Enstrom F28A accident near Pleasanton, California, July 24, 1998
On July 24, 1998 at about 2:00 am local time, a Enstrom F28A (helicopter), registered N288Q, was substantially damaged in an accident near Pleasanton, California. 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 flight instructor's delayed remedial action and the student pilot's failure to maintain rotor RPM. A factor was the downhill terrain.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 24, 1998 · about 2:00 am local time
- Place
- Pleasanton, California · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Enstrom F28A · all F28As on the register
- Registration
- N288Q · no longer on the register · serial 298
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The dual student performed an off-airport pinnacle landing. The CFI stated that the helicopter began to vibrate and moved sideways so he rolled on power. By the time the helicopter reached the edge of the landing area, the rpm had decreased and he could not reposition the aircraft. The CFI reported that he pedal-turned so that the tail was pointing downhill, lowered the collective, and rolled off the throttle. The helicopter slid approximately 300 feet off the top of the hill and down a 30-degree slope. The main rotor blades contacted the ground but the aircraft remained upright. The CFI reported that there were no mechanical malfunctions with the aircraft prior to the accident.
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: airline transport pilot, commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: helicopter; instructor: instrument airplane; instructor: instrument helicopter; instrument: helicopter; rotorcraft: glider; rotorcraft: helicopter
- Flight time: 5,885 hours in all; 36 in this make and model; 40 in the last 90 days; 13 in the last 30 days; 2,465 as pilot in command; 3,016 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 1,088 hours
- Last inspection: annual inspection, May 4, 1997; 3 hours since
- Maximum gross weight: 2,150 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming HIO-360-CIA (piston); 0 hours total
The flight
- Departed from: RHV San Jose CA at 1:30 am
- Destination: LVK Livermore CA
- Flight plan: none
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 280° at 13 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 72°F (22°C), dew point 57°F (14°C)
- Altimeter: 29.00 inHg
- Observation at 1:53 am from LVK
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| 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.