Piper PA 25-235 N90866

Summary

On 7 October 2017 at about 17:45 local time, a Piper PA 25-235 registered N90866, operated by Skyline Soaring Club, was involved in an accident near Front Royal, Virginia, United States. One person was on board and one died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

7 October 2017 at 17:45

Classification

Accident

Location

Front Royal, Virginia, United States

Nearest airport

Front Royal (FRR)

Coordinates

38.9203, -78.2631

Aircraft

Piper PA 25-235

Registration

N90866

Category

Airplane

Year built

1981

Engines

1

Operator

Skyline Soaring Club

Operating rule

Part 91: General Aviation

Purpose of flight

Glider Tow

Phase of flight

Not recorded

Route

Front Royal → Front Royal

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

ERA18FA006

1 person died.

The tow plane pilot's loss of airplane control for reasons that could not be determined based on the available evidence. Contributing to the accident was the glider instructor's diversion of attention away from the tow airplane which resulted in his delay in releasing the tow rope once the tow plane was no longer visible from the glider cockpit.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

A glider was being towed for an introductory flight with the student in the front seat and the glider flight instructor in the rear seat. The glider flight instructor recorded the flight using a digital video camera. At the end of the first video, the tow plane and glider were on the upwind leg of the airport traffic pattern, during initial climb, and the glider was about 200 ft above ground level. The glider's airspeed indicated about 60 knots, and the glider's position relative to the tow plane was consistent with a high-tow position (that is, the glider was positioned slightly above the wake of the tow plane). The video then stopped for unknown reasons. About this time the instructor diverted his attention away from the tow plane. When the instructor looked back toward the tow plane, he did not immediately see it, but then noted that it was below and right of the glider. Analysis and extrapolation of the tow plane and glider flightpaths revealed that during this time the tow plane turned toward the crosswind leg, stopped climbing, and began to descend while the glider continued to climb. The video then showed that the glider's nose then yawed right, and the yaw string was nearly 90° right. The glider's yellow tow rope release handle moved partially aft, and then a snapping sound was heard followed by the tow rope release handle extending further. The tow plane's elevator was in the "up" position at that time, and the glider then turned left and returned to the airport. The tow plane descended nose down into the backyard of a residence and was consumed by postimpact fire. Microscopic examination of the tow rope separation revealed features indicative of overstress separation. This evidence and the snapping sound heard on the second video are consistent with the tow rope breaking about 1 second before the glider instructor fully pulled the tow rope release handle. The up-elevator and nose-down tow plane descent was consistent with the tension on the tow rope lifting the empennage of the tow plane. Examination of the tow plane did not reveal evidence of any preimpact mechanical malfunctions that would have precluded normal operation, and there was no evidence that the pilot attempted to cut the tow rope with the tow plane's guillotine. The tow pilot had a history of hypertension, high cholesterol, and nonocclusive coronary artery disease. The pilot was taking medications to treat these conditions, but they were not considered impairing. According to the tow pilot's autopsy report, his heart was enlarged and he had mild-to-moderate atherosclerosis. Although the pilot's significant coronary artery disease increased his risk for an acute cardiac event, no evidence was found during the autopsy indicating that such an event occurred. On the basis of the available evidence, the investigation could not determine if the tow plane pilot experienced a medical event during the accident flight or why the airplane stopped climbing at 200 ft rather than continuing to climb to the tow-release altitude.

Quoted verbatim from the NTSB record.