# NTSB LAX97LA221: Staudaucher S300D, N540DH, Chandler, AZ, May 31, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 31, 1997, 07:15 local (14:15 UTC) - Place: Chandler, AZ - Coordinates: 33.32088, -111.820373 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.3209&lon=-111.8204&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 10, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 29818 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX97LA221 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29818/pdf - Page: https://openairdocs.org/ntsb/LAX97LA221 ## Probable cause The owner/pilot's decision to use automotive hardware, which had not been heat treated, and the practice of adding aluminum plates to the trailing edge of the aileron without rebalancing the flight controls, which resulted in the separation of the aileron at the attachment fitting. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, maneuvering - miscellaneous,bolt/nut/fastener/clamp/spring - unapproved part (cause) - maintenance,installation - improper, owner/pilot mechanic (cause) - flight control,aileron attachment - separation (cause) - maintenance,inspection - inadequate, owner/pilot mechanic (contributing factor) ## Analysis During practice aerobic maneuvers, the pilot heard a loud bang and noticed that the right aileron had departed the aircraft. The pilot stated that the separation occurred during a 9-G pull from horizontal to a 45-degree nose high angle. A postaccident examination of the aircraft and aileron revealed that the aileron attach points were fabricated with automotive hardware welded to plates which had received no heat treatment. Shim plates were found under the attach brackets. Additionally, the aileron had been modified with an addition of aluminum plates to the trailing edge of the aileron without rebalancing the flight controls. The kit manufacturer said the pilot had found the two nuts which hold the aileron hinge to the aileron loose on several previous occasions. The examination revealed that there were signs of slippage and wear at the right center attach point where the shim plates were inserted. ## Factual narrative On May 31, 1997, at 0715 hours mountain standard time, a Staudacher S300D, N540DH, had the right aileron separate during an in-flight aerobatic maneuver 5 miles south of Chandler, Arizona. The aircraft, registered to and operated by the owner/builder, sustained substantial damage when the aileron struck the horizontal stabilizer and bent it's spar. The certificated commercial pilot was not injured. Visual meteorological conditions prevailed and a flight plan was not filed. The flight originated in Chandler at 0700. The Safety Board was notified of the extent of damage on June 24, 1997. An FAA airworthiness inspector determined that the aileron attach points were fabricated with "automotive hardware welded to plates, receiving no further heat treatment, and then embedded in the aileron spar." Additionally, the aileron had been modified six flights previously with an addition of an aluminum plate to the trailing edge without rebalancing the flight controls. The inspector reported that the owner commonly attempted to improve the aircraft's flight characteristics by moving the aileron fore and aft with shim plates under the attach brackets. According to the FAA inspector, the parts showed signs of slippage and wear at the right center attach point where the shim plates were inserted. According to the kit manufacturer, there are approximately 20 airplanes in service with this type of aileron attach fittings. The kit manufacturer has initiated a modification to the aileron attach fittings and the ailerons to remove the subject fabricated plate and bolt fittings. The kit manufacturer stated that all 20 airplanes in service will receive the modified ailerons and fittings. The owner reported to the kit manufacturer that the "two nuts that hold the aileron hinge to the aileron at the hinge that failed were found loose on several occasions." ## Aircraft - Registration: N540DH (not matched to a registry record) - Reported make and model: Staudaucher S300D - Category: Airplane, amateur-built - Serial number: 20 - Engines: Lycoming O-540 540 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Diane L. Hakala - Airworthiness certificate: Special, Experimental (Special) - Departed: CHD, AZ ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 42; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 1,823 total, 460 in this make and model, 1,400 as pilot in command, 104 in the last 90 days, 56 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 30 statute miles - Lowest ceiling: none - Temperature: 75 °F - Altimeter: 29.00 inHg ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19970531020019A](https://openairdocs.org/incident/19970531020019A), May 31, 1997: Inland S300, Chandler, AZ, Substantial damage. Right aileron seperated. Struck horizontal stabilizer bending spar. Used bogus parts on aileron modifications. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.