Cessna 550 incident near State College, Pennsylvania, March 25, 1999
On March 25, 1999 at about 8:45 pm local time, a Cessna 550, registered N37MH, suffered minor damage in an incident near State College, Pennsylvania (University Park airport). It was a positioning flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
Improper assembly of the left main landing gear (LMLG) actuator by the airplane manufacturer, which resulted in an incorrect 'locked' indication on the LMLG switch, and the subsequent collapse of the LMLG during taxi.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 25, 1999 · about 8:45 pm local time
- Place
- State College, Pennsylvania · University Park · map
- Type
- Incident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 550 · all 550s on the register
- Registration
- N37MH · registry record · serial 550-0153
- Damage
- Minor damage
- Flight
- Positioning flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
When the airplane's left main gear actuator was removed for overhaul, a temporary replacement, provided by the airplane manufacturer, was installed. While taxing after landing, the airplane's left main landing gear collapsed. Disassembly of the actuator revealed the lock ring was installed upside-down. A radiograph view of taken of the lock piston and the ball bearing which operated the lock switch revealed the ball bearing was resting only 1/2 up the ramp on the lock piston; however, the downlock switch was found to indicate locked. Review of the actuator's maintenance records revealed it was repaired by the Cessna Wichita Citation Service Center, Wichita, Kansas, on February 7, 1999. During the repair, the actuator was dissembled and reassembled.
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: airline transport pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 10,500 hours in all; 1,300 in this make and model; 65 in the last 90 days; 19 in the last 30 days; 8,700 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 6,380 hours
- Last inspection: continuous airworthiness programme, March 1, 1999; 19 hours since
- Maximum gross weight: 13,500 lb
- Seats: 9
- Landing gear: retractable
- Engine: P&W JT-15D (turbofan); 0 hours total
The flight
- Departed from: AGC Pittsburgh PA at 8:20 pm
- Destination: UNV
- Flight plan: IFR
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 320° at 7 knots
- Visibility: 20 statute miles
- Sky: scat at 5,000 ft
- Temperature: 43°F (6°C), dew point 18°F (-8°C)
- Altimeter: 30.00 inHg
- Observation at 8:59 pm from UNV
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
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.