Schweizer 269C-1 accident near Chesterfield, Missouri, May 26, 2012
On May 26, 2012 at about 5:20 pm local time, a Schweizer 269C-1 (helicopter), registered N345MH, was substantially damaged in an accident during takeoff near Chesterfield, Missouri (Spirit Of St Louis airport). It was an instructional 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 undercharged and overcharged landing gear dampers, which allowed initiation of the ground resonance event from which the pilot was unable to recover due to his limited experience in helicopters. Contributing to the accident was the ineffective damper inspection conducted by the operator’s maintenance personnel and the improper overhaul procedure by the overhaul facility that resulted in overcharged dampers being provided to the operator. Also contributing was the lack of any final acceptance testing criteria for the dampers in the manufacturer’s overhaul procedure manual.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 26, 2012 · about 5:20 pm local time
- Place
- Chesterfield, Missouri · Spirit Of St Louis · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Schweizer 269C-1 · all 269C-1s on the register
- Registration
- N345MH · registry record · serial 0173
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that the helicopter started to shake as he increased power for takeoff on the solo instructional flight. He reduced engine power, but the oscillations became stronger and ultimately uncontrollable, resulting in substantial damage to the main and tail rotor blades, partial separation of the main rotor mast from the aft fuselage structure, and partial separation of the tail boom from the fuselage. The pilot shut down the engine and exited the helicopter. The pilot was receiving training for the addition of a helicopter rating and was operating the helicopter under the authority of a logbook solo endorsement. Postaccident testing revealed that all four landing gear dampers failed to meet the manufacturer’s specifications. The forward dampers were undercharged, while the aft dampers were overcharged. Maintenance records indicated that the aft dampers had been replaced with overhauled units about 1 month before the accident. The forward dampers had not been replaced. Maintenance procedures required periodic inspection of the landing gear dampers, and the operator stated that the inspection procedure was accomplished after installation of the overhauled dampers. A review of the overhaul procedure for the landing gear dampers revealed that the procedure did not provide for functional testing of the dampers following overhaul, which would have identified the out-of-specification condition before installation.
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
What happened, in order
- Ground resonance during takeoff defining event
The NTSB's findings
- cause Aircraft › Aircraft systems › Landing gear system › Main gear strut/axle/truck › Damaged/degraded
- factor Personnel issues › Task performance › Maintenance › Scheduled/routine maintenance › Maintenance personnel
- factor Organizational issues › Support/oversight/monitoring › Oversight › Oversight of personnel › Maintenance provider
- factor Organizational issues › Support/oversight/monitoring › Documentation/record keeping › Maintenance records › Manufacturer
- factor Aircraft › Aircraft systems › Landing gear system › Main gear strut/axle/truck › Incorrect service/maintenance
Pilot
- Certificate: airline transport pilot, flight instructor
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 4,200 hours
- Last inspection: 100-hour inspection, April 11, 2012; 62 hours since
- Maximum gross weight: 1,750 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming HIO-360-G1A (piston); 0 hours total
- Operator: My Sky LLC
The flight
- Departed from: SUS Chesterfield MO at 5:15 pm
- Destination: SUS Chesterfield MO
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: a few clouds at 4,000 ft
- Temperature: 90°F (32°C), dew point 70°F (21°C)
- Altimeter: 30.01 inHg
- Observation at 5:43 pm from SUS, 5 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight 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.