FAA Federal Aviation Regulations (FARS, 14 CFR)

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Installed system
\1\ minimum      Sampling interval    Resolution \3\
Parameters                    Range           accuracy (to        (per second)          read out
recovered data)
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Relative time (from recorded on   25 hr minimum.....  ±0.125% per       1.................  1 sec.
prior to takeoff).                                    hour.
Indicated airspeed..............  V[INF]m[/INF] in    ±5% or            1.................  1 kt.
to V[INF]D[/INF]    ±10 kts.,
(KIAS) (minimum     whichever is
airspeed signal     greater.
attainable with
installed pilot-
static system).
Altitude........................  -1,000 ft. to       ±100 to           1.................  25 to 150 ft.
20,000 ft.          ±700 ft.
pressure altitude.  (see Table 1, TSO
C51-a).
Magnetic heading................  360°.........       ±5°.....          1.................  1°.
Vertical acceleration...........  -3g to +6g........  ±0.2g in          4 (or 1 per second  0.05g.
addition to       where peaks, ref.
±0.3g             to 1g are
maximum datum.    recorded).
Longitudinal acceleration.......  ±1.0g........       ±1.5% max.        2.................  0.03g.
range excluding
datum error of
±5%.
Pitch attitude..................  100% of usable      ±2°.....          1.................  0.8°.
range.
Roll attitude...................  ±60° or             ±2°.....          1.................  0.8°.
100% of usable
range, whichever
is greater.
Altitude rate...................  ±8,000 fpm...       ±10%              1.................  250 fpm below
Resolution 250                          12,000.
fpm below 12,000
ft. indicated.
Engine Power, Each Engine
1  1  1  1  1  Main rotor speed.  Maximum range.....  ±5%..........     1.................  1% \2\
Free or power turbine...........  Maximum range.....  +5%..........     1.................  1% \2\
Engine torque...................  Maximum range.....  ±5%..........     1.................  1% \2\
Flight Control_Hydraulic
Pressure
Primary (discrete)..............  High/low..........  .............     1.................
Secondary_if applicable           High/low..........  .............     1.................
(discrete).
Radio transmitter keying          On/off............  .............     1.................
(discrete).
Autopilot engaged (discrete)....  Engaged or          .............     1.................
disengaged.
SAS status_engaged (discrete)...  Engaged/disengaged  .............     1.................
SAS fault status (discrete).....  Fault/OK..........  .............     1.................
Flight Controls
Collective......................  Full range........  ±3%..........     2.................  1% \2\
Pedal position..................  Full range........  ±3%..........     2.................  1% \2\
Lat. cyclic.....................  Full range........  ±3%..........     2.................  1% \2\
Long. cyclic....................  Full range........  ±3%..........     2.................  1% \2\
Controllable stabilator position  Full range........  ±3%..........     2.................  1% \2\
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\1\ When data sources are aircraft instruments (except altimeters) of acceptable quality to fly the aircraft
the recording system excluding these sensors (but including all other characteristics of the recording
system) shall contribute no more than half of the values in this column.
\2\ Per cent of full range.
\3\ This column applies to aircraft manufactured after October 11, 1991.

[Doc. No. 25530, 53 FR 26152, July 11, 1988; 53 FR 30906, Aug. 16, 1988, as amended by Amdt. 135-69, 62 FR 38397, July 17, 1997]