NTSB Factual Report

HISTORY OF FLIGHT

On August 29, 2004, approximately 1230 mountain daylight time, a Beech C35 single-engine airplane, N63AC, was destroyed when it impacted a private residence during a forced landing following a loss of engine power near Kalispell, Montana. The airplane was registered to and operated by a private individual. The certificated private pilot and his sole passenger sustained fatal injuries. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 CFR Part 91 personal flight. The local flight departed the Kalispell City Airport (S27) at approximately 1200.

Several witnesses reported seeing the airplane overhead and hearing the engine "sputter", "hesitate", and "cut out", then start again as it was about to turn onto its final approach to Runway 13. Witnesses also reported that the airplane's engine quit before starting to lose altitude, banked to the left, then observed the wings "go vertical" before going straight down. The airplane impacted the front section of a residential home at the second story level, subsequently coming to rest on the front porch of the residence.

Local law enforcement personnel provided the NTSB investigator-in-charge (IIC) with five witness statements from local residents.

Witness #1, a certificated private pilot, stated that he was in the front yard of his home when he heard an airplane approaching form the east and was immediately alarmed from the noise the engine was making and its relative altitude. The witness reported, "...initially the engine sound was very loud, then a few seconds after the initial sound of the engine I heard it let out a very loud bang! Very much similar to an automobile engine backfiring. There was a momentary silence and then the engine reignited and accelerated and let out another loud bang. Again, a moment of silence before reignition, acceleration, and then a final bang. There was no sound after that."

Witness #2 reported hearing an airplane to the north "sputtering" a few times, then a few seconds later observed the airplane clear power lines by about 50 to 100 feet. The witness stated he then observed to airplane banking to its left and its nose starting to go downward, but his house blocked further view of the event.

Witness #3, a certified flight instructor who was preparing to depart S27 reported seeing an aircraft turning at a low altitude to final approach, "...and a half second later went straight down. Looked like a stall/spin to me."

Witness #4, who was home mowing his lawn, reported hearing what sounded like, "...a hesitation, like a weedeater running out of fuel, and [I] thought oh, no." The witness stated that he did not see the airplane crash.

Witness #5 stated that he was standing on his porch at about 1230 when he noticed a plane coming in about the right altitude [with the engine sputtering]. "It started to decrease altitude more than usual, then went left and right twice. Then I heard no engine [noise], then the wings were inverted in a dive, then it hit the house."

Earlier in the day the pilot had successfully passed a biennial flight review with a local flight instructor. In a written statement submitted to the IIC, the flight instructor reported that prior to the flight he spent over two and one-half hours with the pilot, and emphasized the importance of his (the pilot's) knowledge of the airplane's fuel system. The instructor stated that the pilot demonstrated how the [fuel] selector valve worked, as well as the [fuel] gage indicator, the fuel transfer system, and exhibited appropriate overall knowledge of the fuel system. The instructor further stated, "A visual [inspection] of the left main [fuel tank] showed a full tank. The right main was close to full. A visual check showed no water in the fuel." After boarding the airplane and prior to starting the engine, the flight instructor had the pilot explain the fuel system from inside the cockpit. "He changed the selector to each detent, and then changed back to the left main. He then showed me how the fuel indication worked that was on the right panel. He explained the 1 through 5 numbers; No. 2 indicating close to a full tank in the left main confirmed our visual look into the tank." The instructor reported that during the check flight he reduced power to simulate an engine out, which the pilot handled appropriately. The instructor further reported that after the flight, which lasted for 1.2 hours, he and the pilot discussed engine failures over the town, landing on roads, and maintaining airspeed. The instructor stated that after signing the pilot's logbook he instructed him to check the fuel. There was no record to indicate that the airplane was refueled between the check flight and the accident flight. There was also no record to indicate when the airplane was last refueled prior to the instructional flight.

An onsite examination by the IIC, a Federal Aviation Administration (FAA) airworthiness inspector, and a representative of Teledyne Continental Motors revealed that the cockpit and right wing were destroyed. Further examination revealed that the left tip [fuel] tank and right main fuel tank were breached, while the right tip tank, left main fuel tank, and center auxiliary fuel tank were intact. Both main landing gear and the nose landing gear were in the down and locked position, and both wing flaps were partially extended. The aircraft's engine was separated from the aircraft's engine mounts.

On August 30, 2004, the airplane was removed from the accident site and transported to a local airport hangar for further examination by the IIC, an FAA airworthiness inspector, and a representative from Teledyne Continental Motors.

PERSONNEL INFORMATION

According to FAA records, the pilot held a private pilot certificate for single-engine land airplanes. The pilot held a third class medical certificate, which was issued on August 18, 2004. The medical certificate stipulated a limitation that the pilot must wear corrective lenses while operating an aircraft.

On the pilot's most recent application for his airman medical certificate, he listed 1,323 total flying hours, with 20 hours flown in the preceding 6 months. The flight instructor, who administered the pilot's biennial flight review, reported to the IIC that the pilot had told him he had about 700 hours in make and model.

AIRCRAFT INFORMATION

The low wing 1952-model Beech C35 airplane, serial number D-3279, had a retractable landing gear and was configured to carry a maximum of four occupants. The airplane was power by a Continental E225-8 engine, serial number 35337-D-5-8. A review of the airframe and engine logbooks revealed that the last annual inspection was performed on August 12, 2004, at a tachometer time of 1987.9 hours and a total time of 5478.2 hours.

The airplane was equipped with two 20 gallon main fuel tanks located in each wing, of which 17 gallons in each tank was usable. The airplane was also equipped with two 15 gallon wing tip tanks, and a 10 gallon auxiliary fuel tank located in the baggage compartment. All of the fuel in the tip tanks and auxiliary tank was usable.

WRECKAGE AND IMPACT INFORMATION

The accident site was located in a residential area at 921 4th Avenue West, Kalispell, Montana. The elevation of the accident site was 2,946 feet mean sea level, measured with a Global Positioning System (GPS) instrument. Evidence of the initial impact point was observed at the residence where the first and second stories meet just above the front door. The impact heading was measured at 135 degrees magnetic, with the aircraft coming to rest on a magnetic heading of 090 degrees. The airplane's nose/cockpit area came to rest at the home's front door location, while its tail section came to rest on the its front porch railing oriented toward the west at about a 45 degree upward angle. The airplane's engine came to rest in the living room of the house on a magnetic heading of approximately 180 degrees, 9 feet in front and 20 degrees to the right of the aircraft's cabin/cockpit area. The belly of the aircraft just aft of where the trailing edge of the wing is attached to the fuselage, came to rest on the front porch railing of the residence. There was no post impact fire.

The right wing was destroyed, with leading edge crushing observed aft to the forward spar. The main inboard fuel tank was breached, while the outboard tip tank remained intact, with 2 gallons of fuel drained prior to the aircraft being recovered. The aileron and flap remained attached to the wing with some wrinkling observed.

The inboard one-half of the left wing's leading edge exhibited chordwise scratches. The outboard one-half of the leading edge of the wing was crushed aft to the forward spar. The left main fuel tank was intact, with 5 gallons of fuel drained prior to the aircraft being recovered. The left outboard tip tank was breached and no fuel was present. The bottom of the wing was wrinkled through its span. The aileron and flap remained attached to the wing with some wrinkling observed.

The right side of the fuselage, approximately three feet aft of the aft cabin bulkhead was wrinkled with a vertical crease observed. The belly of the airplane in the same area aft of the aft cabin bulkhead was also wrinkled. The left side of the fuselage from the nose of the airplane aft to the cockpit window was wrinkled. No visible damage was observed to the airplane's empennage.

The airplane's center/auxiliary fuel tank was intact, with 1 gallon of fuel drained prior to the recovery of the aircraft.

Cockpit documentation revealed that the placarded fuel selector was positioned midway between the OFF position and the RIGHT MAIN TANK position. The fuel gage indicator selector was in the #2 position, which corresponds to the LEFT MAIN TANK position; the left main fuel tank indicated one-quarter full. Both tip tank boost pump switches were in the OFF position. The throttle and propeller control levers were both observed in the full forward position, the mixture control was in the full rich position, and the carburetor heat control was in. The single throw-over control yoke was in the left position, the landing gear switch was in the DOWN position, and the flap switch was in the UP position. The cowl flap switch was open, the elevator trim indicator was in the green, and the aileron trim indicator indicated right wing down.

The propeller remained attached to the engine. Propeller blade "A" was bowed back about 30 degrees, 16 inches out from the hub, with the tip of the blade bowed forward about 7 degrees. Leading edge damage and diagonal scratching was observed. Propeller blade "B" was bent back around the engine approximately 90 degrees, with longitudinal scratches observed and there no leading edge damage.

MEDICAL AND PATHOLOGICAL INFORMATION

On August 30, 2004, the Flathead County Coroner's Office, Kalispell, Montana, conducted an autopsy of the pilot. Toxicological testing was performed by the FAA's Civil Aeromedical Institute’s (CAMI) Forensic Toxicology and Accident Research Center at Oklahoma City, Oklahoma. The tests were negative for carbon monoxide, cyanide, ethanol, and drugs.

TEST AND RESERCH

On August 31, 2004, and examination of the airframe and engine was conducted under the supervision of the IIC. Control continuity to all flight controls was confirmed. An examination of the engine revealed that all six cylinders remained intact, rocker box covers 1 and 5 were broken, and three engine mounts were broken; the right aft engine mount was intact. Oil was observed on the bottom of the engine in the area of the #2 cylinder and oil reservoir, with oil also observed streaming back on the bottom of the aircraft. The oil cooler was crushed with holes noted in the component. The carburetor remained attached, but the throttle lever was broken off and the air box was crushed downward. The spark plugs were removed with normal wear noted. The electrodes were clean and beige in color. The propeller rotated freely with thumb compression noted on all cylinders. Spark was observed on the right magneto, but no spark from the left magneto. The left magneto was subsequently removed and rotated by hand, which resulted in good spark. The propeller governor control lever was broken.

On September 13, 2004, under the supervision of the IIC, both of the airplane's magnetos were examined at the facilities of Galvin Flying Service, Seattle, Washington. The functional test of the left magneto revealed that it performed to specifications at coming in speed and run speed. The impulse coupling failed to function at any speed. The coupling was then disassembled, inspected for defects, and reassembled. Although no defects were noted, the coupling still failed to function. The harness was then checked with a high tension lead tester. No defects were noted. A functional test of the right magneto revealed that it performed to specifications at coming in and run speed. The harness was then tested with a high tension lead tester, with no defects noted.

On September 15, 2004, under the supervision of the IIC, the airplane's carburetor was examined and at the facilities of Precision Engines, Everett, Washington. The examination revealed that the flow tests were within specifications, with the exception of the lowest two (2) power settings. The idle setting could not be checked due to the throttle shaft being broken.

ADDITIONAL INFORMATION

FUEL

Take-off On Left Main Tank:

According to the POH, "The optional fuel system consist of two 20 gallon main tanks in wings and either one 10 gallon or one 20 gallon auxiliary tank installed in the baggage compartment. All of the capacity of the 10 gallon tank is usable. Use auxiliary fuel in level flight only and do not use for takeoff or landing. Use at least 10 gallons from left main tank before use of auxiliary fuel or right wing tank, as the pressure type carburetor returns about 3 gallons per hour of excess fuel to the left main cell regardless of the cell selected. When operating fuel selector, feel for detent position. Do not take off when Fuel Quantity Gages indicate in Yellow Bank or with less than 10 gallons in each main tank."

(Refer to attachment #1, Pilot Operating Handbook, Beechcraft Bonanza C35, Section II, Limitations, FUEL)

FUEL SYSTEM

Fuel Tank Selection:

The fuel selector valve handle is located forward and to the left of the pilot's seat. Take-offs should be made using the left main tank and landing should be made using the main tank that is more nearly full. In no case should a take-off be made if the fuel indicators are in the yellow band or, with less than 10 gallons of fuel in each main tank.

Switching Fuel Tanks:

When switching fuel tanks, if one tank is allowed to run completely dry, it may be necessary to place the mixture control to Full Rich position and maintain fuel pressure with the Auxiliary (Wobble) Fuel Pump to aid in restarting the engine. If the engine is allowed to stop firing, due to insufficient fuel, refer to the EMERGENCY PROCEDURES section for the Air Start procedure.

(Refer to attachment #2, Pilot Operating Handbook, Beechcraft Bonanza C35, Section VII, Systems Description, FUEL SYSTEM)

EMERGENCY PROCEDURES

Engine Malfunction In Flight

Listed in the EMERGENCY PROCEDURES section under DISCREPANCY CHECKS, Loss of Power 2b(1) is stated, "Select other tank (check to feel detent)".

(Refer to attachment #3, Pilot Operating Handbook, Beechcraft Bonanza C35, Section III, Emergency Procedures)

FAA Airworthiness Directive (AD) 99-05-13

On April 19, 1999, The FAA issued Airworthiness Directive 99-05-13, which applied to the accident aircraft model. The airworthiness directive required installing a placard on the fuel tank selector to warn of the no-flow condition that exists between the fuel tank detents. This AD was the result of reports of engine stoppage on the affected airplanes where the cause was considered to be incorrect positioning of the fuel selector. T

NTSB Probable Cause

The pilot's improper positioning of the fuel tank selector, which resulted in fuel starvation and a subsequent loss of engine power while maneuvering.