Aircraft fuel caps being found on runway and taxiway surfaces - Service Difficulty Alert

AL 2009-04
13 July 2009

Purpose: This advisory deals with aircraft pressurerefuelling caps, which have been identified as foreign object debris (FOD), and are of concern to Canadian airport authorities and Transport Canada Civil Aviation Safety Inspectors (CASI).

Background: This issue was originally brought forward in Service Difficulty Advisory AV-2007-01 which is located at As this continues to remain an issue we are drawing your attention once again to the fact that Airport authorities in Canada and the United States have reported multiple incidents of runway and taxiway surface FOD. The fuel-cap FOD issue is not aircraft-specific. Aircraft that have pressure-refuelling systems in which the fuel caps are mounted underneath the wing without a cover panel are most susceptible to losing their fuel caps. Fuel caps have lanyards to keep them attached to the aircraft; however, most of the time these lanyards are found damaged, detached or removed. It is suspected that this is due to misalignment of the fuel cap when fasten.

Recommended Action:

  • Personnel carrying out aircraft refuelling tasks should take additional care to ensure that the fuel caps are properly engaged and locked into position. Any instance where it is noticed that the fuel cap is missing should be reported to the operator so that the appropriate investigation can be carried out. With the proper attention and care during inspection and refuelling operations, the amount of fuel-cap FOD can be eliminated, or at least greatly decreased.
  • Airport or aerodrome operators should determine if this type of fuel cap is in use by aircraft normally using their airport or aerodrome in order to assess the risk of FOD and mitigate it by adjusting local inspection procedures of the manoeuvring area.

Contact Office:

For more information, please consult; contact a Transport Canada Centre; or contact Bernard Valois, Aerodrome Standards in Ottawa, by phone 613-990-3708, fax 613-954-1602, or e-mail

NOTE: Any further defects or occurrences should be reported to Transport Canada via the Web Service Difficulty Reporting System (WSDRS) or via e-mail at

D. Sherritt Director, Standards

Note: For the electronic version of this document, please consult the following Web address: