Accident - Sept. 2, 2003 - Jamaica, N.Y.
The flight, operated by American Airlines Inc., was scheduled to depart from Dallas-Fort Wor, Texas en route to Newark,N.J..
The airplane was on final approach when the flightcrew attempted to lower the landing gear; however, the nose gear indicator red light remained illuminated and the nose landing gear indicator pin did not extend. The flightcrew performed a low approach and ground personnel stated that the nose gear doors were partially open. The flightcrew subsequently performed an emergency landing, with the nose landing gear retracted. After the airplane came to a stop, the passengers deplaned via the aft door exit. Examination of the airplane revealed that the nose landing gear spray deflector was fractured near the middle, and found in two sections. The right section of the spray deflector had rotated about 180 degrees, and was found wedged between the nose landing gear and the right side of the wheel-well structure. The nose landing gear tire was above the wedged spray deflector section. The left section of the spray deflector was found in it's original position, which was forward, with the nose landing gear retracted. There was evidence of yellow paint transfer on the right upper surface (aft corner) of the spray deflector. Similar paint marks were observed on the left bottom surface (forward corner) of the spray deflector section. In addition, yellow paints chips were found embedded under a screw head at that location. The distance between the two yellow paint marks was approximately 29 inches. The tow operator who participated in the pushback of the airplane prior to takeoff stated that the tow bar became disconnected while the airplane was being towed; however, he did not observe any damage to the airplane. The tow bar was painted yellow and the distance between the tow bar forks was approximately 30 inches.
A fractured nose gear spray deflector due to contact with a tow bar during pushback, which subsequently jammed and prevented nose gear extension during landing. A factor in this accident was the tow operator's failure to detect the damaged spray deflector.
HISTORY OF FLIGHT
On September 2, 2003, about 1139 eastern daylight time, a McDonnell Douglas DC-9-82 (MD-82), N454AA, operated by American Airlines as flight 1048, was substantially damaged during an emergency landing at the John F. Kennedy International Airport (JFK), Jamaica, New York, after the flightcrew was unable to extend the nose landing gear. The 2 flightcrew members, 3 flight attendants, and 133 passengers were not injured. Visual meteorological conditions prevailed and an instrument flight rules flight plan had been filed for the flight that departed the Dallas/Fort Worth International Airport (DFW), Dallas, Texas, and was destined for the Newark Liberty International Airport (EWR), Newark, New Jersey. The scheduled passenger flight was conducted under 14 CFR Part 121.
The first officer was designated as the flying pilot for the flight. While on final approach to EWR, the landing gear was lowered; however, the nose gear indicator red light remained illuminated and the nose landing gear indicator pin did not extend. The first officer executed a missed approach, and flew air traffic control vectors, while the captain attempted to troubleshoot the problem. After performing emergency checklists, which included the emergency gear extension checklist, the captain diverted to JFK, and performed a low approach over runway 4L, a 11,351-foot-long, 150-foot-wide, asphalt runway. Ground personnel who observed the airplane stated that the nose gear doors were partially open, however, the nose gear was not visible. The captain subsequently performed an emergency landing to runway 4L, with the nose landing gear retracted. After the airplane came to a stop, the passengers deplaned via the aft door exit.
The accident occurred during the hours of daylight approximately 40 degrees, 38 minutes north latitude, and 73 degrees, 46 minutes west longitude.
The captain held an airline transport pilot certificate for multiengine-land airplanes. He also held a flight engineer certificate. The captain was also type rated in Boeing 757, 767, Cessna CE-500, and McDonnell Douglas DC-9 series airplanes. American Airlines reported that the captain had accumulated about 13,000 hours of total flight experience, which included 7,680 hours in DC-9 series airplanes.
The captain's most recent Federal Aviation Administration (FAA) first class medical certificate was issued on August 19, 2003.
The first officer held a commercial pilot certificate for multiengine-land airplanes. He also held a flight engineer certificate. American Airlines reported that the first officer had accumulated 10,200 hours of total flight experience, which included 7,600 hours in DC-9 series airplanes.
The first officer's most recent FAA first class medical certificate was issued on July 21, 2003.
The airplane was maintained under a continuous airworthiness inspection program. The airplane had been operated for about 5 hours, since it's most recent inspection, which was performed on August 31, 2003.
Review of the airplane's on board maintenance logbook did not reveal any prior discrepancies regarding the landing gear extension\retraction system.
The reported weather at JFK, at 1144, was: winds from 50 degrees at 12 knots; visibility 10 statue miles; few clouds at 900 feet, ceiling broken at 1,600 feet, and overcast at 2,600 feet; temperature 62 degrees F, dew point 16 degrees F; altimeter 30.13 in/hg.
The airplane was equipped with a Fairchild model FA-2100-1020 solid-state 2 hour cockpit voice recorder (CVR), and a Fairchild model FA2100 solid-state flight data recorder (FDR).
Both recorders were forwarded to the Safety Board's Office of Research and Engineering for examination.
The CVR captured the accident, approximately 49 minutes into the 2 hour recording. The cockpit crew were heard troubleshooting the problem and performing the appropriate checklist items in consultation with company procedures. The recording ended immediately after the airplane came to a stop on the runway.
The FDR was downloaded, and plots were generated for the last 2.6 minutes of the flight. (The plots and tabular data can be found in the public docket)
The airplane touched down about 1/3 of way down the runway. Examination of the runway revealed the airplane's nose contacted the ground about 1 foot to the left of the runway centerline. The nose slid approximately 745 feet, and came to rest 30 feet to the left of the runway centerline.
Airbags were utilized to raise the nose of the airplane, and the airplane was subsequently towed to a hangar for further examination.
Examination of the airplane revealed the forward fuselage belly section exhibited severe scrape damage from station 68 to 168. The forward and aft nose landing gear doors also sustained scraping damage. A 6-inch and 9-inch tear was observed in the pressure bulkhead located at station 110. The nose landing gear remained in the wheel well. The polyurethane nose landing gear spray deflector was fractured near the middle, and found in two sections. The right section of the spray deflector had rotated about 180 degrees, and was found wedged between the nose landing gear and the right side of the wheel-well structure. The nose landing gear tire was above the wedged spray deflector section. The left section of the spray deflector was found in it's original position, which was forward, with the nose landing gear retracted.
There was evidence of yellow paint transfer on the right upper surface (aft corner) of the spray deflector. Similar paint marks were observed on the left bottom surface (forward corner) of the spray deflector section. In addition, yellow paints chips were found embedded under a screw head at that location. The distance between the two yellow paint marks was approximately 29 inches. In addition, the right debris deflector, which extended from the side of the spray deflector exhibited evidence of scrape and measured 3-3/32 inches. The left debris deflector exhibited no damaged and measured 3-10/32 inches.
After removing the wedged spray deflector section, the nose landing gear was extended manually. The airplane was then connected to a ground power unit and a satisfactory functional check of the nose landing gear was performed. In addition, the manual gear extension system performed normally.
Ground personnel who participated in the pushback of the airplane from the gate, prior to departure from DFW, reported that the tow bar became disconnected while the airplane was being towed. According to the tow operator:
"...I put the push out tractor in reverse and started towing the airplane backwards. I was looking behind the push out tractor as I was towing the plane. I felt the tractor slip. I wasn't sure what happened, when I turned around and looked at the airplane, I saw the bar had come loose. I informed the captain of the bar breaking loose and told him to park his brakes. I then told my wing walker to get another tow bar. I told the captain we were getting another tow bar and the captain said if everything was OK, he would leave from the spot that they were at. I told [the captain] it looked OK to me...."
The airplane subsequently taxied for takeoff, and departed without incident.
Examination of tow bars used on the MD-82 at JFK, revealed that the distance between the forks measured approximately 30 inches. The tow bars examined at JFK were painted red; however, according to American Airlines, the tow bar used to tow the airplane at DFW was painted yellow.
TESTS AND RESEARCH
According to McDonnell Douglas, in addition to the accident flight, there were two other occasions where a failed spray deflector from the MD-80/MD-90/717 fleet, was able to pass the side wheel bay structural stops on retraction, wedge above the stops, and prevent gear extension.
A nose gear swing test confirmed that a broken polyurethane spray deflector assembly, when rotated aft by the air stream during gear retraction, could deflect enough to allow the assembly to wedge past the structural stops and subsequently prevent gear extension. At the time of this report, McDonnell Douglas was testing a design change which would alter the structural stops to better assure that a broken spray deflector could not enter the wheel well.
The airplane was released to American Airlines on September 4, 2004.