Amateur-built MMII (MUST accident near Lantana, Florida, August 29, 2009
On August 29, 2009 at about 6:15 pm local time, a amateur-built MMII (MUST, registered N7798R, was substantially damaged in an accident during takeoff near Lantana, Florida (Palm Beach County Park Airport). It was an instructional 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
The delay by both pilots to abort the takeoff resulting in a runway overrun. Contributing to the accident was the unintentional forward movement of the pilot's seat resulting in interference with the control stick.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 29, 2009 · about 6:15 pm local time
- Place
- Lantana, Florida · Palm Beach County Park Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built MMII (MUST
- Registration
- N7798R · no longer on the register · serial 428R
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot stated that he completed the takeoff checklist and began the takeoff roll. The airplane accelerated, and at 75 to 80 miles-per-hour (mph) indicated, he attempted to rotate, but was unsuccessful because of what he thought was his seat restricting aft movement of the control stick. The certified flight instructor (CFI) attempted to move his control stick and was also unable. He (CFI) reduced the throttle and mixture controls, and both applied brake pressure. The airplane went off the end of the runway onto grass and came to rest with the nose landing gear collapsed. The CFI stated that, before takeoff, he confirmed freedom of the flight controls. During the takeoff roll when the airplane had reached 65 mph and the pilot had not begun to rotate he informed the pilot to “…lighten the nose….” The pilot acknowledged, and when at 85 mph, the CFI told the pilot to rotate. The pilot replied that he was trying. The CFI reported he attempted to rotate, applying aft elevator control, and he then felt metal on metal contact. Realizing that a control problem of unknown origin existed, he reduced the throttle and mixture controls, took control of the airplane, and asked the pilot to assist him on the brakes. He avoided the runway end lights and had the canopy released before contacting bushes at the edge of a lake. Both exited the airplane, and the pilot mentioned to him at that time that his seat had slid forward while turning onto the runway resulting in elevator control interference. Postaccident inspection of the airplane by a Federal Aviation Administration airworthiness inspector revealed the left seat was in the most forward position and the flight control stick was in contact with the seat. While in that position the elevator primary and secondary flight control surfaces were in positions corresponding to airplane nose-down input. The left seat was moved aft, and full elevator control authority was obtained. Further examination of the seat revealed the locking mechanism appeared to be operational; however, it was noted that the seat did not contain a cutout which allowed full aft movement of the control stick.
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
- Flight control sys malf/fail during takeoff defining event
- Attempted remediation/recovery during takeoff
- Runway excursion during takeoff (rejected takeoff)
The NTSB's findings
- cause Personnel issues › Action/decision › Action › Delayed action › Flight crew
- factor Aircraft › Aircraft structures › Fuselage › Seat/cargo attach fitting › Unintentional use/operation
Pilot
- Certificate: private
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 1,227 hours in all; 3 in this make and model; 3 in the last 30 days; 1,037 as pilot in command
- Last flight review: August 28, 2009
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: left
- Injury: no injuries
Other crew
- Certificate: airline transport pilot, flight instructor, commercial pilot, private, sport pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane single-engine; instructor: sport pilot; instrument: airplane; rotorcraft: glider; rotorcraft: helicopter
- Flight time: 11,700 hours in all; 16 in this make and model; 212 in the last 90 days
- Last flight review: February 7, 2009
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 194 hours
- Last inspection: condition inspection, January 1, 2009; 14 hours since
- Maximum gross weight: 1,750 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming IO-360-A1A (piston); 0 hours total
The flight
- Departed from: LNA Lantana FL at 7:18 pm
- Destination: LNA Lantana FL
- Flight plan: none
- Runway 15, 3,421 ft by 100 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 140° at 7 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 25,000 ft; scat at 3,700 ft
- Temperature: 90°F (32°C), dew point 73°F (23°C)
- Altimeter: 29.92 inHg
- Observation at 5:53 pm from KPBI, 5 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight 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.
