Originally Posted by
Ver5pen
I’ve never flown with a HUD but talking to those that have it’s a clear upgrade during landings and a bit of a cheat code if I’m being honest by the sounds of it (-3 degree line, FPV, speed trend)
Having said that, Airbus managed to be certified to do CAT 3C with no HUD so there’s not really an economic argument for it- in fact many A350 operators don’t go for the HUD option whereas I believe it’s standard on the 787 (777x also?) and was required to allow 737s to go below CAT 1 minima
All true. Nailing three degrees on a visual approach is a no-brainer. Based on my - not first hand - experience with the MD-80, Dash 8 and CRJ I had always thought of the HUD as a poor man's substitute for autoland (or in the MD-80's case substitute for a more complex fail-operational autopilot system
AFAIK). Flying one in real life for 10 years taught me differently as being able to look out and see the most important instrumentation at the same time imho more more than makes up for having to fly Cat IIIs yourself. Even if combined with autoland against the instinct of the beancounters you get better SA. On top of seeing flight data while looking out the window you get
- a clear picture of how high you are in relation to clouds ahead
- a very high resolution ADI with flight path (when training we always felt we were flying all over the place as the HUD indications kept moving but when you observed the same approach on the PFD everything looked like frozen in place)
- an energy state indication
- a speed deviation indication showing whether you're fast or slow compared to selected speed
- an "upset" mode with clearer guidance towards the normal attitude
- guidance where to point the airplane for a TCAS manoeuvre rather than having to hunt a VS
If there's a fault it's making flying so easy with all the information you need concentrated in a miniature area around the direction of flight that it takes some time to keep the ability to scan when it's not available.