combination of sensor inputs, the evaluation must include an appropriate number of data points for each configuration for which the approval is sought.
The exact number of data points should be agreed upon between the applicant and the FAA and will depend upon the characteristics of the system.
(iv) The data obtained from the flight demonstration should be referenced to the flight deck instrumentation for airplane configuration and airspeed that the flightcrew normally uses to determine airplane performance when operating the airplane manually. Unless it can be shown that the type certificated airplane performance was determined in another manner, the data should not be corrected for actual flap/slat position or airspeed system position error.
(v) If the FMS approval is sought with mix of autopilot or autothrottle computers, each combination should be included during the evaluation.
(vi) The evaluation should include a sufficient number of
• simulated engine out conditions for the takeoff mode to demonstrate that the AFM engine out speed is smoothly captured and maintained. The effects of electrical transients upon the FMS due to the simulated loss of the engine and its associated generator should be assessed.
(vii) At least one actual engine shutdown should be accomplished to evaluate bus and/or generator load switching effects on the FMS. This test may be accomplished on the ground, provided there is nothing associated with flight logic that would invalidate such a simulation.
(viii) An FMS controlled buffet boundary protection margin should be demonstrated for all applicable flight modes by commanding a relatively large speed change at a point close to the boundary. Protection margin over or undershoot transients should not result in buffet.
(ix) The performance management climb, cruise and descent modes should also be evaluated during the flight test demonstration. Unlike the more critical takeoff, landing approach and go-around modes, the primary emphasis should be on the safety and operational characteristics of the speed schedules as opposed to the verification of the actual minimum cost, fuel or time schedules. The flight test should include a functional check of speed, fuel and time schedules as applicable. The operational suitability of these modes should also be evaluated. These modes should affect flightcrew workload and the ease and simplicity of their operation can impact the determination of the minimum flightcrew per § 25.1523.
(x) If an FMS approach autothrottle mode is provided, the control speed should be within + 5 knots of the programmed speed but not less than the computed threshold (minimum) speed. Reference Chapter 2, paragraph 11c(2) of AC 120-29, Criteria for Approving Category I and II Landing Minima for FAR 121 Operators. If the autothrottles are revised as a result of the FMS installation, a qualitative evaluation of Category II and/or autoland characteristics should be made if the airplane has been previously approved for such modes. If a new autothrottle is installed, a quantitative assessment may also be included in the evaluation.
Par 5 25
(xi) If the FMS is used to set power for takeoff by the use of coupled autothrottles, it should be demonstrated that the rate of power increase is sufficient to set the power prior to autothrottle clamp which generally occurs in the 60 to 80 knot range. This becomes increasingly important when operating at high performance conditions associated with light weight, low altitude, maximum takeoff power, and rolling takeoff procedure.
(xii) An evaluation of the fuel state computations should be made for reasonableness when compared with flight planning data.
(xiii) Installation of FNS that are heavily integrated into the airplane displays and controls may result in a change in pilot type rating for Contact should be made as early as possible with the Flight Standards Board for the particular airplane type in accordance with the details described in AC 61-XX, Procedures and Criteria for Determining the Type Rating Requirements for an Aircraft.
Airplane Flight Manual Supplement (AFMS). The AFMS should provide the appropriate system limitations and a comprehensive description of all normal and submodes of system operation including what actions are expected by the flightcrew for each case. A reduction in the amount of material covered may be allowed if the equipment manufacturer's pilot operating manual is required to be on board the aircraft and if the initial version and subsequent revisions are approved by the FAA. The following items, if applicable, should also be addressed in the AFMS.
(1) The compatibility of powerplant intermix and derate with the FMS performance management function.
(2) The AFMS should indicate those functions that have not been evaluated for accuracy by the FAA. The following is an example statement:
¿The accuracy of the FMS range and fuel management information have not been evaluated by the FAA; therefore, airplane range calculations and tuel management must not be predicted upon its use."
(3) The navigation functions, airspace and geographical areas approved for the FMS primary and/or sub-(reversionary) navigation modes should be clearly identified in the AFMS.
(4) The AFMS should describe how the FMS computed and displayed takeoff performance monitor information can vary as the result of varying wind conditions along the runway and the different techniques of applying thrust.
(5) Display of software identifier should be included in the AFMS.
LEROY A. KEITH Manager, Transport Airplane Directorate, Aircraft Certification Service, ANM-100 26 Par 5
Appendix 1 APPENDIX 1 TABLE 1
COMPUTED PERFORMANCE CRITERIA
PARAMETER COCKPIT FMS COMPUTES FMS ERRORS FMS CONTROLS
READABILITY TO THE AFM RESULTING FROM TO THE VALUES WITHIN: SENSOR ACCURACY COMPUTED
COMMANDS WITHIN (STEADY STATE*):
EPR .01 See Note 1 See Note 2 See Note 3 THRUST SET See Note 1 See Note 2 See Note 3 RPM (%) EGT (C) + 8 LIMITING 1 + 0, -1.0 + .5 + 1 RPM (%)
IAS (KTS) + 1 + 2 +5, -2 1 + 2, -0 + 2 @ 100 KTS +5, -0 T.O. & LDG 10 See Note 4 See Note 4 ...
DISTANCE (FEET) PERF See Note 5 See Note 5 See Note 5
LIMIT WT Dual systems displays may differ by the extremes of the sum of columns 3 and 4.
*Control accuracy on "steady state" basis; gusts and other short term disturbances may exceed these during transients.
NOTE 1: Computes thrust setting values to an accuracy that does not introduce appreciable error in the displayed value of the thrust setting parameter when compared to the value shown on the thrust setting charts contained in the AFM.
Typically ‡ .005 EPR or + .25% RPM.
NOTE 2: Errors introduced by sensor inaccuracy may not exceed those associated with the accuracies/readabilities historically deemed acceptable for the display of parameters used in setting thrust by means of reference charts contained in the AFM. Typically + .005 EPR or + .25% RPM.
NOTE 3: Controls all engines to computed commands with an accuracy equal to or better than the pilot's ability to set thrust manually without undue concentration or effort when relying on the thrust setting information sostans see paragraph sti21(1) of this Ac. 5% RPM. For single serve contained in the AFM. Typically NOTE 4: Not shorter than the distance determined by the AFM.
NOTE 5: Not greater than the weight determined from the AFM.
Appendix 1 TABLE 2
LOW ALTITUDE SPEED COMMAND TOLERANCES (STILL AIR)
MODE CONDITION TRANSITION IAS (KTS) STEADY STATE IAS (KTS) +5 TAKEOFF CRITICAL ENGINE Before 35 feet, as close Vz -0 FAILURE VEF < V2 as practical to the speed profile demonstrated durirs performance tests.
CRITICAL ENGINE FAILURE +5 Vz < VEF < (V2 +X) VEr -5 (Note 1.) VEr -2 (Note 2.)
CRITICAL ENGINE FAILURE VEF > (V2 + X) (V½ + X) -5 (Note 3.) (V½ + X) + All Engines N/A Operating TAKEOFF, Critical Engine (V½ + X) -5 (Note 3.) (V½ + x) = NOISE Failure During THRUST Thrust Cutback
CUTBACK All Engines Operating (Vz + X) -2 LANDING Critical Engine (REF +XX) -55 (Note 5.) VREF +XX) *2 APPROACH Failure During GO-AROUND Transition (Initiated at VREF + All Engines (VeEr +XX) - 5 (Note 6.) Veer +Xx) -2 XX during Operating stabilized approach) +5 LANDING All Engs Operating N/A APPROACH & Critical Engine Failure NOTES:
Less than VEr -2 not to exceed 10 sec.; Less than V½ not to exceed 5 sec; Not less than V½ -2 Ness than (V, +3x) -2 not to exceed 10 sec.
Except in pitch limited conditions
3. Less than (REr +X) -2 not to exceed 10 sec.; Less than 1.2Vs1 not to exceed 5 sec.; Not less than 1.2 si -2 *: kes At engine sad not to exce 10 see Not less than 1.2%
9. XX = Landing approach wind speed/gust additive 2