NBAA Unveils New Resource: Managing Risks in Diverse Fleet Operations

Feb. 25, 2025

A new NBAA resource, Managing Risks in Diverse Fleet Operations, considers human factors issues commonly faced by operators of multiple aircraft types, including loss of procedural compliance.

Norman Gionet, a member of the Human Factors Working Group of the NBAA Safety Committee, which developed the guide, and a principal contributor to the resource, shared an example of an operator of both Gulfstream and Falcon aircraft.

“In these aircraft, the cockpit philosophy and layout are completely different, and it can be challenging to switch between the two,” said Gionet. “We often see FOQA [Flight Operations Quality Assurance] data that automatically captures parameters that are outside of the standard operating procedures, such as different flap extension or gear extension speeds.

“Pilots develop different muscle memory for different aircraft,” he added, explaining that pilots who fly one aircraft type frequently and then transition to another type can find it particularly difficult to stay proficient in that second aircraft, even if legally “current,” meeting regulatory requirements for takeoffs, landings and instrument tasks.

Following a 2016 fatal accident at Cleveland’s Burke Lakefront Airport (BKL), the NTSB named mode confusion as a contributing factor to the accident. The pilot was relatively new to the accident aircraft – a Cessna Citation CJ4 – but had hundreds of recent hours in the Citation Mustang. The NTSB identified differences in the autopilot engagement layouts and primary flight displays of the two aircraft as possible contributing factors for the accident.

Managing Risks in Diverse Fleet Operations describes aircraft threats, such as performance and system differences and human factors risks, such as lack of communication and lack of resources, then offers risk mitigations, including through implementation of an effective safety management system.

In the examples above, risks related to pilot dual qualification can be mitigated by rotating training events between aircraft types or requiring minimum experience in a primary aircraft type before permitting qualification in a second type, among other actions.

But the guide isn’t limited to pilots – it also considers technicians maintaining a diverse fleet.

“We geared this resource toward pilots, safety managers, technicians and chief pilots to raise awareness of the risks of a diverse fleet,” said Gionet.

Additional principal contributors were Christopher Bing; Eloy Freitas, Clay Lacy Aviation; Ryan Tollini, Lincoln Financial Group and Jeff Goble, Nimbl.