
When volcanic ash stopped a Jumbo at 37000 feet (2010) - andrewshadura
http://news.bbc.co.uk/2/hi/uk_news/magazine/8622099.stm
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cyberferret
Something to note, is that most commercial aircraft can glide for anything
from 20 to 30 minutes from cruising altitude before they reach sea level. I
recall reading many news reports of this particular 747 'plunging' to the
earth when all engines failed, but that is not the case.

As noted in the article -

> _Eventually, after quarter of an hour without any power, the engines were
> brought back to life._

In fact, every time your pilot/flight attendant announces that you are on
descent to your destination airport, the pilots will have pulled the throttle
back to flight idle, and your aircraft is essentially gliding down towards the
airport. Engines are pretty much not spooled back up until you are on finals,
and the undercarriage/flaps etc. are causing a lot of drag necessitating
engine power again to maintain approach speed.

~~~
zaius
An idle 747 has a glide ratio of around 15:1, meaning they can cover ~150km
from 35,000ft. My favourite example of this is the Gimli Glider -
[https://en.wikipedia.org/wiki/Gimli_Glider](https://en.wikipedia.org/wiki/Gimli_Glider)

~~~
Judgmentality
Thank you for sharing this amazing story!

~~~
tajen
The series Air Crash Investigation has an awesome episode on the Gimli Glider.
A screencam is available on Youtube.

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nimbius
speaking as a former programmer for a large airline, Pilots for small regional
jets usually rely solely on experience, while your average cross-country 737
pilot has a co-pilots experience and a small cross-reference manual in the
event of failures or warning lamps. you're still "flying" the aircraft with
the exception of landing assist and the TCAWS

Jumbo jets are an entirely different beast. You're starting and stopping
procedures are similar to any other commercial jet, however large swaths of
the plane are entirely computer controlled. this includes jet engine ignition
and reignition in case of flameouts. Elevation rate and descent rate are also
computer controlled. Pilots in turn are saddled with phonebook sized procedure
and countermeasure manuals that determine what to do in the event of anything
even remotely out of the ordinary from cracked windshields to broken
elevators.

The fact that these pilots could recover from a massive engine shutdown of
this nature is remarkable, as most pilots are trained to "never stop flying
the plane" in the event of a failure. all engines offline means they either
had to engage the APU mid flight to help power auxiliary systems, or they were
struggling to manually move hydraulics without any assist. Pilots are trained
that engines go through ingestion testing to handle anything and everything,
so its not surprising they thought nothing of the ash...A Rolls Royce Trent
engine might not seem that large but each one delivers nearly 100,000 pounds
of thrust. This, combined with a 10 stage compressor, is enough to overcome
even the most furious rainstorms.

------
iaw
> "Good evening ladies and gentlemen. This is your captain speaking. We have a
> small problem. All four engines have stopped. We are all doing our damnedest
> to get them going again. I trust you are not in too much distress."

I find something very entertaining when I hear stories of pilots/air traffic
controllers communications during emergencies/exciting situations that are
extremely calm.

It reminds me of the classic SR-71 Blackbird "Speed Check" story.

Edit: For those unfamiliar, the story is here
[http://oppositelock.kinja.com/favorite-
sr-71-story-107912704...](http://oppositelock.kinja.com/favorite-
sr-71-story-1079127041)

~~~
beamatronic
Brian Schul, the pilot from that story, was at the Hiller Aviation Museum in
San Carlos today.

~~~
sundvor
Awesome. This story never gets old. I just found this recent video of it as
well:
[https://www.youtube.com/watch?v=8AyHH9G9et0](https://www.youtube.com/watch?v=8AyHH9G9et0)

EDIT: Speeds mentioned in vid are 100 knots higher in the video than GP's link
(1942 vs 1842)?

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tomhoward
Some friends of mine are, for whatever masochistic reasons, avid viewers of
Mayday (aka Air Crash Investigations), and the episode [1] about this event is
one of their very favorites.

I recall the episode mentioning that the passengers and crew from this flight
have stayed in contact and held occasional reunions ever since.

[1]
[http://www.dailymotion.com/video/x4cs1ys](http://www.dailymotion.com/video/x4cs1ys)

~~~
gsich
US documentaries are so hard to watch. After every ad break you get a recap of
the show. Problem is, there are so many ad breaks ...

~~~
switch007
[https://www.youtube.com/watch?v=7MFtl2XXnUc](https://www.youtube.com/watch?v=7MFtl2XXnUc)
is a hilarious parody of this

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eesmith
I once gave this as a counter-example to the old Alcoholics Anonymous saying
"the definition of insanity is doing the same thing over and over and
expecting different results."

In this case, the sanest thing to do was to try and try again to restart the
engines.

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nxc18
I wonder if it will ever make sense to build an aircraft that can fly in these
situations.

Does anyone here have a perspective on the engineering that would be required
to build ash-proof engines? Perhaps similarly, drone/bird-proof engines?

~~~
tim333
Apparently good old fashioned piston engines still work as they have a dust
filter on the air intake like in a car.

~~~
mschuster91
Yeah but just like cars in the desert you risk the dust filter getting totally
clogged by the dust. With a car, you can stop and simply unclog the filter by
hand - impossible on a piston engine in flight.

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noncoml
Off topic but give it’s 2018 in most of the world, I think it’s safe to say
that 2017 was the safest year in aviation history.

