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-   -   High altitude flying and Risk (https://www.pprune.org/questions/583168-high-altitude-flying-risk.html)

IFLY_INDIGO 19th Aug 2016 05:12

High altitude flying and Risk
 
Flying at usual cruising flight levels is good for airline. It saves money.
But it is certainly not good in terms of aerodynamics. It causes severe control issues. Many crashes can be attributed to it.

How many times do we think about it in routine flights while craving/fighting for higher FLs?

Your thoughts..

Capt Claret 19th Aug 2016 05:25


It causes severe control issues. Many crashes can be attributed to it.
Severe control issues. Many crashes.

Really?

DaveReidUK 19th Aug 2016 08:11

Very few crashes happen at high altitudes. :O

vilas 19th Aug 2016 10:55

Want to travel by road?

Dont Hang Up 19th Aug 2016 11:01


Your thoughts...
...my thought?

Your premise is ill informed.

Mad (Flt) Scientist 19th Aug 2016 12:47


...craving/fighting for higher FLs
If anyone were actually doing this it might have a risk.

if people (as they actually do) plan their flights accounting for the performance capabilities of their aircraft, with all the requisite margins, it's no more hazardous at high altitude than at medium (and arguably SAFER than at low)

aterpster 19th Aug 2016 13:12

This is an absurd thread.

oceancrosser 19th Aug 2016 13:53

As the mother said to the student pilot: "Be careful and fly low and slow".

This is one thread for jetblast.

albatross 19th Aug 2016 14:04

Full quote is "Fly low and slow and throttle back in the turns!" I think.

Dan Winterland 19th Aug 2016 16:50


Very few crashes happen at high altitudes
And very few people die flying. What tends to kill them is not flying all of a sudden!

A Squared 19th Aug 2016 22:53


Originally Posted by IFLY_INDIGO (Post 9478529)
But it is certainly not good in terms of aerodynamics. It causes severe control issues. Many crashes can be attributed to it.

Can you name 3 airline crashes attributed to "severe control issues" resulting from high altitudes? I can't. Perhaps they could be considered a factor in AF447 or Air Algerie 5017, but hem maybe not, either. There were a whole bunch of things going wrong with both those flights. All the high altitude loss of control accidents I can think of had something else cause the loss of control.

So I'm coming up short with Airline crashes which can be attributed solely or primarily to "severe control issues" at high altitude.

vilas 20th Aug 2016 16:31

IFLY_INDIGO really?
Some of your questions create the doubt.

aterpster 20th Aug 2016 18:04

Dan Winterland:


And very few people die flying. What tends to kill them is not flying all of a sudden!
I can think of a few exceptions off the top of my head:

MH17 and TWA/UAL over the Grand Canyon and over New York City.

IFLY_INDIGO 21st Aug 2016 17:16

Before posting a negative answer/remark, please ask yourself "how many minutes in your flying career, you have hand flown a commercial jet at high altitudes?". Try maneuvering the airplane in simulator at high altitudes and judge your comfort level yourself. See the airplane reaction.

Its very easy to show your macho in the posts here. My question is for the pilots who accept that 'danger is real' and keep it on their mind

A Squared 21st Aug 2016 17:25

I'm still waiting for your list of accidents which have been attributed to "severe control issues" from high altitude flight.

wiggy 21st Aug 2016 17:46


Try maneuvering the airplane in simulator at high altitudes and judge your comfort level yourself. See the airplane reaction.
Never mind the simulator. Before the days of RVSM it was not uncommon to hand fly airliners (even heavies like the 747) for periods of time at high level, e.g for trimming purposes or just for the sake of it. At no time do I remember reports of there being severe control problems or severe control issues.


Its very easy to show your macho in the posts here.
I'm all for not cruising right on Max level for the sake of it but as in all things there's a balance. Some would regard it as being "macho" if you decided to stay low to penetrate monsoon weather, rather than being up at a sensible FMC related cruise level.

Intruder 22nd Aug 2016 00:02


Before posting a negative answer/remark, please ask yourself "how many minutes in your flying career, you have hand flown a commercial jet at high altitudes?". Try maneuvering the airplane in simulator at high altitudes and judge your comfort level yourself. See the airplane reaction.
Commercial airliner? A few hours. RVSM has made that practice illegal for the most part.

Tactical jets (A-4 and A-6), which are MUCH less stable than a commercial airliner? HUNDREDS of hours! The A-4s I flew seldom had working yaw dampers, much autopilots. Virtually ALL was hand-flown. The A-6 had a better autopilot; but still failed quite often, compared with the 747.

Still, in over 13,000 hours over 40+ years of flying, I have yet to see a "severe control issue" or ANY crash due to high-altitude flight.

We're still waiting for your examples of "severe control issues" and crashes attributed to "Flying at usual cruising flight levels"...

vilas 22nd Aug 2016 18:46


Try maneuvering the airplane in simulator at high altitudes and judge your comfort level yourself. See the airplane reaction
You seem to be traumatised by your sim experience. Every batch during type rating is given handling at FL350 and shown that even at bank angles of over 30 degrees there is substantial margin between MMO and Valpha prot/ Vls. I am sure it was a sim problem. The accidents that happened were because the pilots yanked the stick back in alternate law. Had they done nothing it would have been safe. If you compare CFIT accidents you may change your opinion.

gatbusdriver 24th Aug 2016 23:32

I agree whole heartedly, hand flying at altitude is extremely dangerous if you are close to your max FL and yank the stick back as your are dumped into unreliable airspeed, it could definitely result in death!

Of course you could breath for 1 second, work out what has just happened and why, whilst you are in no real out of trim condition and then apply the necessary memory items.......oh there we go........disaster avoided.

Whilst we (I) talk about unreliable airspeed, has anyone tried 4 degrees and 70% in cruise on the B777 in the sim? Not convinced I would try that myself, more like 2 degrees and 85% (depending on weight etc).

Anyway......jetblast here we come.

GBD

galaxy flyer 25th Aug 2016 02:44

Intruder,

Dropped off the tanker in the mighty Hun one night with lots of fuel. Lead asks for a block to 430. Controller approves and watches us fall out if the sky in the low forties, one by one each plane reached its exact coffin corner. Fun times, especially the descent waiting waiting for enough margin to pull a bit.

Years later, during Desert Storm, hand flew the C-5 across the Atlantic and once back up the Med from the sandbox.

OP,

If you are fearful of operating a jet within the prescribed envelope, may I suggest a career change.

GF


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