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Here's an interesting problem that's troubled me from time to time and a colleague has just asked a variation upon by EMail. I'm also currently dealing with the problem of a 6'4" pilot who wants to redesign his rudder pedals because his buttock - heel length seems to be uncomfortably long for the cockpit in question.
Anthropometric data - or lack of it.
Like most other people in the airworthiness business, I have access to the famous 1950s RAF percentile tables, and can happily quote my dimensions in those terms (5-7% in everything I'll admit to in public sadly).
However, these tables, applying as they do to 1950s RAF pilots are not necessary representative of the current generation of military aircraft - let alone civil aircrew. The advent of the fairer sex on the flight deck, and a wide variety of weights and strengths (full rudder force with a fully extended leg could be a player for example) throws the whole thing.
Does anybody know of any readily available percentile tables which are applicable to modern civilian aircrew. I've looked hard for such data, but other than occasional tables in handbooks on industrial design which have proved somewhat unsatisfactory - have never had much joy.
In a particularly critical environment (single crew air-taxi operations for example) there's also a fair case that some people may be unsuitable for some aircraft types without modification. However, doing this on a pilot-by-pilot basis is somewhat unsatisfactory, and a set of civil percentile tables would make life much more sensible.
I'd also be interested in anybody's experience of this in civil certification - other than some very general guidelines in FAR-25 I can't find any rules laid down anywhere.
Separate advice suggested that the derivation of 5'2" to 6'3" in FAR/JAR 25.777 was based on 2.5 percentile mature female up to 95 percentile mature male. However, I could find nothing to support that explanantion nor could I find anything that formally identified the source anthropometric data that is used. A quick search using "anthropometic" at the NASA technical server
came up with 467 documents, many of which could be incredibly useful. However, what I really need to know is what designers looking for FAR/JAR 25 or BCAR D certification would have used as the standard anthropometric model.
Unlike Genghis or yourself, I am not an engineer. However, it seems to me that such things as ankle rotation angles, ankle to kneee and knee to hip measurements are critical to the hardware design at the bottom while upper torso length, reach and eye position are all important measurements at the top end. Like many things in the FARs, the good ole 5'2" to 6'3" in FAR 25.777 seems to be just a portal to much more detailed data elsewhere.
Does anyone know what BAe used to design the flight deck of the 146 or what Boeing used for the 737 or what Airbus used for the A320 or de Havilland Canada used for the DHC 8?
The NASA documents I mentioned are _not_ aviation documents at all. Oddly, NASA seems not to be responsible for the standards behind FAR (despite the first A).
I am not familiar with Aviation Regs, but I can tell you that internationally applicable Anthropometry Tables must specify:
Population percentile range - NASA uses 5th to 95th Age - NASA uses 40 Sex - NASA uses both male and female Nationality - NASA uses American and Japanese Epoch (sorry, astronomical term, refers to a reference year, because human populations are steadily getting taller) NASA STD-3000 uses 2000 as the reference year.
Thus the range in the tables is 5th percentile Japanese female to 95th percentile American male (luckily the Scandinavian astronaut I know is rather short).
If you can handle a 5 Mb file and are interested in a std not cited in FAR/JAR, I can send you the Rev B of NASA STD-3000 in Acrobat form.
But to not answer your question, _I_ have no idea what data was used for the 146, 737, A320 or Dash-8. I would be interested also.
Stevenson (two dogs)
Mare Crisium Srl
[This message has been edited by Stevenson (edited 25 November 1999).]
Anyway, the document I have is an extract from NASA STD-3000 which is more general (and may be aviation inspired - I haven't read it). Unfortunately, MSIS as it is called, is only available from NTIS for money (140USD) so I am disinclined to check.
My (new) reading of FAR 25.777 is that no HF standard is used. Flight deck designers therefore have plenty of scope to make mistakes. The certification process probably involves two people of indeterminate age or physical type, who just happen to be minimum and maximum height, twiddling the controls and peering at the instruments/displays. Sorry, but that is how I would interpret a requirements document written the way FAR 25.777 is.
My experience is that civil designers do not make use of anthropometric tables for certification purposes, but because they want people to buy their aeroplanes and be happy with them. The standards do vary considerably.
Having said that, the BAe 146 was designed by DH in the 1960s so may have used the UK RAF anthropometric tables.
The "RAF tables", published in the 1950s are widely available and cover a wide range of measurements (buttock to knee, knee to heel, buttock to top of head, back of shoulder to stretched fingertip, etc.) and although the data only covers 1950s RAF aircrew, does give a good exmaple of how tables work. If memory serves (I don't have access to the document in question any more) Def-Stan 00-970 part 1, which is the UK military standard for fixed wing aircraft reproduces these tables but you can probably get them from a good aeronautical library.
FAA AC 25.773-1 "Pilot Compartment View - Design Considerations" dated 1/8/93 quotes the following SAE documents:
ARP 268G "Location and Actuation of Flight deck Controls for Transport Airplanes"
ARP 4101/1 "Seats and restraint Systems for the Flight Deck"
ARP 4101/2 "Pilot Visibility from the Flight deck"
which I believe have been superseded/rewritten to give three parts of the new ARP 4101. In quaint FAA speak, designers etc "are encouraged to refer to the guidance" set out in those documents. When I find them (cheaply), I will let you know whether they are useful to the questions.