Zonk Air Accident

Zonk Air Accident

On November 7, 2010 around dusk, a 1980 PA-31-310 twin engine, turbo charged “Navajo”, operated by Zonk Air Charters, impacted terrain following visual flight rules while operating in an instrument flight rules (IFR) condition. Five miles after takeoff from runway 18 at Lake Tahoe Airport the aircraft hit a communications tower and then dove into the ground. All on board one pilot, and four passengers died in the incident, and the aircraft was destroyed due to the ground impact and post-crash fire. The aircraft was being chartered for a sunset photo shoot with the possibility to continue to Burbank, CA. The airplane’s cargo included four heavy trunks full of camera equipment. (Dillion, 2010)

Upon arrive on the scene it was obvious where the plane had struck the tower. It was also obvious where the aircraft had made contact with the ground. Wing tip marker light remains in each terrain scar along the path indicate which wing hit first. The aircraft appeared burnt and twisted, with soot marks found in the slipstream along the right engine nacelle. The burn marks on the fuselage however were vertical. Examination of the right propeller showed the classic “S” compression. (Dillion, 2010) The left engine showed no slipstream fire, and had a bent prop unlike the right. The main body of the aircraft was mangled beyond recognition, with no cockpit, or passenger area recognizable. Although the instrument panel was destroyed it was quite noticeable that all levers, props, throttle, mixture, and feathering levers were in the forward position. (Dillion, 2010)

The pilot was a fairly new addition to both Zonk Air and the PA-31-310 airframe. Although he was multiengine certified he lacked the correct certifications to man a plane by himself. He only had 15 hours of his 50 hours on twin engines on this specific airframe. He also lacked adequate training to fly in the current IFR conditions present during the time of the accident. He only had 5 hours of actual IFR flight time. At the time of the incident the pilot was 2 days over his “grace” period for the 135-check ride. The pilot was responsible to file all plans, and weather report and there was no VFR or IFR flight plans filed prior to the flight.

The aircraft was a 1980 PA-31-310 twin engine, turbo charged “Navajo” with Lycoming IO0540 reciprocating engines which had been rebuilt. The airframe had 15,000 flight hours and was within 10 hours of its Time Before Overhaul, and 2 hours before its next 100-hour inspection. This aircraft had a max gross weight of 6,500lbs, and an empty weight of 3,900 lbs. Fuel load for this flight was 1,000lbs of fuel, plus 900 in cargo, 800lbs in passengers and 180lbs for the pilot which brought the aircrafts weight to 6,780lbs. It was observed that the cargo was not secure prior to flight. (Dillion, 2010)

Maintenance was contracted to an outside department locally at the field. It was found that the maintenance facility being utilized for this aircraft is inexperienced for this airframe. Maintenance had logged work done approximately 15 hours prior to the mishap which included the correction of a small seep and a readjustment of the turbo waste gates on the right engine. A number of deferred maintenance items were identified while examining the documentation, taking note to the comment “adding cargo nets, and straps to the aircraft flight kit”. (Dillion, 2010)

Zonk Air is a company that has shown to have no incident record. They have however been cited for failure to maintain proper records in accordance with CFR 135 operations. On the morning of the incident management was informed by the pilot that there was still visible fuel seepage from the right engine. In an effort to get the plane off the ground and complete the job management stated that the drips were normal and probably were coming from the vent/fuel cap due to the fuel being topped off. They were aware of the short turn around for the pilot but because of their low staffing of pilots.

It is my determination that the probable cause of this accident was the pilot’s decision to take off from an unfamiliar mountainous airport at dusk under what was determined to be IFR conditions, in an aircraft