SAIB CE-02-34 —

1 SPECIAL AIRWORTHINESS INFORMATION BULLETIN Aircraft Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration No. CE-02-34 June 19, 2002 (Remailed 7/3/02) We post SAIBs on the internet at "av-info.faa.gov" This is information only. Recommendations are not mandatory. CORRECTED COPY: We inadvertently mailed this SAIB with the "revision marks" showing. This may cause misinterpretation. Please use this copy as the official copy and we apologize for any inconvenience. Introduction This Special Airworthiness Information Bulletin (SAIB) advises you, a registered owner of Cirrus SR20 or SR22 airplanes, of a communication radio interference problem with flap operation. Background Cirrus Design Corporation (CDC) and Cirrus operators have discovered a problem where simultaneous radio transmissions and flap operation may cause the flaps to stop in transit; cause the flaps to drive past their selected position; or may cause the flaps to reverse, and drive in the opposite direction. CDC has noted the following operational items: 1. Radio transmissions do not affect the flaps when they are not in transit. 2. Flap position indicator lights match the actual flap location for all instances of normal flap operation and also during interference conditions. However, if a radio transmission has caused the flaps to drive to an intermediate position, no light will be illuminated, and the pilot will not know where the flaps are without visual verification. 3. If flaps are stopped or reversed during transit, resetting the flap switch after the radio transmission will return flap operation to normal. Further investigation determined that radio transmissions were inducing voltage into the flap motor proximity switches that caused the flaps to stop, continue past their selected position, or reverse. CDC sent Owner Service Advisory SA 02-12 to owners, operators, and Service Centers, which recommended a placard stating, "Simultaneous Flap Operation and Com Transmission is Prohibited." In addition, CDC sent a temporary change to the Pilot's Handbook also prohibiting simultaneous flap operation and radio transmission to owners. A Service Bulletin is under development, which will require installation of EMI suppression cores on the flap wiring between the proximity switches and the flap circuit card. We expect the Service Bulletin and parts will be available in July 2002.

2 Recommendation Until the Service Bulletin is incorporated, we recommend that owners and operators of Cirrus SR20 or SR22 airplanes, incorporate Owner Service Advisory SA 02-12, which requires a placard next to the flap switch and incorporate the temporary Pilot's Operating Handbook change, which adds a limitation stating "Simultaneous Flap operation and Com transmission is prohibited." We also recommend that pilots visually verify flap position both prior to and after using the flaps. NOTE: The FAA is considering several options, including rulemaking action, to mandate these recommendations. We will continue to evaluate the results of failures/information reported from this SAIB and all other sources such as Aircraft Owners and Pilots Association (AOPA), Experimental Aircraft Association (EAA), and Type Clubs. We request that operators and mechanics report any failures to Steven Lardinois as addressed below. In addition, you can submit Malfunction or Defect Reports by accessing the FAA AFS-600 web page at http://www.afs600.faa.gov. For Further Information Contact Steven Lardinois, Aerospace Engineer, FAA Chicago ACO, 2300 E Devon Ave., Des Plaines, IL 60103; phone: (847) 294-7379; fax: (847) 294-7834; email: [email protected]