85-26-51 R2 SAAB-FAIRCHILD: Amendment 39-5376 as amended by amendment 39- 5916. Applies to all Model SF-340A series airplanes, certificated in any category. Compliance required as shown below.
To minimize the hazards associated with engine flameout due to potential ice ingestion, accomplish the following, unless previously accomplished:
A. Prior to further flight, install a continuous ignition switch by incorporating the provisions of SAAB-Fairchild SF-340 Service Bulletin SF340- 74-002, Revision 1, dated December 15, 1985.
B. Incorporate the following into the limitations section of the airplane flight manual. This may be accomplished by including a copy of this AD in the airplane flight manual.
1. Takeoff in conditions of slush on the runway is prohibited unless Modification 1185, "Nacelle - Exhaust Nozzle - Improved Drainage and Ventilation of Inlet Protection Device (IPD) and Special Inspection," as described in SAAB-Fairchild Service Bulletin SF340-54-002,Revision 1, dated April 3, 1985, has been accomplished.
2. Turn the engine and propeller anti-ice systems on and set the ignition ("IGN") switch to the continuous ("CONT") position during all operation in which icing could reasonably be expected to occur and for a period of five minutes after these conditions no longer exist. When Modification 1414, "Ignition - Introduction of Auto Ignition System," has been accomplished in accordance with SAAB Service Bulletin SF340-74-004, dated October 24, 1986, or a production equivalent, set the ignition switch to the "NORM" position."
3. In the definition of icing conditions stated in the FAA- approved flight manual on page 2-11, change the temperature stated in "Icing Conditions," paragraph 1, line 4, from "5 degrees C" to "10 degrees C," unless Modification 1319, "Installation of New Lower Inlet, IPD and Exhaust Nozzle," as described in SAAB-Fairchild Service Bulletin SF340-71-017, dated November 22, 1985, has been accomplished. If this modification has been accomplished, "5 degrees C" can remain in the definition.
C. Conduct engine performance monitoring in accordance with General Electric Operating Engineering Bulletin (OEB) 2, Revision 4, dated December 14, 1985, or later FAA- approved revision.
D. Prior to further flight, and at intervals specified in General Electric OEB 4, Revision 4, dated December 14, 1985, or later FAA-approved revisions, perform an inspection and perform maintenance, as necessary, of the ignition system in accordance with that OEB.
E. Unless Modification 1319, as described in paragraph B.3., above, has been accomplished, in the event of an icing encounter, an inspection must be accomplished prior to the next departure to assure that no snow, ice, or slush accumulation is present in or around the inlet or the inlet protection device.
F. Following each flameout or re-ignition event, conduct an inspection of Stage 1 compressor blades, in accordance with General Electric OEB 4, Revision 4, dated December 14, 1985, or later FAA-approved revisions.
G. 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.
H. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.
All persons affected by this directive who have not already received the appropriate service information from the manufacturer may obtain copies upon request to SAAB-SCANIA, Product Support, S-58188, Linkoping, Sweden.
This information 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.
AD 85-26-51 R1 amendment 39-5376, became effective August 18, 1986.
This amendment 39-5916 becomes effective June 17, 1988.