Among the latest innovations on the GE Passport engine is a unique, 52-inch integrated fan blade and disk, called a blisk, which replaces the traditional fan design that incorporates a hub and individual blades. Although GE has successfully used composite versions of a blisk on military and larger commercial engines, the Passport represents the first application of a blisk in the business aviation market. 

“The friction-welded titanium blisk is new on this engine, and it provides significant benefits,” says Perozek. “The blisk enhances performance by allowing greater airflow through the engine because the blisk nose cone is smaller than that on a traditional bladed fan design,” he explains. “In addition, individual blades must fit into slots resulting in performance loss, which is eliminated with the blisk.” Moreover, the Passport achieves a notable reduction in noise and vibration by using a blisk design. There are maintenance advantages as well. By eliminating separate blades, tasks such as blade balancing, lubrication and inspection are unnecessary, thus eliminating a time-consuming and costly maintenance requirement. 

While the blisk is maintainable on the aircraft, the wide-core thick blades have significant damage tolerance and far greater ability to withstand nicks and dents compared to traditional fan blades. “This robust design alleviates concerns for field replacement,” Perozek says. GE’s experience with fan blisks on military engines bears this out by proving prolonged life under severe conditions.