A-91-023
NTSB Safety Recommendation — Aviation
Recommendation text
THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: ISSUE PERMANENT POLICY AND GUIDANCE MATERIAL FOR THE CONTINUED AIRWORTHINESS OF DIGITAL FLIGHT DATA RECORDER (DFDR) SYSTEMS STATING THAT THE MAKE AND MODEL OF THE FLIGHT DATA RECORDER, AND THE MAKE AND MODEL OF THE FLIGHT DATA ACQUISITION UNIT, IF INSTALLED, MUST BE MAINTAINED AS PART OF EACH AIRCRAFT'S RECORDS, AS WELL AS AT LEAST THE FOLLOWING INFORMATION FOR EACH PARAMETER RECORDED: LOCATION OF PARAMETER WORD (2 THROUGH 64 OR 128). ASSIGNED BITS (1 THROUGH 12). RANGE (IN ENGINEERING UNITS WHEN APPLICABLE). SIGN CONVENTION (FOR EXAMPLE, TRAILING EDGE UP = +) . TYPE SENSOR (FOR EXAMPLE, SYNCHRO OR LOW LEVEL DC). ACCURACY LIMITS (SENSOR INPUT). FAA REQUIREMENT (THAT IS, MANDATORY OR NOT MANDATORY). SUBFRAME/SUPERFRAME ASSIGNMENT -- DOCUMENTATION FOR ENGINEERING UNIT CONVERSION. GENERAL EQUATION: PROVIDE A0, A1, A2, AND A3 FOR THE EQUATION Y= A0 + A1X + A2X2 + A3X3 WHERE Y= OUTPUT IN ENGINEERING UNITS AND X= INPUT IN DECIMAL OR CONVERTED COUNTS. NONLINEAR PARAMETERS: PROVIDE A SUFFICIENT NUMBER OF DATA SAMPLES (ENGINEERING UNITS VERSUS RECORDED DECIMAL COUNTS) TO DEVELOP A CONVERSION ALGORITHM THAT WILL ACCURATELY DEFINE THE FULL RANGE OF THE PARAMETER. DISCRETE PARAMETERS: STATUS (THAT IS, 1 = ON, 0 = OFF).
In plain language (FlightFinder summary)
The NTSB asks the FAA to create permanent policy and guidance requiring that aircraft records include the make and model of the flight data recorder and flight data acquisition unit, along with detailed parameter documentation such as bit assignments, ranges, sensor types, and conversion equations.
This plain-language summary is written by FlightFinder to explain the recommendation above. It is not the official wording — the verbatim NTSB text is quoted above.
Details
| Status | Closed - Acceptable Action |
|---|---|
| Mode | Aviation |
| Closed | Aug 16, 2000 |
| NTSB number | 80676 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).