SAIB CE-03-17 —

1 SPECIAL AIRWORTHINESS INFORMATION BULLETIN Aircraft Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration No. CE-03-17 January 13, 2003 We post SAIBs on the internet at "av-info.faa.gov" This is information only. Recommendations are not mandatory. Introduction This Special Airworthiness Information Bulletin (SAIB) provides safety information regarding inspection and operating procedures for the rudder gust lock system to owners and operators of Cessna Model 402C, 414A, and 421C. This particular gust lock design was offered as an option in 1979 and became standard equipment after 1984. Background This action is presented in response to a Malfunction or Defect report, FAA Form 8010-4, on a gust lock installed on Cessna 402-C, N68391, S/N 402C0483. This aircraft reportedly experienced rudder lock shortly after take-off. Through manipulations of the elevator and rudder pedals, the system was unlocked. Upon inspection, maintenance found that the rudder gust lock cam was disfigured. The initiator of this safety recommendation investigated this problem and found that if the gust lock is not disengaged and the aircraft is turned hard to the right, and then, with the nose wheel hard over, the elevator is pulled back the gust lock cam bends up and back. In flight, the cam may now engage the lock pin instead of the release mechanism. Recommendation The FAA recommends the following: a. Within the next 100 flight hours perform an inspection for condition of the rudder gust lock mechanism; pay close attention to the gust lock cam. A minimal clearance of 0.10 inches is needed between the locking pin and any point of cam rotation when the lock is in the stowed, unlocked position. Reference Maintenance Manual section 27-20-03, Rudder Gust Lock -Adjustment/Test for the 402C. Reference sections 7 and 5 of the Maintenance Manuals for the 414A and 421C, respectively. b. You should disengage the rudder gust lock by using the gust lock lever, located above the elevator, during the preflight walk around inspection. c. If not already installed, a placard should be located in the area of the gust lock lever to describe its location and operation. This placard is part of the aircraft type design when the gust lock is installed. This will help remind pilots of the need to disengage the gust lock. Reference Maintenance Manual section 11-20-00 for the 402C. Reference section 1 of the Maintenance Manual for the 414A and 421C.

2 d. The bottom of the gust lock lever needs to be painted red, as per original type design. This aids in both locating the gust lock and providing a visual indication of disengagement. e. You should perform a proper control sweep prior to takeoff to verify freedom of all control surfaces. For Further Information Contact: FAA, Wichita Aircraft Certification Office, Attention: Mr. Bob Busto, 1801 Airport Rd, Room 100, Wichita, Kansas, 67209, telephone (316) 946-4157, email: [email protected]