AL 2000-03
24 March 2000
Security of Emergency Exit Door Latch
During a routine inspection of the emergency exit door (P/N 50-420013-643) on a C90A King Air the AME carried out an operational check of its barometric latching feature. While simulating a pressurized condition by pushing on the hooks of the airlock assembly, it was discovered that with a small tug, the inside handle bolt (P/N 50-420013-371) could slip past the trigger (P/N 50-420013-373) and unlatch the door.
Further examination found that the bolt of the assembly was too short to be securely held by the trigger. Fleet inspection found seven out of eight aircraft failed the test. The door with the factory installed bolt was sent to Raytheon for further investigation. The bolt had 4136 hours TSN.
The consequences of failure are significant enough to warrant a recommendation that, at the next convenient maintenance opportunity, operators of all Beech 90 Series aircraft with an emergency exit using bolt P/N 50-420013-371, do a one-time operational check of their emergency exit latching mechanism during simulated pressurization to ensure the security of the handle.
For further information contact a Transport Canada Centre, or call Mr. Robert Dixon Continuing Airworthiness, Ottawa, telephone (613) 952-4308, facsimile (613) 996-9178 or e-mail dixonro@tc.gc.ca.
For Director, National Aircraft Certification
B. Goyaniuk
Chief, Continuing Airworthiness