14 CFR Appendix E
Helicopter Flight Recorder Specifications
July 13, 2020
Open Table
| Parameters | Range | Accuracy sensor input to DFDR readout | Sampling interval (per second) | Resolution2 read out |
|---|---|---|---|---|
| Time (GMT) | 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 30′. |
| Airspeed | As the installed measuring system | ±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° | 2 | 0.5° |
| Roll Attitude | ±180° | ±2° | 2 | 0.5°. |
| Radio Transmitter Keying | On-Off (Discrete) | 1 | 0.25 sec | |
| Power in Each Engine: Free Power Turbine Speed and Engine Torque | 0-130% (power Turbine Speed) Full range (Torque) | ±2% | 1 speed 1 torque (per engine) | 0.2%1 to 0.4%1 |
| Main Rotor Speed | 0-130% | ±2% | 2 | 0.3%1 |
| Altitude Rate | ±6,000 ft/min | As installed | 2 | 0.2%1 |
| Pilot Input—Primary Controls (Collective, Longitudinal Cyclic, Lateral Cyclic, Pedal)3 | Full range | ±3% | 2 | 0.5%1 |
| Flight Control Hydraulic Pressure Low | Discrete, each circuit | 1 | ||
| Flight Control Hydraulic Pressure Selector Switch Position, 1st and 2nd stage | Discrete | 1 | ||
| AFCS Mode and Engagement Status | Discrete (5 bits necessary) | 1 | ||
| Stability Augmentation System Engage | Discrete | 1 | ||
| SAS Fault Status | Discrete | 0.25 | ||
| Main Gearbox Temperature Low | As installed | As installed | 0.25 | 0.5%1 |
| Main Gearbox Temperature High | As installed | As installed | 0.5 | 0.5%1 |
| Controllable Stabilator Position | Full Range | ±3% | 2 | 0.4%1. |
| Longitudinal Acceleration | ±1g | ±1.5% max range excluding datum error of ±5% | 4 | 0.01g. |
| Lateral Acceleration | ±1g | ±1.5% max range excluding datum of ±5% | 4 | 0.01g. |
| Master Warning | Discrete | 1 | ||
| Nav 1 and 2 Frequency Selection | Full range | As installed | 0.25 | |
| Outside Air Temperature | −50 °C to + 90 °C | ±2° c | 0.5 | 0.3° c |
1Per cent of full range.
2This column applies to aircraft manufactured after October 11, 1991.
3For all aircraft manufactured on or after December 6, 2010, the sampling interval per second is 4.
[Doc. No. 25530, 53 FR 26154, July 11, 1988; 53 FR 30906, Aug. 16, 1988; Amdt. 135-113, 73 FR 12571, Mar. 7, 2008; 73 FR 15281, Mar. 21, 2008; Amdt. 135-121, 75 FR 17047, Apr. 5, 2010]
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