FAA Airworthiness Concern Sheet

Date: August 14, 2009

Full Name: Roger Caldwell
Title:  Aerospace Engineer
Organization:
Denver Aircraft Cert. Office
Department:
ANM-100D
Address:
26805 East 68th Ave., Room 214
City:
Denver  State: CO  ZIP: 80249
Telephone Number:
303-342-1086
E-mail:
roger.caldwell@faa.gov

Make, Model, Series, Serial No.:
Ercoupe415C, 415CD, 415D, 415D, 415G, Forney F1 and F1A, Alon A-2 and A-2A and Mooney M10 aircraft

Reason for Airworthiness Concern:  The in-flight breakup of an Ercoupe Model 415D resulting in two fatalities.

FAA Description of Airworthiness Concern:

On December 13, 2008, an Ercoupe model 415D aircraft crashed after a complete in-flight breakup resulting in (2) fatalities.  The aircraft was being operated at other than cruise flight and was maneuvering.  The inspection of the wreckage reveals that improper maintenance was performed on the wing spar.  Specifically, holes had been drilled into wing spar to facilitate remounting of a seat pan and other unauthorized components.  The drill holes were in the exact location where the wings separated from the aircraft during the in-flight break up.  It was concluded from metallurgy analysis that both wings separated at the points of unauthorized maintenance actions and the drill holes significantly contributed to the overall weakness of the wing spar.  Three (3) aircraft of the same type design were recently inspected by the FAA for maintenance abnormalities to wing spars.  One of the three aircraft had the same modification to the spar pan as the accident aircraft.

At this time, the FAA has not made a final determination on what type of corrective action should be taken.  There is a FAA safety recommendation 09.087 to revise the AD 2003-21-01, requiring a complete wing spar inspection for corrosion, damage, and any unauthorized maintenance actions performed on the wings of all Univair Aircraft Models.  The FAA’s final determination will depend in part on the information received in response to this Airworthiness Concern Sheet (ACS).

Request for Information (Proposed Alternate Inspection/Repair Procedures, Cost Impact, Etc.)

Note:  Any comments or replies to the FAA need to be as specific as possible.  Please provide specific examples to illustrate your comments/concerns):

The ACS is intended as a means for Federal Aviation Administration (FAA) Aviation Safety Engineers to coordinate airworthiness (A/W) concerns with aircraft through Associations and Type Clubs.  Please forward any comments you have to Roger Caldwell via e-mail using the address above.

The FAA encourages comments on this topic, including, but not limited to the following areas:

-                Technical comments on improper maintenance and unauthorized alterations performed on the wing spar as noted above for FAA safety recommendation 09.087.

-                Are the correct models identified in this ACS (Airworthiness Concern Sheet)?

-                Are there alternate methods to address this situation?

-                Have you ever discovered improper or unauthorized maintenance actions or damage as described in this ACS, to e present on any area of the wing spar?

-                Have you ever discovered other related damage or corrosion on the wing spar, not described in this ACS?  If so, what actions did you take to correct the situation?

Response Date Requested:  10/07/09