Incident Overview
A First Air Boeing 727-225, registration C-FIFA, serial number 20381, was operating a scheduled cargo flight from Corcaigh International Airport, Ireland, to East Midlands Airport, England. Shortly after takeoff, while the landing gear was retracting, the aft cargo door light illuminated on the second officer's annunciator panel. The second officer informed the crew as the aircraft climbed through 400 feet above ground level. Shortly thereafter, the No. 3 engine experienced a series of compressor stalls. The captain shut down the engine and requested an immediate return to Corcaigh Airport. The aircraft landed uneventfully; airport emergency response services were standing by. The aft cargo door was found partially open, and the door-opening mechanism was damaged. No one was injured.
Crew and Aircraft Details
The aircraft was on extended chartered operations to Air Contractors Ireland Ltd. The three crew members—captain, first officer, and second officer—had a full day of rest before duty. They were certified and qualified according to regulations. The aircraft was serviced and maintained per directives, with no indication of system malfunction before the flight. Reported weather included a broken ceiling at 3000 feet, tops at 5000 feet, light winds, and good visibility. All events occurred during daylight conditions.
Loading and Pre-Flight Procedures
Upon arrival, the second officer conducted an external inspection and noted the aft cargo and main cargo doors open in preparation for loading, with the aft airstairs deployed. Ground personnel prepared to load through both doors. Servisair Ltd. provided ground handling under DHL Aviation supervision. Under contract, Servisair was responsible for securing all cargo doors, but a local procedure delegated aft cargo door loading to DHL Aviation. The aircraft was loaded while all three crew members were in the cockpit performing pre-start checks. The second officer checked the annunciator panel twice before engine start; both times after loading, the main cargo and aft cargo doors lights were not illuminated, indicating secure doors. The crew initiated the "Clear to Start" checklist. A Servisair agent gave a thumbs-up before start. No pushback was required.
Inflight Events
During takeoff, the captain and first officer focused outward; the second officer monitored engine instruments. After lift-off, as gear was selected up, the second officer saw the aft cargo door light illuminated. After passing take-off obstacle clearance altitude, he informed the crew. Following flap retraction, the No. 3 engine suffered compressor stalls—located a few feet downstream from the aft cargo door. The captain reduced thrust to idle, leveled above the broken cloud layer, and requested an immediate return. The engine was secured, and the aircraft landed on two engines. Emergency services inspected and reported the aft cargo door partially open, hinges slightly bent, and door handle fully protracted. No apparent damage to the engine or structure. The aircraft then taxied to the ramp.
Post-Flight Findings
After shutdown, responsibility for securing the aft cargo door could not be determined between DHL Aviation and Servisair Ltd. The DHL agent who loaded parcels could not recall if he closed the door. Of five parcels loaded aft, two remained on board; one was found on the runway, one on grass past the runway end, and one returned by a nearby resident.
The aft cargo door structure, latches, and hinge attach points were undamaged, but both hinge rods were bent, preventing closure. The door warning mechanism (switch, wires, light) was tested extensively with no faults found. Hinges were dismantled to allow closure; the door then closed and the warning light extinguished. The rear cargo area held pressure within limits. On July 24, with authorization from Irish Aviation Authorities and Boeing, the aircraft was ferried to Copenhagen, Denmark, for repairs—including replacement of bent hinges, locking mechanism, and minor repairs to the No. 3 engine turbine casing damaged by stalls. No damage was found on turbine blades. During repair, the door microswitch was inadvertently discarded and unavailable for analysis.
Investigation Details
The Transportation Safety Board (TSB) was not initially informed; they received information from Transport Canada on July 24. Through coordination with the Irish accident investigation agency, the investigation was delegated to TSB on July 25. Flight data recorder and cockpit voice recorder (CVR) data were downloaded. Annunciator door lights and door status are not recorded in the FDR. The flight lasted 34 minutes after rotation; average speed 200 knots with peaks to 240 knots. The CVR loop was overwritten as power remained on for over an hour post-incident for diagnosis. The CVR contained no data from pre-start to occurrence.
Historical Context
Boeing reported 10 cases of airborne inadvertent door openings for the 727 type since December 1976, including this occurrence. Causes are usually undetermined. One NTSB event (January 5, 1999) determined improper securing by ground personnel and an intermittent warning light due to contamination. Suspected causes in other cases include improper latching combined with malfunctioning warning systems. Faulty microswitch operation is usually due to oil/water contamination, dirty cannon plugs, or wiring issues. Switches are discarded if difficult to clean; they have no shelf life. A few weeks after this incident, an undocumented aft cargo warning light malfunction occurred at Ottawa/Macdonald-Cartier International Airport with the same aircraft type. The warning light was out while the door was open; the switch was cleaned and reinstalled.