Amateur-built REVOLUTION MINI 500 accident near Northampton, Pennsylvania, August 11, 1998
On August 11, 1998 at about 10:32 pm local time, a amateur-built REVOLUTION MINI 500 (helicopter), registered N2XK, was destroyed in an accident near Northampton, Pennsylvania. It was a personal 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
the improper maintenance adjustment and the failure to properly torque the pitch-change link barrel by the owner/builder which resulted in main rotor to tailboom contact and main rotor separation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 11, 1998 · about 10:32 pm local time
- Place
- Northampton, Pennsylvania · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built REVOLUTION MINI 500 REVOLUTION
- Registration
- N2XK · no longer on the register · serial 303
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot departed his home in the home-built helicopter on a maintenance test flight. The purpose of the flight was to track the main rotor system after repair and re-assembly of the helicopter. The main transmission, transmission mast, main rotor system, and tailboom and associated components had been replaced following a rollover accident. The pilot changed the blade track by adjustment of the pitch change links during ground runs prior to takeoff. Witnesses to the accident reported unusual sounds from the helicopter before two sharp reports and an uncontrolled descent. One main rotor blade was found 400 feet from the main wreckage. Examination of the wreckage revealed rotor to tailboom contact. Fracture separation of one rotor blade and fracture of the pitch horn on the same side were due to overload. The pitch change link barrel was loose on the fractured horn with no torque applied to the barrel nuts.
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; single-engine sea; instrument: airplane; rotorcraft: helicopter
- Flight time: 1,440 hours in all; 55 in this make and model; 1,222 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 55 hours
- Last inspection: annual inspection, February 2, 1998; 35 hours since
- Maximum gross weight: 840 lb
- Seats: 1
- Landing gear: fixed
- Engine: Rotax 582 (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: NONE Bangor PA at 10:00 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 270° at 7 knots
- Visibility: 10 statute miles
- Sky: scat at 3,000 ft
- Temperature: 81°F (27°C), dew point 63°F (17°C)
- Altimeter: 29.00 inHg
- Observation at 10:51 pm from ABE, 15 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.