88-25-07 FOKKER B.V.: Amendment 39-6084. Applies to Model F-28 Mark 1000, 2000, 3000, and 4000 series airplanes, certificated in any category. Compliance is required within 12 months after the effective date of this AD, unless previously accomplished:
To ensure the proper operation of the emergency lighting system when required during an emergency situation, accomplish the following:
A. Verify that a three position emergency lighting switch (i.e., OFF, ON, and ARMED) is installed in the cockpit. If such a switch is not installed in the cockpit, install one in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Northwest Mountain Region.
NOTE: Operators may wish to refer to Fokker Service Bulletin F28/33-26, dated October 12, 1983, in determining the means to be used to install a three position switch.
B. Verify that the emergency lighting system illuminates upon loss of normal electrical power when the three position cockpit mounted switch is placed in the armed position.
NOTE: (1) Normal electrical power is considered to be the F-28 AC generator power.
(2) For the purpose of this requirement, the emergency lighting system is considered to consist of both the emergency lights and the evacuation lights; however, all affected operators should be aware that for operations under FAR Part 121, an airplane's emergency lighting system also includes the floor emergency escape path lighting. Any modification to the emergency lighting system should ensure the proper operation of the floor emergency escape path lighting.
C. Accomplish one of the following:
1. Modify the emergency lighting system, in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Northwest Mountain Region, so that upon loss of normal electrical power, the emergency lighting system is powered by its own dedicated battery packs; or
2. Measure the minimum airplane battery voltage necessary to provide the required emergency lighting illumination levels. Modify the emergency lighting control circuit, in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Northwest Mountain Region, to switch from the airplane batteries to the emergency lighting system battery packs prior to dropping below the above determined minimum airplane battery voltage.
D. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM-113, FAA, Northwest Mountain Region.
NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who may add any comments and then send it to the Manager, Standardization Branch, ANM-113.
E. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of the modifications required by this AD.
All persons affected by this directive who have not already received the appropriate service document from the manufacturer may obtain copies upon request to Fokker Aircraft, USA, Inc., 1199 N. Fairfax Street, Alexandria, Virginia 22314. This document may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington.
This amendment, (39-6084, AD 88-25-07), becomes effective January 9, 1989.