Saturday, February 08, 2020

Powerplant System/Component Malfunction/Failure: Cessna U206F Stationair, N71001; accident occurred June 23, 2017 in Page, Coconino County, Arizona

Throttle Control and Cable within Cockpit. 

Throttle Cable Fracture. 

Throttle Control Rod End. 

Throttle Control rod End and sleeve. 

Throttle Connection Point on Throttle Body. 

The Throttle Control Assembly. 

Overall (bottom) and close-up (top) photos of the separated throttle control cable. The two ends were labeled End A and End B, as shown.

Close-up photo showing the location of the throttle control cable separation was in-line with one end of the rod end piece.

Digital microscope images of two circumferential bands of wear (black brackets) on the rod end piece. The views shown are diametrically opposite each other.

Digital microscope image of the separated wires (red arrows) on End B as viewed at an angle.
Digital microscope images of the separated wires (red arrows) on End A as viewed perpendicular (top) and at an angle (bottom). 

The National Transportation Safety Board did not travel to the scene of this accident.

Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Las Vegas, Nevada

Aviation Accident Factual Report - National Transportation Safety Board:

Investigation Docket - National Transportation Safety Board:

Location: Page, AZ
Accident Number: WPR17LA144
Date & Time: 06/23/2017, 1600 MST
Registration: N71001
Aircraft: CESSNA U206F
Aircraft Damage: Substantial
Defining Event: Powerplant sys/comp malf/fail
Injuries: 6 None
Flight Conducted Under: Part 135: Air Taxi & Commuter - Non-scheduled - Sightseeing 

On June 23, 2017, about 1600 mountain standard time, a Cessna U206F airplane, N71001, sustained substantial damage after the pilot executed a precautionary landing about 28 miles southeast of Page, Arizona. The two commercial pilots and four passengers were not injured. The airplane was registered to, and operated by, American Aviation Inc. as a Title 14 Code of Federal Regulations Part 135 scenic flight. Visual meteorological conditions prevailed at the time of the accident and a company visual flight rules flight plan had been filed. The flight originated from Page, Arizona at an unknown time.

The pilot in command (PIC) reported that while they were returning to the airport at 7,500 ft, the airplane would no longer climb; it then slowly started to descend at about 350 ft per minute. Unable to stop the descent, the pilots attempted to troubleshoot the problem, but were not able to restore engine power. The PIC initiated a precautionary landing onto a dirt road. About 125 ft above the ground, the co-pilot took control of the airplane and landed softly onto the road. During the landing roll, the airplane's left wing impacted juniper bushes before it came to rest. As the pilots retarded the throttle to idle, the throttle came out of the control panel along with about two ft of the throttle cable.

During a postaccident examination by a Federal Aviation Administration inspector, it was noted that the throttle control cable separated from the rod end of the throttle body control. Review of the maintenance logs indicated the throttle cable was last installed in 1996.

The throttle cable, to include the rod end, and rod end sleeve were removed from the airplane and sent to the National Transportation Safety Board (NTSB) Materials Laboratory for further examination.

The NTSB Materials Laboratory reported that digital microscope images of the rod end, which was within the rod end sleeve, exhibited two circumferential bands of wear on the ends. The bands were heavier on one side of the pieces, and the band closest to the end had less damage compared to the other band. Corresponding wear was observed on the inner surface of the mating guide piece. The wire strands were observed, and the fracture surfaces were flat and perpendicular to the axes of the strands. No necking or thinning of the individual strands consistent with overstress separation was observed.

Cessna Maintenance Manual indicates that the engine controls and linkages should be examined "each 50 hours for general condition and freedom of movement. These controls are not repairable. Replace throttle, propeller, and mixture controls at each engine overhaul." The operator reported the airplane's annual inspection was completed about 43 hours prior to the accident, and the overhaul 163 hours prior to the accident. The logbooks did not show that the cable had been replaced.

Pilot Information

Certificate: Commercial
Age: 37, Male
Airplane Rating(s): Single-engine Land
Seat Occupied: Left
Other Aircraft Rating(s): None
Restraint Used:
Instrument Rating(s): Airplane
Second Pilot Present: Yes
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Class 1 With Waivers/Limitations
Last FAA Medical Exam: 09/23/2016
Occupational Pilot: Yes
Last Flight Review or Equivalent: 06/04/2017
Flight Time:  535 hours (Total, all aircraft), 15 hours (Total, this make and model), 285 hours (Pilot In Command, all aircraft), 15 hours (Last 30 days, all aircraft)

Co-Pilot Information

Certificate: Commercial
Age: 27, Male
Airplane Rating(s): Multi-engine Land; Single-engine Land
Seat Occupied: Right
Other Aircraft Rating(s): Helicopter
Restraint Used:
Instrument Rating(s): Airplane
Second Pilot Present: Yes
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Class 2 Without Waivers/Limitations
Last FAA Medical Exam: 05/18/2017
Occupational Pilot: Yes
Last Flight Review or Equivalent: 03/16/2017
Flight Time:  685 hours (Total, all aircraft), 35 hours (Last 90 days, all aircraft), 10 hours (Last 30 days, all aircraft) 

Aircraft and Owner/Operator Information

Aircraft Make: CESSNA
Registration: N71001
Model/Series: U206F
Aircraft Category: Airplane
Year of Manufacture: 1973
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number:U20602115 
Landing Gear Type: Tricycle
Seats: 6
Date/Type of Last Inspection: 06/01/2017, 100 Hour
Certified Max Gross Wt.: 3600 lbs
Time Since Last Inspection: 43 Hours
Engines: 1 Reciprocating
Airframe Total Time: 9970 Hours as of last inspection
Engine Manufacturer: Continental
ELT: Installed, not activated
Engine Model/Series: IO-520 LCF
Rated Power: 300 hp
Operating Certificate(s) Held: On-demand Air Taxi (135)

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: PGA, 4316 ft msl
Distance from Accident Site: 28 Nautical Miles
Observation Time: 1553 MST
Direction from Accident Site: 120°
Lowest Cloud Condition: Clear
Visibility:  10 Miles
Lowest Ceiling:None 
Visibility (RVR):
Wind Speed/Gusts: 6 knots /
Turbulence Type Forecast/Actual: / None
Wind Direction: 250°
Turbulence Severity Forecast/Actual: / N/A
Altimeter Setting: 29.92 inches Hg
Temperature/Dew Point: 39°C / -1°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Page, AZ (PGA)
Type of Flight Plan Filed: Company VFR
Destination: Page, AZ (PGA)
Type of Clearance: Unknown
Departure Time:
Type of Airspace:

Wreckage and Impact Information

Crew Injuries:2 None
Aircraft Damage: Substantial
Passenger Injuries: 4 None
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 6 None
Latitude, Longitude: 37.056389, -110.085556 (est)

No comments:

Post a Comment