The concern sheet
Text extracted from the PDF.
Revised 1/24/02 Airworthiness Concern Sheet
Full Name Andrew McAnaul Title Aerospace Engineer Organization Airplane Certification Office Department ASW-150 Address 10100 Reunion Place, Ste. 650 City State ZIP San Antonio, TX 78216 Telephone Number 210-308-3365 E-mail andrew.mcanaul@faa.gov Make, Model, Series, Serial No.:
Air Tractor Model AT-402/402A/402B Serial Numbers 0694 through 1176 Reason for Airworthiness Concern:
Looseness and Cracking/Separation of Rudder from Vertical Fin at Hinge Attach Area Date: 06/16/2008 FAA Description of Airworthiness Concern (Who, What, Where, When, How? Attachments: RA and appropriate data)
The manufacturer Air Tractor has revised Snow Engineering Co. Service Letter #247 to add certain serial number AT-402/402A/402B series airplanes to inspect the rudder and vertical fin attaching structure for loose fasteners, loose or cracked skins, brackets, hinges or spars, and/or corrosion. The Service Letter revision is in response to a recent report of finding an AT-402 with a loose upper rudder hinge.
In-flight separation of an AT-602 and AT-802A rudder from the vertical fin at the upper hinge area, and reports of in-service loose hinges or cracked skins, brackets, hinges or spars, and/or corrosion in rudders on AT-502, AT-602 and AT-802 series airplanes caused us to issue AD 2006-23-14. The in-flight separation in the AT-602 resulted in the fin folding over just above the center hinge. AD 2006-23-14 and Snow Engineering, Inc. Service Letter #247address inspection and terminating action requirements for AT-502, AT-602 and AT-802/802A rudders. They require initial visual inspection of the rudder and vertical fin hinge attach structure at 3,500 hours time-in service (TIS), recurring visual inspections every 100 hours TIS thereafter, and mandatory modification of the rudder with doublers by 5,000 hours TIS as terminating action for the inspections. The latest revision to Service Letter #247 adds the same requirements for AT-402/402A/402B series airplanes.
The FAA requests any information from aircraft owners, operators, or repair facilities for any inspections where cracks, looseness or other discrepancies were found in the rudder-to-vertical fin hinge attach area on AT-402/402A/402B airplanes. Please include a description and location of damage found, the hours TIS for the rudder, and what repair action was taken. A risk assessment accomplished in accordance with the Small Airplane Directorate Airworthiness Concern Process guide for the potential condition is attached. At this time, the FAA has not made a determination as to what type of additional corrective action (if any) should be taken. The resolution of this airworthiness concern could involve an AD action or SAIB, or the FAA could determine that no further action is needed at this time. The FAA’s final determination will depend in part on the information received in response to this ACS. The FAA endorses dissemination of this technical information to all owners/operators and requests association and type club comments.
Attachments: *SDR(s) *A/IDS *SL(s) *SAIB *FAASR/*NTSBSR *AD *AMOC *RA
Notification: FAA *AOPA *EAA Type Club *TC Holder Other: NAAA
Response Requested __/__/__: Emergency (10 days) Alert (30 days) Information (90 days) (Space Bar Adds “X” to Check Boxes) *Service Difficulty Reports (SDRs); Accident/Incident Data System (A/IDS); Service Letter (SL); Special Airworthiness Information Bulletin (SAIB);
Federal Aviation Administration (FAA)/National Transportation Safety Board (NTSB) Safety Recommendation (FAASR/NTSBSR); Airworthiness Directive (AD); Alternate Method of Compliance (AMOC); Risk Assessment (RA); Aircraft Owners & Pilots Association (AOPA);
Experimental Aircraft Association (EAA); Type Certificate (TC)