SAIB CE-05-27

SPECIAL

AIRWORTHINESS

INFORMATION

BULLETIN

Aircraft Certification Service Washington, DC

U.S. Department of Transportation Federal Aviation Administration

CE-05-27 January 20, 2005 www.faa.gov/certification/aircraft This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin informs you, owners and operators of Cessna airplanes listed in Table 1, of a potential problem with foam-filled elevator trim (F-FET) tabs. These tabs may soak up moisture, cause internal corrosion and add weight to the tab, which could also lead to flutter.

The following airplanes were manufactured with F-FET tabs:

TABLE 1 Model Year Serial Numbers Cessna P206 1968 through 1969 P206-0420 through P206-0603 Cessna P206 1970 P20600604 through P20600647 Cessna U206 1968 through 1969 U206-0915 through U206-1444 Cessna U206 1970 through 1986 U20601445 through U20607020 Cessna 207 1969 through 1984 20700001 through 20700788 Cessna 210 1960 through 1984 21057001 through 21064897 Cessna T210 1966 through 1969 T210-0001 through T210-0454 Cessna P210 1978 through 1983 P21000001 through P21000834

Background

Cessna discontinued F-FET tabs (P/N 1234628-1) in 1985. However, we still receive reports of corrosion problems on airplanes that have these foam-filled tabs installed. Moisture can cause internal corrosion between the tab and the foam. For example, moisture condenses in the tab when the airplane is flown high enough that the surrounding air is cold, as normally aspirated and turbocharged airplanes would experience.

When the skin of the trim tab becomes thin enough due to the corrosion, the actuator can pull the fasteners through the skin and disconnect. When this occurs, the tab can flutter. Reports indicate vibrations in the tail section and portions of the elevator tearing away with the trim tab.

The Cessna Pilots Association weekly newsletter, CPA ATIS, Vol. 7, Issue 49, Thursday, December 9, 2004, provides information on how to detect the corrosion, and what is involved in replacing the foamfilled tabs. Cessna Service Bulletin SEB85-7, dated April 5, 1985, includes information about inspecting elevators and trim tabs. A review of the FAA Service Difficulty Reports (SDR) database since 1974, reveals 46 reports involving foam-filled tabs. A review of past issues of AC 43-16A and its predecessors found 23 articles published from 1972 through 2002 on this problem.

2 In addition, Alert Bulletins No. 62, dated August 24, 1953, and No. 50, dated August 6, 1952, discuss maintenance and repairs for control surfaces several years before these airplanes were manufactured. Cessna has sold only 18 replacement trim tabs in the past 5 years. Cessna built more than 16,000 airplanes with F-FET tabs.

Recommendation

We recommend that you replace foam-filled elevator trim tabs (P/N 1234628-1) with “unfoamed” tabs P/N 1234665-1 or 1234665-9 with doublers 1234666-1/-2 per Cessna Service Bulletin SEB92-1, dated January 17, 1992, or an FAA-approved equivalent replacement. Also, note that elevator trim tab P/N 1234665-10 (unfoamed) should comply with mandatory Cessna Service Bulletin SEB00-6 dated July 31, 2000.

For Further Information Contact

Gary Park, Aerospace Engineer, FAA Wichita ACO, Airframe Branch, 1801 Airport Road, Room 100, Wichita, KS 67209; phone: (316) 946-4123; fax: (316) 946-4107; e-mail:

gary.park@faa.gov.