Piper PA 25-235 N7117Z

Summary

On 6 September 2014 at about 19:02 local time, a Piper PA 25-235 registered N7117Z, operated by Sky Sailing Inc, was involved in an accident near Warner Springs, California, United States. One person was on board and one was seriously injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

6 September 2014 at 19:02

Classification

Accident

Location

Warner Springs, California, United States

Nearest airport

Warner Springs (CL35)

Coordinates

33.2844, -116.6697

Aircraft

Piper PA 25-235

Registration

N7117Z

Category

Airplane

Year built

1964

Engines

1

Operator

Sky Sailing Inc

Operating rule

Part 91: General Aviation

Purpose of flight

Glider Tow

Phase of flight

Not recorded

Route

Warner Springs → Warner Springs

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR14LA367

1 person was seriously injured.

The glider pilot's failure to maintain directional control during the initial climb while being towed, which led to the tow plane's unstable flight and its subsequent aerodynamic stall. Contributing to the accident was the tow pilot's delayed release of the glider.

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

Read the full NTSB narrative

The pilot of the tow plane had already launched a series of gliders without incident just before the accident. Downwind departure operations were in effect due to wind conditions and the local topography; the glider pilot had been briefed on the departure procedures earlier in the day and had experience flying the departure. For the accident flight, the glider was moved into position, and the glider pilot indicated his intentions via hand signals. Shortly after takeoff, the glider moved out of position. The glider pilot made corrective control inputs as the flight progressed in the traffic pattern; however, he was unable to establish positive control. The glider violently yanked and pulled the tow plane into unusual attitudes throughout the departure, and a positive rate of climb could not be established. The glider pilot continued to encounter control difficulties consistent with pilot-induced oscillations, and the tow line became slack as the glider gained on the tow plane. The tow plane pilot thought the glider had released, and a few seconds later, as the line went taught, the tow plane was forced into an aerodynamic stall. Both pilots simultaneously released the tow line, and, with minimal altitude remaining for recovery, the tow plane crashed in a field just beyond the runway. The glider returned to the airport and landed without incident.  

Quoted verbatim from the NTSB record.