The Federal Aviation Administration has approved a new turbocharger exhaust clamp designed to address a long-standing reliability issue affecting tens of thousands of turbocharged general aviation aircraft.

Hartzell Engine Tech recently received FAA Parts Manufacturer Approval (PMA) for its patent-pending AeroForce V-Band Clamp, providing aircraft owners with a certified replacement option for components affected by Airworthiness Directive (AD) 2023-09-09.

Longstanding safety concern

For decades, the connection between a turbocharger and an aircraft’s exhaust system has been a known weak point. The connection is secured by a component called a V-band coupling, which holds the exhaust tailpipe and turbocharger together. Exposure to extreme heat and vibration can cause traditional clamps—especially those built with spot welds or riveted joints—to warp or fail.

If a clamp fails, hot exhaust gases can escape into the engine compartment, creating risks that range from engine damage to the potential for in-flight fires.

In response to these concerns, the FAA issued AD 2023-09-09 in 2023. The directive established a 500-hour life limit for spot-welded, multi-segment V-band couplings and a 2,000-hour limit for certain riveted or single-piece units, along with mandatory repetitive inspections.

The directive affects a wide range of turbocharged, reciprocating engine-powered airplanes and helicopters, as well as certain Continental and Lycoming engines. Industry estimates indicate the rule applies to more than 41,000 aircraft and engines.

Parts shortage created operational challenges

While the directive addressed a real safety issue, it also created operational challenges as the supply chain struggled to keep up with demand for replacement parts.

Many aircraft had couplings that exceeded the new life limits, and the limited availability of compliant replacements made it difficult for operators to complete required upgrades. In some cases, aircraft were grounded even though they were otherwise airworthy.

Temporary relief came through an alternative method of compliance (AMOC) issued by Continental Aerospace Technologies, which extended replacement timelines for some affected engines. However, the extension only provided additional time while the industry worked toward a longer-term solution.

New clamp design aims to improve durability

Hartzell Engine Tech began developing an alternative shortly after the 2023 directive was released. Drawing on its experience with exhaust system components and FAA-approved parts manufacturing, the company engineered a redesigned clamp intended to address common failure points.

The AeroForce V-Band Clamp, approved Feb. 27 under an FAA PMA supplement, features a design that reduces the number of welds and rivets typically found in traditional clamps. Instead, it incorporates a braided wire cable and floating retainer, which are intended to improve durability and simplify installation.

According to the company, the new clamp completed engine cell testing, inspections, and regulatory evaluation before receiving FAA approval.

Potential industry impact

Installation of the AeroForce clamp provides operators with a compliant replacement for affected couplings and may eliminate the recurring inspection requirements associated with the AD for spot-welded clamps.

The approval also offers aircraft owners an additional supply option at a time when replacement parts have been difficult to obtain.

Production underway

The AeroForce V-Band Clamp has entered production, with units available through authorized Hartzell distributors. Pricing is expected to be about $1,495 for the Lycoming version and $805 for the Continental version, according to the company.

For aircraft owners working to comply with AD 2023-09-09, the newly approved clamp provides another certified option to address the reliability concerns associated with traditional V-band couplings while helping keep aircraft in service.