Hughes TH-55A accident near Savannah, Georgia, July 31, 1998
On July 31, 1998 at about 1:30 pm local time, a Hughes TH-55A (helicopter), registered N998MC, was destroyed in an accident near Savannah, Georgia. It was a public-use 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).
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The NTSB's probable cause their words, unchanged
The loss of engine power for an undetermined reason, resulting in a forced landing, and an in-flight collision with a ditch. A factor in this accident was a high density altitude.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 31, 1998 · about 1:30 pm local time
- Place
- Savannah, Georgia · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Hughes TH-55A · all TH-55As on the register
- Registration
- N998MC · registry record · serial 6618306
- Damage
- Destroyed
- Flight
- Public-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
According to the pilot this was the second flight on that day. The first flight lasted 1.3 hours with 'no discrepancies noted.' The pilot said the second flight was 'normal' for the first 1/2 hour of flight. He completed five passes, and on the last pass at 40 feet above ground level [field elevation 25 feet msl], with right hand quartering headwind, he reported, '...an engine partial power loss.' He said the '...symptoms were main rotor started to droop below 490 RPM (2900 engine RPM).' He lowered the collective, rolled in full throttle, and raised the collective to stop the decent. He said the rotor RPM 'continued to droop.' The pilot tried to maneuver the helicopter past trees, and a mound of dirt to a flat area on the far side of a ditch. He could not maintain enough altitude or rotor RPM to clear the ditch, and contacted the far side of ditch with the left side of the helicopter. The pilot told investigators, that the helicopter was functioning properly before the accident, and he had no explanation for the loss of rotor RPM. An engine run revealed no discrepancies. A compression check, while the engine was hot, reveled low compression on cylinders No. 1 and 3. Both cylinders were removed, and both cylinders were found to have exhaust valves that were not seated completely. The calculated density altitude, based on a temperature of 31 degrees C (88F), altitude 65 feet msl, and an altimeter setting of 30.05 inches of mercury, all obtained from the Savannah 0953 weather observation, was 1868 feet. The pilot stated that the weight of the helicopter was '...1590 [pounds] at the time of the accident.' The maximum gross weight of the helicopter was 1670 pounds.
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: single-engine land; rotorcraft: helicopter
- Flight time: 2,052 hours in all; 1,050 in this make and model; 2,052 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 5,447 hours
- Last inspection: 100-hour inspection, May 4, 1998; 29 hours since
- Maximum gross weight: 1,670 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming HIO-360-B1H (piston); 0 hours total
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 270° at 7 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 88°F (31°C), dew point 73°F (23°C)
- Altimeter: 30.00 inHg
- Observation at 1:53 pm from SAV
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.
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number MIA98TA215.