Mbb BO-105 accident near Billings, Montana, June 17, 2005
On June 17, 2005 at about 10:30 pm local time, a Mbb BO-105 (helicopter), registered N314MS, was substantially damaged in an accident near Billings, Montana. It was an other work-use 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 pilot's improper in-flight decision to continue a simulated engine-out autorotation after sensing an excessive descent rate at 100 feet above the ground. Factors include the excessive descent rate, variable winds, and a high density altitude.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 17, 2005 · about 10:30 pm local time
- Place
- Billings, Montana · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Mbb BO-105
- Registration
- N314MS · no longer on the register · serial S772
- Damage
- Substantial damage
- Flight
- Other work-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The instructor pilot had just finished giving the other pilot a proficiency check, and had then taken control of the aircraft so that he could perform some maneuvers for his own proficiency. He performed one simulated engine-out autorotation to a touchdown, and was completing his second, when the accident occurred. He initiated the autorotation from about 1,000 feet above the ground (agl), and began establishing a flare attitude at an altitude of 100 feet agl. At that time he noticed that the descent rate of the helicopter was excessive, but instead of adding power along with the increase in collective, he decided to continue the simulation of the power loss. Just prior to touchdown, the pilot established a landing attitude and used all of the available collective to cushion the landing. When the helicopter touched down, the descent rate was still greater than the pilot desired, and immediately after contacting the ground, the main rotor flexed downward and contacted the top of the tail boom. The pilot reported that there were no problems with the aircraft's flight controls or engine, but the variable wind had changed directions during the descent from 1,000 feet agl, and the aircraft was therefore landing with a tailwind. In addition, the pilot states that the density altitude was approximately 5,700 feet, which left little room for error. In his discussion with the NTSB, the pilot stated that under the conditions, he should have initiated a go-around when he sensed the excessive descent rate at 100 feet agl.
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
Flight instructor
- Certificate: flight instructor, commercial pilot
- Ratings: instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 2,730 hours in all; 177 in this make and model; 43 in the last 90 days; 24 in the last 30 days; 2,361 as pilot in command; 308 on instruments
- Last flight review: April 1, 2005
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Last inspection: approved inspection programme
- Maximum gross weight: 5,510 lb
- Seats: 4
- Landing gear: fixed
- Engine: Allison 250-C-20B (turboshaft); 0 hours total
The flight
- Departed from: KBIL Billings MT at 9:30 pm
- Destination: KBIL
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 73°F (23°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.
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.