Mitsubishi MU-2B-35 accident near Hilton Head, South Carolina, August 1, 2001
On August 1, 2001 at about 11:51 am local time, a Mitsubishi MU-2B-35, registered N1VY, was destroyed in an accident near Hilton Head, South Carolina (Hilton Head airport). It was a positioning flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
Improper maintenance/installation and and inadequate inspection of the airplane's flap torque tube joints during routine maintenance by company maintenance personnel, which resulted in the right flap torque tube assembly coupler becoming detached and the flaps developing asymmetrical lift when extended, which resulted in an uncontrolled roll, a descent, and an impact with a tree during approach to land.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 1, 2001 · about 11:51 am local time
- Place
- Hilton Head, South Carolina · Hilton Head · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Mitsubishi MU-2B-35 · all MU-2B-35s on the register
- Registration
- N1VY · no longer on the register · serial 567
- Damage
- Destroyed
- Flight
- Positioning flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The airplane was on final approach to land at Hilton Head Airport, when according to witnesses, it suddenly rolled to the right, and descended, initially impacting trees at about the 70-foot level, and then impacting the ground. A fire then ensued upon ground impact, and the debris field spanned about 370 feet along an azimuth of about 082 degrees. Examination of the airplane wreckage revealed that left wing flap actuator and jack nut measurements were consistent with the wing flaps being extended to 40 degrees, and on the right wing the flap jack nut and actuator measurements were consistent with the right flap being extended to about a 20-degrees. In addition, the right flap torque tube assembly between the flap motor and the flap stop assembly had disconnected, and the flap torque tube assembly's female coupler which attaches to the male spline end of the flap motor and flap stop assembly was found with a cotter pin installed through the female coupler of the flap stop assembly. The cotter pin, had not been placed through the spline and the coupler consistent with normal installation as per Mitsubishi's maintenance manual, or as specified in Airworthiness Directive 88-23-01. Instead, the cotter pin had missed the male spline on the flap motor. In addition, the flap coupler on the opposite side of the flap motor was found to also found to not have a cotter pin installed. Company maintenance records showed that on April 3, 2001, about 87 flight hours before the accident, the airplane was inspected per Airworthiness Directive (AD) 88-23-01, which required the disassembly, inspection, and reassembly of the flap torque tube joints. In addition, on July 9, 2001, the airplane was given a phase 1 inspection, and Bankair records showed that a company authorized maintenance person performed the applicable maintenance items, and certified the airplane for return to service.
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: multi-engine land; single-engine land; instrument: helicopter; rotorcraft: helicopter
- Flight time: 4,184 hours in all; 483 in this make and model; 114 in the last 90 days; 46 in the last 30 days
- Last flight review: March 2, 2001
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
- Injury: fatal
The aircraft
- Airframe total time: 11,612.7 hours
- Last inspection: approved inspection programme, July 9, 2001; 21.3 hours since
- Maximum gross weight: 10,800 lb
- Seats: 8
- Landing gear: retractable
- Engine 1: Garrett TPE331-6-252M (turboprop); 0 hours total
- Engine 2: Garrett TPE331-6-252M (turboprop); 0 hours total
- Fire on the ground
The flight
- Departed from: SAV Savannah GA at 11:41 am
- Destination: HXD Hilton Head SC
- Flight plan: IFR
- Runway 3, 4,300 ft by 75 ft
Weather at the time
- Light: daylight
- Wind: from 040° at 9 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 2,500 ft
- Temperature: 73°F (23°C), dew point 68°F (20°C)
- Altimeter: 30.23 inHg
- Observation at 11:53 am from SAV, 26 miles away
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.