McFarlane cowl flap hinges and steering rod boots approved for Cessnas

McFarlane Aviation Products has received FAA-PMA approval for improved cowl flap hinges for Cessna 172, 180, 182, and 185 aircraft, as well as for the steering rod boot and attaching parts on the Cessna 182.

“Cowl flap hinges wear out due to aerodynamic vibration and vibration of the engine cowling. A lot of high frequency engine vibration is transmitted to the cowling through the baffle seal material,” explained Andy Pritchard, McFarlane IA technician. “This vibration and related hinge wear would be reduced if McFarlane’s low friction Cowl Saver baffle seal material was installed on the engine.”

McFarlane FAA-PMA cowl flap hinges utilize selective fit pins to eliminate looseness that allows the start of vibration wear, according to company officials.

McFarlane also received approval for the steering rod boot and attaching parts on the Cessna 182.

According to McFarlane officials, the company has improved the design of both the boot itself and the retaining flange.

The Cessna boot is single ply fiberglass with a stiff silicone rubber coating that is prone to ripping and tears caused by fatigue and premature infrared heat-related material break down, company officials explain.

McFarlane has used a unique deeper convolute design, a three ply material design incorporating both Kevlar and fiberglass, and a supple high temperature rubber coating, officials add. It also upgraded the original aluminum flange to a stainless steel firewall material.

“The Kevlar and fiberglass work together to prevent wear, fatigue, and heat failures while providing extended fire protection at 2,000°F,” said Dave McFarlane. “We have worked for over 20 years to perfect this boot. It has a tough job to do.”

The boot is located right behind the muffler and holes and tears in the steering rod boot could allow for carbon monoxide, smoke, and even fire to penetrate the firewall and enter the cabin, company officials note.