Subject: Re: Left Right Left
Date: Sun, 28 May 2000 16:15:48 GMT
>I recently completed training in a two-pilot twin-engine helicopter
>simulator which involved engine and system failures and fires. These
>things are so great because you don't have to play around "real world"
>constraints. Though we were careful and deliberate in performing the
>emergency procedures I found that there was still great potential for
>confusion and misidentification of critical systems labeled #1 and #2.
>How many times have we heard of someone inadvertently shutting down the
>good engine? It occurred to me the other day that perhaps a better way
>might be to instead label them left and right (or left, center, and
>right in case of three engines/systems).
>Try this simple experiment. Raise your #1 hand. Had to think for a
>second didn't you. Now raise your right hand. No delay at all. See how
>much more quickly and positively you identified it the second time.
>I doubt I'm the first one to think of this. I just wonder why it hasn't
>gained widespread acceptance as it seems so intuitively obvious to me. I
>can understand that in airplanes with four or more engines the numbering
>system is simpler and more convenient, but only a handful of helicopters
>have more than two.
The issue is a complex one, and I have personally been involved with for
I think the misidentify problem is probably not in labeling and names, because
we don't often just translate from one verbal communication to an action (In
other words, the real problem is probably not the tranlation from tell him
what to do and watch him do it, it is very much more the real confusion about
what to do)
Example - If an engine quits in a twin engine helicopter, there is no
compelling reason to touch any engine control at all, let alone the wrong
one, even if the engine goes to high side, and tries to spin the rotor up to
ridiculous speeds. Many many problems of wrong engine shutdown involve a leap
into action within a few seconds of the failure. During these seconds, the
crew is much more productive just keeping the rotor rpm in the green,
maintianing speed and altitude, and carefully diagnosing the problem.
I teach the concept of leaving everything alone, flying the machine, and after
careful consideration, cleaning up the situation. This was shown to me by "no
sweat Brown" who survived a lost tail rotor in a 100 foot hover by actually
pushing the co-pilot's hands away from the throttles when all hell broke lose.
He flew the machine down to 15 feet and then let the dude cut the motors.
I do think the most important issue with engine identification (after the
leave them alone issue is properly taught) is the need to keep the information
properly layed out spacially, and not rely on word/verbal tags. This means
that we should not label left, right #1 #2 as the sole means of conveying the
info. To ask the crew to read, interpret and act is not the best way to
assure minimum confusion. All the info needed should be grouped in one place,
laterally displayed just like the engines are, and next to the control or
switch used to correct the problem.
One aircraft (a nameless one so I don't get accused of being biased!) was
actually put into service with white tape lined all over the cockpit to guide
the pilot's eyes to all the places where the info was, so his decision time
and accuracy might be helped.
My belief is that all verbal commo stinks. How many times in Basic
Training did some poor snuffy "column left" when the rest of the world did
a "column right?" Try your experiment with the crowd this way. In one group,
ask them to raise their right or left hands immediately, not look at their
buddies. The percent correct will fall, I am sure. In another try, salt a
few friends down front, and ask them to raise the WRONG hand quickly, and
watch the back of the room hand switchers correct their initial wrong
response. Compare all this to another test, where you randomly project a spot
light on the right side or left side of the stage, and ask the group to point
at the light. With no verbal "cognitive task" like the "right-left" or
"#1-#2" decision, the group will almost always point to the light, because
there is no brain translation from space to verbal and back to space.
Our real task is to keep the information in the same context as the decision,
a spacial context, and therefore get fewer mistranslations. Fight for
machines where the gages, warning and caution lights and engine controls are
placed with care to preserve the spacial context, and where the control is
next to the light, so a wrong decision is much less likely. On an S-76 the
correct Fire T handle lights up, and is what you use to shut down the engine,
pull the fuel lever and turn off the generator. Only one control is needed,
and it also is the indicator. This was not coincidence, I helped design it
for that reason - simplicity and spacial correctness.
Also, try to teach your people to never ever touch the engine controls unless
they really really know what is happening. If the power is down, lower the
collective, maintain RPM, start a climb, and then watch stuff for a while. If
power is up, with RPM climbing, and torque thru the roof on one engine, pull
up on the collective, keep the rotor in the green, climb like a banshee
(altitude is almost always your buddie!) and then watch stuff for a while.
The transmission will not break, trust me on that. When you really know that
you have found the bad engine went up, carefully reach out to the engine
control, CONFIRM that it is the right (correct!) one, then slowly pull it
back/roll it off and see what happens. As it takes control, see if the torque
gets better, then slowly continue the action.
If you train people, never let your guys do anything fast with an engine
lever. Never let them touch it within 5 to 10 seconds of the failure, no
matter what (the extremely rare tail rotor failure may be an exception, and
even then, immediate action is only needed in a hover). If a regular
garden variety engine failure has happened, tell them to pull the lever
back while they are filling out the paperwork after the flight. If a rare
high side failure happened, make them confirm the lever with their hand on it,
and make them pull it slowly back, telling you what they expect to happen and
confirming as it happens.