COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Fokker F27 Series Aeroplanes
AD/F27/144 Emergency Lighting 12/97
Applicability: All Fokker Aircraft B.V. Model F.27 Mk.050, Mk0502, and Mk.0604 if Emergency Battery Power Supply Unit, Part Number 60-4915-1 is installed.
Requirement: Fabricate a placard, with the following words in letters at least 2.5mm (0.10 inches) in height and install the placard in clear view of the pilot adjacent to the Emergency Lighting Selector Switch:
CAUTION
WHEN CYCLING EMERGENCY LIGHTING SELECTOR, SWITCH MUST BE LEFT IN “OFF” POSITION FOR AT LEAST 60 SECONDS.
Note: Netherlands AD 1997-060 (A) refers.
Compliance: By the 11 February 1998.
This airworthiness directive becomes effective on 6 November 1997.
Background: Pre delivery testing on a Fokker Model F.27 Mk 050 aircraft has shown that, if the flight crew cycles the Emergency Lighting Selector Switch, within a short time period, to OFF, either from ARMED or ON, and subsequently back to ARMED, the system will actually not be armed. If this switching sequence has occurred, the system will not react either in the event of an electrical power failure, nor when the switch is moved to the ON position. The affected circuitry, which needs a certain time to reset, is only installed in the Emergency Battery Power Supply units identified above.