Accident Sequence
A pilot was receiving a competency flight in a seaplane from an FAA inspector. While returning to the initial departure airport, the pilot descended to 1,000 feet and contacted the control tower for landing instructions. The tower instructed the pilot to enter on a right base. Before acknowledging the instructions, the engines began making loud, rough, and unusual noises. The pilot informed the tower that he was 2 miles south, declared an emergency, and stated he had a bad engine on the left side.
The FAA inspector stated that the pilot started the emergency procedure. The manifold pressure and rpm were fluctuating. The inspector could not determine the dead engine by the dead foot, dead engine method because her rudder pedals were stowed. She pointed out a pasture, and the pilot said they were going to the water. She did not recall the pilot shutting down the engine or feathering the propeller. She could not recall the final seconds of the flight.
The airplane collided with a tree and a canal bank before coming to rest inverted in the canal.
Investigation Findings
Examination of the airframe and flight control systems revealed no evidence of a precrash mechanical failure or malfunction. The left propeller was not feathered. The No. 6 front forward spark plug ignition lead was disconnected from the spark plug. The ignition lead shroud threaded coupling on the No. 4 front forward spark plug was unscrewed, exposing the carbon wire.
Both engines were removed and tested at an authorized FAA-approved repair station. The left engine was placed in an engine test cell, started, developed rated power, and achieved takeoff power. The spark plug lead was removed from the No. 6 forward cylinder. During a magneto check, the left magneto had a 125 rpm drop, and the right magneto had a 75 rpm drop. The drop exceeded the allowable limits in the engine overhaul manual. The right engine similarly started, developed rated power, and achieved takeoff power.
Review of the FAA inspector's FAA Form 4040.6 revealed she was not Event Based Current (EBC) for the 4th quarter of the Flight Standards EBC program. She did not meet the EBC quarterly events required by the end of the 14-day grace period. FAA Order 4040.9 states that for an FAA inspector to be eligible or assigned to perform flight certification job functions, they must be EBC current. Inspectors should not accept assignments without compliance, and managers should not assign non-current inspectors.
The inspector's supervisor was aware she was not current. He contacted the FAA Safety Regulation Branch, FAA Southern Region Headquarters, and stated that FAA Southern Region indicated the inspector could administer the checkride. FAA Southern Region stated that at no time did they approve or agree to an operation outside the parameters of the FARs, Inspector Handbook, or FAA Order.
Probable Cause
The pilot's failure to correctly identify an in-flight emergency (fluctuating manifold pressure and rpm due to a disconnected spark plug lead/unscrewed ignition lead shroud) and failure to complete the engine shutdown procedure once initiated (propeller not feathered), resulting in a forced landing and subsequent in-flight collision with a tree, dirt bank, and canal. Contributing to the accident was the FAA inspector's improper supervision of the pilot, and the improper supervision of the inspector by her supervisor in his failure to follow written procedures/directives when assigning a non-current inspector to conduct a competency flight.