NTSB Identification: DEN84LA288.
The docket is stored on NTSB microfiche number 26631.
Accident occurred Wednesday, September 12, 1984 in VERNAL, UT
Aircraft: BELL 206B, registration: N1086Y
Injuries: 1 Minor,1 Uninjured.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

PLT STATED THAT WHILE ON A HEADING OF 050 DEGS (WIND FROM 270 DEGS AT 5 KTS) THE ACFT BEGAN TO SHUDDER AND VEERED TO THE RIGHT. PLT ATTEMPTED REMEDIAL ACTION BUT ACFT CONTINUED DESCENDING IN A RIGHT SPIRAL TO GROUND CONTACT. EXAMINATION OF THE HELICOPTER DID NOT DISCLOSE ANY MECHANINCAL FAILURE/MALFUNCTION. BELL HELICOPTER TEXTRON, INC., PUBLISHED INFORMATION LETTER 206-84-41 DATED JULY 6, 1984 IN WHICH IT DESCRIBES UNANTICIPATED RIGHT YAW AS, '... THE OCCURRENCE OF AN UNCOMMANDED RIGHT YAW RATE WHICH DOES NOT SUBSIDE OF ITS OWN ACCORD AND WHICH, IF NOT CORRECTED CAN RESULT IN LOSS OF AIRCRAFT CONTROL.' THE PLT WAS IN THE POST SOLO PHASE OF HIS HELICOPTER TRAINING. ONE PASSENGER WAS ON BOARD WHEN THE ACCIDENT OCCURRED.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

AIRCRAFT HANDLING..IMPROPER..PILOT IN COMMAND

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

DIRECTIONAL CONTROL..NOT MAINTAINED..PILOT IN COMMAND

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

SPIRAL..UNCONTROLLED..PILOT IN COMMAND


Contributing Factors

LACK OF TOTAL INSTRUMENT TIME..PILOT IN COMMAND

Index for Sep1984 | Index of months