History of the Flight
On 15 October 2019, the pilot of a Diamond DA42 aircraft, registration N181CW, planned to fly from Seletar Airport, Singapore, to Kuching, Malaysia. The pilot arrived at the aircraft at about 0715 LT and opened the passenger door to stow baggage, then closed and latched it. A licensed mechanic nearby saw that the passenger door was closed and the handle flush with the fuselage. After completing the walk-around check, the pilot entered the cockpit and closed the front canopy. Pre-flight checks were completed, and the pilot called Air Traffic Control (ATC) for engine start-up and taxi clearance. The pilot did not notice any visual "Door Open" warning on the Primary Flight Display (PFD) when starting the engines.
At about 0741 LT, ATC cleared the aircraft to taxi to Runway 03. The pilot executed the BEFORE TAXIING CHECKLIST, which included switching on the Avionics Master Switch (AMS) to energise the avionics bus and audio panel for warning chimes. While at the holding point, the pilot completed the BEFORE TAKE-OFF CHECKLIST, which included checking the PFD for no "Door Open" warning. ATC cleared the aircraft for take-off at about 0750 LT.
After lining up on the runway, the pilot applied power for take-off. When the aircraft reached about 40 knots, the pilot heard "Abort, Abort" on the radio, shouted by the pilot of an aircraft behind who saw the passenger door opening and breaking off during the take-off roll. The pilot closed the throttles to abort the take-off, simultaneously noticing the "Door Open" warning on the PFD, but recalled not hearing any warning chimes. Glancing over his left shoulder, he saw the runway through an opening and thought the door had sprung open, not realising it had detached.
The aircraft slowed and vacated the runway via Taxiway W3 on the left, stopping on the taxiway. The pilot shut down the engines, exited the cockpit, and discovered the passenger door was missing. The detached door was later recovered from the runway.
Injuries to Persons
The pilot was the only person on board and was not injured.
Damage to Aircraft
The passenger door, along with the forward door hinge and part of the aft door hinge, was completely torn off from the door frame. Part of the aft door hinge remained on the door frame. The compression gas spring strut connecting the door to the fuselage was broken. Examination of the detached door showed signs of chafing on the top surface of the door handle, but the door latch mechanism was smooth and the locking bolts and PTFE blocks were undamaged.
Door Warning System
The door warning system consisted of a visual "Door Open" warning on the PFD and an audio warning chime system. The visual warning would appear if the front canopy, passenger door, or any cargo door was not closed and latched, and would only disappear when all doors were closed and latched. The visual warning did not depend on the AMS being on. The aural warning chime system needed to be energised after all doors were closed and latched and the AMS was switched on; the chimes could be heard through the cockpit loudspeaker and the pilot's headset.