Individually Owned: 150,657
Corporate Owned: 137,281
Butts Army Airfield Airport
Aircraft Accident/Incident Report
Fort Carson, Colorado 80926
Wednesday, January 29, 2014 14:32 MST
NTSB Narrative Summary Released at Completion of Accident
According to air traffic control (ATC) audio recordings, a tower controller cleared an airplane for takeoff about 23 seconds after a UH-60 helicopter was cleared for takeoff from a midfield location. The tower controller ensured that a runway separation standard of 3,000 feet was present and did not give a wake turbulence advisory. The flight instructor reported that she was aware of the helicopter’s takeoff and that she perceived adequate separation from the helicopter. The flight instructor incorrectly identified the helicopter as a Bell UH-1, which weighs less than the UH-60. Shortly after takeoff, the airplane encountered the wake vortex of the helicopter and entered a steep left bank. The flight instructor attempted to counteract the left roll with full right aileron inputs, but she was unable to maintain control. The airplane impacted terrain near midfield and came to rest inverted. A review of ATC audio recordings and airplane performance data revealed that the airplane trailed the helicopter by about 48 to 63 seconds at the midfield location and was about 150 to 200 feet above ground level when it encountered the helicopter’s wake vortex.
Current Federal Aviation Administration (FAA) ATC guidance does not require specific wake turbulence separation criteria for a small airplane following a helicopter nor does it require a controller to give a wake turbulence advisory for a small airplane following a helicopter. Current FAA pilot guidance, including the Airman’s Information Manual and an advisory circular on aircraft wake turbulence, also do not recommend separation criteria for a small airplane following a helicopter. After the accident, the FAA issued amended guidance for wake turbulence hazards to pilots and air traffic controllers, including specific wake turbulence separation criteria between small airplanes and helicopters.
NTSB Probable Cause Narrative
The flight instructor’s loss of control after takeoff following a wake turbulence encounter from a preceding helicopter. Contributing to the accident were the flight instructor’s misidentification of the helicopter type and a lack of Federal Aviation Administration wake turbulence separation criteria for a small airplane following a helicopter.
Event Information
| Type of Event | Accident |
| Event Date | 1/29/2014 |
| Event Day of the Week | Wednesday |
| Time of Event | 1432 |
| Event Time Zone | Mountain Standard Time |
| Event City | Fort Carson |
| Event State | COLORADO |
| Event Country | -- |
| Zipcode of the event site | 80926 |
| Event Date Year | 2014 |
| Event Date Month | 1 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 384043N |
| Event Location Longitude | 1044518W |
| Event Location Airport | Butts Army Airfield |
| Event Location Nearest Airport ID | KFCS |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | 0 |
| Degrees magnetic from airport | 360 |
| Airport Elevation | 5838 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1458 Mountain Standard Time |
| Direction of event from weather observation facility (degrees) | 140 |
| Weather Observation Facility ID | KFCS |
| Elevation of weather observation facility | 5838 |
| Distance of event from weather observation facility (units?) | 1 |
| Time Zone of the weather observation | MST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 17000 |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | -- |
| Sky Condition for Lowest Ceiling | Broken |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 5 |
| Dew Point at event time (in degress fahrenheit) | -8 |
| Wind Direction (degrees magnetic) | 170 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 3 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.76 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | METAR KFCS 292158Z AUTO 17003KT 10SM BKN170 05/M08 |
| Event Highest Injury | Minor |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | 2 |
| Injury Total None | -- |
| Injury Total Serious | -- |
| Injury Total All | 2 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 32940 |
| NTSB Notification Source | Federal Aviation Administratio |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Apr 15 2014 4:27PM |
| User who most recently changed record | folm |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N959DA |
| NTSB Number | CEN14TA126 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | VFR |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | DIAMOND AIRCRAFT IND INC |
| Aircraft Model | DA20-C1 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | C0469 |
| Certified Max Gross Weight | -- |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | 2 |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 2 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Dec 18 2013 12:00AM |
| Airframe hours since last inspection | 28 |
| Airframe Hours | 3597 |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | No |
| ELT Type | Unknown |
| Aircraft Owner Name | DOSS AVIATION INC |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | COLORADO SPRINGS |
| Aircraft Owner State | CO |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 809175080 |
| Operator is an individual? | No |
| Operator Name | DOSS AVIATION INC |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | COLORADO SPRINGS |
| Operator State | CO |
| Operator Country | USA |
| Operator Zip code | 809175080 |
| 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) | -- |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | KFCS |
| Departure City | Fort Carson |
| Departure State | CO |
| Departure Country | USA |
| Departure Time | 1432 |
| Departure Time Zone | MST |
| Destination Same as Local Flt | -- |
| Destination Airport Code | KPUB |
| Destination City | Pueblo |
| Destination State | CO |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Apr 15 2014 3:37PM |
| User who most recently changed record | folm |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 13 |
| Runway Length | 4572 |
| Runway Width | 75 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |