Friday, November 28, 2014

Piper PA-18-150 Super Cub, N9720P, Alaska West Air: Accident occurred November 27, 2014 in Nikiski, Alaska

NTSB Identification: ANC15LA005 
Nonscheduled 14 CFR Part 135: Air Taxi & Commuter
Accident occurred Thursday, November 27, 2014 in Nikiski, AK
Probable Cause Approval Date: 03/17/2015
Aircraft: PIPER PA 18-150, registration: N9720P
Injuries: 1 Serious, 1 Minor.

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

The pilot reported that he had flown the airplane for about 20 to 30 minutes to survey the area for possible landing sites. After choosing a landing site, the pilot completed the prelanding checklist, cycled the carburetor heat on, and then placed it in the “off” position. When the airplane was established on short final for landing, the engine lost total power. The pilot attempted to restart the engine by switching fuel tanks and applying carburetor heat, but engine power was not restored. The airplane subsequently collided with rising terrain, which resulted in substantial damage to the fuselage and wings. A postaccident examination of the engine revealed no evidence of any preimpact mechanical problems that would have precluded normal operation. 

Another company pilot, who had landed his airplane at the same location only minutes before the accident airplane approached, stated that carburetor ice accumulated during the descent. Further, the atmospheric conditions at the time of the accident were conducive to the accumulation of carburetor icing at glide and cruise power settings. Therefore, it is likely that, as the pilot reduced engine power, carburetor ice formed, which caused the engine to lose power.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The total loss of engine power due to carburetor icing, which resulted from the pilot’s failure to use carburetor heat while operating at low-power settings in an area conducive to carburetor icing.

On November 27, 2014, at 1117 Alaska standard time, a Piper PA-18-150 airplane, N9720P, collided with terrain after a total loss of engine power while maneuvering for an off-airport landing near Nikiski, Alaska. The certificated commercial pilot sustained serious injuries and the sole passenger sustained minor injuries. The aircraft was registered to Summit Leasing LLC and operated by Alaska West Air, Inc., under the provisions of 14 Code of Federal Regulations Part 135 as an on-demand commercial air taxi flight. Visual meteorological conditions prevailed for the entire flight, and a company flight plan was filed. The flight originated from Kenai, Alaska approximately 1030.

In a statement provided to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot stated that prior to the accident he flew approximately 20 to 30 minutes surveying the area for possible landing sites. During this time, he applied carburetor heat three or four times to check for carburetor ice. After a landing site had been selected, the pre-landing checklist was completed, and the carburetor heat was placed in the off position. On short final the engine lost all power. The pilot then switched fuel tanks and turned the carburetor heat back on, but the engine would not restart. The airplane subsequently collided with an area of rising terrain just short of the intended landing site, sustaining substantial damage to the fuselage and wings.

On December 1, 2014, the NTSB IIC, along with another NTSB investigator performed a post-accident examination of the airframe and engine. Control cable continuity was established from the cockpit control to the engine for the throttle, mixture, carburetor heat and cabin heat.

On December 11, the NTSB IIC, along with another NTSB investigator, performed a follow-up examination of the engine and fuel system. No anomalies, contamination, or evidence of malfunction was found in any of the engine accessories. The cylinders, pistons, valve train, crankshaft, and other internal components were all without evidence of anomaly or malfunction that would have precluded normal operation. 

Both magnetos were removed from the engine and the coupling was rotated. When the coupling was rotated, a blue spark was produced from each terminal, in rotational order.

The closest weather reporting facility was the Kenai Airport, Kenai, about 31 miles southeast of the accident site. At 1053, an aviation routine weather report (METAR) from the Kenai Airport was reporting in part: wind from 010 degrees at 3 knots; sky condition, clear; visibility, 10 statute miles; temperature 10 degrees F; dewpoint 9 degrees F; barometric pressure 30.23 inHG.

According to a carburetor icing probability chart, an airplane operating in the ambient conditions at the accident site could expect light carburetor icing while at cruise of glide power. 

Another company pilot who landed at the same location only minutes before the accident aircraft approached, stated that during the descent, his aircraft had accumulated carburetor ice during the approach.

A Lycoming Service Instruction states in part, "if icing conditions are suspected, apply 'Full Heat.' In the case that full power needs to be applied under these conditions, as for an aborted landing, return the carburetor heat to 'Full Cold' after full power application.

Federal Aviation Administration Flight Standards District Office: FAA Anchorage FSDO-03

Alaska State Troopers today identified the pilot injured in a Thanksgiving Day crash as 55-year-old Brad Adams, of Soldotna. His only passenger was a 16-year-old boy whom troopers have not publicly named. 

Adams suffered "serious but non-life-threatening injuries," troopers wrote. The teenager was treated and released for minor injuries. 

Troopers say Adams was flying a Super Cub owned by Nikiski-based Alaska West Air. Someone called 911 to report the downed plane at 11:36 a.m. Thursday in an area on the west side of Cook Inlet known as Kustatan Bench. The company responded to the crash in an R44 helicopter and flew the pilot and teen to a Soldotna hospital. 


Alaska State Troopers say a small plane crashed on the west side of Cook Inlet Thursday morning, with two injured occupants flown to Soldotna for treatment.

According to AST spokesman Tim DeSpain, a helicopter from the 11th Air Force’s Rescue Coordination Center at Joint Base Elmendorf-Richardson was sent to the scene. Troopers were informed of the crash shortly before noon, but didn't immediately have further information on the plane that crashed.

“It’s across the inlet from Nikiski,” DeSpain said. “It sounds like from the air they could see two people.”

Clint Johnson, the National Transportation Safety Board's Alaska chief, confirmed that the plane -- a Piper PA-18 Super Cub with two occupants on board -- crashed at an airstrip on the west side of Cook Inlet at about noon Thursday.

"This accident happened on landing," Johnson said. "Initial, preliminary information is that the pilot experienced a loss of engine power and the airplane crashed shortly after that."

Johnson said both of the plane's occupants were injured in the crash.
"One was seriously injured, and one had injuries considered minor," Johnson said.

Central Emergency Services spokesman Brad Nelson said medics were alerted that two patients from the crash were headed to Central Peninsula Hospital. A Channel 2 viewer sent a photo of the patients being transferred to medics from an arriving helicopter.

“They are bringing two victims to the Soldotna hospital,” Nelson said. “Our crews are going to meet them there.”

A plane went down on the west side of Cook Inlet sometime before noon on Thursday, according to Alaska State Troopers. 

 Two people were rescued via helicopter, said Troopers spokesperson Tim DeSpain.

“The plane crash was seen from the air, pretty much across the inlet from Nikiski and they could see two people,” DeSpain said.

It is unclear which organization’s helicopter rescued the two after they were spotted.

“It may have been a private company,” he said.

The two people rescued from the downed flight were both injured and taken to Central Peninsula Hospital where CES firefighters helped to offload them into the facility, said Central Emergency Services Capt. Lesley Quelland. She didn’t know much about the crash.

“We were notified of it when we got dispatched to a helicopter coming into Soldotna airport with two victims from the crash,” she said. “We asked dispatch to have them redirect to the hospital landing.”

DeSpain said he did not know the identities of the two injured people. No one from the National Transportation Safety Board office in Anchorage was available to talk about the the crash.

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