MD Helicopter 900 accident near Fredonia, Arizona, October 16, 2003
On October 16, 2003 at about 11:50 pm local time, a MD Helicopter 900, registered N179PA, was substantially damaged in an accident near Fredonia, Arizona (Bear Dip Landing Zone airport). It was a public-use flight under public-use (government) rules. No one was hurt; 5 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
the pilot's in-flight loss of control due to the fatigue fracture and separation of the force limiting control rod (an integral part of the anti-torque system), which resulted in the helicopter's uncommanded yaw/spin and subsequent collision with terrain.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 16, 2003 · about 11:50 pm local time
- Place
- Fredonia, Arizona · Bear Dip Landing Zone · map
- Type
- Accident
- Injuries
- No one was hurt; 5 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- MD Helicopter 900
- Registration
- N179PA · registry record · serial 900-00021
- Damage
- Substantial damage
- Flight
- Public-use flight · public-use (government) rules
The NTSB's narrative final · quoted from the NTSB record
As the NOTAR (No Tail Rotor) helicopter entered a normal descent for landing, the pilot experienced a loss of control following the failure of the anti-torque system. The helicopter entered an uncommanded and uncontrollable right spin as it descended to ground impact. During the approach, and after passing over a group of trees, while the helicopter was about 15 to 30 feet above ground level (agl) and 60 feet from the intended touchdown location, the helicopter began a rapid, uncommanded right yaw. The pilot input full left pedal pressure in an effort to stop the rotation. Despite his attempts, the pilot's control inputs had no effect on the spin rate. The pilot retarded the left engine throttle, and maneuvered the helicopter away from the trees as it continued to descend. Upon touchdown, the helicopter rolled on its left side, and the main rotor blades impacted terrain. The helicopter's NOTAR anti-torque yaw control system utilizes a transmission driven fan with variable pitch blades to supply air to circulation control slots on the tail boom and a pilot-controlled directional jet thruster nozzle. Movement of the anti-torque control pedals changes the fan blade pitch to produce more airflow to the circulation control slots and the anti-torque thruster nozzle. As the pedals are displaced from center toward either extreme of travel, the airflow increases proportionally. During post-accident examination of the NOTAR control system, a fracture and separation was found in the force limiting control rod. With the rod assembly disconnected, the NOTAR fan blades assume a neutral pitch, preventing a sufficient volume of air in the tail boom to provide anti-torque control and maintain a heading. The helicopter had previous mechanical problems with the rod assembly and it was replaced about 779 hours prior to the accident. Using a scanning electron microscope, an examination of the fracture surface revealed that the rod separated due to a fatigue crack originating from the base of the thread roots, and final tension overload. There was no evidence of damage sites, foreign material inclusions, or other potential fracture initiating conditions.
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: single-engine land; instructor: helicopter; rotorcraft: helicopter
- Flight time: 10,032 hours in all; 547 in this make and model; 121 in the last 90 days; 36 in the last 30 days
- Last flight review: January 1, 2003
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 2,761 hours
- Last inspection: 100-hour inspection, September 29, 2003; 41.5 hours since
- Maximum gross weight: 6,250 lb
- Seats: 10
- Landing gear: fixed
- Engine 1: Pratt & Whitney 206E (turboshaft); 0 hours total
- Engine 2: Pratt & Whitney 206 (turboshaft); 0 hours total
The flight
- Departed from: North Rim AZ at 11:10 pm
- Destination: Fredonia AZ
- Flight plan: VFR
Weather at the time
- Light: daylight
- Wind: from 220° at 6 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 72°F (22°C), dew point 18°F (-8°C)
- Altimeter: 30.36 inHg
- Observation at 11:53 pm from GCN, 25 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 4 |
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.