Sikorsky CH-54B accident near Corvallis, Oregon, April 7, 2009
On April 7, 2009 at about 10:30 pm local time, a Sikorsky CH-54B (helicopter), registered N719HT, was substantially damaged in an accident during standing (engine(s) operating) near Corvallis, Oregon (Corvallis Municipal airport). 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 improper assembly of main rotor blade control components by the operator's maintenance personnel, which resulted in the main rotor blade's divergent path and their contact with the tail rotor drive shaft during ground operation following landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 7, 2009 · about 10:30 pm local time
- Place
- Corvallis, Oregon · Corvallis Municipal · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Sikorsky CH-54B
- Registration
- N719HT · registry record · serial 69-18469
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot and certified flight instructor departed for a local area instructional flight during which the pilot practiced a series of takeoffs and landings. During ground operations, the crew stated that they felt an unusual vibration, which was partially mitigated by keeping the collective pitch raised about 2 inches from the full down position. The pilot reported that he decided to adjust his seat position so he landed and handed off the controls to the certified flight instructor (CFI). The CFI lowered the collective to the full down position in preparation for the seat adjustment operation. At this time he noticed a vibration, which was followed by a loud "bang." The subsequent helicopter examination revealed that two of the six main rotor blades had diverged from their normal plane of rotation and impacted the tail rotor drive system, resulting in the number 5 and 6 tail rotor drive shaft sections separating from the helicopter. The investigation and examination of the helicopter found that during maintenance performed at an undetermined date by the operator's mechanics, the bell cranks that connect to the main rotor blades' control rods had been incorrectly installed in a reversed manner. This allowed the swash plate to travel outside of its designed range.
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
What happened, in order
- Aircraft maintenance event during prior to flight
- Miscellaneous/other during standing (engine(s) operating) defining event
The NTSB's findings
- cause Personnel issues › Action/decision › Action › Incorrect action performance › Maintenance personnel
- cause Aircraft › Aircraft handling/service › Maintenance/inspections › (general) › Incorrect service/maintenance
- cause Aircraft › Aircraft propeller/rotor › Main rotor system › (general) › Incorrect service/maintenance
Flight instructor
- Certificate: airline transport pilot, flight instructor
- 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: airplane; instrument: helicopter; rotorcraft: glider; rotorcraft: helicopter
- Flight time: 19,000 hours in all; 1,100 in this make and model; 50 in the last 90 days; 15 in the last 30 days; 18,700 as pilot in command; 13,500 on instruments
- Last flight review: September 17, 2008
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: no injuries
Co-pilot
- Certificate: flight instructor, commercial pilot
- Ratings: single-engine land; instructor: helicopter; instructor: instrument helicopter; rotorcraft: helicopter
- Flight time: 2,982 hours in all; 1,100 in this make and model; 180 in the last 90 days; 60 in the last 30 days; 2,356 as pilot in command; 298 on instruments
- Last flight review: October 17, 2008
- Medical certificate: Class 1
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 5,365 hours
- Last inspection: approved inspection programme, March 1, 2009; 12 hours since
- Maximum gross weight: 47,000 lb
- Seats: 3
- Landing gear: fixed
- Engine 1: P & W JFTD12A-5A (turboshaft); 0 hours total
- Engine 2: P & W JFTD12A-5A (turboshaft); 0 hours total
- Operator: Helicopter Transport Services, Inc.
The flight
- Departed from: Corvallis OR at 10:00 pm
- Destination: Corvallis OR
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 120° at 8 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 66°F (19°C), dew point 48°F (9°C)
- Altimeter: 29.76 inHg
- Observation at 9:55 pm from CVO
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight 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.