CAT.IDE.A.191 Lightweight flight recorder

OPERATIONAL PERFORMANCE REQUIREMENTS

(a)If the flight recorder records flight data, it should record at least the following parameters:

(1)pitch attitude or pitch rate,

(2)roll attitude or roll rate,

(3)heading (magnetic or true) or yaw rate,

(4)latitude,

(5)longitude,

(6)positioning system: estimated error (if available),

(7)pressure altitude or altitude from a positioning system,

(8)time,

(10)ground speed,

(11)positioning system: track (if available),

(12)normal acceleration,

(13)longitudinal acceleration, and

(14)lateral acceleration.

(b)If the flight recorder records images, it should capture views of the main instrument displays at the pilot station, or at both pilot stations when the aeroplane is certified for operation with a minimum crew of two pilots. The recorded image quality should allow reading the following indications during most of the flight:

(1)magnetic heading,

(2)time,

(3)pressure altitude,

(4)indicated airspeed,

(5)vertical speed,

(6)turn and slip,

(7)attitude,

(8)Mach number (if displayed),

(9)stabilised heading, and

(10)tachometer indication or equivalent indication of propulsive thrust or power.

(c)If the flight recorder records a combination of images and flight data, each flight parameter listed in (a) should be recorded as flight data or by means of images.

(d)The flight parameters listed in (a), which are recorded as flight data, should meet the performance specifications (range, sampling intervals, accuracy limits and resolution in read-out) as defined in the relevant table of EUROCAE Document ED-112 ‘Minimum Operational Performance Specification for Crash Protected Airborne Recorder Systems’, dated March 2003, or EUROCAE Document ED-155 ‘Minimum Operational Performance Specification for Lightweight Flight Recording Systems’, dated July 2009, or any later equivalent standard accepted by EASA.

(e)The operational performance requirements for the flight recorder should be those laid down in:

(1)EUROCAE Document ED-155 or any later equivalent standard accepted by EASA for lightweight flight recorders; or

(2)EUROCAE Document ED-112 or any later equivalent standard accepted by EASA for crash-protected flight recorders.

ADDITIONAL USEFUL INFORMATION

(a)Experience has shown the usefulness, for analysing incidents and for training purposes, of recording additional information. In particular, audio of the flight crew compartment and information on the handling of the aircraft (such as position of flight controls, position of engine controls, fuel and oil indications, aircraft configuration selection), and an external view are very useful for such purposes. To capture such information, simple equipment such as an integrated microphone and integrated camera may be sufficient.

(b)If the flight recorder includes optional capabilities such as described in (a), their recording duration is recommended to be at least 2 hours.

(c)If the flight recorder is capable of acquiring flight parameters from some aircraft systems, it is advised to give priority to the flight parameters listed in Annex II-B to EUROCAE Document ED-155 or the flight parameters listed in Annex II-A to EUROCAE Document ED-112. Indeed, these flight parameters were selected based on their relevance in many safety investigations.

INSTALLATION OF CAMERAS When cameras are installed for the purpose of CAT.IDA.A.191, it is advised to install them so that they do not capture images of head and shoulders of the flight crew members whilst seated in their normal operating position.

RECORDING ACCURACY OF ATTITUDE RATE PARAMETERS In the case of attitude rate parameters (pitch rate parameter, yaw rate parameter, roll rate parameter), the accuracy limit specified in EUROCAE Document ED-155, dated July 2009, was found to be unclear. Therefore, the following additional guidance is provided:

(a)If the attitude rate parameter is provided by an approved system of the aeroplane, accuracy greater than as provided by this system is not expected for this attitude rate parameter.

(b)If the attitude rate parameter is provided by a dedicated gyroscope, it is advisable that the gyroscope meets the following performance:

(1)errors caused by linear accelerations less than ±3°/sec (equivalent to ±1% of 300°/sec recording range) for all combinations of parameter values and linear acceleration values in the respective ranges [-300°/sec; +300°/sec] and [-3g; +6g];

(2)errors caused by temperature less than ±5°/sec for all combinations of parameter values and temperature values in the respective ranges [-300°/sec; +300°/sec] and [-40°C; +85°C];

(3)angular random walk of the gyroscope equal to or less than 2°/sqrt(hour); and

(4)bias stability of the gyroscope significantly less than 360°/hour (for instance, 50°/hour).

FUNCTION TO MODIFY IMAGE AND AUDIO RECORDINGS The purpose of the function modifying the image and audio recordings is to allow the flight crew to protect their privacy by making such recordings inaccessible using normal techniques. The activation of this function is subject to the commander’s approval (refer to CAT.GEN.MPA.105). However, the equipment manufacturer or a safety investigation authority might still be able to retrieve these recordings using special techniques.