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Head Worn Display for use in Flight Deck Emergency Situations Disclosure Number: IPCOM000235479D
Publication Date: 2014-Mar-04
Document File: 4 page(s) / 304K

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The Prior Art Database


Being unable to view the primary instrumentation in the flight deck is one of the most serious emergencies on board an aircraft. Smoke can obscure the instrumentation and severely limit the view through the flight deck windows. A Head Worn Display (HWD) can overcome many of the disadvantages associated with current Emergency Vision Systems, and provide essential information to both the Pilot Flying and Pilot Monitoring. The addition of head-tracking capability allows the presentation of conformal imagery, which can aid the Pilot in landing the aircraft even when flight deck visibility is reduced.

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Head Worn Display for use in Flight Deck Emergency Situations


Commercial Aviation has an excellent safety record. High standards for pilot training, coupled with the reliability and safety of today's commercial aircraft, has led to an extremely low probability rate for accidents and incidents. Even when an abnormal or emergency situation occurs, pilot knowledge and experience together with step-by-step instructions to resolve the issue (as found in checklists) typically result in a safe outcome. However, one of the most dangerous emergencies on board an aircraft is the presence of smoke on the flight deck. Not only can it be very difficult and time-consuming to isolate the cause of the smoke, but increasing levels of obscuration can make it nearly impossible for the pilot to see anything inside or outside the flight deck.


Being unable to view or use the primary instrumentation in the flight deck (Figure 1) is one of the most serious emergencies on board an aircraft. As well as totally obscuring the instrumentation, smoke can also severely limit the forward and side view through the flight deck windows, making landing nearly impossible.

Because of the various potential sources of smoke within the aircraft and engines, the checklist procedure to isolate the affected system can eat up precious time, during which it can become difficult, if not impossible to read and interpret the instrumentation. Obscuration of the Primary Flight Display can lead to loss of aircraft control.

Figure 1 Smoke on the Flight Deck

Emergency vision systems, such as that illustrated in Figure 2, can be fitted to the flight deck to provide an inflatable box or tent inside of which the pilot is assured of smoke-free visibility. This is typically achieved through a constant flow of air at higher than ambient flight deck pressure. The downside to this type of system is that it has to be physically erected in case of smoke and the viewable instrumentation is limited.

Technical Discussion

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Figure 2 Inflatable Smoke Hood

A Head Worn Display (HWD) as shown in Figure 3, by its very nature, sits directly in front of the eyes. An image is directly presented on each display by means of Switchable Bragg Gratings (SBG) or other similar technology. The images may be identical (which creates a planar, or 2D image) or independent (which can be used to create a 3D image).

Figure 3 Head Worn Display

This allows only a very small air gap between the eyes and the display(s) such that smoke does not obscure the image presented to each eye. At a minimum, primary flight data can be presented on the HWD in a non-conformal manner. The information would remain referenced to the display, and be viewable wherever the pilot positions his/her head. The display may be collimated (focused at infinity) or non-collimated.

With the aid of head tracking, additional information such as Synthetic Vision (Figure 4) and/or Enhanced Vision can be presented on th...