7/30/97/ AC 29-2B A minimum of three normal takeoffs (and landings) should be conducted to ensure that aircraft lighting (internal and external) is adequate to allow normal Category A operations at night.
Engine failures should be simulated from points along the recommended takeoff profile. Night OEl rejected takeoffs and continued takeoffs from the TDP should be conducted to ensure adequate night field of view and realization of Category A field lengths.
(iii) If special airfield marking/lighting is used as a reference or to define the TDP, the aircraft external lighting should be evaluated to ensure the airfield marking/lighting is adequately visible for night operations.
Par 60A 109
ALL ENGINE
CLIMBOUT →
ACCELERATE TO VY
WHEN CLEAR OF OBSTACLES
OEI CLIMBOUT
ACCELERATE
TO VTOSS TDP
VERTICAL CLIMB 15' FIGURE 60A-1. CATEGORY A VERTICAL TAKEOFF PROFILE GROUND LEVEL HELIPORT 110 Par 60A
ALL ENGINE
CLIMBOUT
TDP - ACCELERATE TO VTOSs
VERTICAL CLIMB & 15 FEET
TAKEOFF PATH REJECTED MINIMUM
OEI FLIGHT PATH 200 ft.
1 Vross and positive rate of 1 climb Takeoff distance FIGURE 60A-2. CATEGORY A VERTICAL TAKEOFF PROFILE ELEVATED HELIPORT Par 60A 111
61.-63. RESERVED.
Intentionally Left Blank 112 (thru 114) Par 61
64. § 29.63 (Amendment. 29-12) TAKEOFF: CATEGORY B.
a. Explanation.
(1) Takeoff distance is the horizontal distance measured from an initial position to a point 50 feet above the takeoff surface with all engines operating within approved limits.
(2) The height-velocity diagram is normally developed and accepted prior to conducting takeoff distance tests. Takeoff distance tests are conducted avoiding the critical areas of the diagram. The amount of power utilized in determining takeoff distance may not be greater than that used in constructing the takeoff corridor and "knee" portions of the height-velocity diagram. Power might also have to be constrained, depending upon the amount of excess power available, so that a "reasonable" nose down pitch attitude is not exceeded during the initial portion of the takeoff run. Acceptable values used during past programs include:
Hover power + 10 percent (not to exceed rated engine takeoff power limits)
(il) A percent transmission limiting torque (not to exceed rated engine takeoff power limits), and Engine (or transmission) limiting power for the particular ambient conditions.
(3) The critical center of gravity should be used for takeoff distance tests.
Critical center of gravity should be established analytically or from previous testing and may be forward or aft depending on the type of rotorcraft. Items that should be considered in determining the critical center of gravity are climb performance and cockpit visibility. At least two gross weights should be flown at each test altitude, if weight accountability is desired, in order to validate the manufacturers prediction of weight effects.
(4) The speed utilized at the 50-foot point in the takeoff profile (V50 speed) may be largely determined by the ability to obtain reliable, repeatable airspeed indications which can also comply with § 29.1323. Section 29.1323 ties the airspeed system accuracy requirements to the climbout speed. The climbout speed should be that speed attained at 50 feet in complying with § 29.63.
b. Procedures.
(1) Instrumentation. A ground station will measure ambient temperature, humidity (if applicable), and wind. For allowable wind conditions and engine power considerations refer to Paragraph 55 of this advisory circular. A photo panel or hand Par 64 115
recording method may be utilized, as necessary, to record engine and flight parameters. A phototheodolite, takeoff and landing camera, or other approved instrumentation is utilized to measure distance, heights, speed, and time.
(2) Conduct of the Test. If the applicant elects to show weight effects on distance, at least two weights should be flown and, depending on the range of takeoff and landing altitudes to be approved, at least two test altitudes should be flown.
Altitudes should be sufficiently far apart to include a major portion of the approved takeoff and landing altitude range. Takeoff profiles should be started from an initial condition. For takeoffs from a hover, the hover height should be determined by performing fixed collective takeoffs as described in Paragraph 57 of this advisory circular. "Takeoff" power should be smoothly applied and the aircraft nose lowered as necessary to accelerate without gaining excessive altitude. It must be possible to conduct a consistent takeoff profile clear of the height-velocity diagram with normal pilot effort and skill. A minimum of five good runs should be flown by the FAAJAUTHORITY pilot at each altitude and weight. Runs by the company and FAA/AUTHORITY pilot may be averaged. Effects of missing the V50 speed by some amount (+ 5 knots, for example) or other small changes in profile should be evaluated to determine if gross performance changes result from small piloting errors. Engine failures should be conducted along the takeoff profile to assure safe landing capability. Past programs have shown the low speed point immediately after addition of power to be particularly critical. Night takeoffs should at least be qualitatively evaluated to assure the takeoff procedures are compatible for night operation.
(3) Test Results. Test results are utilized in constructing the flight manual takeoff distance charts required by § 29.1587. The takeoff surface utilized in conducting these takeoff distance and engine failure tests should be included in the flight manual. The "climbout speed" should also be defined and included in the flight manual. The airspeed utilized at the 50-foot point in the conduct of these tests must be clearly defined to allow compliance with § 29.1323. Test results may be extrapolated in accordance with guidance contained in Paragraph 55 of this advisory circular.
(4) Test Techniques. For the FAA/AUTHORITY test data runs which will result in rotorcraft flight manual (RFM) performance, only the operational cockpit instrumentation as shown on the minimum equipment list and the piloting procedures from the RFM should be used. A useful technique is to "lead" the targeted Vso speed by a fixed amount, so that a smooth, consistent, and operationally realistic transition may be made between the acceleration and climbout phases; e.g., begin rotation at 35 knots to achieve 46 knots passing 50 feet. This and other pertinent information defining the takeoff flight path are required flight manual entries per § 29.1587(b).
116 Par 64
TAKEOFF PROFILE
HEIGHT ABOVE GROUND (FEET) AVOID _ 5 KTS MINIMUM MARGIN AVOID
VELOCITY (KNOTS) FIGURE 64-1. CONVENTIONAL TAKEOFF PROFILE CATEGORY B Par 64 117
7/30/97 AC 29-2B
65. RESERVED.
Intentionally Left Blank Par 65 118
66. § 29.65 (Amendment 29-15) CLIMB: (ALL ENGINES OPERATING).
a. Explanation.
(1) Section 29.65 requires in part that the steady rate of climb be determined for each Category B rotorcraft with maximum continuous power on each engine for the range of weights, altitudes, and temperatures for which certification is requested. The climb airspeed should be the best rate-of-climb (Vy) for standard day sea level conditions at maximum weight and at a speed(s) selected by the applicant for other conditions not to exceed VNE The applicant can either publish a climb schedule in accordance with the above or utilize a constant climb airspeed for all conditions.
Equivalent levels of safety have been found wherein the applicant was allowed to select a climb airspeed that was not the actual Vy. The selected airspeed must be consistent with the speed used to show compliance with such items as cooling, stability, etc. The rate-of-climb resulting from the selected climb airspeed versus that from the actual Vy shall not differ to an extent that a pilot will be encouraged, by appreciable increases in climb performance to fly a climb airspeed different from that published in the Flight Manual.
(2) For Category A rotorcraft, if VNE at any altitude is less than the maximum gross weight sea level standard day condition Vy, the steady rate-of-climb must be determined at the climb speed(s) selected by the applicant not to exceed NE. The climb performance must be determined from 2,000 feet below the altitude from where VNE intersects Vy up to the maximum altitude for which certification is requested. This should be done utilizing maximum continuous power on each engine with the landing gear retracted.
b. Procedure to Determine Vy.
(1) Sawtooth climbs may be used to determine the best rate-of-climb airspeed Vy. If such a technique is used, climbs should be flown in pairs on opposite headings 90° to the winds at the test altitude. This procedure will minimize any windshear effects. All testing should be done in smooth air. Windshear is usually an indication of unstable air or a temperature inversion and should be avoided. The climbs are flown on reciprocal headings for approximately 5 minutes through a 1,000-foot band, or a comparable time/altitude band, using maximum continuous power at a constant airspeed. Periodic power adjustments may be necessary. Additional reciprocal heading climbs must also be conducted at different airspeeds sufficient to bracket the lowest point of the power required versus airspeed curve. This technique can be repeated at different altitudes to obtain Vy throughout the altitude range.
(2) Level flight performance (speed power) may also be used to determine the best rate-of-climb airspeed (Vy). The testing should be done in smooth air. The advantage of this method is that less time is required, and the accuracy is equivalent to the sawtooth climb method. The test can be repeated at various altitudes to determine Par 66 119
the Vy throughout the altitude range desired for the rotorcraft. The test at each altitude should be conducted at a constant weight over sigma (W/). The test is normally started at the desired W/o with maximum continuous power, or at VNE, in level flight. A series of points should be taken, reducing airspeed 10 to 15 knots between points, with the lowest speed point at approximately 20 to 30 knots. Weight should be computed for each point and the test altitude adjusted to maintain a constant W/o. After the data are reduced to standard day conditions, the minimum power required airspeed will be the Vy speed.
(3) Prior to the flight test, the rotorcraft should be ballasted to the desired gross weight and the critical center of gravity. The airspeed should be stabilized prior to data acquisition. Data to be recorded includes time, altitude, airspeed, ambient temperature, engine parameters, torque(s), rotor RPM, fuel reading, aircraft heading, external configuration, etc. Power setting, weight, and climb airspeed should be planned prior to flight. For some turboshaft engines, temperature and/or engine speed limits may be reached prior to a limiting torque. The test team should verify that the resulting power utilized in these tests closely approximates the power producing capabilities of installed minimum specification engine.
c. Procedure to Determine all Engine Operating Climb Performance.
(1) Background. Continuous climbs are conducted at the appropriate climb airspeeds as outlined above in order to obtain the rotorcraft's climb performance for the flight manual. By-products are a qualitative evaluation of the rotorcraft handling characteristics in a climb and engine data to assist in the determination of installed power available.
(2) Techniques. The techniques used to determine this performance may be the same as those used in the Vy determination. The climbs are conducted on reciprocal headings at the established airspeed(s) through the target altitude range.
The same parameters are recorded. The rotorcraft will usually climb very rapidly during the first few thousand feet; therefore, the data acquisition method must be timely if accurate results are expected. This procedure is usually repeated at weight extremes.
The resulting data must then be corrected for power and weight. Power and weight corrections are satisfactory, provided the test powers and weights closely approximate the target values to make the weight and power corrections accurate. Once this data is finalized and corrected for all the flight test variables, interpolation for intermediate weights can be made with a high degree of reliability. If the rotorcraft has any stability augmentation system, vent systems, etc., which may influence the climb performance, then it must be accounted for. Caution should be taken that anti-ice, air-conditioning, etc., are not on unless the performance is being established specifically for those conditions.
120 Par 66
66A. § 29.64 and 29.65 (Amendment 29-39) CLIMB: (GENERAL AND ALL ENGINES OPERATING).
a. Explanation.
(1) Amendment 29-39 relocated and clarified the general climb requirements into a new § 29.64 and added requirements to determine Category A climb performance in § 29.65. The guidance material presented in Paragraph 67 does not apply to rotorcraft certified with Amendment 29-39 or later. Sections 29.64 and 29.65 require that the steady rate of climb be determined with maximum continuous power on each engine for the range of weights, altitudes, and temperatures for which certification is requested. The climb airspeed should be the best rate-of-climb (Vy) for standard day sea level conditions at maximum weight and at a speed(s) selected by the applicant for other conditions not to exceed VNE. The applicant can either publish a climb schedule in accordance with the above or utilize a constant climb airspeed for all conditions.
Equivalent levels of safety have been found wherein the applicant was allowed to select a climb airspeed that was not the actual Vy. The selected airspeed should be consistent with the speed used to show compliance with such items as cooling, stability, etc. The rate-of-climb resulting from the selected climb airspeed versus that from the actual Vy shall not differ to an extent that a pilot will be encouraged by appreciable increases in climb performance to fly a climb airspeed different from that published in the Flight Manual.
(2) If VNE at any altitude is less than the maximum gross weight sea level standard day condition Vy, the steady rate-of-climb should be determined at the climb speed(s) selected by the applicant not to exceed VNE. The climb performance should be determined from 2,000 feet below the altitude from where VE intersects Vy up to the maximum altitude for which certification is requested. This should be done utilizing maximum continuous power on each engine with the landing gear retracted.
b. Procedure to Determine Vy.
(1) Sawtooth climbs may be used to determine the best rate-of-climb airspeed Vy. If such a technique is used, climbs should be flown in pairs on opposite headings 90° to the winds at the test altitude. This procedure will minimize any windshear effects. All testing should be done in smooth air. Windshear is usually an indication of unstable air or a temperature inversion and should be avoided. The climbs are flown on reciprocal headings for approximately 5 minutes through a 1,000-foot band, or a comparable time/altitude band, using maximum continuous power at a constant airspeed. Periodic power adjustments may be necessary. Additional reciprocal heading climbs should also be conducted at different airspeeds sufficient to bracket the lowest point of the power required versus airspeed curve. This technique can be repeated at different altitudes to obtain Vy throughout the altitude range.
Par 66A 121
(2) Level flight performance (speed power) may also be used to determine the best rate-of-climb airspeed (Vy). The testing should be done in smooth air. The advantage of this method is that less time is required, and the accuracy is equivalent to the sawtooth climb method. The test can be repeated at various altitudes to determine the Vy throughout the altitude range desired for the rotorcraft. The test at each altitude should be conducted at a constant weight over sigma (W/). The test is normally started at the desired W/o with maximum continuos power, or at VNE, in level flight. A series of points should be taken, reducing airspeed 10 to 15 knots between points, with the lowest speed point at approximately 20 to 30 knots. Weight should be computed for each point and the test altitude adjusted to maintain a constant W/o. After the data are reduced to standard day conditions, the minimum power required airspeed will result in the airspeed for maximum rate of climb. However, aircraft stability may suggest that a higher climb speed may be used for Vy.
(3) Prior to the flight test, the rotorcraft should be ballasted to the desired gross weight and the critical center of gravity. The airspeed should be stabilized prior to data acquisition. Data to be recorded includes time, altitude, airspeed, ambient temperature, engine parameters, torque(s), rotor RPM, fuel reading, aircraft heading, external configuration, etc. Power setting, weight, and climb airspeed should be planned prior to flight. For some turboshaft engines, temperature and/or engine speed limits may be reached prior to a limiting torque. The test team should verify that the resulting power utilized in these tests closely approximates the power producing capabilities of installed minimum specification engine.
c. Procedure to Determine all Engine Operating Climb Performance.
(1) Background. Continuous climbs are conducted at the appropriate climb airspeeds as outlined above in order to obtain the rotorcraft's climb performance for the flight manual. By-products are a qualitative evaluation of the rotorcraft handling characteristics in a climb and engine data to assist in the determination of installed power available.
(2) Techniques. The techniques used to determine this performance may be the same as those used in the Vy determination. The climbs are conducted on reciprocal headings at the established airspeed(s) through the target altitude range.
The same parameters are recorded. The rotorcraft will usually climb very rapidly during the first few thousand feet; therefore, the data acquisition method should be timely if accurate results are expected. This procedure is usually repeated at weight extremes.
The resulting data should then be corrected for power and weight. Power and weight corrections are satisfactory, provided the test powers and weights closely approximate the target values to make the weight and power corrections accurate. Once this data is finalized and corrected for all the flight test variables, interpolation for intermediate weights can be made with a high degree of reliability. If the rotorcraft has any stability augmentation system, vent systems, etc., which may influence the climb performance, 122 Par 66A