Date: | Thursday 5 March 2015 |
Time: | 11:02 |
Type: | McDonnell Douglas MD-88 |
Owner/operator: | Delta Air Lines |
Registration: | N909DL |
MSN: | 49540/1395 |
Year of manufacture: | 1987 |
Total airframe hrs: | 71195 hours |
Cycles: | 54865 flights |
Engine model: | Pratt & Whitney JT8D-219 |
Fatalities: | Fatalities: 0 / Occupants: 132 |
Other fatalities: | 0 |
Aircraft damage: | Substantial, written off |
Category: | Accident |
Location: | New York-La Guardia Airport, NY (LGA) -
United States of America
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Phase: | Landing |
Nature: | Passenger - Scheduled |
Departure airport: | Atlanta Hartsfield-Jackson International Airport, GA (ATL/KATL) |
Destination airport: | New York-La Guardia Airport, NY (LGA/KLGA) |
Investigating agency: | NTSB |
Confidence Rating: | Accident investigation report completed and information captured |
Narrative:Delta Air Lines flight 1086, a McDonnell Douglas MD-88, N909DL, was landing on runway 13 at New York-LaGuardia Airport (LGA) when it departed the left side of the runway, contacted the airport perimeter fence, and came to rest with the airplane's nose on an embankment next to Flushing Bay. The 2 pilots, 3 flight attendants, and 98 of the 127 passengers were not injured; the other 29 passengers received minor injuries. The airplane was substantially damaged.
Flight 1086 was a regularly scheduled passenger flight from Atlanta-Hartsfield-Jackson Atlanta International Airport, Georgia, where it departed at 09:23 hours local time.
Given the winter weather conditions at LaGuardia, the flight crew was concerned about the available landing distance on runway 13 (7003 ft / 2135 m). While en route to LGA they spent considerable time analyzing the airplanes stopping performance.
The flight crew also requested braking action reports about 45 and 35 minutes before landing, but none were available at those times because of runway snow clearing operations. The unavailability of braking actions reports and the uncertainty about the runways condition created some situational stress for the captain, who was the pilot flying.
After runway 13 became available for arriving airplanes, the flight crews of two preceding airplanes (which landed on the runway about 16 and 8 minutes before the accident landing) reported good braking action on the runway, so the flight crew expected to see at least some of the runways surface after the airplane broke out of the clouds. However, the flight crew saw that the runway was covered with snow, which was inconsistent with their expectations based on the braking action reports and the snow clearing operations that had concluded less than 30 minutes before the airplane landed. The snowier-than-expected runway, along with the relatively short runway length and the presence of Flushing Bay directly off the departure end of the runway, most likely increased the captains concerns about his ability to stop the airplane within the available runway distance, which exacerbated his situational stress.
The captain made a relatively aggressive reverse thrust input almost immediately after touchdown. Both pilots were aware that 1.3 EPR was the target setting for contaminated runways.
As reverse thrust EPR was rapidly increasing, the captains attention was focused on other aspects of the landing, which included steering the airplane to counteract a slide to the left and ensuring that the spoilers had deployed, which was a necessary action for the autobrakes to engage. The maximum EPR values reached during the landing were 2.07 on the left engine and 1.91 on the right engine, which were much higher than the target setting of 1.3 EPR. These high EPR values likely resulted from a combination of the captains stress; his relatively aggressive reverse thrust input; and operational distractions, including the airplanes continued slide to the left despite the captains efforts to steer it away from the snowbanks alongside the runway. All of these factors reduced the captains monitoring of EPR indications. The high EPR values caused rudder blanking, which occurs on MD-80 series airplanes when smooth airflow over the rudder is disrupted by high reverse thrust, and a subsequent loss of aerodynamic directional control. Although the captain stowed the thrust reversers and applied substantial right rudder, right nosewheel steering, and right manual braking, the airplanes departure from the left side of the runway could not be avoided because directional control was regained too late to be effective.
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 airports 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.
PROBABLE CAUSE:
The National Transportation Safety Board determines that the probable cause of this accident was the captains inability to maintain directional control of the airplane due to his application of excessive reverse thrust, which degraded the effectiveness of the rudder in controlling the airplanes heading. Contributing to the accident were the captains (1) situational stress resulting from his concern about stopping performance and (2) attentional limitations due to the high workload during the landing, which prevented him from immediately recognizing the use of excessive reverse thrust.
METAR:
15:24 UTC / 10:24 local time:
KLGA 051524Z 04007KT 1/4SM R04/2600V2800FT SN FZFG VV009 M03/M04 A3013 RMK AO2 P0004
15:51 UTC / 10:51 local time:
KLGA 051551Z 01008KT 1/4SM R04/2800V3500FT SN FZFG VV009 M03/M05 A3012 RMK AO2 SLP199 P0006 T10331050
16:22 UTC / 11:22 local time:
KLGA 051622Z 01008KT 1/4SM R04/3000VP6000FT SN FZFG VV011 M03/M05 A3012 RMK AO2 SFC VIS 1/2 P0003
Accident investigation:
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| |
Investigating agency: | NTSB |
Report number: | NTSB/AAR-16/02 |
Status: | Investigation completed |
Duration: | 1 year and 6 months |
Download report: | Final report |
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Sources:
NTSB
Flightradar24
Liveatc.net
Location
Images:
photo (c) NTSB; New York-La Guardia Airport, NY (LGA); 05 March 2015; (publicdomain)
photo (c) Sergio Cardona; New York-La Guardia Airport, NY (LGA); 05 March 2015
photo (c) NTSB; New York-La Guardia Airport, NY (LGA); March 2015; (publicdomain)
photo (c) Leonard J. DeFrancisci; New York-La Guardia Airport, NY (LGA); 05 March 2015; (CC:by-sa)
photo (c) NTSB; New York-La Guardia Airport, NY (LGA); 05 March 2015; (publicdomain)
photo (c) NTSB; New York-La Guardia Airport, NY (LGA); 05 March 2015; (publicdomain)
photo (c) Formulanone; Atlanta-William B. Hartsfield International Airport, GA (ATL/KATL); 12 January 2015; (CC:by-sa)
Revision history:
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