De Havilland DHC-8-400 - Service Difficulty Alert

AL 2001-04
21 August 2001

Type II/III Emergency Exit Door Functional Check

A recent incident occurred in which the forward right emergency exit door could not be opened during crew training. An investigation identified that the seal retainer on the top of the upper door had come into contact with the fuselage upper stop, preventing the door from opening.

To ensure the emergency door is usable if required in an emergency, Transport Canada strongly recommends the functional check identified in Bombardier All Operator Message (AOM) 30 dated 17 August 2001 be conducted on each aircraft at the next convenient maintenance check, but no later than 31 August 2001. Repeat the functional check at each subsequent "L" check, except as noted in paragraph 4 of the Bombardier AOM, where it is to be repeated as a daily check.

The result of each functional check must be reported to the Bombardier Technical help desk within 24 hours of completing the check.

Bombardier is developing service checks and repairs methods which, when applied to an aircraft, will terminate the need for the repeated functional checks.

Any defects or further occurrences should be reported by sending a Service Difficulty Report to Transport Canada, Continuing Airworthiness, Ottawa.

For further information, contact a Transport Canada Centre, or Mr. Luc Deniger, Continuing Airworthiness, Ottawa, telephone (613) 952-5385, facsimile (613) 996-9178 or e-mail

For Director, National Aircraft Certification

B. Goyaniuk
Chief, Continuing Airworthiness