BOGSAT
Aircraft HUD EVS Advanced Avionics

Why HUD Resistance?

I think anyone in our profession flying heavy iron and questioning the outright and obvious safety advantages and operational/mission efficiency value of HUDs is flying at night with a hood. More so if they disavow or otherwise eschew HUDs for the “old school ways” of traditional head-down instrument flying and associated techniques.

My position on this isn’t just an assessment of the intuitively obvious or an epiphany brought on by fascination with “new” technologies. It is distinctly a matter of both personal experience, having flown HUDs as a former fighter pilot, and the facts as reported by numerous peer reviewed studies – all as supported by a lot of anecdotal evidence from legions of professional pilots for air carriers (PAX and cargo).

Ignoring the anecdotal for a moment, it strikes me as ludicrous that anyone would deny the overt and manifold advantages of using HUDs in all phases of flight. That said, there are some pilots who think like this … not to mention a lot of air carrier CFOs who are bottom line focused to the point of out-of-hand exclusion of HUDs (and EVS) because of their inability to determine/justify a sufficient ROI on the expenses involved – safety notwithstanding (as all risk is not just mitigated, it’s also amortized, isn’t it?).

All this aside, the value of using HUDs for significant safety improvements in aircraft operations in less-than-desirable weather conditions – even day/night CAVU – has been well understood for a long time, and, in fact, it is empirically proven (see the Flight Safety Foundation Special Report – HEAD-UP GUIDANCE SYSTEM TECHNOLOGY – A CLEAR PATH TO INCREASING FLIGHT SAFETY, November 2009 https://flightsafety.org/files/hgs_nov09.pdf and https://www.flightsafety.org/fsd/fsd_sep91.pdf – covering accidents from 1995 – 2007 – noting that this later study updated work on the same subject that Flight Safety Foundation completed in 1990 for accidents from 1959 to 1989.

In the Executive Summary on Page 1 of the 2009 report, referring to HUDs as Head-up Guidance System Technology (HGST), the study concludes that, “in modern jet aircraft (glass cockpit) the HGST might have prevented or positively influenced 38% of the accidents overall. Of those accidents where the pilot was directly involved, such as takeoff and landing and loss-of-control accidents, the likelihood of accident prevention due to HGST safety properties becomes much greater, 69% and 57%, respectively.”

Further, as Matt Thurber reported in AINoline–(May 12, 2012), “In a study of worldwide accidents that occurred from 1995 through 2007, the Flight Safety Foundation found that an HGS would have likely or highly likely prevented the following percentage of accidents:

  • 38% of all the accidents/incidents;
  • 69% of takeoff and landing accidents;
  • 57% of loss-of-control accidents;
  • 3% of miscellaneous accidents;
  • 19% of propulsion accidents; and
  • 3% of undercarriage-related accidents.”

In its own 2011 undertaking, NASA Langley Research Center rendered the same assessment regarding the utility and efficacy of HUDs in general (whether fixed or Head Worn Display – HWD) https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110011184.pdf :

“The advantages of a HUD in commercial and business aircraft operations are many, but three hold particular appeal:

The conformal display of critical flight parameters/symbology increases safety by reducing the visual accommodation and re-accommodation that the pilot would otherwise have between reading head-down instrumentation and transitioning to out-the-window visual references during operations such as approach, landing, taxiing, and take-off.

The safety benefits of the HUD were recently quantified (Flight Safety Foundation, 2009). The study found that HUDs prevented or positively influenced 38% of accidents overall in modern glass cockpits. Of those accidents where the pilot was directly involved, such as takeoff or loss-of-control, the “safety advantage” of the HUD became much higher (69% and 57%, respectively).

The explicit display of flight path and energy information on the HUD promotes precision touchdown capability and energy management – i.e., maximizing landing performance (minimizing aircraft wear-and-tear). Studies show that significantly lower touchdown sink rates are flown under manual than automatic landings (Rustenburg, Tipps, and Skinn, 2001) and experimental evidence show that the HUD promotes better sink rate control and touchdown performance (Bailey, Kramer, and Williams, 2010; Kramer et al, 2011)”

I could go on highlighting and citing studies but the point to this exercise is imminently and decisively clear – HUDs are a well-proven and highly effective cockpit technology insertion that not only make sense form an operational efficiency standpoint but they are also (to a great degree) a very powerful and exceptionally positive tool for significantly improved and repeatable progress in flight safety – in all phases of flight.

To be fair a good majority of pilots from my experience are all over the concept (and concept of operations) of putting HUDs (and EVS, SVS, CVS) into cockpits as indicated here reference the official 2017 position of the International Federation of Air Line Pilots’ Associations https://www.skybrary.aero/bookshelf/books/4503.pdf – and they make the point – in all phases of flight.

There are many other studies and affirmations of the efficacy achieved in precision flying using HUD technology but I would like to relate a recent anecdotal conversation with a highly experienced ATP I ran into.

I was having lunch at a local deli the other day when we were approached by a fellow who asked what we did as he’d noticed the Archein logo on our shirts. We told him we were working on after-market HUD/EVS mod/installs for air transport category aircraft.

“About damned time!”, he exclaimed.

Turns out he’s a check Captain for American flying 777s.e He spoke of his HUD “experience” flying 737s for another carrier. He was amazed that they didn’t have one for the right seat too – the seat from which he regularly flew.

He went on to explain that when the Captain was using the HUD on approaches, and he was monitoring the approaches as the FO, that his head-down instruments would generally be stable, showing little to no deviation or trending – yet when he’d look over at the Captain he would observe him constantly making control inputs that would otherwise be contra-indicated by the instruments from the right seat that were not showing the deviations. Obviously the Captain was seeing and responding HUD inputs.

This little vignette points out something else that’s pretty damn important as a matter of existing and emerging realities in today’s (and tomorrow’s) air traffic arena – something we should all be thinking about – constantly improving our ability to do precision flying in the precision based navigation environment of the NextGen system.

We hope you found value in this first BOGSAT installment. Here are some of the BOGSAT installments coming your way over the next few months:

“EVS – What’s a Picture Really Worth ~ When You Really (No Kidding) Need Even Just a Peek?”

“Fixed HUD vs Head-Worn ~ Helmet Fires Could Be Coming Your Way”
“ADS-B ~ Why All the Whining – and How Willis in the Fifth Element Predicted All of This?”

“EFVS ~ So, How Many Cameras Are There That Are Actually EFVS Accredited?”

“Cooled vs Uncooled ~ Physics Can Be a Real Bitch”
“SVS is an Alternate Reality ~ What You Don’t See Could Actually Be Right in Front of You”

“CVS ~ How Many Phenomenologies Does ~ How Many Ways Can I See Thee?”

“FANS ~ What’s with the Other 1 JAN 2020 Mandate No One is Going on About?”

“HUD Mandates ~ What Do They Know in China That We Don’t?”

As will always be standard for BOGSAT – we look forward to your comments, questions and suggestions as we look to open and sustain dialogue on issues and information related to precision aircraft navigation and flight technologies.

Like This Article? Please Share!

Share on linkedin
Share on facebook
Share on twitter
Share on email

More Articles