Finger Problems…or Poor Ergonomics?

[Old Man Rotor]

Piggy backing on the thread that “tacks” posted……

Let’s hassle over those dam annoying, inconvenient, expensive and dangerous items that exist and continue to exist, and which manufactures don’t see the merit in correcting!!!!

You know the things I mean:….

• Those bloody Governor switches on the B212 / 412 that catch the non attentive pilot out on a regularly basis, and

• The positioning of the DME and Window Wiper Switch on the BK 117 that has scratched more windows than you can count.

I won’t admit to the first, but the second makes me curse and smile at least weekly.

[SASless]

Oh...to hear the sound....when a gov switch on a 212 gets thrown at a hover....rather than the hydraulics switch. It will make one set a tea cup down and head for cover! Hows about the Nimrod that made that mistake....not once...but twice in a week....on the ground during the runup....and got promoted too.

[Lu Zuckerman]

In the design of a military aircraft it is necessary to adhere to the requirements of MIL-STD-1472 “Human engineering design criteria for military systems, equipment and facilities”. Among other things it defines the placement of switches, the juxtaposition of switches and the distances between switches. This is not to say that they don’t get it wrong sometimes but when they do there is a change order written and the designs modified and implemented when possible. However on a civil aircraft even though they are used in the military the pilots get what the designers give them. If the military operator finds a problem they pay to have it rectified. If a civil operator finds a problem he gets an STC and then he can sell the change to other operators.

In the meantime what you see is what you get. WYSIWYG

:E :E

[idle stop]

Civil/Military: that's a bit harsh, Lu.
Those of us involved in Flight Test work hard to ensure that the gotchas are eliminated: though none of us is perfect. In the old days the manufacturer's test pilots and the military tp team would each have a go at finding and eliminating HP/Ergonomic problems. However, in these days of jointery trialling the second independent review may no longer happen, or the mindset may already cause an oversight.
On a personal note, having recently nipped in the bud another pilot's (from a different organisation than my outfit) attempt at 212 hara-kiri, I would put the HYD switches as far as possible from the AUTO/MANUAL switches in the 212/412. Actually, below the SCAS/AFCS/HELIPILOT controller would be my ideal.
Anyway, there's lots more about.....
How many UK Army pilots remember just how quiet it could go in the Scout if you put the heater on? (For the uninitiated, fuel cock and heater controls were identical units very close to each other, but fuel control fore/aft movement and heater control a horizontal movement.)
Ho Ho!

[Shawn Coyle]

Having nearly snagged the Governor Auto/Manual switch many, many years ago on a UH-1N (military equiv to Bell212) I wondered why no-one has seen fit to change the switch.
Since it happened to me, it has obviously happened to many others, but how many others?
Has the switch design ever been implicated in an accident?
Why has no-one complained to the authorities?
I know of no reason why you need immediate access to the switch (there should be no situation that requires it to be used immediately), so why no change it to a guarded or covered switch?
Surely, no STC would be needed.

[Lu Zuckerman]

To: idle stop & Shawn Coyle

Regarding Bell helicopters:

OH-58 = Civil design WYSIWYG

Bell Huey = Designed to mil specs. that existed at that time. Most likely MIL STD 1472 was not in existence at that time and if it were it was not fully defined.
Bell 212 = Derived from 205 but not to mil specs. If a problem existed in the 205 it was most likely in the 212.
Bell 412 = See 212 above.
Bell 214 = Derivation of the 205, 212 but not designed to military specifications. If it was bad in the 205 it was bad in the 214.
Bell Cobra = Derived from the 205 but not to a military specification. This applies to all Cobra models. None of them were designed to a military specification and the pilots got what Bell gave them.

:E :E

[Ascend Charlie]

Shawn - agree about the switch in the Huey, snagged it with the cuff of a flying glove many times, but fortunately not enough to lift it out of its gate.
But one rather senior officer, flying leader in Vietnam, made the other formation members wonder what was going on when his aircraft suddenly left the formation vertically upwards. They tried to follow him up, but suddenly he whistled back vertically down through the pack, with pieces of molten turbine blade spitting out the back.
His explanation was that a clipboard he picked up had a pencil attached to it with string, and the string pulled the switch into manual fuel. Absolute full throttle for a short time, then engine failure shortly thereafter.
The (very junior) copilot had a totally different version of events - the senior officer was looking at the switch with a look of puzzlement, then reached over and switched it through, just to see what would happen. The copilot's version never saw the light of day, and the end result was that all clipboards had to be attached to the map pocket with string short enough that it couldn't reach the manual fuel switch!!:8

[griffinblack]

In the AS350 we had the rotor brake and fuel shut of lever located under the collective. It took a little bit of effort to cock your wrist so that you could reach these levers if/when needed. At the time our squirrels had an inefficient/ineffective gust lock. One of our trainees had a hot start, and attempted to activate the fuel shut off lever. His fore arm caught the collective as he was activating the fuel shut off and he became airborne. Unfortunately his flight only lasted a matter of seconds before he smite the ground.

I also understand that the PC9 had an accident with some confusion with respect to levers on the throttle quadrant. I QFI directed his pax (a none type endorsed pilot) to activate the gear/flap(?) lever. I believe the fuel shut of/emergency fuel (?) was/is located nearby and he shut the aircraft down – both ejected safely, but some embarrassment for the Kiwi exchange QFI.

[idle stop]

Lu:

What you say reinforces the need for test pilots (and FTEs) to be involved at the design stage. This was done extensively with the EH101 cockpit definition and also, I believe, with the MD900. There are doubtless many other examples.

But just because it's one way for civil operations doesn't mean that it shouldn't or can't be changed for military use. I have fair experience of customising off-the-shelf civil aircraft for military use: a deal of thought and work goes into subtle reconfigurations of instruments, switches and ancillary controls in the cockpit.

I contest the implication that military certification standards are more rigorous than civil standards: I've worked in both areas. Without looking through AC29-C (the FAA Certification Guide), I'm pretty sure you'll find the switchery and control protocols in there too, just as in Mil Stds.

Anyway, if it's wrong, then the operators air safety system should pick it up and generate change: but only if the problems are being reported. I'm sure we aviators often fall short in this area!

As to the Governor Auto/Manual switch on the 212 et al, it was explained to me once that gating the switch could waste precious nano-seconds in the event of an urgent need to operate the switch. Next question: What about an interlock microswitch, so moving the switch has no effect unless throttle fully closed? Well, was the answer, sometimes microswitches and interlocks fail....
I wonder whether statistically more engines have been trashed by inadvertent Gov switch operation than there have been incidents of needing to use the switch in anger: but I guess we know the answer. The best protection is still to proceed with caution and give those switches RESPECT! And, as in my previous post, it does help to configure the console so that the Hyd and Gov switches have some distance between them.

[Shawn Coyle]

idle stop
Thanks for the post. The point I was trying to make was that there should not be any emergency in the Bell 212 that calls for the immediate selection of manual governor - the certification standards, even back in the 70's, should have seen to that.
So why have we accepted this situation for so long?
Your point about how many engines inadvertantly burnt out vs. bad engines saved is an excellent one.
Having put a little thought (actually all the brain cells I can muster these days) into this, a solution as simple as a raised circular guard on both sides of the switches would prevent inadvertant activation while still permitting immediate access to them. I think I'll put that into our UH-1N....

[212man]

On our 212s the Gov panel has been moved to the top right hand side of the centre console, to prevent (as far as possible) this inadvertant selection. The other key is to have rigid SOPs when making selections, especially wrt two crew cross checking. Hands flashing around randomly during post start checks, is a bad thing.

On a more modern note; on the EC-155, the RPM high/norm switch is located just above the number one engine switch. Inattention in its use could well involve selecting the engine to IDLE rather than the RPM to NORMAL; with 30 second ratings, that's expensive!

[Shawn Coyle]

My rough calculations is that 30 second ratings are sort like the Mastercard ads -
using 30 second rating when not needed - $1,000 per second
having 30 second rating when needed - priceless.

[Red Wine]

I can't for the life of me establish any emergency or requirement that would have me grabbing at the governer switch on the 212/412 in a nanosecond....all emergencies, actions, procedures that I can think of, has the frictions off, throttle back to flight idle, check, then double check that you have the correct switch, activating it, then advancing the throttle again.....so my view view its not a time issue!!

Our company did go through the exercise of placing a cover over a modified double actioned switch [Giving you a triple action for activation]..the cover being similar to the Cable Cutter or Intercom Failure Covers....

BHT [Medium Aircraft Tech Folk] in DFW had no problem with this idea, but still couldn't see [or admit] that they should also do it??

In the end it all got to hard, and nothing changed.

[Lu Zuckerman]

To: Red Wine

BHT [Medium Aircraft Tech Folk] in DFW had no problem with this idea, but still couldn't see [or admit] that they should also do it??

In Iran we were having a high number of instrument light failures on our AH1-Js. With the lights inoperative the helicopters could not fly at night which really effected our training program. I did a design analysis on the power supply and found a design error on the part of the power supply vendor.

This problem was exacerbated by the installation instructions, which lead to the crushing of the power supply and the dislodging of one or more of the electrical components on the circuit board..

I notified Bell about it and they indicated that they were going to change vendors. They never changed vendors nor did they modify the installation instructions. I left the program a year later and we were still having the same problem.

:E :E

[idle stop]

Red Wine:
Totally agree there should be no need for panic actions: was just passing on one of the explanations for no guard on the switch I was given, some time ago, by somebody in 212Man's outfit! I would guess that equally, he doesn't agree with this either!