Appendix B to Part 135 - Airplane Flight Recorder Specifications
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                                                       Installed system
                                                          \1\ minimum      Sampling interval    Resolution \4\
           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]so[/INF] to   5% or         1.................  1% \3\.
                                   V[INF]D[/INF]       10 kts.,
                                   (KIAS).             whichever is
                                                       greater.
                                                       Resolution 2 kts.
                                                       below 175 KIAS.
Altitude........................  -1,000 ft. to max   100 to        1.................  25 to 150
                                   cert. alt. of A/C.  700 ft.
                                                       (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  0.03g.
                                                       addition to         where peaks, ref.
                                                       0.3g          to 1g are
                                                       maximum datum.      recorded).
Longitudinal acceleration.......  1.0g........  1.5% max.     2.................  0.01g.
                                                       range excluding
                                                       datum error of
                                                       5%.
Pitch attitude..................  100% of usable....  2.....  1.................  0.8
Roll attitude...................  60 or   2.....  1.................  0.8
                                   100% of usable
                                   range, whichever
                                   is greater.
Stabilizer trim position........  Full range........  3% unless     1.................  1% \3\.
                                                       higher uniquely
                                                       required.
      Or
Pitch control position..........  Full range........  3% unless     1.................  1% \3\.
                                                       higher uniquely
                                                       required.
  1  1  1  1  1  Engine Power,
           Each Engine
Fan or N[INF]1[/INF] speed or     Maximum range.....  5%..........  1.................  1% \3\.
 EPR or cockpit indications used
 for aircraft certification.
      Or
Prop. speed and torque (sample    ..................  ..................  1 (prop speed), 1
 once/sec as close together as                                             (torque).
 practicable).
Altitude rate \2\ (need depends   8,000 fpm...  10%.          1.................  250 fpm Below
 on altitude resolution).                              Resolution 250                          12,000
                                                       fpm below 12,000
                                                       ft. indicated.
Angle of attack \2\ (need         -20 to        2.....  1.................  0.8% \3\
 depends on altitude resolution).  40 or of
                                   usable range.
Radio transmitter keying          On/off............  ..................  1.................
 (discrete).
TE flaps (discrete or analog)...  Each discrete       ..................  1.................
                                   position (U, D, T/
                                   O, AAP).
                                     Or.............
                                  Analog 0-100%       3.....  1.................  1% \3\
                                   range.
LE flaps (discrete or analog)...  Each discrete       ..................  1.................
                                   position (U, D, T/
                                   O, AAP).
                                     Or.............
                                  Analog 0-100%       3.....  1.................  1% \3\.
                                   range.
Thrust reverser, each engine      Stowed or full      ..................  1.................
 (Discrete).                       reverse.
Spoiler/speedbrake (discrete)...  Stowed or out.....  ..................  1.................
Autopilot engaged (discrete)....  Engaged or          ..................  1.................
                                   disengaged.
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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\ If data from the altitude encoding altimeter (100 ft. resolution) is used, then either one of these
  parameters should also be recorded. If however, altitude is recorded at a minimum resolution of 25 feet, then
  these two parameters can be omitted.
\3\ Per cent of full range.
\4\ This column applies to aircraft manufacturing 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 ]