳定的风速和风向，直升机跟随伴随车飞行实现模拟效果，大幅降低对试飞环境风速条件的要求，提高试飞效率。
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Figure CN121448642B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of helicopter airworthiness compliance verification technology, specifically relating to a method for verifying the airworthiness compliance of helicopter near-ground handling characteristics. Background Technology
[0002] The hovering and near-ground maneuverability of helicopters are their core advantages over fixed-wing aircraft, making them irreplaceable in rescue, exploration, and other scenarios. According to Part 27 of the Civil Aviation Administration of China's Civil Aviation Regulations, "Airworthiness Requirements for Normal Category Rotary-Wing Aircraft," and Part 29, "Airworthiness Requirements for Transport Category Rotary-Wing Aircraft," helicopters must be able to operate in both ground effect and non-ground effect without loss of control in all orientations, from wind speeds of 0 to at least 8.74 m / s (17 knots). However, current airworthiness regulations and related advisory circulars do not directly provide specific methods for verifying compliance. Summary of the Invention
[0003] Purpose of the invention: To provide a method for verifying the airworthiness compliance of helicopter near-ground handling characteristics, which is used to demonstrate that the helicopter's near-ground handling characteristics meet the requirements of airworthiness regulations, and to determine its maximum side-flight and rear-flight speeds as well as its hovering wind speed envelope.
[0004] Technical solution
[0005] A method for verifying the airworthiness compliance of helicopter near-ground handling characteristics includes the following steps:
[0006] Step 1: Determine the flight test status of near-ground handling characteristics based on the expected flight envelope and performance;
[0007] Step 2: Determine the test parameters for flight testing;
[0008] Step 3: Conduct pre-flight preparations;
[0009] Step 4: At the test flight site at an altitude of 0 meters, hover with the maximum effective hovering weight G. IGE Conduct near-ground control characteristic tests with ground effect using combinations of corresponding front left, front right, rear left, and rear right extreme center of gravity; and use the maximum hovering weight G in ground effect. OGE The near-ground control characteristics without ground effect were tested by combining the corresponding front left extreme center of gravity, front right extreme center of gravity, rear left extreme center of gravity, and rear right extreme center of gravity.
[0010] Step 5: Determine the critical center of gravity based on the results of various weight and center of gravity combinations during ground effect and non-ground effect test flights;
[0011] Step Six: At test airports at other altitudes up to the maximum takeoff and landing altitude, hover at the maximum effective hovering weight G. IGEConduct near-ground control characteristic tests with ground effect and critical center of gravity, using the maximum hovering weight without ground effect G. OGE Conduct near-ground control characteristics tests without ground effect and at the critical center of gravity;
[0012] Step 7: Based on the test flight results of Steps 4 and 6, determine the maximum side-flight and rear-flight speeds of the helicopter, as well as the hovering wind speed envelope.
[0013] Furthermore, in step one, the specific process is as follows:
[0014] S11. Determine the altitude of the test airport based on the takeoff and landing altitude envelope, with intervals of approximately 1500 meters from altitude 0 meters to the maximum takeoff and landing altitude.
[0015] S12. Determine the test flight weight and center of gravity combination based on hovering performance and center of gravity envelope, and the maximum effective hovering weight G. IGE Maximum hovering weight without ground effect G OGE The combination of the corresponding front left extreme center of gravity, front right extreme center of gravity, rear left extreme center of gravity, and rear right extreme center of gravity;
[0016] S13. Determine the ground takeoff altitude H for the ground effect test flight based on the hovering altitude recommended in the takeoff procedure. IGE ;
[0017] S14. Determine the ground clearance H for no-ground-effect test flights based on twice the rotor diameter. OGE .
[0018] Furthermore, in step two, the flight test parameters include:
[0019] S21. Determine the environmental test parameters, including wind speed, wind direction, air pressure altitude, and atmospheric temperature;
[0020] S22. Determine the helicopter test parameters, including ground clearance, ground speed, control inputs, attitude angle, heading angle, sideslip angle, engine torque, and rotor speed.
[0021] Furthermore, in step three, the preparations before the test flight are as follows:
[0022] S31. Prepare an accompanying vehicle with at least two people inside, including a driver and an observer;
[0023] S32. Install a wind speed and wind direction meter on the roof of the accompanying vehicle;
[0024] S33. Install a device inside the accompanying vehicle to display and record local time and anemometer measurement results;
[0025] S34. Synchronize the time display / recording of the accompanying vehicle with the time display / recording of the helicopter;
[0026] S35. Prepare a portable radio for communication between personnel in the accompanying vehicle and the helicopter test flight crew.
[0027] Furthermore, in step four, the specific process is as follows:
[0028] S41. The accompanying vehicle travels to the runway and checks whether the anemometer and display equipment are functioning properly. After the check is completed, the accompanying vehicle stops at one end of the runway with its front facing the other end of the runway, records the wind speed and wind direction, and notifies the helicopter.
[0029] S42. The helicopter flies from back to front at the required altitude to the vicinity of the escort vehicle, aligning the nose of the helicopter with the runway axis. During the helicopter's approach, the escort vehicle checks the impact of the rotor downwash on the anemometer's measurement results. If the impact is found, the helicopter is notified to move away.
[0030] S43. After preparation, the helicopter issues the command "Start, 10km / h". The accompanying vehicle slowly accelerates along the runway. The helicopter maintains a visible position and relative distance to the accompanying vehicle at the required altitude and follows it along the runway. When the wind speed measurement result of the anemometer stabilizes at 10km / h, the accompanying vehicle reports "Wind speed 10km / h, wind direction X°" to the helicopter and maintains the current speed. The helicopter reports "Wind speed 10km / h, wind direction X°, in position" and maintains the current following state for 10 seconds. After 10 seconds, the helicopter reports "X° completed, next X+△°", where △ is the test angle interval.
[0031] S44. The accompanying vehicle continues to maintain its current speed, paying attention to any wind speed / direction shifts and promptly notifying the helicopter. The helicopter adjusts its attitude, increasing its heading by △°, and maintains a visible position and relative distance to the accompanying vehicle at the required altitude, following the vehicle along the runway. After the helicopter completes its adjustment, it reports "Wind speed 10km / h, wind speed X+△°, in position" and maintains the current following position for 10 seconds. After 10 seconds, the helicopter reports "X+△° complete, next X+2△°."
[0032] S45. When the escort vehicle approaches the end of the runway, the escort vehicle reports "Approaching the end of the runway, preparing to switch sides". The helicopter confirms "Preparing to switch sides" and slows down to make way for the escort vehicle. The escort vehicle slows down, turns, and stops at one end of the runway with its front facing the other end of the runway. It records the wind speed and wind direction and notifies the helicopter. The helicopter flies from back to front to the vicinity of the escort vehicle at the required altitude, aligning the nose of the helicopter with the runway axis.
[0033] S46. Once ready, the helicopter issues the command "Continue, 10 km / h". The accompanying vehicle slowly accelerates along the runway. The helicopter maintains a visible position and relative distance to the accompanying vehicle at the required altitude and follows it along the runway. When the anemometer's wind speed measurement stabilizes at 10 km / h, the accompanying vehicle reports "Wind speed 10 km / h, wind direction Y°" to the helicopter and maintains the current speed. The helicopter reports "Wind speed 10 km / h, wind direction Y°, in position" and maintains the current following state for 10 seconds. After 10 seconds, the helicopter reports "Y° complete, next Y+△°".
[0034] S47. Repeat S41 to S46 to complete all wind directions with a wind speed of 10km / h;
[0035] S48. Repeat S41 to S47 to complete all wind directions with wind speeds of 20km / h, 30km / h, 40km / h up to the maximum side-flying and rear-flying speeds.
[0036] S49. The helicopter test flight crew conducted Cooper-Harper ratings at various wind speeds and directions for each test flight point. A score of 1 to 3.5 was considered satisfactory, and 4 to 6.5 was considered acceptable.
[0037] Furthermore, in step five, based on the minimum control margins of the longitudinal, lateral, and directional control channels under various weight and center of gravity combinations during ground effect and non-ground effect test flights, the control channel with the relatively smallest control margin among these three control channels is determined, and the center of gravity state in this control channel with the minimum control margin is determined as the critical center of gravity.
[0038] Furthermore, the test flight process in step six is the same as that in step four.
[0039] Furthermore, in step seven, based on the longitudinal, lateral, and directional control margins of all flight test points under various weight and center of gravity combinations during ground effect and non-ground effect flight tests, as well as the Cooper-Harper rating scores, a control margin of not less than 10% and a score of 1 to 6.5 are used as the pass criteria. Flight test points that exhibit engine surge or excessively high intake temperature during the flight test are excluded. The maximum side-flight and rear-flight speeds of the helicopter and the hovering wind speed envelope are then determined.
[0040] In summary, the beneficial effects of the present invention are as follows:
[0041] 1. The basic principle of near-ground handling characteristics flight testing is to simulate wind speed and direction by lateral and rearward flight of the helicopter. In order to eliminate the interference of ambient wind, it is generally necessary to conduct the test under near-windless conditions (ambient wind speed ≤ 1.5 m / s). When using this invention, a stable wind speed and direction can be obtained through the accompanying vehicle. The helicopter follows the accompanying vehicle to achieve the simulation effect, which greatly reduces the requirements for wind speed conditions in the flight test environment and improves flight test efficiency.
[0042] 2. During near-ground test flights, helicopter test flight crews must constantly monitor the actual distance between the helicopter and the ground and obstacles to prevent ground contact hazards. Using this invention, the helicopter maintains the required altitude and ground speed by maintaining a visible position and relative distance to the accompanying vehicle. The test flight crew does not need to check the altitude and ground speed through onboard instruments, allowing them to focus their attention outside the aircraft. This effectively reduces the workload of the test flight crew and improves flight test safety. Attached Figure Description
[0043] Figure 1 This is a diagram illustrating the relative wind speed of the accompanying vehicle.
[0044] Figure 2 This is a schematic diagram of a helicopter following an escort vehicle during a test flight at different angles. Detailed Implementation
[0045] A method for verifying the airworthiness compliance of helicopter near-ground handling characteristics includes the following steps:
[0046] S1. Determine the flight test status of near-ground handling characteristics based on the expected flight envelope and performance, specifically including the following steps:
[0047] S11. Determine the altitude of the test airport based on the takeoff and landing altitude envelope, with intervals of approximately 1500 meters from altitude 0 meters to the maximum takeoff and landing altitude.
[0048] S12. Determine the test flight weight and center of gravity combination based on hovering performance and center of gravity envelope, and the maximum effective hovering weight G. IGE Maximum hovering weight without ground effect G OGE The combination of the corresponding front left extreme center of gravity, front right extreme center of gravity, rear left extreme center of gravity, and rear right extreme center of gravity;
[0049] S13. Determine the ground takeoff altitude H for the ground effect test flight based on the hovering altitude recommended in the takeoff procedure. IGE ;
[0050] S14. Determine the ground clearance H for no-ground-effect test flights based on twice the rotor diameter. OGE .
[0051] S2. Determine the flight test parameters, specifically including the following steps:
[0052] S21. Determine the environmental test parameters, including wind speed, wind direction, air pressure altitude, and atmospheric temperature;
[0053] S22. Determine the helicopter test parameters, including ground clearance, ground speed, control inputs, attitude angle, heading angle, sideslip angle, engine torque, and rotor speed.
[0054] S3. Pre-flight preparations, including the following steps:
[0055] S31. Prepare an accompanying vehicle with at least two people inside, including a driver and an observer;
[0056] S32. Install a wind speed and wind direction meter on the roof of the accompanying vehicle;
[0057] S33. Install a device inside the accompanying vehicle to display and record local time and anemometer measurement results;
[0058] S34. Synchronize the time display / recording of the accompanying vehicle with the time display / recording of the helicopter;
[0059] S35. Prepare a portable radio for communication between personnel in the accompanying vehicle and the helicopter test flight crew.
[0060] S4. At the test flight field at an altitude of approximately 0 meters, hover at the maximum effective hovering weight G. IGE Conduct near-ground control characteristic test flights with the corresponding combinations of front left extreme center of gravity, front right extreme center of gravity, rear left extreme center of gravity, and rear right extreme center of gravity (ground clearance H). IGE ), with the maximum hovering weight without ground effect G OGE Conduct near-ground control characteristic tests without ground effect using combinations of the corresponding front left extreme center of gravity, front right extreme center of gravity, rear left extreme center of gravity, and rear right extreme center of gravity (at an altitude of H). OGE The specific steps include:
[0061] S41. The accompanying vehicle travels to the runway and checks whether the anemometer and display equipment are functioning properly. After the check is completed, the accompanying vehicle stops at one end of the runway with its front facing the other end of the runway, records the wind speed and wind direction, and notifies the helicopter.
[0062] S42. The helicopter flies from back to front at the required altitude to the vicinity of the escort vehicle, aligning the nose of the helicopter with the runway axis. During the helicopter's approach, the escort vehicle checks the impact of the rotor downwash on the anemometer's measurement results. If the impact is found, the helicopter is notified to move away.
[0063] S43. Once ready, the helicopter issues the command "Start, 10km / h". The accompanying vehicle slowly accelerates along the runway. The helicopter maintains a visible position and relative distance to the accompanying vehicle at the required altitude and follows it along the runway. When the anemometer's wind speed measurement stabilizes at 10km / h, the accompanying vehicle reports "Wind speed 10km / h, wind direction X°" to the helicopter and maintains the current speed. The helicopter reports "Wind speed 10km / h, wind direction X°, in position" and maintains the current following state for 10 seconds. After 10 seconds, the helicopter reports "X° complete, next X+30°" (in 30° intervals, which can be adjusted appropriately).
[0064] S44. The accompanying vehicle continues to maintain its current speed, paying attention to any wind speed / direction shifts and promptly notifying the helicopter. The helicopter adjusts its attitude, increasing its heading by 30°, and maintains a visible position and relative distance to the accompanying vehicle at the required altitude, following the vehicle along the runway. After the helicopter completes its adjustment, it reports "Wind speed 10km / h, wind speed X+30°, in position" and maintains the current following position for 10 seconds. After 10 seconds, the helicopter reports "X+30° complete, next X+60°."
[0065] S45. When the escort vehicle approaches the end of the runway, the escort vehicle reports "Approaching the end of the runway, preparing to switch sides". The helicopter confirms "Preparing to switch sides" and slows down to make way for the escort vehicle. The escort vehicle slows down, turns, and stops at one end of the runway with its front facing the other end of the runway. It records the wind speed and wind direction and notifies the helicopter. The helicopter flies from back to front to the vicinity of the escort vehicle at the required altitude, aligning the nose of the helicopter with the runway axis.
[0066] S46. Once ready, the helicopter issues the command "Continue, 10 km / h". The accompanying vehicle slowly accelerates along the runway. The helicopter maintains a visible position and relative distance to the accompanying vehicle at the required altitude and follows it along the runway. When the anemometer's wind speed measurement stabilizes at 10 km / h, the accompanying vehicle reports "Wind speed 10 km / h, wind direction Y°" to the helicopter and maintains the current speed. The helicopter reports "Wind speed 10 km / h, wind direction Y°, in position" and maintains the current following state for 10 seconds. After 10 seconds, the helicopter reports "Y° complete, next Y+30°" (in 30° intervals, which can be adjusted appropriately).
[0067] S47, and so on, to complete all wind directions with a wind speed of 10km / h;
[0068] S48. And so on, completing all wind directions with wind speeds of 20km / h, 30km / h, 40km / h up to the maximum side and rear flight speeds;
[0069] S49. The helicopter test flight crew conducted Cooper-Harper ratings at various wind speeds and directions for each test flight point. A score of 1 to 3.5 was considered satisfactory, and 4 to 6.5 was considered acceptable.
[0070] S5. Analyze the test flight results of S4. Based on the minimum longitudinal, lateral, and directional control margins that appear under various weight and center of gravity combinations in the ground effect test flight and the non-ground effect test flight, first determine the control channel with the relatively smallest control margin among the three control channels, and then determine the center of gravity state with the minimum control margin in this control channel as the critical center of gravity.
[0071] S6. At test airports at other altitudes up to the maximum takeoff and landing altitude, with the maximum effective hovering weight G. IGEConduct near-ground control characteristics test flights with critical center of gravity (at altitude H). IGE ), with the maximum hovering weight without ground effect G OGE Conduct near-ground control characteristics test flights with critical center of gravity (at altitude H) without ground effect. OGE For specific steps, see S41 to S49.
[0072] S7. Analyze the flight test results of S4 and S6. Based on the longitudinal, lateral, and directional control margins of all flight test points under various weight and center of gravity combinations in ground effect and non-ground effect flight tests, as well as the Cooper-Harper rating scores, a control margin of not less than 10% and a score of 1 to 6.5 are adopted as the pass criteria. Flight test points that exhibited engine surge, excessively high intake temperature, or other phenomena during the flight test are eliminated. Determine the maximum side flight and rear flight speeds of the helicopter, as well as the hovering wind speed envelope.
Claims
1. A method for verifying the airworthiness compliance of helicopter near-ground handling characteristics, characterized in that: Includes the following steps: Step 1: Determine the flight test status of near-ground handling characteristics based on the expected flight envelope and performance; Step 2: Determine the test parameters for flight testing; Step 3: Conduct pre-flight preparations; Step 4: At the test flight site at an altitude of 0 meters, hover with the maximum effective hovering weight G. IGE Conduct near-ground control characteristic tests with ground effect using combinations of corresponding front left, front right, rear left, and rear right extreme center of gravity; and use the maximum hovering weight G in ground effect. OGE Flight tests were conducted on near-ground control characteristics without ground effect, using combinations of the corresponding front left, front right, rear left, and rear right extreme centers of gravity. The process is as follows: S41. The accompanying vehicle stops at one end of the runway with its front facing the other end of the runway, records the wind speed and direction, and notifies the helicopter. S42. The helicopter flies from back to front at the required altitude to the vicinity of the escort vehicle, aligning the nose of the helicopter with the runway axis. S43. The helicopter initiates the command "Start, 10km / h". The accompanying vehicle slowly accelerates along the runway, and the helicopter follows the accompanying vehicle along the runway at the required altitude. When the wind speed measurement result of the anemometer stabilizes at 10km / h, the accompanying vehicle reports to the helicopter "Wind speed 10km / h, wind direction X°" and maintains the current speed. The helicopter reports "Wind speed 10km / h, wind direction X°, in position" and maintains the current following state for 10 seconds. After 10 seconds, the helicopter reports "X° completed, next X+△°", where △ is the test angle interval. S44. The accompanying vehicle continues to maintain its current speed; the helicopter adjusts its attitude, increasing the heading by △°; after the helicopter has adjusted, it reports "Wind speed 10km / h, wind speed X+△°, in position" and maintains the current following state for 10s; after 10s, the helicopter reports "X+△° complete, next X+2△°"; S45. When the escort vehicle approaches the end of the runway, the escort vehicle reports "Approaching the end of the runway, preparing to switch sides". The helicopter confirms "Preparing to switch sides". The escort vehicle turns its front towards the other end of the runway, records the wind speed and wind direction and notifies the helicopter. The helicopter flies from back to front to the vicinity of the escort vehicle at the required altitude, so that the heading of the helicopter is aligned with the runway axis. S46. The helicopter issues the command "Continue, 10km / h". The accompanying vehicle slowly accelerates along the runway, and the helicopter follows the accompanying vehicle along the runway at the required altitude. When the wind speed measurement result of the anemometer stabilizes at 10km / h, the accompanying vehicle reports to the helicopter "Wind speed 10km / h, wind direction Y°" and maintains the current speed. The helicopter reports "Wind speed 10km / h, wind direction Y°, in position" and maintains the current following state for 10 seconds. After 10 seconds, the helicopter reports "Y° completed, next Y+△°". S47. Repeat S41~S46 to complete all wind directions with a wind speed of 10km / h; S48. Repeat S41~S47 to complete all wind directions with wind speeds of 20km / h, 30km / h, 40km / h up to the maximum side-flying and rear-flying speeds. S49. The helicopter test flight crew conducted Cooper-Harper ratings at various wind speeds and directions at the test flight points. A score of 1 to 3.5 was considered satisfactory, and 4 to 6.5 was considered acceptable. Step 5: Determine the critical center of gravity based on the results of various weight and center of gravity combinations during ground effect and non-ground effect test flights; Step Six: At test airports at other altitudes up to the maximum takeoff and landing altitude, hover at the maximum effective hovering weight G. IGE Conduct near-ground control characteristic tests with ground effect and critical center of gravity, using the maximum hovering weight without ground effect G. OGE Conduct near-ground control characteristics tests without ground effect and at the critical center of gravity; Step 7: Based on the test flight results of Steps 4 and 6, determine the maximum side-flight and rear-flight speeds of the helicopter, as well as the hovering wind speed envelope.
2. The method according to claim 1, characterized in that: Step one, the specific process is as follows: S11. Determine the altitude of the test airport based on the takeoff and landing altitude envelope, with intervals of approximately 1500 meters from altitude 0 meters to the maximum takeoff and landing altitude. S12. Determine the test flight weight and center of gravity combination based on hovering performance and center of gravity envelope, and the maximum effective hovering weight G. IGE Maximum hovering weight without ground effect G OGE The combination of the corresponding front left extreme center of gravity, front right extreme center of gravity, rear left extreme center of gravity, and rear right extreme center of gravity; S13. Determine the ground takeoff altitude H for the ground effect test flight based on the hovering altitude recommended in the takeoff procedure. IGE ; S14. Determine the ground clearance H for no-ground-effect test flights based on twice the rotor diameter. OGE .
3. The method according to claim 2, characterized in that: In step two, the flight test parameters include: S21. Determine the environmental test parameters, including wind speed, wind direction, air pressure altitude, and atmospheric temperature; S22. Determine the helicopter test parameters, including ground clearance, ground speed, control inputs, attitude angle, heading angle, sideslip angle, engine torque, and rotor speed.
4. The method according to claim 3, characterized in that: In step three, the preparations before the test flight are as follows: S31. Prepare an accompanying vehicle with at least two people inside, including a driver and an observer; S32. Install a wind speed and wind direction meter on the roof of the accompanying vehicle; S33. Install a device inside the accompanying vehicle to display and record local time and anemometer measurement results; S34. Synchronize the time display / recording of the accompanying vehicle with the time display / recording of the helicopter; S35. Prepare a portable radio for communication between personnel in the accompanying vehicle and the helicopter test flight crew.
5. The method according to claim 4, characterized in that: In step five, based on the minimum control margins of the longitudinal, lateral, and directional control channels under various weight and center of gravity combinations during ground effect and non-ground effect test flights, the control channel with the smallest control margin among these three control channels is determined, and the center of gravity state in this control channel with the smallest control margin is determined as the critical center of gravity.
6. The method according to claim 5, characterized in that: The test flight process in step six is the same as in step four.
7. The method according to claim 6, characterized in that: In step seven, based on the longitudinal, lateral, and directional control margins of all flight points under various weight and center of gravity combinations during ground effect and non-ground effect flight tests, as well as the Cooper-Harper rating scores, a control margin of not less than 10% and a score of 1 to 6.5 are used as the pass criteria. Flight points that exhibit engine surge or excessively high intake temperatures during the flight test are excluded. The maximum side-flight and rear-flight speeds of the helicopter and the hovering wind speed envelope are determined.