A-81-107
NTSB Safety Recommendation — Aviation
Recommendation text
THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: INCORPORATE THE FOLLOWING INFORMATION IN THE DC-9 SERIES -10 THROGH -50 AIRCRAFT FLIGHT MANUALS UNDER THE ABNORMAL HYDRAULICS-OUT LANDING SECTION AND THE NORMAL LANDINGS ON WET/SLIPPERY RUNWAYS SECTION: THE MAXIMUM RUDDER EFFECTIVENESS AVAILABLE IS SUBSTANTIALLY REDUCED DURING REVERSE THRUST OPERATION AS FOLLOWS: ENGINE THRUST MAXIMUM RUDDER SETTING EFFECTIVENESS AVAILABLE(PERCENT)*/ FORWARD IDLE 100 REVERSE IDLE 65 1.3 EPR (REVERSE) 25 1.6 EPR (REVERSE) MINIMAL */RUDDER EFFECTIVENESS ALSO DECREASES WITH DECREASING AIRSPEED.
In plain language (FlightFinder summary)
The FAA is asked to update the DC-9 series -10 through -50 aircraft flight manuals by adding a note under the abnormal hydraulics-out landing and normal landings on wet/slippery runways sections. The note should state that maximum rudder effectiveness is substantially reduced during reverse thrust operation, with specific effectiveness percentages for forward idle, reverse idle, and two reverse thrust settings, and that rudder effectiveness also decreases as airspeed decreases.
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 | Mar 19, 1985 |
| NTSB number | LAX80FA111 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).