EMERGENCY AIRWORTHINESS DIRECTIVE - AOPA

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1 EMERGENCY AIRWORTHINESS DIRECTIVE Aircraft Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration We post Emergency ADs on the internet at "www.faa.gov" DATE: February 20, 2005 AD #: AD 2005-05-51 Send to all owners and operators of The Cessna Aircraft Company (Cessna) Models 402C and 414A airplanes. This AD applies to all Models 402C and 414A airplanes that do not have a spar strap modification incorporated on each wing spar following Cessna Service Bulletin MEB02-5, dated June 24, 2002, and Cessna Service Kit SK402-47, dated June 24, 2002. Discussion What events have caused this AD? The FAA has received reports of and is analyzing data from cracks found in the wings of two Cessna Model 402C airplanes. On the first airplane, early information indicates the airplane had severe cracking on its left wing in the vicinity of the front spar and outboard engine beam. The lower spar cap had completely failed at about Wing Station (WS) 114. The airplane also had cracks in the lower wing skin and the web splice doubler. Also found were two popped rivets: one between the heat shield and the wing skin and another between the factory installed web splice doublers and web. The airplane had 20,355 total hours time-in-service (TIS). During the airplane’s most recent flights before the cracking was found, the pilot noticed progressive deterioration in roll trim. The flights required the pilot to use aileron trim for level flight to keep the wings level. The airplane landed safely and inspection revealed the cracks. On the second airplane, fatigue cracks were found at about WS 114 in the lower spar cap of another Model 402C airplane that had over 20,000 total hours TIS. Fatigue analysis shows that similar fatigue cracks could also develop in the wings of the Model 414A airplanes. Is there any current regulatory action to address this area of the Cessna 402C airplanes? Airworthiness Directive (AD) 2000-23-01, Amendment 39-11971 (65 FR 70645), currently requires repetitive visual inspections of the forward, aft, and auxiliary wing spars for cracks on Cessna Model 402C airplanes. These inspections are at intervals not to exceed 110 hours TIS. Logbook records indicate that both airplanes with cracked spars were in compliance with AD 2000- 23-01. What is FAA’s determination? The FAA’s analysis so far shows the inspections of AD 2000-23-01 should be done more frequently and particular attention paid to the following areas: 2 Just Outboard of the Engine Beam • The lower spar cap at WS 114. • The three rivets on both the inboard and outboard sides of WS 114 (total of six rivets) in the lower spar cap as viewed from the access hole. • The spar web at WS 112.5. Just Inboard of the Inboard Engine Beam • The lower spar cap between WS 80 and WS 89. • The two attach bolts just inboard of the WS 89.18 rib. Therefore, FAA has decided to issue an AD to detect and correct cracking in the wing spars of the affected airplanes before the cracks grow to failure. Such a wing failure could result in the wing separating from the airplane with consequent loss of control of the airplane. In addition, we are working with Cessna to develop more extensive solutions to this cracking problem. The FAA anticipates issuing future airworthiness directives (ADs) to address this issue. These ADS may include, but are not necessarily limited to, more intensive inspection procedures and already developed FAA-approved spar strap modifications. What does this AD require? This AD supersedes AD 2000-23-01 to require the visual inspections of the forward, aft, and auxiliary wings spars for cracks more frequently on type design Model 402C airplanes. It adds inspection requirements for the Model 414A airplanes. The AD does not affect those airplanes that incorporate a spar strap modification on each wing following Cessna Service Bulletin MEB02-5, dated June 24, 2002, and Cessna Service Kit SK402- 47, dated June 24, 2002. Provisions are included in this emergency AD to position the airplane to a home base, hangar, maintenance facility, etc. Presentation of the Actual AD This rule is issued under 49 U.S.C. Section 44701 (formerly section 601 of the Federal Aviation Act of 1958), pursuant to the authority delegated to me by the Administrator, and is effective immediately upon receipt of this action. 2005-05-51 THE CESSNA AIRCRAFT COMPANY: Directorate Identifier 2005-CE-06-AD. When Does This AD Become Effective? (a) This emergency AD becomes effective upon receipt. Are Any Other ADs Affected By This Action? (b) This AD supersedes AD 2000-23-01, Amendment 39-11971 (65 FR 70645). 3 What Airplanes Are Affected by This AD? (c) This AD affects Model 402C and 414A airplanes, all serial numbers, that: (1) are certificated in any category; and (2) do not incorporate a spar strap modification on each wing spar following Cessna Service Bulletin MEB02-5, dated June 24, 2002, and Cessna Service Kit SK402-47, dated June 24, 2002. What is the Unsafe Condition Presented in This AD? (d) This AD is the result of extensive cracks found in the wing spars of two of the affected airplanes. We are issuing this AD to detect and correct cracking in the wing spars before the cracks grow to failure. Such wing failure could result in the wing separating from the airplane with consequent loss of control of the airplane What Must I do to Address This Problem? (e) Inspections: Perform both an external and internal inspection of the forward, aft, and auxiliary wing spars for cracks at the times below that are applicable (pay particular attention to the areas specified in paragraph (f) of this AD). Do these inspections following the ACCOMPLISHMENT INSTRUCTIONS section of Cessna Service Bulletin MEB99-3, dated May 6, 1999 (Model 402C); or Cessna Service Bulletin MEB00-7, dated June 24, 2002 (Model 414A): Affected Airplanes Initial Inspection Repetitive Interval (1) For all Model 402C airplanes with fewer than 15,000