Monday, July 11, 2016

Aeropro CZ A220, N151J, registered to a private individual and operated by the pilot: Accident occurred July 19, 2016 in McCarthy, Alaska

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

Additional Participating Entities:
Federal Aviation Administration / Flight Standards District Office; Anchorage, Alaska
Rotax Aircraft Engines; Vernon, British Columbia, Canada

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

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

http://registry.faa.gov/N151J

Aviation Accident Factual Report - National Transportation Safety Board

Location: McCarthy, AK
Accident Number: ANC16LA047
Date & Time: 07/19/2016, 1000 AKD
Registration: N151J
Aircraft: AEROPRO CZ A220
Aircraft Damage: Substantial
Defining Event: Loss of engine power (partial)
Injuries: 1 None
Flight Conducted Under: Part 91: General Aviation - Personal 

On July 19, 2016, about 1000 Alaska daylight time, a tail-wheel equipped, Aeropro CZ A220 airplane, N151J, sustained substantial damage following a loss of directional control during takeoff from an unimproved airstrip about 5 miles south of McCarthy, Alaska. The certificated private pilot was not injured. The airplane was registered to a private individual and operated by the pilot under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as a personal cross-country flight. Visual meteorological conditions prevailed and a visual flight rules flight plan was filed. The flight was planned from the airstrip to the Wasilla Airport (IYS), Wasilla, Alaska.

The pilot stated that while attempting to takeoff, shortly after raising the tail of the airplane, a partial power loss occurred. While attempting to maintain directional control, the power loss ceased, and full power returned. The pilot was unable to input the correct amount of rudder pressure quickly enough to compensate for the increase in left turning tendencies resulting in the airplane impacting surrounding terrain and sustaining substantial damage to the wings, tail and fuselage.

A video of the attempted takeoff shows that during the takeoff sequence, as the tail lifts, sound changes consistent with engine surging can be heard. This occurs three times during the takeoff roll before directional control is lost. The video is located in the public docket for this accident.

The aircraft was equipped with a Rotax 912 ULS engine with a dual carburetor system. The 1/3 carburetor was associated with cylinders 1 and 3, while the 2/4 carburetor was associated with cylinders 2 and 4.

A postaccident examination revealed that the throttle valve lever on the 1/3 carburetor was bent inwards and made contact with the carburetor chamber top. The throttle control was actuated inside the cockpit several times, and would eventually push the throttle valve lever past the point of contact on the carburetor chamber top. The throttle valve lever would travel just off the idle stop prior to contacting carburetor chamber top, resulting in the 1/3 carburetor near the idle position during the point of contact, as shown in this photo.


Figure 1: 1/3 carburetor contacting the chamber top 


The throttle valve lever on the 2/4 carburetor was in good condition and did not make contact with the carburetor chamber top. The throttle control was actuated inside the cockpit several times and it would reach its full travel from idle stop to the full throttle stop position. No anomalies were found with the 2/4 Carburetor.

A postaccident engine test run was performed with the engine still mounted on the accident airplane's airframe. The engine was not run at full power due to impact damage sustained to the propeller, but it was operated at various idle power settings. The effects of the throttle valve lever on the 1/3 carburetor making contact with the carburetor chamber top was inconclusive during this test run. However, the run verified the engines ignition, fuel, oil and coolant systems were operating normally. The engine run revealed no mechanical anomalies that would have precluded normal operation. 

A second engine test took place in Vernon B.C, Canada on February 2nd under the direction of the NTSB. A different Rotax 912ULS engine was mounted on an engine test stand with a calibrated propeller. The 1/3 carburetor throttle valve lever was modified to duplicate the 1/3 carburetor throttle valve lever that was found on the accident engine. The 1/3 carburetor throttle valve lever was bent inward to make contact with the carburetor chamber top. The engine was run at various power settings prior to applying full power. The 1/3 carburetor throttle valve lever stuck against the chamber top, the engine ran rough and would not accelerate to maximum RPM.

The 1/3 carburetor throttle valve lever was then manually pushed forward past the point of contact on the carburetor chamber top resulting in a burst of engine power, immediately followed by a smooth running engine at maximum RPM. This scenario was consistent with video evidence obtained by the NTSB during the investigation.

The closest weather reporting facility is Valdez Airport, Valdez, Alaska, about 98 miles southwest of the accident sire. At 0956, a METAR was reporting in part: wind from 080° at 16 knots, gusting to 21 knots; sky condition, clear; visibility, 10 statute miles; temperature 77° F; dewpoint 48° F; barometric pressure 29.88 inches of mercury.

Pilot Information

Certificate: Private
Age: 67, Female
Airplane Rating(s): Single-engine Land
Seat Occupied: Left
Other Aircraft Rating(s): None
Restraint Used: 4-point
Instrument Rating(s): None
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Sport Pilot None
Last FAA Medical Exam: 04/22/2010
Occupational Pilot: No
Last Flight Review or Equivalent: 09/23/2015
Flight Time:  558 hours (Total, all aircraft), 110 hours (Total, this make and model), 433 hours (Pilot In Command, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Manufacturer: AEROPRO CZ
Registration: N151J
Model/Series: A220
Aircraft Category: Airplane
Year of Manufacture: 2013
Amateur Built: No
Airworthiness Certificate: Experimental Light Sport
Serial Number: 37513
Landing Gear Type: Tailwheel
Seats: 2
Date/Type of Last Inspection: 03/22/2016, Condition
Certified Max Gross Wt.: 1235 lbs
Time Since Last Inspection: 13 Hours
Engines: 1 Reciprocating
Airframe Total Time: 179.1 Hours at time of accident
Engine Manufacturer: Rotax
ELT:  C126 installed, activated, did not aid in locating accident
Engine Model/Series: 912ULS
Registered Owner: On file
Rated Power: 100 hp
Operator: On file
Operating Certificate(s) Held: None 

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: PAVD, 60 ft msl
Observation Time: 1756 UTC
Distance from Accident Site: 98 Nautical Miles
Direction from Accident Site: 261°
Lowest Cloud Condition: Clear
Temperature/Dew Point: 25°C / 9°C
Lowest Ceiling: None
Visibility: 10 Miles
Wind Speed/Gusts, Direction: 16 knots/ 21 knots, 80°
Visibility (RVR):
Altimeter Setting: 29.88 inches Hg
Visibility (RVV):
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: McCarthy, AK (15Z)
Type of Flight Plan Filed: VFR
Destination: WASILLA, AK (IYS)
Type of Clearance: None
Departure Time: 1000 AKD
Type of Airspace: Class G

Airport Information

Airport: MCCARTHY (15Z)
Runway Surface Type: Dirt; Grass/turf
Airport Elevation: 1532 ft
Runway Surface Condition: Dry
Runway Used: N/A
IFR Approach: None
Runway Length/Width:
VFR Approach/Landing: None 

Wreckage and Impact Information

Crew Injuries: 1 None
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 None
Latitude, Longitude: 61.428611, -142.925000 (est)

NTSB Identification: ANC16LA047
14 CFR Part 91: General Aviation
Accident occurred Tuesday, July 19, 2016 in McCarthy, AK
Aircraft: AEROPRO CZ A220, registration: N151J
Injuries: 1 Uninjured.

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

On July 19, 2016, about 1000 Alaska daylight time, a tailwheel-equipped, light sport, experimental, Aeropro CZ A220 airplane, N151J, sustained substantial damage following a loss of directional control after a partial loss of engine power during takeoff from an unimproved airstrip about 5 miles south of McCarthy, Alaska. The certificated private pilot, the sole occupant, was not injured. The airplane was registered to a private individual and operated by the pilot under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as a personal cross-country flight. Visual meteorological conditions prevailed and a visual flight rules flight plan was filed. The flight was planned from the airstrip to the Wasilla Airport (IYS), Wasilla, Alaska.

During an interview with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on July 20, 2016, the pilot stated that while attempting to takeoff, shortly after raising the tail of the airplane, a partial power loss occurred. While attempting to maintain directional control, full engine power abruptly returned. The pilot was unable to input the correct amount of rudder pressure quickly enough to compensate for the increase in left turning tendencies, resulting in the airplane impacting surrounding terrain and sustaining substantial damage to the wings, empennage and fuselage.

The closest weather reporting facility is the Valdez Airport, Valdez, Alaska, about 98 miles southwest of the accident site. At 0956, an aviation routine weather report (METAR) was reporting, in part: wind from 080 degrees at 16 knots, gusting to 21 knots; sky condition, clear; visibility, 10 statute miles; temperature 77 degrees F; dew point 48 degrees F; altimeter, 29.88 inHG.

The airplane was equipped with a Rotax 912ULS engine. A detailed wreckage examination is pending recovery of the airplane.

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