
What do all the controls in an aeroplane cockpit do? - lisper
http://www.quora.com/What-do-all-the-controls-in-an-aeroplane-cockpit-do?share=1
======
Animats
The example aircraft is a modernized Boeing 737. First flight in 1967 and
still being manufactured, 47 years later. That's a long production run.

The description of the controls is long, but there are two main divisions -
flying the aircraft, and systems management. One of the big problems in
cockpit design is keeping the pilot from spending too much "head down time" on
systems management.

The 737 was the first jet transport designed for a flight crew of two.
Previous jets had a flight engineer as well. Further back in aviation history,
there were navigators and radio operators. (BOAC even had a "flight clerk",
equipped with a typewriter, on some flights.) As crew size dropped, the pilots
picked up more system management duties. This remains a problem. Cockpit
automation generally means that the systems take care of themselves unless
something goes wrong. Then the pilots have to devote a lot of attention to
dealing with the problem. Crashes have occurred because the pilots were
dealing with some system problem and not focused on driving.

~~~
thenmar
Which crashes in particular were caused by attention to systems problems? I
believe you - I'm just curious.

~~~
Patrick_Devine
The recent crash at SFO was caused by mistakenly thinking the airplane was
working a different way than it was actually working. The pilots thought the
autothrottles were engaged when they weren't and were fixated on trying to
land the plane manually; something they hadn't done in a long time.

[http://en.wikipedia.org/wiki/Asiana_Airlines_Flight_214](http://en.wikipedia.org/wiki/Asiana_Airlines_Flight_214)

~~~
ghaff
Which is the sort of problem we'll likely see more of as "mostly autonomous"
systems become increasingly common. For example, it's easy to imagine that it
will become possible (whether or not we elect to go down that route) to design
cars that can be self-driving most of the time but which will require a human
to take over in some scenarios. The good news is that those scenarios will
presumably be mostly low speed ones--the handoff timeframe pretty much has to
be of minute rather than second magnitude--but you could still end up with an
increasing number of drivers who have very little actual driving experience.

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nlh
I remember seeing this posted on Quora a while ago and it still stands out as
one of the best answers I've ever read. And the biggest takeaway for me was
(and still is):

"Redundancy. Aircraft manufacturers are really, really (really) big on
redundancy."

~~~
danjayh
This is a true takeaway. Redundancies are even layered - for example, there
may be redundant computing modules, running redundant (and possibly
independently developed software). These computing modules may be multi-
processor, have multiple banks of RAM and flash, etc ... but not used in the
typical COTS way. Instead of being devoted to increasing computing power, they
are devoted to ... you guessed it, redundancy. In highly critical hardware,
you could physically remove one of the CPUs from the board while it was
running, and the system would log a fault and keep on ticking without so much
as a timing jitter.

EDIT: Also, for those of you who don't mind working for a massive corporation
instead of a startup, avionics is a fascinating niche of computing. It's what
I do, and I love it :) They pay is a bit worse, but hey, I have a pension. It
also helps that many aerospace companies are in lower cost of living areas
than startups. More importantly, the problems of next-gen avionics are
completely unique, unsolved, and engaging.

~~~
kika
Boeing or LM? I worked for Tupolev - Tu-214D, auxiliary fuel system control
module, which actually did D in the name (which means Dalnii, Long Range in
Russian).

My famous takeaway from these times was \--- ARINC Report 431: No Fault Found
– A Case Study provides the final report of AMC Task Group 116 formed to
discover the causes of “No Fault Found” in avionics equipment during test.
This standard identifies sources and provides recommendations for improvement.
\---

~~~
danjayh
Neither ... it's a subcontractor. Also your mention of ARINC brings to mind
another thing - the business environment is way different than most of tech.
Patent lawsuits are basically unheard of. Many of the companies within the
field are not only competitors, but typically also partners in one or more
ventures. The reason ARINC jogged that memory loose is that Rockwell Collins
bought ARINC a while back, and then spun off the standards making division so
as not to damage their credibility as the standards-creator for aviation. When
I think of, say, mobile ... I just don't see those companies behaving that
way.

~~~
kika
Exactly, I felt the same. I believe it (cooperation, attention to detail, much
less hype and lawsuits, etc) is because of the responsibility. If I sue
competing startup and they will get distracted and miss their scaling problem
and begin to return 502 errors - herd will call me a "fighter", some call me
"this jerk, who's smarter in the courtroom than at the keyboard", etc, VCs
will like me, anyway, I win. If I sue someone making a competing ARINC
interface, they get distracted, miss a race condition and then 502 people
die... I also get distracted, and another 404 people die. Well, it's a little
bit worse than 502 error. And there's so many training and so many manuals,
books, anecdotes around how many people may die if we don't "put enough
assert()s in our code" that you just stop thinking about hype and lawsuits and
gold miners.

------
omegant
As a complementary curiosity, an Airbus A320 has 575 buttons and knobs (that
includes alphanumerical pads and double knobs), and 364 circuit brakers. I had
so many kids asking how many buttons there are at the cockpit, that I finally
spent a Madrid - Rome flight counting them (under the surprised look of the
captain).

I guess that a long haul model like a A 380 has more or less the same, maybe
some dozens more due to the increased system complexity (more engines, extra
hydraulic and electric sys..) but the brakers are located at the instrument
bay under te cockpit and that makes it look a bit les cluttered).

------
schoen
When I was a kid I had the _Space Shuttle Operator 's Manual_

[http://www.amazon.com/Shuttle-Operators-Manual-Revised-
Editi...](http://www.amazon.com/Shuttle-Operators-Manual-Revised-
Edition/dp/0345341813)

which was pretty awesome (it wasn't used for crew training, it's a
popularization of what's involved in operating a Shuttle). It also takes you
through a pretty substantial number of control switches and indicators, even
while simplifying things.

I wonder if there's a way to compare the complexity of the body of knowledge
that jet pilots have mastered (this explanation doesn't even go into
aerodynamics or flying skills, or the purpose or physics of some of the
systems it alludes to, or rules and procedures, or abbreviations or jargon) to
what doctors know about bodies, pathology, diagnosis, and medical
interventions.

~~~
frik
NASA released many old manuals to the public, including several Space Shuttle
PDFs.

Flying the space shuttle is more like programming a flight computer and
checking the flight data. There are some manual overwrites, that's the
challenging part.

e.g.
[http://www.nasa.gov/centers/johnson/pdf/390651main_shuttle_c...](http://www.nasa.gov/centers/johnson/pdf/390651main_shuttle_crew_operations_manual.pdf)

~~~
schoen
Wow, that manual is a _lot_ more detailed than the popularization.

Isn't there also a flying-it-like-a-glider part after re-entry? But I guess
that's a pretty small fraction of the mission.

------
gte525u
Most of the quora answers seem to ignore the significant shift in avionics
that has occurred with the general adoption of glass cockpits.

In older aircraft, you would've been staring at a wall of gauges, lamps, and
buttons i.e., C130[1]. These, for the most part, have been consolidated into
large multi-function displays (MFDs) like the C130 AMP [2] or C-5M [3] with
the remaining analog controls are either there for emergency use or for the
pilot's benefit like the yoke.

The MFDs generally reduce pilot workload by consolidating relevant data into
task-oriented screens. However, the main driver was more likely the
significant weight reductions and costs associated with manufacture and
maintenance of the aircraft - fewer cockpit components and simpler wiring.

Ultimately, the types of controls are similar between the older and new
aircraft. The notable exception is the keyboard(?!) in the A380s [4].

[1]
[http://commons.wikimedia.org/wiki/File:C-130_Hercules_cockpi...](http://commons.wikimedia.org/wiki/File:C-130_Hercules_cockpit_hg.jpg)
[2] C130 AMP
[http://www.edwards.af.mil/shared/media/photodb/photos/091109...](http://www.edwards.af.mil/shared/media/photodb/photos/091109-F-9999X-001.jpg)
[3] C5M
[http://upload.wikimedia.org/wikipedia/commons/9/9f/C-5M_Cock...](http://upload.wikimedia.org/wikipedia/commons/9/9f/C-5M_Cockpit.jpg)
[4] A380 [http://www.aerospace-
technology.com/uploads/newsarticle/6889...](http://www.aerospace-
technology.com/uploads/newsarticle/688953/images/141058/large/1-a380-cockpit.jpg)

------
tempestn
There's an article in the Atlantic about this answer:
[http://www.theatlantic.com/technology/archive/2012/03/the-
st...](http://www.theatlantic.com/technology/archive/2012/03/the-story-behind-
that-9-000-word-quora-post-on-airplane-cockpits/254489/)

------
frik
The first quora comment is long and interesting, but the "photos" are from a
flight simulator, probably Flight Simulator X from Microsoft. And flying a
plane in that simulator is not that hard, something one can learn in a few
hours. And all the knobs have tooltips too.

~~~
ejdyksen
The photos are from a 3rd party add-on 737, from a company called PMDG:

[http://precisionmanuals.com](http://precisionmanuals.com)

They make _extremely_ high detail planes, with incredibly in-depth
simulations. Many real commercial pilots use this software to train (although
they can't earn training hours with it).

To fly it correctly, it takes more than a few hours to learn.

~~~
frik
Interesting, thanks for the details.

That's the deep link:
[http://precisionmanuals.com/pages/product/FSX/ngx8900.html](http://precisionmanuals.com/pages/product/FSX/ngx8900.html)

The embedded videos shows a scenic Innsbruck city airport in the alps:
_Innsbruck Airport is well known for having a difficult approach due to
surrounding terrain, prohibiting certain aircraft types from operating at the
airport.[3] The approach and descent is a very complicated process—the Alps
create vicious winds and currents, which the pilot has to deal with throughout
the process. Because there are mountains all around, the plane usually circles
the airport, enters a pattern, to decrease both speed and altitude._
[http://en.wikipedia.org/wiki/Innsbruck_Airport](http://en.wikipedia.org/wiki/Innsbruck_Airport)

------
wheaties
And this is why I'll go up to my IFR and maybe dual prop but nothing more.
That guy is the kind d of person I want flying my plane, maybe. Only if he
handles context switching well...

~~~
omegant
Don't be afraid of all that complexity, most of that swithches are used
sparingly or at all during each flight. The ones that get more use are the
common flight controls and navigation aids (FMC, autopilot, etc...). I'm
airbus 320 pilot by the way.

~~~
ckib16
Yes exactly. It's the same way in fighters. The vast majority of switches are
used maybe once. There were some F-16 switches that I never touched in 11
years. In fact, some switches are actually secured with copper wire to be used
only in certain emergencies.

Believe me, you can handle it. IFR is all about cross-check, preparation and
staying ahead of the jet. Not the number of switches available to you.

------
frik
I read on HN that Quora pivoted and joined Ycombinator, more for for exposure
I guess? It was basically a StackOverflow alternative with real names. Will be
interesting to see how their piviot to something else turns out.

Source:
[https://news.ycombinator.com/item?id=7723278](https://news.ycombinator.com/item?id=7723278)

~~~
vpontis
They definitely didn't pivot on joining YCombinator.

You can read some answers as to why Quora joined YC here:
[http://www.quora.com/Why-did-Quora-join-
the-2014-Y-Combinato...](http://www.quora.com/Why-did-Quora-join-
the-2014-Y-Combinator-batch).

