Boeing 369E accident near Mesa, Arizona, September 24, 1998
On September 24, 1998 at about 10:40 pm local time, a Boeing 369E (helicopter), registered N685F, was substantially damaged in an accident near Mesa, Arizona (Falcon Field). 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
A hard landing caused by the pilot's improper flare during a simulated autorotatative landing. A factor in the accident was the soft wet sod landing area.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 24, 1998 · about 10:40 pm local time
- Place
- Mesa, Arizona · Falcon Field · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Boeing 369E
- Registration
- N685F · no longer on the register · serial 0512E
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The instructor pilot and his student were practicing autorotations to a turf area, which was wet and soft. The instructor pilot demonstrated a 180-degree autorotation, which he said appeared to finish with a normal deceleration flare and touchdown. After touchdown the instructor pilot stated he heard a loud rattling sound coming from the tailboom. The aircraft was examined and found that during the autorotation, the tailrotor blades had hit the ground causing damage to the tail rotor blades and tailboom, and it had severed the tail rotor driveshaft. Ground witnesses said the helicopter hit the ground harder than normal.
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: flight instructor, commercial pilot
- Ratings: instructor: helicopter; rotorcraft: helicopter
- Flight time: 2,082 hours in all; 167 in this make and model; 97 in the last 90 days; 37 in the last 30 days; 2,049 as pilot in command; 1,480 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 3,245 hours
- Last inspection: annual inspection, June 23, 1998; 74 hours since
- Maximum gross weight: 3,000 lb
- Seats: 4
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
The flight
- Departed from: FFZ Falcon Field AZ at 10:00 pm
- Flight plan: none
- Runway 0, 300 ft by 75 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 290° at 5 knots
- Visibility: 50 statute miles
- Sky: clear
- Temperature: 91°F (33°C), dew point 0°F (-18°C)
- Altimeter: 29.00 inHg
- Observation at 10:48 pm from FFZ
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.