Aviation Accident Summaries

Aviation Accident Summary CHI99LA066

CREAL SPRINGS, IL, USA

Aircraft #1

N3689W

Piper PA-32-260

Analysis

The pilot said the airplane climbed to 5,000 feet above mean sea level. He said he attempted to adjust the mixture control, but was unable to do so because of a mechanical problem. According to the pilot, the engine stopped running about 30 minutes after switching to the left wingtip fuel tank. He said, 'I thought of changing the gas tank switch, but thought that I had at least 1 hour [of] gas in all of my tanks so I didn't.' While approachng a field in which to land the airplane collided with trees and the ground. The on-scene investigation revealed the fuel tanks had ruptured during the collision sequence. The fuel selector was found in the 'Left Tip Tank' position. No anomalies were found with the engine or its accessories that would have resulted in a loss of power. The Piper PA-32-260 Owner's Handbook provides the procedures on how to handle an 'Engine Power Loss in Flight.' Among the procedures to be followed is, '1. Fuel Selector- Switch to another tank containing fuel. 2. Electric Fuel Pump- On... .'

Factual Information

On January 16, 1999, at 0930 central standard time (cst), a Piper PA-32-260, N3689W, piloted by a private pilot, was destroyed during a collision with trees and the ground while maneuvering for a forced landing. The airplane's engine experienced a total loss of power while at cruise altitude. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was operating on an IFR flight plan. The pilot and passenger reported minor injuries. The flight departed Chesterfield, Missouri, at 0840 cst. Before departing on the flight the pilot said he did an engine "...preflight runup..." that revealed "...nothing abnormal... ." During N3689W's climb to its assigned altitude of 5,000 feet above mean sea level (msl) the pilot said he began to lean the fuel mixture. He said, "I glanced... at the EGT [exhaust gas temperature gauge] meter but it hadn't moved yet, so I turned the knob a bit more to lean out the mixture." The pilot said the EGT did not change after the second time he leaned the mixture. He said he noticed that the "...mixture rich knob... was unscrewing but not turning the rod. I then screwed it back on... ." The pilot said he tried to pull the mixture control rod out with a pair of pliers and did not notice a change in the EGT. He said he didn't "...think we'd have any trouble flying [with a] rich [mixture] that day anyway because it was cold and [the airplane was] at 5,000 feet... ." Shortly after attempting to adjust the mixture the pilot said he switched the fuel selector to the "...left wingtip tank as I usually do on long flights... ." The pilot said he flew the airplane for 30 minutes consuming fuel from the left wingtip tank. He said he noticed the left wingtip tank fuel gauge was reading "...somewhere past half full..." when the engine suddenly stopped running. After the engine's total power loss, the pilot said he slowed the airplane to its best glide speed and turned on the electric fuel pump switch. He said, "I thought of changing the gas tank switch, but thought that I had at least 1-hour of gas in all of my tanks so I didn't. I pushed the mixture rich knob all the way in and tried to restart the engine, without success." The pilot said he flew the airplane toward a field because he decided the airplane would not glide to the airport he had chosen. He said he was unable to turn the airplane to the left and approach his chosen field. He said he turned the airplane to the right and its pitch attitude "dropped." The pilot said he applied elevator back-pressure to regain a glide attitude during the turn. He said he believed he had another field made when he was "...suddenly surprised by a tree top... ." The airplane collided with the treetop and descended to the terrain. The pilot said the passenger noted fuel leaking from the right wing. He reported the right wing was crumpled against the passenger side door. The on-scene investigation revealed the fuel tanks had been ruptured during impact. The fuel selector was found in the "Left Tip Tank" position. Flight control cable continuity was established. However, cable tension could not be checked due to the airframe and control cable damage. The throttle, mixture, propeller and carburetor heat controls were found in the full forward position. They would not function due to airframe damage. The throttle position on the carburetor was in the full "Open" position. The mixture control on the carburetor was in the "Lean" position. No obstructions were found in the carburetor air intake filter or box. Fuel was present from the engine driven fuel pump to the carburetor. No fuel was found in the carburetor. The engine driven fuel pump functioned when power was applied to it. The carburetor flow check met the manufacturer's standards. N3689W had flown about 50 minutes from takeoff to ground impact. According to the pilot, the power setting was 23 inches of manifold pressure and 2,300 rpm during the climb toward his assigned altitude. The Textron Lycoming Operator's Manual for the O-540 engine showed its "Full Rich" fuel consumption rate was about 15.7 gallons per hour at the previously stated manifold and propeller rpm settings. The wingtip fuel tank holds 16.9 gallons usable fuel, according to the Owners Handbook. A copy of the fuel consumption chart is appended to this report. According to the pilot, he had filled the fuel tanks to the "brim" about three to four weeks before the flight. He said the airplane was not flown between its last refueling and the accident flight's date. The FAA Approved Airplane Flight Manual directs the pilot to "...use main [fuel] tanks first." The Owner's Handbook states, "In order to keep the airplane in best lateral trim during cruise flight, the fuel should be used alternately from each main tank, and when they are nearly exhausted, from each tip tank." Excerpts from these documents are appended to this report. According to a representative from Piper Aircraft Corporation, making a left turn would require more control input pressure to obtain the desired roll rate and bank when the airplane is out of lateral balance. The last known refueling of N3689W was on December 13, 1998, when 3.7 gallons of fuel were added to the fuel tanks. A copy of the refueling record is appended to this report. The Piper PA-32-260 Owner's Handbook provides the procedures on how to handle an "engine power loss in flight." Among the procedures to be followed are, "1. Fuel Selector-Switch to another tank containing fuel. 2. Electric Fuel Pump-On... ." An excerpt from the Owner's Manual is appended to this report.

Probable Cause and Findings

was the pilot having the fuel tank selector in the improper position and not following the airplane manufacturer's emergency procedures to restore a loss of power. A factor in this accident was fuel starvation.

 

Source: NTSB Aviation Accident Database

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