Johnson REVOLUTION MINI-500 accident near Shermans Dale, Pennsylvania, July 26, 1998
On July 26, 1998 at about 10:00 pm local time, a Johnson REVOLUTION MINI-500 (helicopter), an amateur-built aircraft,, registered N805JJ, was substantially damaged in an accident near Shermans Dale, Pennsylvania (Haunstein Ultralight Park 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
The builder/pilot's carburetor modification that did not allow for rapid fuel demand, which resulted in a loss of engine power of final approach.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 26, 1998 · about 10:00 pm local time
- Place
- Shermans Dale, Pennsylvania · Haunstein Ultralight Park · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Johnson REVOLUTION MINI-500 REVOLUTION, amateur-built
- Registration
- N805JJ · no longer on the register · serial 0236
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
After 45 minutes of flight, and on final approach, the engine lost power. The helicopter landed hard, the main rotor struck the tail boom, and the helicopter rolled over on its left side. Examination of the helicopter revealed fuel and oil were available, and the throttle linkage was intact. The pilot/owner had recently installed a Power Enhancement Package to the Rotax 582 UL DCDI engine, and adjusted the needle jets to produce suitable EGTs. Based on subsequent research, the pilot stated that engine problems could have occurred going from half, to full throttle rapidly because the main jet was too restrictive to allow enough fuel to pass through quickly. The NTSB database revealed 23 Mini-500 accidents in 1997 and 1998. Within that list, 11 involved a loss of engine power. The Rotax 582 operator's manual stated: ' Danger! This engine, by its design, is subject to sudden stoppage! Engine stoppage can result in crash landings. Such crash landings can lead to serious bodily injury or death. Never fly the aircraft equipped with this engine at locations, airspeeds, altitudes, or other circumstances from which a successful no-power landing cannot be made, after sudden engine stoppage.'
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: private
- Ratings: rotorcraft: helicopter
- Flight time: 129 hours in all; 52 in this make and model; 10 in the last 90 days
- Medical certificate: Class 3 (valid medical--no waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 52 hours
- Last inspection: annual inspection, July 12, 1998; 8 hours since
- Maximum gross weight: 840 lb
- Seats: 1
- Landing gear: fixed
- Engine: Rotax 582ULDCDI (piston); 0 hours total
The flight
- Departed from: NA Klingerstown PA at 9:30 pm
- Destination: 0PA2 PA
- Flight plan: none
- Runway 11, 500 ft by 100 ft
Weather at the time
- Light: daylight
- Wind: from 200° at 6 knots
- Visibility: 15 statute miles
- Sky: clear
- Temperature: 81°F (27°C), dew point 63°F (17°C)
- Altimeter: 30.00 inHg
- Observation at 9:50 pm from MDT, 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.