Appendix 1 A1-4 LNAV lateral navigation LODA letter of design approval M Mach number MAC mean aerodynamic chord MCS master caution system MCT maximum continuous thrust MD design dive Mach MDA minimum descent altitude MDF demonstrated flight diving Mach MEL minimum equipment list MF medium frequency MFC maximum Mach for stablity characteristics MFD multi-function display min. minute(s) MLRC long range cruise Mach MLS microwave landing system MMEL master minimum equipment list MMO maximum operating Mach MSL mean sea level MWS master warning system MUH minimum use height N1 rotational speed of low pressure compressor (turbine engine) N2 rotational speed of high pressure compressor (turbine engine) NAS national airspace system NAV navigate NM nautical mile(s) NFE normal flight envelope OAT outside air temperature OEW operating empty weight OFE operational flight envelope PA public address
Appendix 1 A1-5 PFC porous friction course PIO pilot induced oscillation Q dynamic pressure R/A radio altimeter RFI radio frequency interference
r.p.m. revolutions per minute RMI radio magnetic indicator RNAV area navigation RNP required navigation performance RTO rejected takeoff RVP Reid vapor pressure RVR runway visual range SAS stability augmentation system SAT 1. static air temperature
2. satisfactory (when used with the handling qualities rating method)
SATCOM satellite communications secs. seconds SELCAL selective calling system S/F slow/fast SR special regulation STC supplemental type certificate STOL short takeoff and landing SWC stall warning computer TAT total air temperature TAWS terrain awareness and warning system TCAS traffic collision avoidance system TCDS type certificate data sheet TIA type inspection authorization TIR type inspection report TOW takeoff warning TSO technical standard order
Appendix 1 A1-6 T/W thrust-to-weight ratio UNSAT 1. unsatisfactory
2. failed V1 maximum speed in the takeoff at which the pilot must take the first action
(e.g.; apply brakes, reduce thrust, deploy speed brakes) to stop the airplane within the accelerate-stop distance. It also means the minimum speed in the takeoff, following a failure of the critical engine at VEF, at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance.
V2 takeoff safety speed V2MIN minimum takeoff safety speed V35 speed at a height of 35 feet above the takeoff surface VD design diving speed VDF demonstrated flight diving speed VEF speed at which the critical engine is assumed to fail during takeoff VFC maximum speed for stability characteristics VFE maximum flap extended speed VFR visual flight rules VG vertical gyros VHF very high frequency VLE maximum landing gear extended speed VLO maximum landing gear operating speed VLOF lift off speed VMC visual meteorological conditions VMC minimum control speed with the critical engine inoperative VMCA minimum control speed in the air VMCG minimum control speed on the ground VMCL minimum control speed during approach and landing with all engines operating VMCL(1 out) minimum control speed during approach and landing with one engine inoperative VMCL-2 minimum control speed during approach and landing with one critical engine inoperative (for airplanes with three or more engines)
Appendix 1 A1-7 VMCL-2(2 out) minimum control speed during approach and landing with two engines inoperative (for airplanes with three or more engines) VMO maximum operating limit speed VMU minimum unstick speed VNAV vertical navigation VOR very high frequency omnidirectional range VORTAC very high frequency omnidirectional range tactical air navigation VREF reference landing speed VS stalling speed or the minimum steady flight speed at which the airplane is controllable VS0 stalling speed or the minimum steady flight speed in the landing configuration VS1 stalling speed or the minimum steady flight speed in a specific configuration VSR reference stall speed VSR0 reference stall speed in the landing configuration VSR1 reference stall speed in a specific configuration VSW speed at which the onset of natural or artificial stall warning occurs WAT weight, altitude, temperature W/δ weight/delta
Symbol Definition
Δ incremental change in value δ ratio of atmospheric pressure at any altitude to the pressure at sea level max maximum friction coefficient available between a tire and the runway surface
Appendix 2 A2-1
Appendix 2
Function and Reliability Tests - § 21.35(b)(2).
1. Explanation.
a. In order to accomplish satisfactorily the objectives concerning additional flight tests and the extent thereof, the Administrator deems it necessary that:
(1) A comprehensive and systematic check be made, in flight, of the operation of all components to determine whether they “function properly” (i.e., perform their intended function without introducing safety hazards).
(2) Sufficient FAA test experience, and supplementary experience gained from operators’ route proving tests, should be obtained and evaluated to give reasonable assurance that the airplane is “reliable” (i.e., should continue to function properly in service).
NOTE: In order to obtain wider experience, manufacturers are encouraged to cooperate with airlines or other responsible operators in operating airplanes with provisional type certificates under service conditions.
(3) Appropriate corrective action be taken when the need therefore is determined under subparagraphs (1) and (2) of this paragraph.
2. Procedures. The principal FAA flight test pilot for the project will act as coordinator of all flight activities during the official program, and that pilot (or a designated alternate) will participate in all flights. Other FAA personnel will not board the function and reliability (F & R) airplane(s) during these activities, particularly in regard to flight plans and procedures, unless authorized by the flight test pilot. The manufacturer’s pilot should be in command of all flights, but FAA pilots will fly the airplane to determine compliance with § 21.35(b)(2). Other FAA personnel (e.g., representatives of other divisions and specialists) will participate in the flight tests, when deemed necessary, to accomplish the purpose of the tests.
a. Test Time. It is highly desirable that function and reliability test programs be administered uniformly so that the program and flight time for a given project would be approximately the same, regardless of which FAA ACO administered the project. This is difficult to achieve without establishing fixed arbitrary test times, which would obviously be contrary to the intent of § 21.35 (b)(2). The following procedure, which permits considerable flexibility, is therefore established as guidance for administering F & R test programs:
(1) For a turbine engine-powered airplane incorporating engines of a type not previously certificated, § 21.35(f)(1) requires an F & R test program of at least 300 hours. This 300 hour minimum may also be applied to a complex new airplane model (e.g., an airplane with an electronic flight control system (fly by wire)). Though some F & R test requirements can be
Appendix 2 A2-2 completed concurrently with certification testing (if relevant design conformity can be shown), experience has indicated the desirability of obtaining at least 150 hours on a production configured airplane. For a previously certificated airplane, the F & R program requirement should be commensurate with the modifications or changes.
(2) When supplementary experience is not taken into account, and the airplane is conventional with regard to complexity and design features and does not incorporate engines that have not been previously certificated (including derivative engines), it has been found that function and reliability tests can be performed within 300 hours. This time may be reduced if credit is granted for certain types of component testing (see paragraph 2e(2) of this Appendix) and for supplementary experience (see paragraph 2a(3)(c) of this Appendix). However, it may be necessary to increase the 150-hour minimum F & R test requirement of § 21.35(f)(2) if difficulties are encountered or for unusual cases of complexity.
(3) When satisfactory supplementary experience is available and taken into account the following allowances should be used as a guide and applied with judgment in reducing the official flight test time. However, in any case, the official F & R test program should provide sufficient time to accomplish the objective of paragraph 1a(2) in accordance with the procedures described in paragraphs 2e(3) and (4).
(a) For Intensive Experience. When the allowance is based on the total time of any one airplane in airline crew training and similar intensive operations, two hours of such operation may be considered equivalent to one hour of official testing.
(b) For Miscellaneous Experience. When the allowance is based on the total time of any one airplane, five hours of such experience may be considered equivalent to one hour of official testing.
(c) Reduction for Supplementary Experience. Whenever a reduction of official test time is desired on the basis of supplementary experience, such experience should be adequately recorded and submitted to the responsible FAA aircraft certification office as described in paragraph 2f(2) of this appendix.
b. Test Airplane. To facilitate completion of the type certification procedure, one airplane, in production configuration or equivalent, should be used for the official functional and reliability tests while another airplane (or airplanes) is used for the routine-type tests. In this case, the test time on at least one airplane would be sufficient to accomplish the objective of paragraph 1a(2) of this appendix.
c. Modified Types. The procedure outlined in paragraph d., below, applies to new type designs. When a design employs components (parts) identical to those used in previous designs, credit may be given for the supplementary experience available for such components. When a design is modified (e.g., several versions of the same basic type with different engines, propellers, etc.), the modified features and components should be rechecked in accordance with paragraph 2e(6), below.
Appendix 2 A2-3
d. Test Program. The project engineers of the responsible FAA ACO will propose guidelines for developing an F & R test program at the preflight type board meeting (prior to commencement of FAA certification flight tests) and coordinate this with the airplane manufacturer. Near the conclusion of the type certification tests, the FAA certification engineers will again meet with the manufacturer to review the experience gained in those tests, review changes made in the design, consider any additional supplementary experience, and revise the proposed F & R test program accordingly. In application, there is generally considerable overlap of the certification and F & R test programs, thus making a definite transition point indiscernible.
e. Planning and Execution of Test Program. The following points should be considered:
(1) The test program should be sufficiently well planned to enable its execution in an efficient manner without overlooking important items. Documentation should focus on the test objective(s) but does not necessarily require the type of detail maintained for type certification testing. The FAA project engineers will review the design features and equipment (appliances) with respect to the general objective and prepare a list showing:
(a) Components and systems to be checked in accordance with the procedures described in the below paragraph 2e(4).
(b) A brief description of the operations to be performed, where these are not obvious (referencing any necessary operating instructions).
(c) Special checks or likely critical conditions.
(d) Estimated flight time required.
(2) Allowance may be made for those functional tests whose requirements are covered by part 25 type certification tests. Allowance may also be made for qualification-type testing of new features and equipment; however, the flight test program should be planned to determine the adequacy of these tests and the accuracy of the simulated operating environment (e.g., to determine whether the actual environmental conditions such as temperature variation, etc., are covered by the test simulations) when these may be critical, and to determine whether the installation and connected systems are satisfactory. This does not imply that flight tests must be conducted under the most severe outside air temperatures likely to be encountered in service. It should normally be possible to determine the effects of extreme outside temperatures on local temperatures by extrapolation or by suitable correction factors. The FAA project engineers will then make a consolidated estimate of the total flight time required, allowing for overlapping, and adjust this in accordance with the “Test Time” outlined in the above paragraph 2a.
(3) This program will be arranged to permit the principal FAA flight test pilot to become thoroughly familiar with the operational aspects of the airplane in its anticipated service environment.
(4) All components of the airplane should be intensively operated and studied under all operating conditions expected in service and obtainable within the time and geographical
Appendix 2 A2-4 limitations of the tests. Intensive operation means repeated operation of components in various sequences and combinations likely to occur in service. Particular attention should be given to potential sources of crew error, excessive crew workload or coordination, and the procedures that would be required in the event of malfunction of any component. The testing should also include an evaluation of operations with various MEL items declared/simulated inoperative.
This intensive type of testing should be conducted in all cases, but the length of time for which it is continued will depend upon the supplementary experience available for the particular type, as outlined in the above paragraph 2a, “Test Time.”
(5) Ground inspections should be made at appropriate intervals during the test program to determine whether there are any failures or incipient failures in any of the components that might be a hazard to safe flight. The normal maintenance procedures should be employed during the F&R Program and carefully documented for review.
(6) When design changes are made during the course of the test, or when the official test airplane differs from those on which supplementary experience is obtained, the modified items will be rechecked in accordance with the above procedures. Every effort should be made to include such items in the program in such a way as to avoid unduly extending the overall test time. To this end, the Administrator may accept, in lieu of additional flight tests:
(a) Special tests of the original and revised components in which the conditions causing failure are intensified.
(b) Ground qualification tests of differing components when the test methods have been validated as being representative of actual flight conditions.
f. Reports and Records.
(1) A log should be kept of all flights, and accurate and complete records kept of the inspections made of all defects, difficulties, and unusual characteristics and sources of crew error discovered during the tests, and of the recommendations made and action(s) taken. Items for which design changes may be required will be reported to the manufacturer and the appropriate FAA ACO.
(2) If supplementary experience is to be taken into account, similar records of such experience should be kept and submitted to the responsible FAA ACO, together with a list of the differences between the airplane on which the experience was obtained and the official test airplane. When supplementary experience is obtained on a large fleet of airplanes (for example, military operations) of the same or a comparable type (see the above paragraph 2e(6)), these records may consist of statistical summaries in lieu of complete records for each individual airplane.
(3) At the conclusion of the official tests, a summary report should be prepared by the participating pilots, engineering specialists, and manufacturing inspectors and made a part of the type inspection report.
Appendix 2 A2-5
Appendix 3 A3-1
Appendix 3
Historical Development of Accelerate-Stop Time Delays
1. Explanation.
a. As the rules pertaining to transport category airplane accelerate-stop distances have developed over the years, the interpretation of those rules, with regard to pilot actions, recognition times, and delay times, has also changed. The paragraphs below provide a historical perspective on the application of pilot recognition and delay times, with references to the applicable part 25 amendment number.
b. In accordance with § 21.101(a) and (b), the certification basis for a derivative airplane type may be the regulations specified in the type certificate of the basic airplane, depending upon the extent and nature of the changes to the airplane. For those cases where the original certification basis can be retained, the guidance presented in paragraphs 2a and b., below, may be used to show compliance with the appropriate regulations. (For more information related to determining a derivative airplane’s certification basis, see AC 21.101-1, Change 1, “Establishing the Certification Basis of Changed Aeronautical Products.”)
c. Regardless of the certification basis, the effects of brake wear state on energy absorption capability and stopping performance must be addressed in order to comply with § 21.21(b)(2).
The responsible FAA ACO should be contacted to establish the applicable brake wear criteria for a specific airplane type.
2. Procedures.
a. Pre-amendment 25-42 Accelerate-Stop Time Delays. Parts 1 and 25 of Title 14 of the CFR, prior to amendments 1-29 and 25-42, respectively, defined V1 as the critical engine failure speed. When this definition of V1 was applied to the accelerate-stop criteria of § 25.109 and the V1 criteria of § 25.107(a)(2), the implication was that engine failure and engine failure recognition could occur simultaneously. It was recognized that this simultaneous occurrence could not be achieved in actual operations, and that defining V1 as the engine failure speed resulted in a conflict with § 25.101(h), which requires allowance for time delays in execution of procedures. In order to resolve this conflict, V1 was applied as the engine failure recognition speed, and appropriate time delays were developed for showing compliance with § 25.101(h).
Figure 1 shows a pictorial representation of the accelerate-stop time delays that were considered acceptable for compliance with § 25.101(h) before Amendment 25-42 (effective March 1, 1978).
Paragraph 2a(7) of this appendix provides guidance on reflecting these time delays in the AFM accelerate-stop distances.
Appendix 3 A3-2 Figure 1. Accelerate-Stop Time Delays
(Pre-Amendment 25-42)
(1) trec = engine failure recognition time. The demonstrated time from engine failure to pilot activation of the first deceleration device, this action indicating recognition of the engine failure. For AFM data expansion purposes, in order to provide a recognition time increment that can be executed consistently in service, it has been found practical to use the demonstrated time or 1 second, whichever is greater. If the airplane incorporates an engine failure warning light, the recognition time includes the time increment necessary for the engine to spool down to the point of warning light activation, plus the time increment from light “on” to pilot action indicating recognition of engine failure.
(2) ta1 = the demonstrated time interval between activation of the first and second deceleration devices.
(3) ta2 = the demonstrated time interval between activation of the second and third deceleration devices.
(4) t = a 1-second reaction time delay to account for in-service variations. If a command is required for another crewmember to actuate a deceleration device, a 2-second delay, in lieu of the 1-second delay, should be applied for each action. For automatic deceleration devices that are approved for performance credit for AFM data expansion, established times determined during certification testing may be used without the application of the additional time delays required by this paragraph.
(5) The sequence for activation of deceleration devices may be selected by the applicant in accordance with § 25.101(f). If, on occasion, the desired sequence is not achieved during testing, the test need not be repeated; however, sufficient tests should be conducted to establish acceptable values of ta.
Appendix 3 A3-3
(6) If additional devices are used to decelerate the airplane, their respective demonstrated times, plus any additional required time delays, should be included until the airplane is in the full braking configuration.
(7) For the purpose of flight manual calculations, the 1-second delay for each action may be added at the end of the total demonstrated time. Regardless of the manner in which the time delays are applied, the flight manual calculations should assume the airplane does not decelerate during the delay time increments.
b. Amendment 25-42 thru amendment 25-91, Accelerate-Stop Time Delays. Amendment 25-42, effective March 1, 1978, introduced several new requirements affecting accelerate-stop distance determination. One of the most significant changes of Amendment 25-42 was the requirement to determine an all-engines-operating accelerate-stop distance to account for the many rejected takeoffs that were not the result of an engine failure. Amendment 25-42 also introduced into the regulations an engine-failure speed, VEF; redefined the takeoff decision speed, V1; revised the accelerate-stop distance criteria to correspond to the VEF and V1 definitions; and added a 2-second time delay between V1 and the first action to decelerate the airplane during which the airplane continues accelerating with the operating engines at takeoff thrust. Figure 2 shows a pictorial representation of the accelerate-stop time delays in accordance with the provisions of part 25, including Amendment 25-42:
Figure 2. Accelerate-Stop Time Delays
(Amendment 25-42 thru amendment 25-91)