NTSB Factual Report

HISTORY OF FLIGHT

On June 21, 2005, approximately 0930 mountain daylight time, a Cessna 320E multiengine airplane, N3438Q, was destroyed following a loss of power and forced landing about one nautical mile west of the Missoula International Airport (MSO), Missoula, Montana. The pilot and sole passenger received serious injuries. The airplane was registered to a private individual and operated by Map Incorporated, of Missoula, Montana. Visual meteorological conditions prevailed for the planned cross-country flight, which was operated in accordance with 14 CFR Part 91, and a flight plan was not filed. The flight was originating at the time of the accident, with its destination being MSO after completing an aerial mapping mission in Idaho.

After recovering from serious injuries sustained in the accident the pilot submitted a written report to the NTSB investigator-in-charge (IIC), dated November 15, 2005. In the statement the pilot reported that prior to taking off the airplane checked out normal during the run up. The pilot stated that the takeoff was normal, but approximately 100 to 200 feet above ground level (AGL) the right engine quit. The pilot reported that he secured the right engine by pulling back the throttle, feathering the propeller, shutting off the mixture, and turning the fuel selector to OFF. The pilot further reported that at this time he was in a 5 degree bank to the left, then turned about 25 degrees to the left toward a field to avoid some trees. The pilot stated, "Due to the loss of the right engine, we had lost all the altitude we had gained on takeoff and ended up in the gullies at the west end of the airport. Once the engine was feathered the airplane was climbing slowly, but because of the height of the hill, we hit just short of the top of the hill. The hill rose up rather steep at the end of the field we had flown across and I couldn't get enough altitude to clear it. The top of the hill was quite a bit higher than the trees we had flown between. I kept full power on the engine just before touchdown." The pilot reported that he touched down in a wings level, nose high attitude to avoid it [the airplane] "digging in." The pilot further reported that after the airplane came to a stop, and just before he and his passenger exited the burning aircraft, he heard a loud explosion. In a telephone conversation with the IIC on June 15, 2006, the pilot stated that the gross takeoff weight of the aircraft was 5,382.6 pounds. According to Cessna Aircraft Company, maximum certificated gross takeoff weight for the Cessna 320-E airplane is 5,300 pounds.

Two Federal Aviation Administration (FAA) air traffic controllers who witnessed the accident, supplied individual statements to the NTSB IIC, both dated June 21, 2005. The first tower controller reported observing the accident aircraft near the 2,000-foot remaining marker of Runway 29, when the pilot radioed the tower of a right engine failure. The controller stated that the airplane appeared to be too high to land on the remaining runway available, but was cleared to land as an option. The controller reported observing the aircraft veer to the right, and then veer to the left crossing the extended centerline of Runway 29, about one-half mile and 50 feet AGL. The controller stated, "When it became clear that the airplane would not be able to maintain flight, and prior to impact, which occurred approximately 1 mile west of the airport, I advised them that help was on the way." The ground controller observed a puff of dust and the onset of black smoke." The second tower controller reported hearing the pilot say that he had lost his right engine while departing Runway 29. The controller stated that he then observed the airplane over the departure end of the runway at a low altitude, fly past the departure end in level flight, and then veer slightly to the right. The controller further stated that he observed the aircraft make a shallow left turn toward the south while descending, then lost sight of the airplane behind some trees and rising terrain about 1 mile west-southwest of the departure end of Runway 29. The controller reported, "I observed a cloud of dust rising from just south of the last observed location, and shortly thereafter I observed black smoke rising from the same location."

An FAA airworthiness inspector, who traveled to the accident site, reported that both engines had separated from the airplane, and that with the exception of the right wing and tail section, the entire aircraft had been consumed by fire. During the recovery process it was observed that the airplane's right engine, which had separated from the right wing, was recovered from an adjoining canal located approximately 25 feet from where the main wreckage came to rest. The compressor section of the engine's turbocharger had separated from the engine and was also recovered from the canal. The aircraft was subsequently moved to a secure storage facility at the Missoula International Airport for further examination by the NTSB, FAA, and parties to the investigation.

PERSONNEL INFORMATION

The pilot possessed an airline transport pilot certificate with single-engine and multiengine land ratings, and a flight instructor certificate for airplane single and multiengine, and instrument airplane. The pilot reported a total flying time of 5,100 hours, with 3,000 hours being in the same make and model as the accident aircraft. The pilot further reported that he had flown 25 hours in the last 90 days, 15 hours in the last 30 days, and 5 hours in the preceding 24 hours. The pilot's most recent biennial flight review was conducted in the accident airplane on August 11, 2004. The pilot was in possession of a valid second class FAA medical certificate, dated January 25, 2005. The medical certificate stipulated no limitations; however, it did include a waiver for color blindness.

AIRCRAFT INFORMATION

The airplane was a fixed wing, multiengine, 1966 Cessna 320E, serial number 320E0038, equipped with two TSIO-520E reciprocating 300 horsepower engines, manufactured by Teledyne Continental Motors. At the time of the accident the right engine, serial number 182800R, had accumulated a total time of 4,865.2 hours, and 1,167.1 hours since its most recent major overhaul. The airplane's left engine, serial number 176291R, had accumulated a total time of 3,310.2 hours, and 287.2 hours since its last major overhaul. The aircraft's most recent annual inspection was conducted on February 16, 2005, at the facilities of Minuteman Aviation, Missoula, Montana. At this time, and in compliance with Airworthiness Directive 84-26-02, new induction air filters, Donaldson Filtration Solutions Air Filters, were installed on both engines. (Refer to Attachment #3, Description of Work Performed) The time interval between the annual inspection and the time of the accident was 54.4 hours.

On March 22, 2006, the mechanic who installed both the left and right engine air-induction filters on N3438Q during the annual inspection of February 16, 2005, submitted a written statement outlining the step-by-step procedure he used in the replacement of the components. In his statement the mechanic related that to the best of his recollection he replaced the left air-induction filter and then the right one about one hour later. The mechanic further stated that this was the first instance that he could recall where he ever encountered induction filters packaged with a sheet of paper inserted inside the induction filter. (Refer to Attachment #4, mechanic's statement)

METEOROLOGICAL CONDITIONS

At 0931, the MSO Automated Surface Observing System reported wind calm, visibility 10 statute miles, temperature 18 degrees C, dew point 11 degrees C, and an altimeter setting of 30.06 inches of Mercury.

WRECKAGE AND IMPACT INFORMATION

Ground scaring and GPS data revealed that the aircraft's initial impact point occurred 4,435 feet from the departure end of Runway 29 on a magnetic heading of 266 degrees, and at an elevation of 3,172 feet MSL. A second impact point was observed 211 feet from the initial impact point on a magnetic heading of 226 degrees and an altitude of 3,128 feet MSL. Additional ground scaring was observed, which revealed that the airplane slid an additional 91 feet on a magnetic heading of 200 degrees before rotating to the left and coming to rest in an upright position on a magnetic heading of 070 degrees, 4,640 feet from the departure end of Runway 29. This positioned the airplane at an elevation of 3,141 feet MSL at latitude 046 degrees 55.501 minutes North and longitude 114 degrees 07.557 minutes West. The energy path was oriented along lightly pastured rolling terrain, on a down slope of approximately 20 degrees, which displayed sooting and thermal damage from a fire.

The right engine, which separated from the airframe and its propeller, was located in a drainage ditch/canal approximately 25 feet south of where the main wreckage came to rest. The right engine's turbocharger compressor section, which had separated from the engine, was also recovered from the canal. It was observed during the initial recovery that paper of a foreign nature was wedged in the turbocharger between the impeller and its housing. The engine's propeller was located at the second impact point with all three blades attached to their respective propeller hubs; each blade was observed to be in the feathered position.

The left engine was found separated from the airframe but intact and lying on its left side, approximately 2 feet in front of the airplane's nose section facing west. The propeller remained attached to the engine. All three blades exhibited leading edge damage and twisting, with nearly 90 degree aft bending.

The cabin/cockpit areas and both inboard wing sections were consumed by fire. The left main tip tank was attached to the outboard wing section and exhibited thermal signatures. The right main wing tank had separated from the wing with thermal signatures observed. The tail section of the airplane, including the elevator, vertical stabilizer, and rudder were intact with only minimal damage noted; there were no thermal signatures present.

All wing flaps and landing gear were in the retracted position. All flight controls were accounted for during the examination of the airplane; however due to the extensive damage to the airplane, it was not possible to confirm flight control continuity.

TESTS AND RESEARCH

On June 24, 2005, under the supervision of the NTSB IIC, an examination of the airplane's #2 (right) engine was conducted by a representative from Teledyne Continental Motors at the facilities of Minuteman Aviation, Inc., Missoula International Airport, Missoula, Montana. The results of the examination failed to reveal any abnormalities with the engine, which would have prevented normal operation. The engine's fuel pump, fuel manifold valve, and fuel nozzles and lines were retained by the NTSB IIC for further examination. (See Attachment #1, Teledyne Continental Motors, Inc., Engine Field Analysis Report)

On July 27, 2005, the NTSB IIC personally examined the #2 engine's turbocharger. It was noted that the impeller could not be rotated, and that a close visual inspection revealed numerous pieces of paper wedged between the component's impeller and the impeller's housing. Following disassembly of the turbocharger and extraction of numerous pieces of paper by the IIC, a further inspection of the paper revealed printed data appeared to match printed data on a Donaldson Filter Solutions Aircraft Filters Service Instructions sheet, P47-8873 for FAA-PMA Dry-Type General Aviation Filters. Inspection of a new packaged filter revealed that the instruction sheet (8 1/2 x 11 folded into a quarter sheet), along with a sticker are placed inside the filter canister and the canister is placed in a plastic bag. The sticker was at the bottom of the bag while the instructions were molded to the inside of the filter.

On November 14, 2005, at the request of the NTSB IIC, and under the supervision of a representative from the FAA, the #2 (right) engine's fuel pump, fuel manifold valve, and fuel nozzles and lines were examined at the facilities of Teledyne Continental Motors, Inc., Mobile, Alabama. The examination of the components revealed no abnormalities which would have prevented normal operation. (See Attachment #2, Teledyne Continental Motors, Inc., Component Analysis Report)

PERFORMANCE

Information provided by a Cessna Aircraft Company air safety investigator revealed that based on the following published single-engine climb performance data, the airplane should have been able to climb at a rate of 384 feet per minute: (See Attachment #4, Single Engine Climb Data, Figure 6-8)

MSO elevation: 3,205 feet MSL

Temperature: 64 degrees F (18 C)

Aircraft gross weight: 5,300 lbs

Flaps: UP

Landing gear: UP

Inoperative propeller: Feathered

Wing bank: 5 degrees toward operating engine

Throttle (good engine): Full Throttle, 2700 RPM, mixture at recommended fuel flow

Note: Reduce rate of climb 25 feet per minute per 10 degrees above standard rate

of 47 degrees

ADDITIONAL INFORMATION

The airplane, minus parts retained by the NTSB IIC, was released to the owner's representative, CTC Services Aviation (LAD Inc), of Grand Junction, Colorado, on June 24, 2005. Parts retained were subsequently released to the owner's representative, Discount Aircraft Salvage, Deer Park, Washington, on January 17, 2006.

NTSB Probable Cause

Terrain clearance was not possible as a result of a right engine failure. Factors contributing to the accident included the rising terrain, foreign material being ingested into the engine's turbocharger, which obstructed the turbocharger's impeller, the failure of company maintenance personnel to ensure that the air filter instruction sheet was removed after maintenance had been completed on the airplane, and the pilot's inadequate preflight planning and decision in taking off in excess of the airplane's maximum certificated gross takeoff weight.