NTSB Factual Report

HISTORY OF FLIGHT

On January 7, 2003, at 1232 central standard time, a Piper PA-23-250 (Aztec), N74AA, owned and piloted by a commercial pilot, was substantially damaged during a forced landing in Barrington Hills, Illinois. Visual meteorological conditions prevailed at the time of the accident. The business flight was being conducted under the provisions of 14 CFR Part 91 and was not on a flight plan. The pilot reported no injuries. The flight departed Watertown Municipal Airport (RYV), Watertown, Wisconsin, approximately 1145 cst, with an intended destination of Schaumburg Regional Airport (06C), Schaumburg, Illinois.

The pilot reported that, while in cruise flight, "the left engine started to sputter." He stated that he switched fuel tanks and verified the mixture was rich. "The plane was descending and I went to the single engine glide speed." Shortly thereafter the other engine also started to sputter. At this point, "the plane was continuing to descend." The pilot stated that he setup for a forced landing into a small field. However, he overshot his intended touchdown point and impacted trees adjacent to the field. "I hit trees that were about 50' high in a glide attitude. The plane struck the ground in a wooded area."

PERSONNEL INFORMATION

The pilot held a commercial pilot certificate with single and multi-engine land airplane, as well as instrument airplane, ratings. The certificate was issued by the Federal Aviation Administration (FAA) on November 16, 1998. The pilot held a third class medical certificate issued on July 31, 2002, with a limitation of "Must wear corrective lenses."

AIRCRAFT INFORMATION

The aircraft was a 1966 Piper Aztec, PA-23-250, serial number 27-3288. The Aztec is a 6-place, twin-engine airplane. It was owned and operated by the pilot and was used for business purposes. According to the pilot, the total time on the airframe was approximately 7,600 hours.

According to FAA records, the aircraft was originally approved with a total fuel capacity of 144 gallons under Type Certificate 1A10. This included 36 gallon inboard and outboard main fuel tanks in each wing. Installation of 24 gallon auxiliary fuel tanks in each wing tip was approved by the FAA under Supplemental Type Certificate (STC) SA1480WE. This modification was completed on the accident aircraft on October 6, 1993, and was referenced on a Major Repair and Alternation form (FAA form 337). The total fuel capacity with this modification was 192 gallons.

METEOROLOGICAL INFORMATION

The routine aviation weather report (METAR) at the Palwaukee Municipal Airport (PWK), Wheeling, Illinois, 15 nm east of the accident site, at 1253 cst, was recorded as:

Wind: 250 degrees magnetic at 15 knots, gusting to 21 knots;

Visibility: 10 sm;

Sky Condition: Overcast at 10,000 feet agl;

Temperature: 2 degrees Celcius;

Dew Point: -3 degrees Celcius

Altimeter: 29.83 inches of mercury.

WRECKAGE INFORMATION

The Safety Board's on scene investigation began on January 7, 2003, approximately 1400 cst. The accident site was located in a wooded area adjacent to a residence in Barrington Hills. The latitude and longitude of the site was determined to be 42 degrees 08 minutes 20 seconds North and 88 degrees 14 minutes 30 seconds West, respectively.

The upper branches of the trees were broken in an area approximately 10 feet in diameter, centered approximately 30 feet northeast of the aircraft resting point. There were no significant breaks immediately above the aircraft.

The aircraft wreckage was contained in an area approximately 30 feet by 30 feet. The fuselage rested on the ground, in an upright position, aligned on a 130 degree magnetic heading. The nose assembly separated from the aircraft and was approximately 8 feet southeast of the fuselage. The aft fuselage and empennage, although still attached to the aircraft, was twisted to the left at a 90 degree angle to the longitudinal axis of the main fuselage, and upward approximately 75 degrees relative to the terrain. This portion of the empennage was resting against a tree. The left horizontal stabilizer separated from the aft fuselage/empennage and rested in a tree adjacent to the left side of the fuselage, approximately 10 feet above ground level.

Both wings remained attached to the fuselage. The aft, inboard edge of the left wing was separated from the fuselage by approximately 4 inches. The wings exhibited multiple indentations along the leading edges. The outboard 2½ feet of the left wing tip separated from the main wing and came to a rest approximately 14 feet southeast of the main fuselage. The right wing tip was adjacent to the main wing, however it was detached completely.

The inboard main fuel tanks were empty. The outboard main tanks contained fuel, however an exact amount could not be determined. Both wing tip tanks were separated and ruptured.

Flight control surfaces remained attached to the airframe. One exception was the left elevator, which was separated from the tail with the left horizontal stabilizer. Flight control continuity existed from each attached control surface to the cockpit flight control column.

The engines were in proper position, relative to the remainder of the airframe. The right engine was dislocated upward and outboard, relative to the wing position, with the spinner resting against a tree. The propeller was intact and appeared to be undeformed. The left engine appeared intact and properly aligned with the relative wing position. The propeller and spinner were intact. The propeller appeared undeformed with the exception of one blade, which was bent aft approximately 45 degrees over a 9 inch length beginning at the tip.

The powerplant control quadrant was intact. The throttle, propeller pitch and mixture controls were all at the forward stops. The fuel selector levers were in the full aft position, adjacent to a placard stating: "36 gal main on". Pressure crossfeed lever was in the "on" position. Engine control continuity existed on both engines.

The tachometer associated with the left engine indicated 7,668.90 hours. The tachometer associated with the right engine indicated 269.84 hours.

ADDITIONAL INFORMATION

The pilot stated he departed the Schaumburg Regional Airport (06C) approximately 0900 cst and arrived at Watertown Municipal Airport (RYV) approximately 1000 cst that morning. He reported he had about 1-1/2 hours of fuel in the inboard main tanks on departure from 06C. The accident flight from RYV lasted approximately 45 minutes.

Upon arrival at RYV, he requested the fixed base operator (FBO) line service personnel top off the inboard main fuel tanks. He stated prior to departure for his return trip to 06C, he verified that the fuel tank caps were present and secure, but he did not remove any of the fuel caps to visually check fuel quantity.

The aircraft was configured with 3 fuel tanks in each wing, the production inboard and outboard main tanks and the auxiliary wing tip tanks. The inboard and outboard main tanks were configured with a sub-flush fuel cap that was covered by a small, hinged panel. The auxiliary tank fuel cap was a standard, twist-off type. This cap protruded above the wing contour and was not covered by a secondary panel.

According to the FBO at RYV, the aircraft was fueled with 40.0 gallons of 100 low lead aviation gas. The line service personnel who fueled the aircraft stated the pilot requested the outboard fuel tanks be topped off. During an interview, when questioned about the configuration of the fuel cap, he reported the tanks he fueled had standard, twist-off caps. He did not have to open a panel in order to access the fuel cap. In addition, he stated the caps of the tanks fueled were 6 inches to 1 foot from the end of each wing. The individual went on to state the pilot was present at the aircraft during fueling and he did not visually verify fuel quantity prior to departure.

A post-accident examination of each engine was completed. The fuel flow divider units for both engines were disassembled and did not contain any fluid. The diaphragms were intact. No other anomolies were noted.

According to FAA records, the pilot had been involved in one prior fuel-related accident, which occurred in November 1984.

NTSB Probable Cause

The pilot's improper fuel management, which resulted in fuel starvation. An inadequate preflight inspection and the trees encountered during the forced landing were contributing factors.