Enhancing Safety with a Reversed Speed Tape: A Glass Cockpit PFD Perspective

In modern aircraft, the Primary Flight Display (PFD) plays a crucial role in providing pilots with vital information to ensure safe flight operations. The Speed Tape, a fundamental component of the PFD, is designed to display an aircraft's airspeed, often with various warning bars indicating critical speed limits. However, I propose that a simple yet effective modification could enhance safety: reversing the direction of the Speed Tape.

Currently, most glass cockpit PFDs, including those from Boeing and Airbus, feature a Speed Tape that runs from bottom to top. This layout has been adopted as a standard for several decades, but it may not be the most intuitive or safe design. In my opinion, inverting the Speed Tape could significantly improve pilot understanding of its warning bars.

Consider the following scenario: when an overspeed warning appears on the Speed Tape's top, pilots are required to push the sidestick backward to respond to the warning. Conversely, during low-speed conditions, they need to push the stick forward. This dichotomy can be confusing, especially for less experienced pilots or those operating in high-stress environments.

The Gulf Air A320 accident in Bahrain serves as a poignant reminder of the importance of pilot orientation and reaction time. The investigation found that the pilots applied 11 seconds of forward input on the sidestick following an overspeed warning, ultimately contributing to the tragic outcome. It is possible that the reversed Speed Tape layout played a role in this disorientation.

Inverting the Speed Tape would align its warning bars with the actual pilot response required during critical phases of flight. For example, an overspeed warning bar on the bottom of the tape would necessitate a backward stick input, while a low-speed warning bar at the top would require forward motion. This design change could reduce pilot disorientation and improve their ability to respond effectively to warning indications.

While this proposal may seem simple, it has the potential to positively impact safety in modern glass cockpit aircraft. By reevaluating our assumptions about PFD design and incorporating more intuitive layouts, we can work towards a safer and more efficient flight environment.

Glass cockpit pfd