Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Whetstone, Arizona 85616
Friday, August 24, 2007 12:28 MST
NTSB Narrative Summary Released at Completion of Accident
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.
NTSB Probable Cause Narrative
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.
Event Information
| Type of Event | Incident |
| Event Date | 8/24/2007 |
| Event Day of the Week | Friday |
| Time of Event | 1228 |
| Event Time Zone | Mountain Standard Time |
| Event City | Whetstone |
| Event State | ARIZONA |
| Event Country | -- |
| Zipcode of the event site | 85616 |
| Event Date Year | 2007 |
| Event Date Month | 8 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 314343N |
| Event Location Longitude | 1101709W |
| Event Location Airport | -- |
| Event Location Nearest Airport ID | -- |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Pilot |
| Time of the weather observation | |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | -- |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | -- |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | 5000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 30 |
| Air Temperature at event time (in degrees celsius) | 33 |
| Dew Point at event time (in degress fahrenheit) | 15 |
| Wind Direction (degrees magnetic) | -- |
| Variable Wind Indicator | Variable |
| Wind Speed (knots) | -- |
| Wind Velocity Indicator | Light and Variable |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.05 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 3 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 22792 |
| NTSB Notification Source | FAA ROC |
| NTSB Notification Date | Aug 24 2007 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Feb 22 2011 8:54AM |
| User who most recently changed record | broda |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Scottsdale, AZ |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N605RN |
| NTSB Number | SEA07IA237 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | RAYTHEON CO |
| Aircraft Model | COBRA |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 005 |
| Certified Max Gross Weight | 105 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | -- |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Conditional |
| Date of Last Inspection | Feb 1 2007 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | 15 |
| ELT Installed | No |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | Raytheon Co |
| Aircraft Owner Street Address | PO box 11337 |
| Aircraft Owner City | Tucson |
| Aircraft Owner State | AZ |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 85734 |
| Operator is an individual? | No |
| Operator Name | -- |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | -- |
| Operator State | -- |
| Operator Country | -- |
| Operator Zip code | -- |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | -- |
| Certified for Part 133 or 137 Operation | -- |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | -- |
| Indicates Domestic or International Flight | -- |
| Operator carrying Pax/Cargo/Mail | -- |
| Type of Flying (Per_Bus / Primary) | Instructional |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | Yes |
| Departure Airport Code | -- |
| Departure City | Whetstone |
| Departure State | AZ |
| Departure Country | USA |
| Departure Time | 1105 |
| Departure Time Zone | MST |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | -- |
| Destination City | -- |
| Destination State | -- |
| Destination Country | -- |
| Specific Phase of Flight | Approach |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jul 1 2014 9:14AM |
| User who most recently changed record | broda |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |