AD 75-05-04 ACTIVE

75-05-04 WHELEN ENGINEERING COMPANY INCORPORATED: Amendment 39-2098. Applies to aircraft incorporating Whelen Engineering Company Incorporated A427 strobe light flash tubes manufactured before November 1, 1974. Compliance required within the next 100 hours time in service unless already accomplished.

(a) To preclude possible ignition of flammable fluids or vapors by arcing at the strobe light flash tube, install on the base of Whelen Engineering Company Incorporated A427 flash tubes a pressure sensitive vinyl label conforming to Whelen Engineering Company Incorporated Drawing A-30052, Revision 1, dated October 15, 1974, or latter FAA approved revision. Scotch Brand Type 33+ vinyl plastic electrical tape or equivalent tape approved by an FAA Maintenance/Avionics Inspector can be used in lieu of the vinyl label. If vinyl plastic electrical tape is used, it must be formed to cover the rivet at the rear of the flash tube without covering the identifying part number. If the flash tube incorporates a label, the new label or tape may be installed directly over the old label. Install the label or tape only when the label or tape and the flash tube are at a temperature above 50 degrees F.

(b) The installation required by this AD constitutes preventive maintenance and may be performed by persons authorized to perform preventive maintenance under FAR 43.

(c) Upon request with substantiating data submitted through an FAA Maintenance/Avionics Inspector, equivalent methods of compliance with this AD may be approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, New England Region.

NOTE: For the requirements regarding the listing of compliance and method of compliance with this AD in the airplane's permanent maintenance record, see FAR 91.173.

This amendment becomes effective thirty (30) days after publication in the Federal Register.