Amateur-built S300D accident near Chandler, Arizona, May 31, 1997
On May 31, 1997 at about 2:15 pm local time, a amateur-built S300D, registered N540DH, was substantially damaged in an accident near Chandler, Arizona. It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
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.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 31, 1997 · about 2:15 pm local time
- Place
- Chandler, Arizona · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built S300D
- Registration
- N540DH · no longer on the register · serial 20
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; instrument: airplane
- Flight time: 1,823 hours in all; 460 in this make and model; 104 in the last 90 days; 56 in the last 30 days; 1,400 as pilot in command; 244 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: ctr
The aircraft
- Last inspection: annual inspection
- Maximum gross weight: 1,700 lb
- Seats: 1
- Landing gear: fixed
- Engine: Lycoming O-540 (piston); 0 hours total
The flight
- Departed from: CHD AZ at 2:00 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 30 statute miles
- Sky: clear
- Temperature: 75°F (24°C), dew point 0°F (-18°C)
- Altimeter: 29.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.