Aviation Accident Summaries

Aviation Accident Summary NYC07LA121

Syracuse, NY, USA

Aircraft #1

N1799U

DOUGLAS DC-9-31

Analysis

While at its departure airport, a Douglas DC-9-31’s baggage was loaded by contract ramp personnel. After departure, the airplane was climbing through approximately 20,000 feet mean sea level (msl), when the flight crew heard a "loud pop" and the cabin depressurized. The flight crew donned their oxygen masks and diverted to the closest airport in point of time, and landed uneventfully. Postflight inspection of the accident airplane revealed a 12-inch by 5-inch fuselage skin tear, approximately 6 feet forward of the forward cargo door. During the course of the investigation it was revealed that at some point during the aircraft luggage off-loading or loading process, the engine of the belt loader quit operating. The senior of three ground agents working the flight decided to move the belt loader away from the airplane by pushing the belt loader with a luggage tug; however, during the attempt to move the belt loader, the tug’s cab contacted the fuselage. The senior ground agent then advised "don’t say anything" to one of the other employees who was working the flight with him, and the airplane departed and later depressurized. The senior ground agent’s actions were contrary to published guidance in the company’s training handbook and operation manual.

Factual Information

HISTORY OF FLIGHT On May 18, 2007, at 1300 eastern daylight time, a Douglas DC-9-31, N1799U, operated by Northwest Airlines (NWA) as flight 1411, was substantially damaged when it experienced a cabin decompression during climb from Syracuse Hancock International Airport (SYR), Syracuse, New York. The 2 certificated pilots, 2 flight attendants, and 95 passengers were not injured. Day visual meteorological conditions prevailed, and an instrument flight rules (IFR) flight plan was filed for the flight destined for Detroit Metropolitan Wayne County Airport (DTW), Detroit Michigan. The scheduled passenger flight was conducted under 14 Code of Federal Regulations (CFR) Part 121. According to the NWA, while at SYR, contract ramp personnel from Air Wisconsin Airlines Corporation (AWAC) had loaded the baggage for the flight. After departure, the airplane was climbing through approximately 20,000 feet mean sea level (msl), when the flight crew heard a "loud pop" and the cabin depressurized. The flight crew donned their oxygen masks and initiated an emergency descent to 10,000 feet msl. During the descent, the passenger oxygen masks in the cabin deployed automatically as the aircraft lost pressurization. Once the aircraft reached 10,000 feet, the flight crew diverted towards Buffalo Niagara International Airport (BUF), Buffalo, New York. After landing, the airplane was inspected by airport emergency personnel and taxied to the gate. PERSONNEL INFORMATION The captain held an airline transport pilot (ATP) certificate with multiple ratings, including airplane multi-engine land, and a type rating for the Douglas DC-9. According to records provided by NWA, he reported a total flight time of 10,509 hours, with 8,750 hours in the Douglas DC-9. His last Federal Aviation Administration (FAA) first-class medical certificate was issued on April 6, 2007. The first officer held an ATP certificate with multiple ratings, including airplane multi-engine land, and a type rating for the Douglas DC-9. According to records provided by NWA, he reported a total flight time of 1,852 hours, with 531 hours in the Douglas DC-9. His last FAA first-class medical certificate was issued on June 13, 2007. AIRCRAFT INFORMATION The airplane was manufactured in 1969. The airplane's most recent continuous airworthiness inspection was completed on May 17, 2007, and at the time of the inspection, it had accumulated 83,094 total hours of operation. METEOROLOGICAL INFORMATION The reported weather at SYR, at 1254, included: wind 280 degrees at 5 knots, visibility 10 miles, broken clouds at 4,200 feet, temperature 12 degrees Celsius, dew point 3 degrees Celsius, and an altimeter setting of 30.23 inches of mercury. WRECKAGE AND IMPACT INFORMATION Postflight inspection of the accident airplane by an FAA inspector revealed a 12-inch by 5-inch fuselage skin tear, approximately 6 feet forward of the forward cargo door on the right side of the airplane. Further inspection revealed that a crease in the skin of the fuselage existed forward of the tear, consistent with the skin being damaged by a foreign object. Further examination by NWA’s maintenance personnel revealed that the fuselage skin tear existed between fuselage station (FS) 294 and FS 313, and between longerons (L)-19R and L-20R. The crease was found to be between FS 275 and FS 294. No frame or longeron damage was discovered in either location. TESTS AND RESEARCH NWA personnel and FAA inspectors found metal shavings on the tarmac where the accident airplane had been parked at SYR. Examination of the belt loader used during the loading process revealed that the belt loader had red paint flakes adhering to the front right hand corner, which matched the height of red paint scrape marks on the front left bumper of a luggage tug. The top right-hand forward corner of the luggage tug exhibited scrape marks, missing paint, and exposed metal. Tire marks, consistent with luggage tug tire tread markings, were found on the tarmac forward of the belt loader’s normal loading position, and beneath the area were the damage to the accident airplane occurred. Measurements of the top of the luggage tug cab were consistent with the height of the aircraft damage. Personnel Statements According to the NWA station manager and AWAC ground agents, at some point during the aircraft luggage off-loading or loading process in SYR, the engine of the belt loader quit operating. Three of the contractor’s ground agents attempted to manually push the belt loader away from the aircraft but were unable to do so. The senior of the three decided to use a luggage tug to push the belt loader away from the airplane by entering the "Safety Diamond/Zone" with the luggage tug from the front right-hand side of the airplane, close to, and parallel with the fuselage. The front left bumper of the tug was then positioned on the right front corner of the belt loader, and at some point during or immediately after pushing the belt loader away from the airplane, the upper right-hand side of the tug’s cab contacted the fuselage. The senior ground agent then advised "don’t say anything" to one of the other ground agents who was working the flight with him. Company Guidance According to the AWAC Ramp Operations Training Handbook and Station Operation Manual, maneuvering any "piece of equipment" to within "closer than five (5) feet," and use of any vehicle for any purpose other than what they were "designed" for was prohibited. Additionally, Guidance for immediately reporting safety concerns or hazards, which could pose an imminent threat to "life or health," were included. ADDITIONAL INFORMATION Contractor Corrective Actions On June 1, 2007 The contractor issued an AWAC Station Management Control Memo (SM07-16) to all of their station personnel advising that, "It is imperative that when a piece of equipment comes in contact with an aircraft leaving a scratch, dent, hole, etc., the incident must be reported immediately," and advised their personnel that, "It is beyond a concern of potential discipline; it is the ultimate significance of ensuring there is no risk of safety of flight." Additionally, they also reminded their personnel to never violate the "5 Foot Rule" when in the Safety Diamond/Zone of the aircraft, and that the only exceptions to the rule were the beltloader, airstairs, and jetbridge, which require a guide person at all times when within the Safety Diamond/Zone, and that if there were a situation outside of this exception, that they were required to contact their manager for direction and guidance. On June 5, 2007, AWAC forwarded training materials to all of their stations for review by all of their station management and "ground employees." These materials included, a safety poster and talking points for discussion and ramp safety education. These materials highlighted, correct driving patterns around airplanes, the "5 Foot Rule," use of a guide person, situational awareness, standard operating procedures, directives to seek guidance from the station manager in the event of unusual situations, and the connection of ramp duties and requirements being directly related to safe aircraft departures.

Probable Cause and Findings

The senior ground agent's failure to follow written procedures and directives.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports