The FAA has issued a special airworthiness information bulletin urging inspections of air inlet hoses used on some models of Piper single and multiengine aircraft.
The SAIB affects Piper PA-28 Cherokee, PA-32 Cherokee Six/Lance, PA-34 Seneca, PA-44 Seminole, and PA-46 Malibu airplanes. It was issued after the FAA reviewed accident and incident data and determined that a collapse of the air inlet hose may have been responsible for 23 instances of unexplained engine power loss.
The air inlet hose "may be between the air filter and the fuel injector, carburetor or carburetor heat box depending on the airplane model," says the SAIB, issued Aug. 6. "A collapsed hose reduces airflow to the engine and could result in a rough running engine or a loss of power."
The SAIB discussed the investigation of a loss-of-power-after-takeoff accident involving a PA-28-140 in November 2013, and alerted owners, operators, and maintenance personnel of affected models of the need to conduct inspections of the air inlet hose of each airplane’s engine(s) within the next 25 hours of time in service. The inspections should ensure that the air inlet hose does not have broken or loose cords on external surfaces; loose or displaced supporting wire; or signs of wear, perforation, deterioration, or collapse. The inspection should also verify that the installed air inlet hose is an approved Piper part.
An air inlet hose observed to exhibit any of the conditions noted, or found not to be an approved Piper part, should be replaced "before the next flight."
The SAIB said that "at this time" the FAA has not found the airworthiness concern to be an unsafe condition that would warrant issuing an airworthiness directive.