NTSB Identification: FTW87FA177.
The docket is stored on NTSB microfiche number 35977.
Accident occurred Monday, July 27, 1987 in CARROLLTON, TX
Probable Cause Approval Date: 06/16/1989
Aircraft: AERO COMMANDER 520, registration: N4164B
Injuries: 2 Minor.

NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

ACFT WAS DESTROYED WHEN IT STRUCK PWR LINES AND THE GRND DURING A SINGLE ENG GO-AROUND. FOLLOWING A LEFT ENG SHUT DOWN DUE TO SEVERE VIBRATIONS, THE PLT OVERFLEW ONE ARPT TO RETURN TO HIS HOME BASE. EN ROUTE, HE ELECTED NOT TO GO TO FULL PWR DUE TO A 3 MIN LIMITATION HE DID NOT WANT TO EXCEED. THE PLT OVERSHOT THE RWY WHILE MANUALLY EXTENDING THE NOSE GEAR AND ELECTED TO ATTEMPT A RT 270 DEG TURN TO RETURN TO FINAL WHILE AT 100-150' AGL. NLG DID NOT EXTEND DUE TO HYD PUMP BEING ON LEFT ENG AND NO PRESSURE. DURING THE TURN, THE PLT LOST CONTROL AND THE ACFT STRUCK THE WIRES. INVESTIGATION REVEALED THAT ONE OF THE BLADE PITCH CHANGE LINKS ON THE LEFT PROP HAD DISCONNECTED, ALLOWING ONE BLADE TO FREE FLOAT. THE LINK PIN ASSEMBLY HAD BACKED OUT AS A RESULT OF THE SAFETY SCREW BACKING OUT DUE TO DAMAGED AND STRIPPED THREADS AND AN IMPROPER LENGTH SCREW BEING INSTALLED. PROPS HAD 1/4' SAFETY SCREWS INSTALLED INSTEAD OF 3/8'.

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

PROPELLER SYSTEM/ACCESSORIES,PITCH CHANGE MECH..DISCONNECTED

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

AIRSPEED(VMC)..NOT MAINTAINED..PILOT IN COMMAND

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

DIVERTED ATTENTION..PILOT IN COMMAND

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

PROPELLER SYSTEM/ACCESSORIES,PITCH CHANGE MECH..STRIPPED THREAD

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

MAINTENANCE,OVERHAUL..INADEQUATE..OTHER MAINTENANCE PERSONNEL

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

PROPELLER SYSTEM/ACCESSORIES,PITCH CHANGE MECH..INCORRECT

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

MAINTENANCE,INSTALLATION..IMPROPER..PILOT IN COMMAND



Contributing Factors

GO-AROUND..ATTEMPTED..PILOT IN COMMAND


Index for Jul1987 | Index of months