Amateur-built M-500A accident near Lakeland, Florida, April 20, 1998
On April 20, 1998 at about 4:30 pm local time, a amateur-built M-500A (helicopter), registered N105WB, was substantially damaged in an accident near Lakeland, Florida (Lakeland-Linder Regional airport). 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
a hex nut on the cyclic flight control pushrod bolt had backed off for undetermined reason(s) and allowed the bolt to become disconnected from the control yoke teeter block, resulting in a loss of cyclic control and subsequent roll over during an emergency landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 20, 1998 · about 4:30 pm local time
- Place
- Lakeland, Florida · Lakeland-Linder Regional · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built M-500A
- Registration
- N105WB · registry record · serial 0058
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot stated he was on base turn to final for a fly bye, when he experienced a 1 to 1 vertical vibration. He informed the tower that he was going to land, and started a deceleration. The helicopter veered to the right, and the pilot applied left antitorque pedal. The nose started to tuck down, then the helicopter collided with the ground and rolled over on its right side. Examination of the helicopter flight control system revealed a hex nut backed off the cyclic flight control push rod bolt, and the bolt became disconnected from the control yoke teeter block. This resulted in a loss of cyclic control.
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, private
- Ratings: single-engine land; rotorcraft: helicopter
- Flight time: 3,000 hours in all; 40 in this make and model; 28 in the last 90 days; 15 in the last 30 days; 2,400 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: frt
The aircraft
- Airframe total time: 108 hours
- Last inspection: annual inspection, November 1, 1997; 23 hours since
- Maximum gross weight: 885 lb
- Seats: 1
- Landing gear: fixed
- Engine: Rotax 582UL (piston); 0 hours total
The flight
- Departed from: LAL at 3:30 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 12 statute miles
- Sky: broken clouds at 2,500 ft; not recorded
- Temperature: 81°F (27°C), dew point 68°F (20°C)
- Altimeter: 29.00 inHg
- Observation at 3:56 pm from LAL
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.
Other NTSB records under N105WB the same tail number, which may have belonged to a different aircraft at the time
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.