Attitude indicator
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In short, no.
The F-16 ADI bars are only position indicators and are not pitch and bank command. The only command guidance are the heading caret on the HUD compass tape and the command steering cue on the HUD during ILS approach. They show heading to steer and flight path to steer respectively. This is in contrast to airplanes like the A-4, T-45, A-10 whose bars which appear on the ADI are pitch and bank steering.
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In short, no.
The F-16 ADI bars are only position indicators and are not pitch and bank command. The only command guidance are the heading caret on the HUD compass tape and the command steering cue on the HUD during ILS approach. They show heading to steer and flight path to steer respectively. This is in contrast to airplanes like the A-4, T-45, A-10 whose bars which appear on the ADI are pitch and bank steering.
can you rely on the F-16 ADI when landing in event of HUD failure?
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Legally you can’t rely on the HUD. It’s not IFR certified (FAA/NAS and I assume ICAO too). That might have changed in the last few years I don’t know.
For landing you have to look out the window. For approach to minimums, yeah ADI is part of the instrument scan. I have done a full instrument landing procedure from IAF to minimums with my head between my knees referencing just the altimeter, ADI, VSI, AOA, and HSI. The first I look up is when the alarm goes off at 600’ radalt. Everyone should try it from time to time. It’s educational.
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In RL do pilots have the option of turning the HUD off, when landing – or is it required SOP to keep it on, in normal operational circumstances?
In a separate thread I was recently saying, that in the sim at least, I land much better with HUD turned off… I have a hard time mentally focusing past it, to develop a sense of my speed and altitude … probably because everything is in perfect focus on a 2D monitor in front of my face, with no depth perception. I suspect in RL that the HUD is less obtrusive, probably not an issue that way. But I don’t know. I’ve landed single-engine Cessnas and Pipers, but I’ve never had the luxury of a HUD.
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I think it might be a case of legal to turn off HUD but make you unpopular with your boss
Dimming the HUD plus uncage declutter I find is most improvement. Sim users tend to use full bright a lot and I feel it’s suboptimal.
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Definitely min-brightness, for landing/approach.
I heard you can get more fine-grained dimming if you bind it to an analog axis … but I haven’t tried. Maybe worth setting up a vJoy axis for that, if so.
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In RL do pilots have the option of turning the HUD off, when landing – or is it required SOP to keep it on, in normal operational circumstances?
It can depend on the jet - forex, in the Hornet the HUD is considered the Primary flight instrument - so no, a pilot wouldn’t turn it off under normal circumstances. But in the T45A it was not considered Primary, so there were normal Training instances where you did turn it off.
In a separate thread I was recently saying, that in the sim at least, I land much better with HUD turned off… I have a hard time mentally focusing past it, to develop a sense of my speed and altitude … probably because everything is in perfect focus on a 2D monitor in front of my face, with no depth perception. I suspect in RL that the HUD is less obtrusive, probably not an issue that way. But I don’t know. I’ve landed single-engine Cessnas and Pipers, but I’ve never had the luxury of a HUD.
I hear this all the time from people that are RL pilots and new to simming - and I think you are correct, in that creating a visual interpretation of depth perception from a 2D image is a skill to be learned. And yes - I hold a Private ticket, but I still find it far easier to land with a HUD in front of my face once I learned how to actually interpret it, and use it. It’s much more like doing Instrument procedure all the time, and it’s something that improves with practice like everything else.
I’ve debriefed a LOT of RL fighter pilots and every now and then I’ll get one that will pause and tell me - “you know, you have to scan a HUD”. Yes - it’s just like your instrument panel and you have to learn to use it that way…and use Reject Modes to you comfort - starting with clearing that DED garbage out of the HUD, in the case of the Viper - there’s a selection for that, and BTW - once you get the habit of hawking the Indexer in your visual scan, hawking the DED becomes second nature and having it in the HUD just seems silly.
Another point I recently made to some of my sim student’s is that “it’s not just what you see, it’s how you see”. I told them to think about machine vision and how machines do that, and they improved a great deal. I also gave them some of those 3D staring picture-puzzles to gaze at an that helped them realize that there are techniques to be applied that help.
There is always a way.
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Legally you can’t rely on the HUD. It’s not IFR certified (FAA/NAS and I assume ICAO too). That might have changed in the last few years I don’t know.
For landing you have to look out the window. For approach to minimums, yeah ADI is part of the instrument scan. I have done a full instrument landing procedure from IAF to minimums with my head between my knees referencing just the altimeter, ADI, VSI, AOA, and HSI. The first I look up is when the alarm goes off at 600’ radalt. Everyone should try it from time to time. It’s educational.
HUD is now certified for LVP for civil aircraft. It even can be used to replace some redundancies. Of course you have to be properly trained:
https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_120-118.pdf
c. Use of Autoland or Head-Up Guidance at U.S. Type I Facilities or Equivalent.
(1) Operators may conduct autoland or HUD operations at runways with facilities other
than those with published CAT II/III IAPs without need for special demonstrations, if the aircraft
type AFM does not preclude the intended operation. For autoland system use on CAT I facilities,
OpSpec C061 is issued if required. For HUD system use on CAT I facilities, OpSpec C062 is
issued if required. Precautions to be taken for such operations include the following:
(a) The operator must not conduct automatic landings, or landing operations using a
HUD, to any runway unless the certificate holder determines the flight control guidance and
instrument approach guidance systems being used permit safe automatically flown or
HUD-guided approaches and landings to be conducted at that runway.
(b) The runway and associated instrument procedure must have no outstanding
NOTAMs or chart notes that would preclude the use of the autoland or HUD system
(e.g., “Localizer unusable inside the threshold,” or “Glideslope unusable below xxx feet”). -
Legally you can’t rely on the HUD. It’s not IFR certified (FAA/NAS and I assume ICAO too). That might have changed in the last few years I don’t know.
You cant rely solely on the HUD. As of at least 2014 it is IFR certified as a primary flight instrument in the F-16. You can fly the approach to minima based on the HUD, using the heads down instruments as backup. Obviously below minima you must be heads up, visual with the runway, with sufficient visibility.
The ADI is a primary flight instrument, and can be relied upon for flying instrument approaches. Before the HUD was certified, it was required to be relied upon for flying instrument approaches. The SAI is a backup flight instrument in case the ADI fails.
For landing you have to look out the window. For approach to minimums, yeah ADI is part of the instrument scan. I have done a full instrument landing procedure from IAF to minimums with my head between my knees referencing just the altimeter, ADI, VSI, AOA, and HSI. The first I look up is when the alarm goes off at 600’ radalt. Everyone should try it from time to time. It’s educational.
I think I got more out of flying heads down approaches in BMS than I did out of the rated sim while I was doing my instrument rating. Ditto that its very educational.
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There’s a great article Semper Viper article from the late Joe Bill Dryden from I believe the early 90s at the latest discussing using the HUD as your primary instrument display. I can’t find the link to the .pdf of the collection of his articles right now though.
I’m not sure about USAF policy on HUD focused instrument flight reference, but it seems like while the US Navy trains occasionally still for HUD failures, they have embraced the HUD as your primary instrument reference officially. Effectively, as long as you can still fly the traditional steam/glass instruments when you need to in the really rare instance of HUD failure, the HUD is overall a better tool, especially over steam gauges. But that doesn’t mean you should skip non-HUD instrument flight either.
In a modern airliner or even newer light GA planes, having the FPM and the rest of the data on the glass cockpit is a big so really then the main thing you are gaining using a HUD would be looking out to see when you breakout on an approach. But Block 50/52 and before, it’s stupid simple to scan the HUD and use the FPM even if you can fly the traditional gauges. I’m really curious to hear how most current generation Viper drivers truly fly the HUD or eyes down in instrument. Joe Bill Dryden was ahead of his time trying to convince everyone that the HUD was a great advance when most of the pilots had started their career with steam gauges. There has been a generational shift even in flight training at my level where you embrace the technology more and more (I’m a civilian CFII). Of course, I still say in a lot of ways learning the traditional ways first is better because it is easier to add the technology later to enhance your skills instead of them being a crutch that you depend on to build SA, etc.
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learning the traditional ways first is better because it is easier to add the technology later to enhance your skills instead of them being a crutch that you depend on to build SA, etc.
I may have said this before, but one of the reasons I love the Viper is that it still has big, easy to read analog instruments for airspeed, altitude, attitude, engine rpm/ftit/nozzle, etc… but also the technology is there too. It’s the perfect hybrid.
I’ve been learning to fly the Hornet and I’m loving it, but I miss the big easy-to-scan gauges… and the beautiful unobstructed bubble canopy of course
In my struggles with the Hornet, I sometimes found it helpful to do the cheesy rename-CkptArt-subfolder trick to get the default Viper cockpit for the Hornet. It retains the F18-specific HUD elements but now all the analog instruments are easier to see, and more familiar.
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I heard you can get more fine-grained dimming if you bind it to an analog axis … but I haven’t tried. Maybe worth setting up a vJoy axis for that, if so.
Confirmed – very very nice, esp for night flying.
The max brightness/opacity seems about the same as with keyboard, or clicking the rotary wheel. But the minimum brightness/opacity is much lower.
Wow this ventured pretty OT … sorry for thread-jacking.