As part of its ongoing investigation into last week’s accident at LaGuardia Airport where Delta Air Lines flight 1086 veered off the runway shortly after touching down, the NTSB released its second investigative update.
On Thursday, March 5, 2015 at approximately 11:18 A.M., Delta flight 1086, a Boeing MD-88 flying from Atlanta to LaGuardia exited the runway and came to rest with its nose on an embankment. There were 127 passengers (including 2 lap children) and 5 crewmembers on board the flight. Twenty three passengers received minor injuries, and others were transported to the hospital for evaluation. All passengers have been released from the hospital.
Since arriving on scene, the NTSB, with assistance from the FBI, has documented the runway markings and the airplane. The airplane departed the left side of runway 13 about 3,000 feet from the approach end of the runway. The tracks were on a heading of about 10 degrees from the runway heading. About 4,100 feet from the approach end of the runway, the airplanes left wing initially struck the airport’s perimeter fence, which is located on top of the berm, and the airplane tracks turn back parallel with runway 13. About 5,000 feet from the approach end of the runway, the airplane came to rest with its nose over the berm,. The left wing of the airplane destroyed about 940 feet of the perimeter fence.
Significant damage to the airplane was noted, including:
- Damage on the left wing’s leading edge slats, trailing edge flaps, and flight spoilers.
- The breach of the left wing fuel tank was noted in the area of the outboard end of the outboard trailing edge flap.
- Damage to the front radome, weather radar and to the underside of the fuselage from the front of the airplane all the way back to the area of the left front passenger door.
- Damage was also noted in the nose landing gear well and main electronics bay.
- The tailcone handle in the main cabin was actuated.
- The autobrake selector switch in the cockpit was found in the “max” position.
As part of the investigative process, the following investigative groups have been formed: Operations and Human Performance, Airworthiness, Airports, Flight Data Recorder, Cockpit Voice Recorder, and Maintenance Records. Below is a summary of some their work, to date.
The Maintenance Records group began reviewing the maintenance records on Saturday and that work is ongoing:
- Delta Air Lines is the original owner of the accident airplane and took delivery of it on December 30, 1987.
- The aircraft had 71,195.54 flight hours and 54,865 flight cycles at the time of the accident.
- The last major maintenance visit took place on September 22, 2014 in Jacksonville, Fla. This visit was part of the airplane’s regularly scheduled maintenance program, and included tests of the auto brake, antiskid and auto spoiler systems.
- The last overnight service check was completed March 2, 2015 in Tampa, Fla.
Investigators with the Airworthiness group will continue to examine and test the antiskid, autobrake and thrust reverser systems today.
The Operations and Human Performance groups interviewed the flight crew on Saturday in Atlanta, Ga. The crew stated:
- They based their decision to land on braking action reports of “good,” which they received from air traffic control.
- That the runway appeared all white when they broke out of the overcast, moments before landing.
- That the automatic spoilers did not deploy but that the first officer quickly deployed them manually.
- That the auto brakes were set to ‘max’ but that they did not sense any wheel brake deceleration.
- The captain reported that he was unable to prevent the airplane from drifting left.
An NTSB air traffic control specialist has gather the following information: another Delta Air Lines MD-88 airplane landed on runway 13 about 3 minutes prior to flight 1086 (the FDR has been sent to the NTSB recorder lab and investigators will interview this flight crew in the coming days) and confirmed that air traffic controllers relayed the braking action reports to the flight crew of 1086,which were based on pilot reports from two other flights that landed several minutes prior to flight 1086. Both earlier flights reported the breaking action on the runway as “good”.
A preliminary readout of the Flight Data Recorder found:
- That the autopilot was engaged until the airplane was about 230 feet above the ground.
- That the airspeed during the final approach was about 140 knots and touchdown occurred at about 133 knots.
- That the airplane’s heading deviated to the left and it departed the runway shortly after touchdown.
- That there are degradations in recorded signal quality around the time the airplane departed the runway and extraction and verification of the data is continuing.
- The quick access data recorder on flight 1086 was also recovered and that recorder is being readout at NTSB headquarters today.
An NTSB meteorologist is examining the weather conditions at the time of the accident.
The Cockpit Voice Recorder group plans on convening at NTSB headquarters Tuesday, to begin developing the CVR transcript.