Monday, February 6, 2017

Luscombe 8A Silvaire, N4948E: Fatal accident occurred September 07, 2015 at Hobby Field Airport (77S), Creswell, Lane County, Oregon

Milo Skinner grew up flying with his grandfather Hal Skinner. Milo learned to fly from instructor Holly Robinson; he soloed for the first time the day after his 16th birthday - before he earned his driver's license.


Hal Skinner was one of the founding members of the Oregon Aviation Historical Society.


Milo Skinner


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

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

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

Aviation Accident Data Summary - National Transportation Safety Board: https://app.ntsb.gov/pdf

FAA Flight Standards District Office:  FAA Portland FSDO-09

Hal W. Skinner, Jr: http://registry.faa.gov/N4948E

NTSB Identification: WPR15FA258 
14 CFR Part 91: General Aviation
Accident occurred Monday, September 07, 2015 in Creswell, OR
Probable Cause Approval Date: 01/31/2017
Aircraft: SILVAIRE LUSCOMBE 8A, registration: N4948E
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 commercial pilot and pilot-rated passenger were departing in the tailwheel-equipped airplane. The flight was the first flight following the airplane's most recent annual inspection. One witness heard a radio transmission over the airport's common traffic advisory frequency that the airplane was experiencing a fire and returning to the airport. Another witness stated that his attention was drawn to the airplane when he heard a "pop," which was followed by a loss of power. All witness accounts were consistent with the airplane entering a steep left bank between 200 and 250 ft above ground level. As the airplane turned, the nose dropped, and the airplane descended to the ground. None of the witnesses observed any smoke or fire coming from the airplane before impact. The airplane was consumed by a postcrash fire. Despite the pilot's report of a fire, there were no mechanical malfunctions or anomalies found with the airplane or engine, and the investigation was unable to determine the source of the in-flight fire, if any. 

The terrain in front of the airplane as it departed the airport was mainly open, flat farm fields; such an area would be favorable for a straight-ahead, forced landing. Although the pilot perceived some anomaly during takeoff that prompted him to initiate a forced landing, the airplane did not have sufficient altitude to complete the 180-degree turn back to the runway. The pilot failed to maintain sufficient airspeed, which resulted in the airplane exceeding its critical angle-of-attack and subsequently entering an aerodynamic stall and spin during the attempted turn.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The pilot's decision to return to the runway shortly after takeoff, and his failure to maintain adequate airspeed during the turn, which resulted in the airplane exceeding its critical angle-of-attack and experiencing an aerodynamic stall and spin.



HISTORY OF FLIGHT

On September 7, 2015, at 0958 Pacific daylight time, a Silvaire Luscombe 8A, N4948E, was destroyed when it impacted terrain, and was subsequently consumed by postcrash fire, just after takeoff from Hobby Field Airport (77S), Creswell, Oregon. The commercial pilot and private pilot-rated passenger were fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the flight, which was originating at the time of the accident. The personal flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. 

A flight instructor inside a building at the airport heard a radio call from the accident airplane over the common traffic advisory frequency. The transmission indicated that the airplane was experiencing a fire and would be returning for an emergency landing. The witness looked out the window and observed the accident airplane near the departure end of runway 33 in a steep left bank. He saw the airplane's nose "drop," and subsequently lost sight of the airplane behind a row of trees. He called 911 as he ran toward the airplane to render assistance, and upon arriving at the site, the wreckage was on fire. He stated that when emergency responders arrived about 3 minutes later, the airplane was "largely consumed" by fire. 

A mechanic at the airport stated that his attention was drawn to the airplane when he heard a loud "pop," followed by a loss of engine power. He observed the airplane enter a left turn from the upwind leg of the traffic pattern at an altitude of about 200 feet. He stated that the airplane appeared to stall, and he lost sight of it behind a tree line. 

Two witnesses located north of the airport observed the airplane as it departed from runway 33. One of the witnesses stated that his attention was drawn to the airplane as it entered a "roll" just after takeoff, appeared to "nose dive" into the ground, and subsequently caught fire. Another witness, who was a rated pilot, stated that he heard the engine "lose power," then observed the airplane enter a left turn that he perceived as "an emergency 180 return to the runway." He stated that the airplane appeared to lose airspeed as the left wing "dropped abruptly," and the airplane entered a "steep" nose-down attitude as it descended to ground contact. 

None of the witnesses observed any smoke or fire coming from the airplane prior to impact. 

METEOROLOGICAL INFORMATION

The nearest weather observation facility was located at Mahlon Sweet Field Airport (EUG), Eugene, Oregon, about 15 nautical miles to the northeast. Although instrument meteorological conditions (IMC) were reported at EUG about the time of the accident, witness accounts and photos from the accident site just after the accident indicated that visual flight rules (VFR) conditions prevailed at 77S.

PERSONNEL INFORMATION 

The 35 year old pilot seated in the left seat held a commercial pilot certificate with ratings for airplane multi- and single-engine land, and instrument airplane. He also held a flight instructor certificate with ratings for airplane single-engine and instrument. His most recent FAA medical certificate was issued on March 20, 2009. Review of personal flight logs indicated that he had about 1,400 total hours of flight experience; however, his recent flight experience could not be determined based on the records available. The pilot was not required to hold an FAA medical certificate, as the accident airplane met the requirements of a light sport aircraft.

The 83 year old pilot rated passenger held a private pilot certificate with a rating for airplane single-engine land. He did not hold an FAA medical certificate. Review of the owner's logbook revealed that he had about 967 total hours of flight experience, with about 3 hours in the 12 months prior to the accident. 

AIRPLANE INFORMATION 

The two-seat, high-wing, tailwheel-equipped airplane was issued an airworthiness certificate in 1960, and was registered to the owner in September 2011. It was equipped with a Continental Motors, Inc. A&C65 series, 65-hp reciprocating engine. Review of maintenance logbooks revealed that the most recent annual inspection was completed on August 31, 2015, at which time the airplane had accumulated 1,832.3 total hours in service, and the engine had accumulated 680.3 hours since overhaul. The accident flight was the first flight after the annual inspection.

AIRPORT INFORMATION

77S is located at an elevation of 541 ft mean sea level, and is equipped with a single asphalt runway, oriented 15/33 and measuring 3,102 ft long by 60 ft wide. The terrain beyond the north side of the airport comprised open farm fields. 

WRECKAGE AND IMPACT INFORMATION

The airplane came to rest upright on airport property about 400 feet west of the departure end of runway 33, on a magnetic heading of about 61 degrees. The airplane remained largely intact; however, the wings, forward fuselage, and cockpit area were entirely consumed by postcrash fire, and the aft fuselage displayed thermal damage. The empennage remained intact and was relatively undamaged, with the exception of thermal damage to the underside of the left horizontal stabilizer and elevator. The soot observed on the fuselage and empennage did not display any streaking patterns. Continuity was confirmed from all flight controls to the cockpit area. The fuel selector was found in the "on" position. The single fuel tank was ejected from the airplane on impact, and contained a small amount of fuel. Due to impact and thermal damage, no reliable information could be obtained from the cockpit instruments.

The wreckage was recovered from the site and transported to a secure storage facility for further examination of the engine. The wooden propeller displayed impact and thermal damage, and less than one foot of each blade remained at the hub. The propeller remained attached to the engine. The cylinders remained attached and relatively undamaged, with the exception of the #4 cylinder, which displayed a radial fracture stemming from the inboard and outboard sides of the induction and exhaust ports, and extended around the cylinder head to the spark plug seat. The cylinder was removed, and both the piston and cylinder displayed signatures of normal wear. Both top and bottom spark plugs displayed normal wear.

The top spark plugs were removed from the #1-3 cylinders, and the crankshaft was rotated by hand at the propeller. Valvetrain continuity was confirmed to all cylinders, and the #1-3 cylinders exhibited compression when tested with the thumb method. The valve covers were removed, and all rocker arms were intact and oil-coated, and moved freely during engine rotation. The top and bottom spark plugs from cylinders #1-3 displayed normal wear. 

The carburetor was separated from its mount and remained attached at its air intake. The carburetor was removed and examined, and the throttle control arm actuated freely by hand through its full travel. The throttle control cable remained attached to the arm. The carburetor was partially disassembled, and contained no fuel. No anomalies were observed of the venturi, float bowl, or metal float. The fuel inlet screen was free of debris, and the fuel inlet fitting was separated and thermally damaged. The airbox remained attached to the carburetor, and the carburetor heat control lever was intact and thermally damaged. 

The bottom portion of the gascolator remained attached to the firewall, and the fuel primer line fitting remained secure. The gascolator bowl, screen, and fuel primer line were destroyed by fire and were not located. 

The oil sump remained attached to the engine and displayed impact damage. The oil filter screen was removed and free of debris. Several smooth, round pieces of metal were found in the oil filter screen port, consistent with molten solder. The oil pressure line from the sump fitting to the firewall was consumed by fire.

Both magnetos exhibited significant thermal damage to their cases and ignition harnesses, and could not be rotated by hand. The magnetos were removed, and accessory drive continuity was confirmed.

MEDICAL INFORMATION

Autopsies were conducted by the Office of the State Medical Examiner, Clackamas, Oregon. The cause of death for both occupants was listed as multiple blunt force injuries. 

Toxicological testing was performed on both occupants by the FAA Bioaeronautical Sciences Research Laboratory in Oklahoma City, Oklahoma. The commercial pilot tested negative for carbon monoxide, ethanol, and all tested-for drugs and their metabolites. 

Testing on the passenger was positive for amitriptyline in liver and blood, nortriptyline in liver and blood, oxycodone in liver (0.124 ug/mL) and blood (0.037 ug/mL), and oxymorphone in liver (0.207 ug/mL). 

ADDITIONAL INFORMATION

The #4 cylinder was sent to the NTSB Materials Laboratory in Washington, D.C., for metallurgical analysis. Visual examination of the cylinder assembly revealed the cast aluminum head portion contained multiple cracks. The port for the intake valve was fractured. The push rod tube (housing) for the exhaust valve showed evidence of bending deformation in the direction of the push rod housing for the intake valve. The exhaust pipe leading out of the exhaust valve was compressed and pushed against the pushrod housing for the exhaust valve. The cover for the valve rocker arms also showed evidence of deformation. The inner face of the steel cylinder portion (located at the bottom of the head) contained no evidence of a crack, and the head portions of the intake and exhaust valves were intact. Detailed binocular microscope examination of the exposed fracture faces of the cast head portion revealed rough and coarse grain texture features consistent with overstress separation in aluminum casting. The fracture faces showed no evidence of fatigue cracking.

A pamphlet published by the FAA Safety Team entitled, "Aircraft Control After Engine Failure on Takeoff" stated, "Studies have shown that startle responses during unexpected situations such as a powerplant failure during takeoff or initial climb have contributed to loss of control of aircraft…Research indicates a higher probability of survival if you continue straight ahead following an engine failure after takeoff. Turning back actually requires a turn of greater than 180 degrees after taking into account the turning radius. Making a turn at low altitudes and airspeeds could create a scenario for a stall/spin accident."


NTSB Identification: WPR15FA258
14 CFR Part 91: General Aviation
Accident occurred Monday, September 07, 2015 in Creswell, OR
Aircraft: SILVAIRE LUSCOMBE 8A, registration: N4948E
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 September 7, 2015, at 0958 Pacific daylight time, a Silvaire Luscombe 8A, N4948E, was destroyed when it impacted terrain, and was subsequently consumed by postcrash fire, just after takeoff from Hobby Field Airport (77S), Creswell, Oregon. The private pilot/owner and commercial pilot were fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the flight, which was originating at the time of the accident. The personal flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91.

A flight instructor inside a building at the airport heard a radio call from the accident airplane over the common traffic advisory frequency, indicating that the airplane was experiencing a fire and would be returning for an emergency landing. The witness looked out the window and observed the accident airplane near the departure end of runway 33 in a steep left bank. He saw the airplane's nose "drop," and subsequently lost sight of the airplane behind a row of trees. As he ran toward the airplane to render assistance, he called 911, and upon arriving at the site, the wreckage was on fire. He stated that when emergency responders arrived about 3 minutes later, the airplane was "largely consumed" by fire.

A mechanic at the airport stated that his attention was drawn to the airplane when he heard a loud "pop," followed by a loss of engine power. He observed the airplane enter a left turn from the upwind leg of the traffic pattern at an altitude of about 200 feet. He stated that the airplane appeared to stall, and he lost sight of it behind a tree line.

Two witnesses located north of the airport observed the airplane as it departed from runway 33. One of the witnesses, a rated pilot, stated that he heard the engine "lose power," then initiate a left turn that he perceived as "an emergency 180 return to the runway." He stated that the airplane appeared to lose airspeed as the left wing "dropped abruptly," and the airplane entered a "steep" nose-down attitude as it descended to ground contact. The other witness north of the airport stated that his attention was drawn to the airplane as it entered a "roll" just after takeoff, appeared to "nose dive" into the ground, and subsequently caught fire.

None of the witnesses observed any smoke or fire coming from the airplane prior to impact.

The airplane came to rest upright on airport property about 400 feet west of the departure end of runway 33, on a magnetic heading of about 61 degrees. The airplane remained largely intact; however, the wings, forward fuselage, and cockpit area were entirely consumed by postcrash fire, and the aft fuselage displayed thermal damage. The empennage remained intact and was relatively undamaged, with the exception of thermal damage to the underside of the left horizontal stabilizer and elevator. The soot observed on the fuselage and empennage did not display any streaking patterns. Continuity was confirmed from all flight controls to the cockpit area. The fuel selector was found in the "on" position. The single fuel tank was ejected from the airplane on impact, and contained a small amount of fuel. Due to impact and thermal damage, no reliable information could be obtained from the cockpit instruments.

The wreckage was recovered from the site and transported to a secure facility for further examination.

The nearest weather observation facility to 77S was Mahlon Sweet Field Airport (EUG), Eugene, Oregon; located about 15 nautical miles to the northeast. Although instrument meteorological conditions (IMC) were reported at EUG about the time of the accident, witness accounts and photos from the accident site just after the accident indicated that visual flight rules (VFR) conditions prevailed at 77S.

No comments: