US regulators have ordered a change to Boeing MD-80 flight manuals to include a check that elevators are not jammed in the trailing-edge down position.
Operators of the type must revise the manual, within three months, to state that this check must be carried out prior to every flight.
“Both elevators must be faired with or above the stabiliser surface, or maintenance action is required to verify elevator freedom of movement,” the amendment declares.
Boeing has clarified that a jammed elevator could result in the aircraft’s being unable to rotate on take-off, potentially leading to a rejected take-off at above the V1 threshold speed – and a possible high-speed runway excursion.
The change covers the MD-80 series up to the MD-88, and also includes older McDonnell Douglas DC-9 variants.
According to the US FAA’s newly-adopted directive, initially proposed in November last year, the measure has been prompted by “the discovery of jammed elevators during take-off”.
It says the directive takes effect on 12 June.
