Sunday, August 20, 2017

Piper PA-30 Twin Comanche, N931JS, registered to Hamilton Services Group Inc and operated by Gateway Aviation Ltd: Accident occurred February 16, 2014 at Allentown Queen City Municipal Airport (KXLL), Lehigh County, Pennsylvania

Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Allentown, Pennsylvania

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

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

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

Registered Owner: Hamilton Services Group Inc

Operator: Gateway Aviation Ltd

http://registry.faa.gov/N931JS

NTSB Identification: ERA14LA133
14 CFR Part 91: General Aviation
Accident occurred Sunday, February 16, 2014 in Allentown, PA
Probable Cause Approval Date: 11/03/2014
Aircraft: PIPER PA-30, registration: N931JS
Injuries: 2 Uninjured.

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 flight instructor reported that he simulated a right engine failure, which required the pilot receiving instruction to perform a single-engine, full-stop landing. The pilot receiving instruction maintained the correct airspeed on final but flared the airplane a little high, which resulted in a “solid touchdown.” Shortly after touchdown, while the flight instructor was guarding the rudder pedals with his feet, the airplane veered heavily left, which he attempted to correct with full right rudder and brake. Runway skid marks indicated that the airplane yawed left as it continued to veer left and then collide with a snow bank off the left side of the runway. Postaccident examination of the nose landing gear steering system and the fractured left main landing gear trunnion revealed no evidence of preimpact failures or malfunctions that would have precluded normal operation. No mechanical reason for the loss of directional control was identified during postaccident examination.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The flight instructor’s failure to maintain directional control during the landing.

On February 16, 2014, about 1440 eastern standard time, a Piper PA-30, N931JS, experienced a loss of directional control during landing and collided with a snowbank at Allentown Queen City Municipal Airport (XLL), Allentown, Pennsylvania. The certified flight instructor (CFI) and commercial rated student were not injured. The airplane was substantially damaged. The airplane was registered to Hamilton Services Group, Inc., and was operated by Gateway Aviation, Ltd., under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as an instructional flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The flight originated about 5 minutes earlier from Lehigh Valley International Airport (ABE), Allentown, Pennsylvania.

The CFI stated that the purpose of the flight was for the student to practice simulated single engine failures during various phases of flight. The flight departed from XLL about 1330, and flew to the practice area where the student performed airwork. The flight then proceeded to ABE, where the student successfully performed a simulated single engine full-stop landing. While taxiing for takeoff, the airplane encountered slush. The flight departed ABE returning to XLL where the flight joined the upwind leg for runway 25. The CFI reported that the wind at the time was approximately 5 knots within 20 degrees of runway heading, while a surface aviation observation from XLL about 5 minutes before the accident indicates in part the wind was from 290 degrees at 7 knots.

The CFI simulated a failure of the right engine by bringing the right throttle to idle, which prompted the student to correct for and secure the 'failed' engine. He did perform the procedure correctly, and before turning onto crosswind, the CFI advanced the right throttle to 13 inches of manifold pressure (per the manufacturer's recommendation), and the flight continued in the traffic pattern for runway 25. The student applied the necessary aileron and rudder corrections to account for the 'failed' right engine, and turned onto final approach to runway 25.

While on final approach with flaps fully extended to the landing position, the student kept the longitudinal axis of the airplane aligned with centerline, and maintained 'blue line' indicated airspeed plus ten knots. As the flight approached the runway the student flared a little high or early, with a resulting "solid touchdown" on the dry runway on the main landing gears. Though the CFI could tell the touchdown was going to be firm or harder than average, he didn't feel the need to take over the controls or initiate a go-around since the landing was no worse than others he has had in this aircraft in the past. While guarding the rudder pedals with his feet, shortly, if not immediately after touchdown, the aircraft pulled heavily to the left, which he (CFI) attempted to correct with full right rudder and right brake application. Having no affect the airplane continued to veer to the left and collided with a snowbank off the left side of the runway at about 25 knots. The airplane was removed from the site for further examination.

Postaccident inspection of the airplane following recovery by a FAA airworthiness inspector revealed no evidence of preimpact failure or malfunction of the nose landing gear steering system, or of the left main landing gear trunnion, which exhibited evidence of overload fracture. The FAA inspector also reported observing skid marks on the runway from all three landing gear tires; the skid mark from the nose landing gear tire was very close to the skid mark made by the left main landing gear tire, consistent with the airplane yawing to the left.

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