Raytheon CO COBRA incident near Whetstone, Arizona, August 24, 2007
On August 24, 2007 at about 7:28 pm local time, a Raytheon CO COBRA, registered N605RN, was substantially damaged in an incident near Whetstone, Arizona. It was an instructional flight under general aviation rules (Part 91). No one was hurt; 3 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The student pilot's failure to follow proper procedures, specifically not verifying that the mode switch was in the automatic position before changing the pilot address, which resulted in a loss of aircraft control. Contributing to the accident was the flight instructor's inadequate supervision of the student pilot.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 24, 2007 · about 7:28 pm local time
- Place
- Whetstone, Arizona · map
- Type
- Incident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Raytheon CO COBRA
- Registration
- N605RN · no longer on the register · serial 005
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
Note: This case was reclassified from an accident to an incident as a result of applicable revisions to 49 Code of Federal Regulations Part 830.2, as amended at 75 FR 51955, Aug. 24, 2010. The case was previously identified under accident number SEA07LA237. The unmanned aircraft system (UAS) was operating at a private airstrip used for UAS testing. The operation involved a ground-based flight crew of three pilots: a flight instructor, a student pilot, and a supplemental pilot. Additionally, an observer was present. The student pilot, who was being supervised by the flight instructor, was controlling the aircraft using the Pilot Console, which is a computer-based interface. Alternatively, the aircraft can be controlled through a Manual Pilot Console. While the accident aircraft was orbiting on autopilot, the Manual Pilot Console was used to control another aircraft that was involved in ground testing. In order to control the other aircraft using the Manual Pilot Console, the pilot address of that specific aircraft was entered using the Pilot Console. Also, the mode switch on the Manual Pilot Console, which switches between automatic and manual aircraft control, was placed in the manual position. Following the ground testing, the Manual Pilot Console was placed on a table with the switch still in the manual position and the pilot address still set for the other aircraft. All evaluations were completed, and the accident aircraft was readied for landing due to low fuel and approaching rain. Using the Pilot Console, the student pilot initiated the automatic landing sequence. The flight instructor's attention was distracted from the primary flight display by a request from the observer. Meanwhile, the student pilot noticed that the pilot address for the Manual Pilot Console was still on the address of the other aircraft. Without verifying that the mode switch was in the automatic position, he changed the pilot address to the address of the accident aircraft. Changing the address with the mode switch in manual position resulted in a disconnect of the accident aircraft's autopilot. Before the supplemental pilot could pick up the Manual Pilot Console and assume control, the aircraft, now in manual mode with the autopilot disconnected, rolled to the left, entered a vertical dive, and impacted the ground. As a result of the accident, the operator incorporated a software/hardware fail-safe making it impossible to change the pilot address for the Manual Pilot Console if the mode switch is in the manual position. The switch must now be moved to the automatic position prior to making the pilot address change.
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: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane; rotorcraft: glider; rotorcraft: helicopter
- Flight time: 1,936 hours in all; 1,162 in this make and model; 26 in the last 90 days; 8 in the last 30 days; 1,713 as pilot in command; 27 on instruments
- Last flight review: August 1, 2006
- Medical certificate: Class 2 (with waivers/limitations)
- Injury: no injuries
Dual student
- Certificate: flight instructor, commercial pilot
- Ratings: single-engine land; instructor: airplane single-engine; instructor: glider; instrument: airplane; rotorcraft: glider
- Flight time: 3,500 hours in all; 4 in this make and model; 40 in the last 90 days; 9 in the last 30 days; 3,200 as pilot in command; 800 on instruments
- Last flight review: June 1, 2006
- Medical certificate: Class 2 (with waivers/limitations)
- Injury: no injuries
The aircraft
- Airframe total time: 15 hours
- Last inspection: condition inspection, February 1, 2007
- Maximum gross weight: 105 lb
- Landing gear: fixed
- Engine: Aero Engines DA-150 (piston); 0 hours total
The flight
- Departed from: Whetstone AZ at 6:05 pm
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 30 statute miles
- Sky: scat at 5,000 ft
- Temperature: 91°F (33°C), dew point 59°F (15°C)
- Altimeter: 30.04 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 3 |
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.