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ASN Wikibase Occurrence # 122832
Last updated: 25 April 2019
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Type:Silhouette image of generic AS50 model; specific model in this crash may look slightly different
Eurocopter AS 350B2 Ecureuil
Owner/operator:Sovereign International Equities, LLC
Registration: N747CH
C/n / msn: 3794
Fatalities:Fatalities: 0 / Occupants: 3
Aircraft damage: Substantial
Location:near Fort Worth Alliance Airport, TX -   United States of America
Phase: Approach
Departure airport:Fort Worth, TX (AFW)
Destination airport:Fort Worth, TX (AFW)
Investigating agency: NTSB
The pilot had recently purchased the helicopter and was receiving flight training from a certified flight instructor (CFI). During practice traffic pattern work, the helicopterís hydraulic system was turned off to simulate hydraulic failure on the flight control system. During the approach, the airportís ground controller reported that they were on the wrong radio frequency, so the CFI changed the radio to the correct frequency. The helicopterís airspeed slowed and the helicopter entered an uncommanded left yaw. The CFI tried to regain control by adding right pedal, trying to gain for forward airspeed, and reducing power. The helicopter did not respond to the CFIís control inputs. Subsequently, the helicopter impacted the ground, rolled on to its side, and a postcrash fire ensued. A postaccident examination of the helicopter revealed no preimpact mechanical malfunctions or failures that would have precluded normal operations. A review of the helicopterís flight manual reveals the note: ďCaution, Do not attempt to carry out hover flight or any low speed maneuver without hydraulic pressure assistance. The intensity and direction of the control feedback forces will change rapidly. This will result in excessive pilot workload, poor aircraft control, and possible loss of control." Additionally, one or both pilots may have been distracted by the incorrect radio frequency.
Probable Cause: The pilotís loss of control due to his not maintaining adequate airspeed and altitude during a simulated hydraulic flight control failure. Contributing to the accident was the flight instructorís inadequate supervision and delayed remedial response.



Revision history:

30-May-2011 01:36 gerard57 Added
30-May-2011 03:46 RobertMB Updated [Aircraft type, Location, Nature, Departure airport, Source, Narrative]
31-May-2011 03:36 RobertMB Updated [Aircraft type, Registration, Cn, Operator, Source]
30-Sep-2016 17:06 Aerossurance Updated [Time, Operator, Location, Phase, Destination airport, Source, Narrative]
21-Dec-2016 19:25 ASN Update Bot Updated [Time, Damage, Category, Investigating agency]
27-Nov-2017 16:54 ASN Update Bot Updated [Operator, Other fatalities, Departure airport, Destination airport, Source, Narrative]

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