History of Flight
On May 28, 2010, at approximately 1220 eastern daylight time, a Cessna 560XL, registration N662QS, sustained minor damage when the main cabin door opened in flight shortly after departure from Westchester County Airport (HPN), White Plains, New York. The two pilots and two passengers were not injured. Visual meteorological conditions prevailed, and the flight operated under an instrument flight rules flight plan. The corporate flight was destined for Nantucket Memorial Airport (ACK), Massachusetts, and was conducted under Title 14 Code of Federal Regulations Part 91K.
Following the incident, the captain and first officer were interviewed separately by Federal Aviation Administration (FAA) inspectors. Both pilots were qualified to act as captains in the Cessna 560XL, and their roles for the incident flight were defined by the operator. The captain was the pilot flying, while the first officer was the pilot monitoring. During the pre-flight safety briefing with passengers, the first officer closed the cabin door. He recalled rotating the door locking handle but could not remember the direction. He also did not recall checking the door post locking indicator lights or the cockpit indicator.
After completing checklists, the crew taxied slowly toward runway 16, encountering a delay before clearance for takeoff. During the delay, the captain focused on air traffic control communications and building a mental picture of nearby traffic. Just after takeoff, the captain heard the cabin door leaking, and the first officer saw the DOOR SEAL/CABIN DOOR annunciator light illuminated. The first officer did not recall the master caution annunciator illuminating.
The crew requested and received clearance to return to runway 16. While on the downwind leg, the main cabin door opened. The crew declared an emergency and landed uneventfully with the door open.
Aircraft Information
According to the Cessna 560XL maintenance manual, the cabin door is located on the left forward side, hinged at the bottom, opening outward. It features a pre-catch mechanism to assist in holding the door closed before locking. Eight locking pins, mechanically linked to internal and external lock/unlock handles, extend into door frame sockets. Three pins are on each side of the door and two at the top.
Six electrical switches monitor the door's closed and locked position: four actuated by upper and lower side locking pins, one monitoring the door vent, and one monitoring the door locking mechanism position. The switches connect to the cockpit warning annunciator panel. The CABIN DOOR annunciator extinguishes only when all six switches are closed. If any switch toggles from locked to unlocked, both the CABIN DOOR and MASTER CAUTION annunciators illuminate. Resetting the MASTER CAUTION extinguishes it, but the CABIN DOOR annunciator remains lit. A DOOR LOCKS panel on the door post has six LEDs indicating positions of locks, handle, and vent door. Each LED illuminates when its respective switch senses an unlocked position and extinguishes when locked or closed. When the door is locked, the door vent light extinguishes after several seconds, and vibration from the closing vent can be felt near the bottom of the door. Additionally, nine indicator windows show phosphorescent green flags when the door is properly closed and locked.
The cockpit annunciator panel provides system notifications. The CABIN DOOR annunciator (yellow) is on the bottom row, sixth column from the right. The GROUND IDLE annunciator (white) is directly above it on the first row. Normally, the GROUND IDLE annunciator illuminates after engine start and during taxi, and is the only annunciator lit just before takeoff.
Personnel Information
The captain held an airline transport pilot certificate with ratings for single- and multi-engine land airplanes. His most recent first-class medical certificate was issued in July 2009. He reported 7,459 total flight hours, with 1,737 hours in the incident airplane make and model.
The first officer held an airline transport pilot certificate with ratings for single- and multi-engine land airplanes. His most recent first-class medical certificate was issued in April 2010. He reported 5,964 total flight hours, with 1,432 hours in the incident airplane make and model.
Meteorological Information
At 1156, recorded weather at HPN included calm winds, broken ceiling at 3,200 feet, visibility 10 statute miles, temperature 19°C, dew point 11°C, and an altimeter setting of 29.98 inches of mercury.
Flight Recorders
The aircraft was equipped with a cockpit voice recorder, which was retained and reviewed at the NTSB Vehicle Recorders Laboratory. The recording revealed events consistent with the crew's statements. During the engine start checklist, the crew noted 'cabin door closed' and 'lights out.' Shortly after, they noted annunciators and instruments were checked. The runway items checklist was completed, with the crew noting 'lights, heat, and lights out.'
Tests and Research
Two FAA inspectors examined the main cabin door after the incident. They found that the door had been over-extended when it opened in flight and scraped against the runway during landing. Damage prevented normal closing, though the door could be opened and closed with force from inside and outside. Detailed inspection showed the pre-catch mechanism operated normally, and no visual indication of any locking pin or pin socket failure was found. The DOOR LOCK panel annunciator lights and the CABIN DOOR annunciator functioned normally, including illumination of the MASTER CAUTION when the door was opened. The inspectors noted that if electrical power was applied (from battery or power cart) with the cabin door open, the CABIN DOOR annunciator remained steadily illuminated until the door was closed. Illumination of the MASTER CAUTION with a blinking CABIN DOOR annunciator would occur only after the door was closed, locked, then unlocked and reopened.
Additional Information
According to the operator's Expanded Normal Procedures, the Engine Start checklist required both pilots to: close and latch the cabin door, verify cabin door pin indicators are visible, verify cabin door red LEDs are extinguished, and verify the cockpit Cabin Door annunciator is extinguished. The Runway Items flow checklist required the pilot monitoring to ensure all annunciator lights were extinguished except GROUND IDLE after being cleared for takeoff.