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Pt. 121, App. B
Appendix B to Part 121—Airplane Flight Recorder Specification
Parameters
Range
Accuracy sensor input to DFDR readout
Sampling interval (per second)
Resolution 4 readout
Time (GMT or Frame Counter) (range 0 to 4095, sampled 1 per frame)
24 Hrs
±0.125% Per Hour
0.25 (1 per 4 seconds)
1 sec.
Altitude
−1,000 ft to max certificated altitude of aircraft
±100 to ±700 ft (See Table 1, TSO-C51a)
1
5′ to 35′ 1
Airspeed
50 KIAS to V so, and V so to 1.2VD
±5%, ±3%
1
1 kt.
Heading
360°
±2°
1
0.5°
Normal Acceleration (Vertical)
−3g to + 6g
±1% of max range excluding datum error of ±5%
8
0.01g.
Pitch Attitude
±75°
±2°
1
0.5°
Roll Attitude
±180°
±2°
1
0.5°
Radio Transmitter Keying
On-Off (Discrete)
±2°
±2%
Thrust/Power on Each Engine
Full Range Forward
±2°
1 (per engine)
0.2% 2
Trailing Edge Flap or Cockpit Control Selection
Full Range or Each Discrete Position
±3° or as Pilot's Indicator
0.5
0.5% 2
Leading Edge Flap or Cockpit Control Selection
Full Range or Each Discrete Position
±3° or as Pilot's Indicator
0.5
0.5% 2
Thrust Reverser Position
Stowed, In Transit, and Reverse (Discrete)
1 (per 4 seconds per engine)
Ground Spoiler Position/Speed Brake Selection
Full Range or Each Discrete Position
±2% Unless Higher Accuracy Uniquely Required
1
0.2% 2.
Marker Beacon Passage
Discrete
1
Autopilot Engagement
Discrete
1
Longitudinal Acceleration
±1g
±1.5% max range excluding datum error of ±5%
4
0.01g.
Pilot Input and/or Surface Position—Primary Controls (Pitch, Roll, Yaw) 3
Full Range
±2° Unless Higher Accuracy Uniquely Required
1
0.2% 2.
Lateral Acceleration
±1g
±1.5% max range excluding datum error of ±5%
4
0.01g.
Pitch Trim Position
Full Range
±3% Unless Higher Accuracy Uniquely Required
1
0.3% 2.
Glideslope Deviation
±400 Microamps
±3%
1
0.3% 2.
Localizer Deviation
±400 Microamps
±3%
1
0.3% 2.
AFCS Mode and Engagement Status
Discrete
1
Radio Altitude
−20 ft to 2,500 ft
±2 Ft or ±3% Whichever is Greater Below 500 Ft and ±5% Above 500 Ft
1
1 ft + 5% 2 above 500′.
Master Warning
Discrete
1
Main Gear Squat Switch Status
Discrete
1
Angle of Attack (if recorded directly).
As installed
As installed
2
0.3% 2
Outside Air Temperature or Total Air Temperature.
−50 °C to + 90 °C
±2 °c
0.5
0.3 °c
Hydraulics, Each System Low Pressure
Discrete
0.5
or 0.5% 2
Groundspeed.
As installed
Most Accurate Systems Installed (IMS Equipped Aircraft Only)
1
0.2% 2
If additional recording capacity is available, recording of the following parameters is recommended. The parameters are listed in order of significance:
Drift Angle
When available, As installed
As installed
4
Wind Speed and Direction
When available, As installed
As installed
4
Latitude and Longitude
When available, As installed
As installed
4
Brake pressure/Brake pedal position
As installed
As installed
1
Additional engine parameters:
EPR
As installed
As installed
1 (per engine).
N1
As installed
As installed
1 (per engine).
N2
As installed
As installed
1 (per engine).
EGT
As installed
As installed
1 (per engine).
Throttle Lever Position
As installed
As installed
1 (per engine).
Fuel Flow
As installed
As installed
1 (per engine).
TCAS:
TA
As installed
As installed
1
RA
As installed
As installed
1
Sensitivity level (as selected by crew)
As installed
As installed
2
GPWS (ground proximity warning system)
Discrete
1
Landing gear or gear selector position
Discrete
0.25 (1 per 4 seconds)
DME 1 and 2 Distance
0-200 NM;
As installed
0.25
1 mi.
Nav 1 and 2 Frequency Selection
Full range
As installed
0.25
1 When altitude rate is recorded. Altitude rate must have sufficient resolution and sampling to permit the derivation of altitude to 5 feet.
2 Per cent of full range.
3 For airplanes that can demonstrate the capability of deriving either the control input on control movement (one from the other) for all modes of operation and flight regimes, the “or” applies. For airplanes with non-mechanical control systems (fly-by-wire) the “and” applies. In airplanes with split surfaces, suitable combination of inputs is acceptable in lieu of recording each surface separately.
4 This column applies to aircraft manufactured after October 11, 1991.
[Doc. No. 25530, 53 FR 26147, July 11, 1988; 53 FR 30906, Aug. 16, 1988]