Accident Sequence
On January 14, 2014, at approximately 1447 eastern standard time, an Israel Aircraft Industries Gulfstream 200, registration N720QS, operated by NetJets Aviation, Inc., sustained substantial damage when the auxiliary power unit (APU) service door opened in-flight near Savannah, Georgia. Both airline transport pilots were not injured. Visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed for the local flight, which departed Savannah/Hilton Head International Airport (SAV) at 1436. The post-maintenance operational check flight (OCF) was conducted under 14 Code of Federal Regulations Part 91.
During climb through 16,000 feet at 280 knots, the crew heard a "thud" and felt a momentary shudder. No other anomalies were observed, and handling remained normal. Upon landing at SAV, the crew saw that the APU service door was open and bent, still attached at its aft hinge point. The lower latches were down and locked; the side latches were open and "bent as if torn away." The lower portion of the rudder was substantially damaged due to contact with the door.
Maintenance History
The airplane had undergone general maintenance, including repairs for a recurring landing gear position indication issue. Returned to service on January 9, 2014, a subsequent OCF revealed the gear issue persisted. Additional maintenance on January 10 found a fuel leak in the APU compartment from a fuel line fitting; an o-ring was replaced and leak testing showed no anomalies. A second OCF still showed the gear issue. Further maintenance occurred from January 10 to 14, and the airplane was returned to service on January 14.
Prior to the accident flight, the crew performed a preflight inspection, which included only a visual check of the APU service door security, as the door could only be accessed with a ladder. No anomalies were noted. Review of work orders showed that before each OCF on January 9 and 10, a full post-maintenance inspection included verifying aft fuselage accesses, antennas, and vents for security. Before the accident flight, only areas that had received maintenance since the prior OCF were inspected. The APU door was not accessed and no maintenance was performed in the APU area between January 10 and the accident flight.
Previous Events
According to the airframe manufacturer, between 2005 and 2014, five other in-flight APU service door events occurred on G200 airplanes, resulting in minor damage. In October 2008, the manufacturer issued maintenance and operations letter G200-MOL-08-0009 reminding crews to inspect all service and access doors for security before flight. On February 21, 2014, letter G200-MOL-14-0002 advised verifying proper seating and latching of the APU service door.
Review of previous events revealed that during manufacturing, forward APU service door latches may have been trimmed to prevent interference, possibly causing insufficient overlap with the doubler. On May 30, 2014, service bulletins 200-52-403 and 280-52-136 were issued for latch inspection on G200 and G280 airplanes. Examination of the accident airplane's latches immediately after the event showed proper overlap between latches and doubler.