A Cognitive Engineering Analysis of the Vertical Navigation (VNAV) Function

Abstract

Verbatim from NASA NTRS. Not paraphrased, not summarized.

A cognitive engineering analysis of the Flight Management System (FMS) Vertical Navigation (VNAV) function has identified overloading of the VNAV button and overloading of the Flight Mode Annunciator (FMA) used by the VNAV function. These two types of overloading, resulting in modal input devices and ambiguous feedback, are well known sources of operator confusion, and explain, in part, the operational issues experienced by airline pilots using VNAV in descent and approach. A proposal to modify the existing VNAV design to eliminate the overloading is discussed. The proposed design improves pilot's situational awareness of the VNAV function, and potentially reduces the cost of software development and improves safety.

Authors

• Sherry, Lance RAND/Honeywell International, Inc.
• Feary, Michael NASA Ames Research Center
• Polson, Peter Colorado Univ.
• Mumaw, Randall Boeing Computer Services Co.
• Palmer, Everett NASA Ames Research Center