cockpit design

[badrace]

Anyone has expeirence on how to evaluate cockpit instruments/control&indications .i.e: comparing traditional/morden/future cockpit design Or human factors concerning cockpit design .Any discussion about cockpit design welcome.Thanks for sharing .

[john_tullamarine]

This is the province of certification test pilots and the like.

If your thread doesn't get enough interest in Tech Log, we can move it over to Genghis' arena in the Flight Test area after a week or two.

[badrace]

Exactly ,thanks! But we are the ones who use them on a daily basis,we should know where it's going .

[Denti]

IFALPA and some local pilots unions do have committees (aircraft design and operation) about that subject. They do contribute during the design phase of new planes by all large aircraft manufacturers as well as later on during normal line operation. The members of those committees are usually a mix of normal line pilots and line pilots with additional qualification. Sadly the IALPA web server seems to be down at the moment, but once it's up there should be information about it.

[safetypee]

Flight deck evaluations etc are generally subjective, thus depend on ‘expertise’. This requires wide ranging experience, which enables comparisons. Evaluators also require a good working knowledge of certification regulations which define acceptable solutions. Unfortunately, due to the subjective nature of the task the regulations also tend to be subjective, e.g. CS (FAR) 25.1303, 1309, 1322, AMC 25-11.

A quantitative system for workload evaluation was devised in France in the early days of Airbus (A300-A310, 3 crew – 2 crew flight deck). This defined each panel and switch in terms of the angular displacement and distance from the crew. It also considered panel orientation, frequency and occasion of use, and together with a rating of ‘look, touch, move (switch/turn)’ provided a measure of workload, but not always in context.

Aircraft handing rating scales (see Google ‘Cooper-Harper’) for aircraft control and operation provide support for a subjective evaluation.
The ‘Bedford’ workload rating scale based on Cooper-Harper (Google ‘Bedford Workload Scale’) has been used successfully as a relative measure of workload, but this as with most rating scales, requires very careful definition of the tasks undertaken in the evaluation.

Pilot unions etc, can contribute to the design process, but IMHO not always with great success. An example was the first edition of the SAE EFIS guide which due to the individuals involved was based on the MD 11, and thus had little relevance to other manufacturers’ concepts.
My experience with ‘avionics’ customers (predominantly up-market Biz Jet operators) were that the pilots had a wish list for everything, but without actually knowing how or when they might be used. This was particularly noticeable with ‘older’ chief pilots who required the latest / best, but failed to understand the systems and in some cases could not work them.
Biz-Jets / GA flight deck system designs appear to have a different design concept from the major commercial aircraft.
The ‘lightweight’ GA systems are have been more innovative and the design led by the avionics vendor – displays available before the aircraft. More recently, many of these systems have been used successfully in regional aircraft, the choice and installation often being driven by cost.
Commercial manufacturers tend to invest more in total concept evaluation during the design process and specify what systems the avionics vendor should provide – display design done with the aircraft; thus, we see greater differences in Airbus vs Boeing. It is during these early evaluations that operators can contribute up-to-date / real life situations which more accurately define the task (see above), but they rarely contribute to the actual design concept.

There are many problems such as what appears to work in one aircraft may not be so successful in another aircraft or even in the same type where situations change (context); these require considerable design thought, simulation, and operational evaluation. Most manufactures aim for and achieve excellence, but this depends on ‘fallible’ human judgment – assumption about use and abuse of equipment and the operational situations.
Also, the industry is in a constant state of change, where new or ‘unforeseen’ situations, different standards of operation, training, knowledge, and application, alter the perception of previously well designed systems.
Human perception and operational situations change faster than the design and evaluation process; humans forget, are complacent, and design assumptions are often invalidated or overlooked due to evolving behaviours.

[Genghis the Engineer]

I also think that this topic belongs best in the flight test forum, but will leave that to John to decide whether to move it or not.

There are two different topics here I think: firstly how do you go about evaluating a cockpit? and secondly what are the technologies available for new and future cockpits?

Both are huge topics, for which there are numerous references, textbooks, course notes and suchlike that most people "in the game" have on the shelf. A quick search on Google Scholar shows up several thousands references, most of them in peer reviewed literature split between technology journals, ergonomic journals and suchlike. A quick search around the internet also shows numerous courses at places such as NTPS, Cranfield et.al. which include aspects of cockpit design.

So, to be frank, you may as well have asked "how do I go about designing an aeroplane", if anything, it's an easier question.

I suggest Badrace you might do worse than reconstruct your question - tell us what sort of cockpit (fighter, ultralight, part 23, part 25, part 27...) you are looking to assess, for what role - and probably ask the question in flight test where there are lots of people who have assessed lots of cockpits.

G

[john_tullamarine]

I also think that this topic belongs best in the flight test forum

On the basis that whatever I do will be wrong, I'll leave it here for the time being and then, as soon as it starts to wane, move it over with a long term redirect for those who have been following it.

[badrace]

Your guys are really good and experienced!Thanks!
Is there a flight test forum here?
Since I've been a pilot or MD and airbus for over 15 years ,lately I got
involved in writing an essay on cockpit designing from a pilot's pespective based on my own experience .I did looked up FAR part 25/23 771 through 777 ,but most of these regulations are very vague,and there is little related advisory ciculars ,so I really appreciate if people have experience in these areas can help me with some examples which fills the context ;also line pilots who does have expectations on designs you want to see ,pls reply.Thanks a million!

[Genghis the Engineer]

Flight Test Forum (http://www.pprune.org/flight-testing-50/).

Big aeroplane cockpit design is very much an iterative process - based upon experience and precedence, so most development is about small carefully analysed changes from what works - and what of-course thousands of pilots are already familiar with.

Those changes should in an ideal world be subject to rigorous ergonomic analysis, consultation, and flight testing. In an ideal world.

In practice most manufacturers have an unfortunate tendency to keep these designs away from the test pilots and other professionals (line pilots, human factors specialists) who might slow things up by introducing lots of complicated opinions - and these changes often then land in the flight test department with "just get it certified as quickly as possible" directive - absolutely the wrong way to do it, but it's what often happens.

G

[Self Loading Freight]

There are also issues of training and qualification across types. If you make a cockpit too different to what's gone before, you'll make it harder to learn for those with experience - and increase the likelihood of mistakes even after type qualification. And, if you're selling into a large carrier with a lot of aircraft you've sold them before, you'll lose a big advantage if you make your new type too different to the old. The other chap can make the argument that if the carrier is going to need a lot of retraining anyway, why not get something really good? And new is always good, right?

I learned this in the distant past when I used to go to Pprune meets, because it's always bothered me that so many aspects of flight decks (especially the mundane bits that only really matter when things go wonky) are clearly awkward hangovers from the past and I've always been a passionate fan of usability. It was one of the first questions I asked over a beer, and that answer was one of the first real lessons for me that usability is far more complex than just being logical about things. Humans, even pilots, depend on many factors to do their jobs well, and you've got to really understand humans before you have a chance with human factors.

R

(The fact that pilots were human too was also something impressed on me deeply from those Pprune nights. But that's a different story...)

[safetypee]

Genghis, I agree with most of your post, but “ In practice most manufacturers have an unfortunate tendency to keep these designs away from the test pilots and other professionals … , IMHO not so.

I was fortunate to have been involved in several design / developments of flight deck systems during the ‘expansive’ transition with the first generation EFIS and digital guidance. The flight test and designed teams were integrated; I was ‘the pilot in design’ with considerable sway in the design process and held responsibility for co-ordinating inputs from test pilots, trainers, and operators.
My contemporary test pilots in major manufacturers and regional design teams had similar access and responsibility.

S.L.F., some good points.
Understanding humans in designing a flight deck (or anything else) should start with understanding yourself.

badrace. Consider how ‘you’ fly an aircraft, how each instrument / control is used, and in what circumstances. Then choose or define a suitable description for the instrument, explain why each differs from any other, how each aspect works, e.g. dial ASI with needle (and digital counter), needle angular position on the dial, rate of change, limits, colour, etc. How are these features might be used for configuration change, low / high speed alerting, flight path transitions climb/cruise/descent, i.e. when do you look at the ASI - why.

In your task you might wish to compare the aircraft which you have operated, but the types quoted (MD vs Airbus) might cause problems with diverse philosophies; a simpler task could be to compare the alternatives of strip and dial formats for the 737 EFIS PFD.
Always ask questions – about the display and yourself. For some interesting debates consider strip speed; why do they have trend vectors, what is the source of the information and how might it work during a stall? What is the ASI display size relative to dials – and think about area as well as length.
Why do some strip altimeters have small chevrons about the datum value or on the moving scale?

What are the important aspects of a display format … … the items which are removed to de-clutter it.

You can make what ever you wish of the subject, but IMHO you will never satisfy ‘a pilot’, at best you hope for a balanced debate, preferably with you holding the high ground of safety and simplicity.

[badrace]

Could you give me more detailed examples?As you mentioned you've been involved in the certification of first generation EFIS , so according to your experience ,how are the line pilots will get involved ;most of the HF certification process would include an evaluating module by random line pilots ,for instance ,how much infomation on a PFD gives the pilot unreasonable concertration or fatigue;for pilots come from traditional cockpits ,how this EFIS will affect there SCAN? Thanks!

[barit1]

As a young design engineer, I received a bit of wisdom from an older/wiser guy - No matter how you try to make a device fool-proof, sooner or later an even bigger fool will come along and **** it up for you.

He and I pondered the wisdom of what we deemed his original thought. I have since discovered that Herbert Spencer (1820-1903) beat him to it:

"The ultimate result of shielding men from the effects of folly is to fill the world with fools."

That said, I offer a few recent accidents that may be related to this phenomenon.

That said, I've made a like inquiry here (http://www.pprune.org/flight-testing/414708-attitude-display-research-canada.html).