NTSB Factual Report

HISTORY OF FLIGHT

On April 17, 2000, at 1220 Eastern Daylight Time, a Piper PA-12, N3813M, was substantially damaged while maneuvering to pick up a banner on Runway 36 at the Norfolk Municipal Airport (32M), Norfolk, Massachusetts. The certificated commercial pilot/owner was fatally injured. A visual flight rules flight plan was filed for the flight conducted under 14 CFR Part 91. Visual meteorological conditions prevailed.

A witness was working approximately 50 yards from the runway when the accident occurred. In his written statement, he said:

"The plane was attempting to pick up a banner, missed the first time, circled around for a second attempt, came down for the pick-up, flew up steeply, the engine cut out, then the plane nosed down and hit the ground. The engine cut out at approximately 100 feet."

A second witness, also working approximately 50 yards from the runway, stated the following in his written statement:

"The pilot was picking up a banner and on the second attempt the plane approached the catch rope. The plane climbed to about 100 feet and then the engine stalled without power. The plane nosed over and descended with a slight recovery as it hit the ground."

A third witness was standing west of the runway and videotaped the airplane's attempt to pick up the banner. A copy of this tape was made available to the Safety Board. A review of the videotape revealed that the airplane approached the two banner poles and catch rope at low altitude. Prior to flying between the poles, engine sounds were heard to increase. When the airplane flew over the catch rope, another increase in engine sound was heard and the airplane flew upwards. At that time, the airplane flew out of the camera's view, but could still be heard. After the last increase in engine sounds, the engine sounds decreased, followed by two surges of the engine. The camera was then focused back on the airplane which was in an approximate 45 degree nose down descent. Prior to contacting the ground, one last surge of the engine was heard.

The accident occurred during the hours of daylight approximately 42 degrees, 7 minutes north latitude, and 71 degrees, 22 minutes west longitude.

PILOT INFORMATION

The pilot held a commercial pilot certificate with ratings for single and multi-engine land, single-engine sea, and instrument airplane. He also held an airframe and power plant certificate.

His most recent Federal Aviation Administration (FAA) second class medical certificate was issued on July 1, 1999.

The pilot was the owner and operator of Cape Cod Flying Service, Inc. According to the pilot's logbook, the last entry was July 1, 1999. At that time, he had accumulated 5,498 total flight hours. The last entry logged in the accident airplane was on February 8, 1994, for a scenic flight. The last banner towing flight logged in the accident airplane was on September 2, 1993.

METEOROLOGICAL CONDITIONS

Weather at Norwood Memorial Airport, Norwood, Massachusetts, approximately 10 nautical miles northeast of 32M, was wind from 100 degrees at 11 knots gusting to 19 knots, visibility 10 SM, scattered clouds at 11,000 feet, temperature 44 degrees Fahrenheit, dewpoint 35 degrees Fahrenheit, and altimeter setting 30.27 inHG. The relative humidity was 70.3 percent.

WRECKAGE EXAM

The airplane wreckage was examined at the accident site on April 18, 2000, and all major components were accounted for at the scene. The airplane came to rest upright on an approximate heading of 360 degrees.

Examination of the wreckage revealed that the altimeter, tachometer, and vertical speed indicator (VSI) were not connected to their respective hosing and cables. The knurled fitting that attached the tachometer cable to the tachometer was found unscrewed, and the threads were undamaged.

Both wings exhibited leading edge impact damage and wrinkling. The wing center section was peeled away from the airplane by rescue personnel. Wing strut tubing was found compressed on both sides, and a section of the right strut assembly was found to have penetrated through the bottom and top surfaces of the right wing. The airframe tubing of the empennage was bowed downwards and was resting on the tail wheel. The tail section was intact and undamaged. Control cable continuity was established from the cockpit area to all control surfaces.

The airplane had been serviced with 3.8 gallons of 100 LL fuel at Mansfield Municipal Airport, Mansfield, Massachusetts, the morning of the accident. Approximately 27 gallons of 100 LL fuel was drained from the airplane at the accident site. The fuel was absent of contamination. All fuel lines from the wings to the glass fuel strainer, which was found broken, were clear of obstructions. Small patches of sediment were found on the surface of the fuel strainer screen. Both fuel selector handles were intact and secured to their respective fuel selector valves. Both valves were found in the "main" tank position.

The throttle was in the "full RPM" position, the mixture handle was in the full "rich" position, and the carburetor heat handle was in the "off" position.

The engine was removed from the airframe and examined. The carburetor was broken off the engine, but remained partially attached by throttle linkages. The propeller and hub assembly were intact and secure to the engine. One blade exhibited chord wise scratches on the outer 1/3 section of the blade and was bent aft. The other blade exhibited leading edge chord wise scratches along the outer 2/3 section of the blade and was bent aft.

Engine valve train continuity and cylinder compression were obtained on all four cylinders by manual rotation of the propeller flange. The oil pressure screen and oil sump screen were absent of debris. Both magnetos produced spark to all leads when rotated. The top and bottom spark plugs were removed, appeared light gray in color, and the oval electrodes exhibited erosion.

The carburetor was disassembled. No fuel was found in the carburetor bowl, but approximately one ounce of fuel was inside the accelerator pump chamber. The carburetor screen was absent of debris and the composite floats were intact. All of the internal components of the carburetor were intact.

AIRPLANE INFORMATION

According to the airplane's logbooks, the last annual inspection was performed on June 18, 1999, at a tachometer time of 4,260.0. At the time of the accident, the tachometer read 4,357.1.

MEDICAL INFORMATION

An autopsy was performed by the Office of the Chief Medical Examiner, Boston, Massachusetts, on April 18, 2000. Toxicological testing was performed by the FAA Toxicology Accident Research Laboratory, Oklahoma City, Oklahoma.

ADDITIONAL INFORMATION

According to the Bridgeport Flight Service Station, Bridgeport, Connecticut, Norfolk Airport was closed and permission was necessary from the airport manager to conduct operations at the airport. According to a representative of the airport owner's insurance company, the pilot did not have permission to operate at the airport the day of the accident.

According to the Flight Training Handbook/AC 61-21A:

"In the float-type carburetor, the fuel is evaporated and vaporized immediately downstream from the throttle valve at the narrowest portion of the carburetor venturi. The effect of the evaporating fuel and decreasing air pressure causes a sharp drop in temperature within the carburetor venturi. In moist air or high relative humidity, the moisture in the air entering the carburetor condenses and, because of the lowered temperature, may result in the formation of ice. When ice forms in the carburetor, it tends to choke off the flow of air and reduce the power output, or even prevent the engine from operating.

"Carburetor ice can be prevented or eliminated by raising the temperature of the air entering the carburetor venturi through the use of a heating device controlled by the pilot. The pilot should apply carburetor heat whenever conditions are conducive to icing an in the manner recommended by the airplane manufacturer."

According to a carburetor icing probability chart issued by the Department of Transportation (DOT) and FAA in June 1982, weather conditions were conducive for "serious icing at cruise power."

The wreckage was released on April 18, 2000, to the manager of Hopedale Industrial Airport, Hopedale, Massachusetts.

NTSB Probable Cause

The loss of power for undetermined reasons, which resulted in an inadvertent stall during at banner pick-up.