posted on Sep, 14 2016 @ 11:49 AM
On March 5, 2015 a Delta MD-88 landing at LaGuardia ran off the side of the runway and struck the perimeter fence and a berm, significantly damaging
the aircraft. Twenty-nine passengers suffered minor injuries. It took 17 minutes to evacuate the aircraft after the accident, which broke one wing
and spilled fuel around the aircraft. The aircraft suffered damage to the batteries that resulted in a loss of intercom and PA systems in the
As a result of the accident, the NTSB has issued 10 recommendations for the FAA, including for cabin and flight crews, and two for Boeing. One of the
recommendations for Boeing is a step to prevent rudder blanking. The cause of the accident was found to be the captain's excessive use of reverse
thrust, which led to loss of rudder control. There was a left crosswind, and a reverser differential that allowed the aircraft to drift left. In
aircraft with tail mounted engines, such as the MD-88, when reverse thrust is applied, the cans push the air forward, and over the rudder and
elevators. Too much reverse thrust, and the rudder will no longer be able to effect control of the aircraft. In the MD-88, Boeing recommends an EPR
no higher than 1.3 on contaminated runways, as this one was. The NTSB found that the EPR went as high as 2.07 on the left engine, and 1.91 on the
right, which began the initial pull to the left.
After investigating 80 landings on other MD-88 aircraft, the NTSB found that 40% exceeded the 1.6 recommendation for dry runways, and in the 14 that
were on potentially contaminated runways, every one exceeded 1.3, and 57% exceeded 1.6. That means that in all of those landings, the rudder would
have been ineffective if it had been required to straighten the aircraft as it went down the runway.
WASHINGTON—The U.S. NTSB is recommending that the FAA, Boeing and airlines explore and mitigate a relatively obscure directional-control problem
linked to aircraft with tail-mounted engines.
The action came as the board held its final hearing into the March 5, 2015, runway excursion of a Delta Air Lines MD-88 landing at New York’s
LaGuardia Airport during a snowstorm. The aircraft was substantially damaged after striking the airport’s perimeter fence and a berm, but there were
only minor injuries to 29 of the 127 passengers.
Among 14 new recommendations adopted by the board, 10 were for the FAA, dealing with a mix of pilot, cabin crew and airport-safety upgrades; two were
directed to Boeing, both related to controllability of MD-80-family aircraft on the ground.