SAIB CE-04-66

SPECIAL

AIRWORTHINESS

INFORMATION

BULLETIN

Aircraft Certification Service Washington, DC

U.S. Department of Transportation Federal Aviation Administration

CE-04-66 April 29, 2004 www.faa.gov/certification/aircraft This is information only. Recommendations aren’t mandatory.

Introduction:

This Special Airworthiness Information Bulletin alerts you, owners and operators of Mooney Aircraft Company Model M20 airplanes (year model 1966 through 1978) with Dukes Part No. 1057-00-5, -5E, -5F, -5G, of possible premature failure of the landing gear actuators.

Background:

Mooney issued Service Bulletin (SB) 20-190 to provide maintenance and gear replacement procedures for the Mooney landing gear with the Dukes P/N 4196-00-1C or International Telephone and Telegram (ITT) P/N LA11C2110 actuators only. We issued AD 75-23-04, applicable to all M20 series airplanes equipped with Mooney Electric Gear System, Dukes P/N 4196-00-1C, and referenced the procedures in SB 20-190. A later revision of SB 20-190 included the ITT P/N LA11C2110 landing actuator.

We have received several Service Difficulty Reports (Maintenance or Malfunction Defects) regarding the premature failures of the Dukes P/N 1057-00-5, -5E, -5F, and -5G. We determined that some operators were inappropriately maintaining these products with the wrong service instructions (SB 20-190) creating the premature failure of the landing gear actuator. This could prevent the landing gear from functioning properly and could result in a gear-up landing situation.

M20 airplanes with the Dukes 4196-00-1C and the ITT LA11C2110 actuators have a 20:1 speed ratio, made possible with a double lead worm shaft, and the Dukes 1057-00-5 actuator uses a 40:1 speed ratio, made possible with a single lead worm shaft.

Recommendation:

To prevent premature failure of the landing gear actuators, we strongly recommend that owners and operators of the M20 airplanes referenced above stop using SB 20-190 to perform maintenance of these actuators. You should consult the appropriate M20 Service and Maintenance Manual.

For Further Information Contact:

Mr. Garry D. Sills, Aerospace Engineer, FAA Fort Worth ACO, 2601 Meacham Blvd, ASW-150, Fort Worth, TX 76137-4298; phone: (817) 222-5154; fax: (817) 222-5960; e-mail:

garry.d.sills@faa.gov.