- Date
- July 23, 1998, 19:00 local (Jul 24, 1998, 02:00 UTC)
- Place
- Pleasanton, CA
- Injuries
- 2 uninjured
- Damage
- Substantial damage
- Phase of flight
- Landing
- Aircraft
- N288QEnstrom F28A
- Weather
- Visual (VMC) · Day
- Status
- Completed · report March 30, 2000
- Report
- Approved by Office Director
- FAA report
- 19980723017639A
- Case key
- 43554
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The flight instructor's delayed remedial action and the student pilot's failure to maintain rotor RPM. A factor was the downhill terrain.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
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.
Factual narrative
On July 23, 1998, at 1900 hours Pacific daylight time, an Enstrom F28A, N288Q, overshot the intended landing area and slid down a 30-degree hillside near Pleasanton, California. The aircraft sustained substantial damage. The certified flight instructor and dual student/owner, the sole occupants, were not injured. The local instructional flight last departed the Reid-Hillview Airport in San Jose, California, at 1830, and was en route to Livermore, California. Visual meteorological conditions prevailed and no flight plan was filed.
The certified flight instructor (CFI) reported that he and the student were practicing off-airport landings. The student performed a pinnacle approach and landing. The CFI stated that the helicopter started to vibrate and move sideways so he rolled on power. By the time the helicopter reached the edge of the landing area, the rpm had decreased. The CFI reported that he was not able to reposition the helicopter to a higher area, so he pedal-turned to put the tail 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.
Aircraft
- Registration
- N288Q
- Reported as
- Enstrom F28A
- Category
- Helicopter
- Serial number
- 298
- Airframe hours
- 1,088
- Engine
- Lycoming HIO-360-CIA, 205 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Instructional · Part 91
- Operator
- William Mohler, doing business as Los Gatos Construction Co. Inc
- Registered owner
- Los Gatos Construction Co. Inc
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · May 4, 1997 · 3 hours before
- Departed
- RHV · San Jose, CA
- Destination
- LVK · Livermore, CA
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 59
- Certificates
- Airline transport, Commercial
- Airplane ratings
- Single-engine land, Single-engine sea, Multi-engine land
- Instrument ratings
- Helicopter
- Medical
- Class 2, Valid Medical--w/ waivers/lim
- Seat
- Left
- Flight hours
- 5,885 total · 36 in this make and model · 2,465 as pilot in command · 40 in the last 90 days · 13 in the last 30 days · 2 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 280° at 13 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 72 °F, dew point 57 °F
- Altimeter
- 29.00 inHg
- Observed at
- LVK
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.