Accident Overview
On July 15, 2012, at 0900 eastern daylight time, a Piper PA-18-150, registration N8048D, operated by Barnstormers Flite Signs Inc. under 14 CFR Part 91 as a banner tow flight, sustained substantial damage after colliding with an airport perimeter fence. The commercial pilot reported no injuries. Visual meteorological conditions prevailed at the time, and no flight plan had been filed. The flight originated from Grand Strand Airport (CRE) in North Myrtle Beach, South Carolina, at 0845.
Pilot Account
The pilot reported that he turned onto final approach at 300 feet above ground level (agl) and reduced engine power to idle. Airspeed was between 60 and 70 mph. Carburetor heat was not activated, which he stated was company policy. When the airplane reached about 10 feet agl and 50 feet from the banner pickup poles, he applied full power and observed the rpm at 2,500—100 rpm below full power. He pitched the nose up and climbed to 200 feet, during which rpm continued to decrease to 1,500. Lowering the nose, he confirmed the throttle was full forward. Increasing mixture produced no change. Unable to maintain altitude, the pilot informed the tower he was going down. He reduced throttle to idle, lowered flaps fully, and executed a forced landing beyond the banner tow grass area, clearing a berm and striking the airport perimeter fence. The airplane nosed over and came to a stop; the engine ceased running. The pilot turned the fuel off at the fuel selector. He stated no mechanical problems with the airframe or flight controls were experienced before the accident.
Owner's Statement
The registered owner of Barnstormers Flite Signs Inc. stated, "It has never been the company policy of Barnstormers Flite Signs to advise a pilot 'NOT' use the carb heat in the event of any emergency situation for obvious reasons."
Weather and Carburetor Icing Conditions
The temperature at the time of the accident was 73 degrees Fahrenheit, with a dew point of 72 degrees Fahrenheit. According to the carburetor icing chart, the airplane would encounter serious icing at glide power. Review of Advisory Circular 91-51A, "Effect of Icing on Aircraft Control and Airplane Deice and Anti-Ice Systems," notes in paragraph 5, Discussion b., that there are two kinds of icing significant to aviation: structural icing and induction icing. Sub-section c. states that small aircraft engines commonly employ carburetor or pressure fuel injection systems, both holding potential for icing that can cause engine failure. Paragraph (1) advises that carburetor icing can occur at temperatures between 13°C (20°F) and +21°C (70°F) with visible moisture or high humidity. Carburetor ice can be detected by a drop in rpm in fixed-pitch propeller airplanes, and some engines are equipped with carburetor heat for prevention and removal of ice.
Damage
The airplane sustained substantial damage in the collision with the fence.