Thursday, August 3, 2017

Cessna 182D Skylane, N9936T: Fatal accident occurred August 28, 2016 near Rock Creek Airport (RC0), Clinton, Missoula County, Montana

Aviation Accident Final Report - National Transportation Safety Board: https://app.ntsb.gov/pdf

NTSB Identification: WPR16FA170
14 CFR Part 91: General Aviation
Accident occurred Sunday, August 28, 2016 in Clinton, MT
Probable Cause Approval Date: 08/09/2017
Aircraft: CESSNA 182, registration: N9936T
Injuries: 2 Fatal.

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.

The private pilot was conducting a local flight in the airplane, which he was planning to purchase. A witness saw the airplane initially overfly the runway from east to west, then turn back to the east and onto a right downwind for landing to the west on runway 25; the witness, who was a pilot, reported that the wind was directly down the runway about 8 knots. When the airplane was on a short final approach about 15 ft above the runway, it suddenly turned 90° to the right, in what the witness estimated was a bank angle of about 30° to 40°. The airplane continued at a low altitude toward the north perimeter of the airport where it impacted a stand of trees, then proceeded through the trees before coming to rest upright on the south shoulder of an interstate highway. Shortly thereafter, a postcrash fire erupted and consumed the airplane. A postaccident examination of the airframe and engine did not reveal any mechanical anomalies that would have precluded normal operation. The reason for the sudden right turn while on short final approach could not be determined during the investigation.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The sudden right turn on approach to landing for reasons that could not be determined because postaccident examination did not reveal any anomalies that would have precluded normal operation.

Mark Melotz

Darrell Ward


The National Transportation Safety Board traveled to the scene of this accident.

Additional Participating Entities:
Federal Aviation Administration / Flight Standards District Office; Helena, Montana
Textron Aviation; Wichita, Kansas
Continental Motors, Inc.; Mobile, Alabama

Investigation Docket  - National Transportation Safety Board: https://dms.ntsb.gov/pubdms

Aviation Accident Factual Report - National Transportation Safety Board:  https://app.ntsb.gov/pdf

http://registry.faa.gov/N9936T




NTSB Identification: WPR16FA170
14 CFR Part 91: General Aviation
Accident occurred Sunday, August 28, 2016 in Clinton, MT
Aircraft: CESSNA 182, registration: N9936T
Injuries: 2 Fatal.

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.

HISTORY OF FLIGHT

On August 28, 2016, about 1445 mountain daylight time, a Cessna 182D, N9936T, impacted terrain following a loss of control while attempting to land at the Rock Creek Airport (RC0), Clinton, Montana. The private pilot and the passenger were fatally injured, and the airplane was destroyed. The local flight was being operated as a 14 Code of Federal Regulations Part 91 personal, and a flight plan was not filed. Visual meteorological conditions prevailed for the flight, which departed about 1400 from Missoula International Airport (MSO), Missoula, Montana, with RC0 as its destination.

According to a friend of the pilot who is also a pilot and witnessed the accident, the airplane initially overflew the airport from east to west, then turned back to the east on an extended right downwind for runway 25. The witness stated that when the airplane was on final approach it was stable, and the wind was out of the west, "...right down runway 25 at about 8 knots." The witness further stated that when the airplane was about 15 ft above the runway and preparing to land, it suddenly turned 90° to the right, at what he estimated to be about a 30° to 40° bank angle. The airplane subsequently collided with a stand of trees that bordered the runway on the north and then impacted the ground before coming to rest upright on the shoulder of an interstate highway (I-90). Shortly thereafter, a fire erupted, which consumed the forward two-thirds of the airplane.

PERSONNEL INFORMATION

The pilot held a private pilot certificate for airplane single-engine and multiengine land airplane ratings. The pilot's personal flight logbook was not recovered during the investigation. According to data provided by the Federal Aviation Administration (FAA), the pilot was issued a third-class airman medical certificate on December 12, 2014, with the restriction, "must have available glasses for near vision." On the application for this medical certificate, the pilot listed a total flight time of 632 hours.

The witness/friend reported that for several months, the pilot had been attempting to purchase the airplane and had been flying it. He estimated that the pilot had accumulated 5 to 8 hours of flight time in the airplane.




AIRCRAFT INFORMATION

The Cessna 182D was a four-seat, high-wing, fixed-gear airplane, serial number 18253036. The airplane was equipped with a Continental Motors O-470-L1 engine, serial number 66983-6-L, and a McCauley 2A36C29-A, two-bladed, adjustable pitch propeller.

According to partial copies of maintenance records, as of the most recent annual inspection, which was completed on June 22, 2016, the total time on the engine since major overhaul was 934.8 hours, with a tachometer reading of 2,135.0 hours. The previous annual inspection was completed on June 15, 2005, at a tachometer reading of 2,133.0 hours; the engine had accumulated 2 hours in the 11-year span between the two inspections.

METEOROLOGICAL INFORMATION

At 1453, MSO, located about 23 nautical miles west of the accident site, reported wind calm, visibility 10 miles, sky clear, temperature 23°C, dew point -1°C, and an altimeter setting of 30.07 inches of mercury.



WRECKAGE AND IMPACT INFORMATION

Examination of the accident site indicated that the airplane struck tress that were located about 650 ft. west-northwest of the approach end of runway 25 and about 270 ft. north of the runway centerline. The airplane came to rest upright on the south shoulder of I-90 on a magnetic heading of about 145°. The airplane was destroyed by thermal and impact damage.

A postaccident examination of the airframe and engine, attended by representatives from the National Transportation Safety Board, the Federal Aviation Administration, Textron Aviation, and Continental Motors, Inc., revealed the following:

The majority of the fuselage was consumed by the postcrash fire. The right wing leading edge was crushed aft in a curve pattern, which was most pronounced about mid-span. The left wing leading edge was crushed aft, with slightly more crushing at the wing tip area. The empennage aft of the baggage compartment was not burned and remained intact.

Flight control cable continuity was established for all flight controls from the cockpit to the control surface attach points. There was a separation of the aileron balance cable, which appeared to be a result of a tension overload. The flap handle was found in a flap extended position; however, as it was not in a detent, exact flap position could not be determined. The trimmable horizontal stabilizer screw jack was measured at 7.1 inches, which equates to the normal takeoff position.

The engine remained partially attached to the airframe and exhibited thermal and impact damage. The induction and exhaust systems were impact damaged, and the oil sump was crushed upward. The airframe firewall was wrapped around the rear of the engine.

The exhaust system was crushed upward, and the muffler was partially crushed and pushed into the oil sump. The induction system balance tube was crushed into the crankcase.

Both magnetos were partially separated from their mounting flanges and exhibited thermal and impact damage. Each rotated freely when rotated by hand but did not produce spark, and water was observed leaking from both. Examination of both magnetos by a magneto repair station revealed that the left magneto did not function due to thermal damage. The right magneto functioned properly producing spark at all terminals.

The spark plugs exhibited light and dark colored combustion deposits, and the electrodes were worn out when compared to the Champion Check-a-Plug chart. The ignition harness exhibited thermal damage.

The carburetor remained attached to the induction system and was thermally damaged. The mixture control arm and shaft were bent. The throttle control arm moved with resistance; however, debris from the post impact fire was observed around the throttle plate. The fuel screen was removed and found to be free of debris. When the fuel bowl was removed, thermal damage to all of the interior components was observed.

The fuel strainer sustained thermal and impact damage, which compromised the component. Some light debris was noted on the fuel strainer screen. The glass bowl was intact.

The oil pump was disassembled. The pump housing contained oil and exhibited normal operating signatures and evidence of light particle passage. The oil cooler remained attached to the engine and exhibited thermal and impact damage.

The exterior of the cylinders exhibited thermal damage. When the combustion chambers were examined with a lighted borescope, no anomalies were noted. The crankshaft was rotated by hand using the propeller. Continuity through the valve train to the accessory section was confirmed, and there was thumb compression on all six cylinders.

The starter was separated from the starter adaptor. The generator remained attached to the engine and exhibited thermal and impact damage.

The vacuum pump was removed and disassembled with no anomalies noted.

With the propeller governor removed, the drive gear turned freely by hand; no oil was being discharged. The control arm moved freely by hand from stop to stop.

The two-bladed propeller remained attached to the crankshaft propeller flange. One blade was relatively undamaged. The other blade was loose in the hub, bent slightly forward at mid blade, and exhibited leading edge polishing and chord-wise scratches.

The examination of the engine and airframe did not reveal any anomalies that would have precluded normal operation.

MEDICAL AND PATHOLOGICAL INFORMATION

The Montana State Medical Examiner performed an autopsy on the pilot. The cause of death was attributed to multiple blunt force injuries.


The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, conducted forensic toxicology examinations on specimens from the pilot. No carbon monoxide was detected in blood; no ethanol was detected in urine, and testing was not performed for cyanide. The drug salicylate, a metabolite of aspirin, was detected in urine.









NTSB Identification: WPR16FA170
14 CFR Part 91: General Aviation
Accident occurred Sunday, August 28, 2016 in Clinton, MT
Aircraft: CESSNA 182, registration: N9936T
Injuries: 2 Fatal.

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. 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.

On August 28, 2016, about 1445 mountain daylight time, a Cessna 182D, N9936T, was substantially damaged following a loss of control and impact with terrain while attempting to land at the Rock Creek Airport (RC0), Clinton, Montana. The pilot and passenger were fatally injured. The local flight was being operated in accordance with 14 Code of Federal Regulations Part 91, and a flight plan was not filed. Visual meteorological conditions prevailed for the flight, which had departed about 45 minutes prior to the accident from the Missoula International Airport (MSO), Missoula, Montana, with RC0 as its destination.

According to a witness who observed the accident, who is also a certified commercial pilot, upon the airplane's arrival it overflew the airport from east to west, then turned back to the east on an extended right downwind. The witness stated that when the airplane was on final approach it was stable, with the wind being out of the west, "...right down runway 25 at about 8 knots." The witness further stated that when the airplane was about 40 feet above the runway and preparing to land, it suddenly veered 90 degrees to the right, in what he estimated to be about a 30-degree bank angle. The airplane subsequently collided with a stand of trees that bordered the runway on the north, then impacted the ground before coming to rest upright on the shoulder of an Interstate highway. Shortly thereafter, a fire erupted, which consumed the forward two-thirds of the airplane.

The airplane was recovered to a secured location for further examination.

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