Saturday, December 17, 2005

Sign Language

Sam's rant involving poorly trained ground crews who didn't recognize the hand signal for "connect ground power" reminded me of all the times I've wished people on the ground or in other cockpits spoke sign language. I have learned some sign language in order to communicate a deaf relative, and it is infinitely frustrating when all the tools I need to transmit a message are literally at my fingertips, but the recipient doesn't have the information required to decode the message.

So I have to resort to more primitive forms of sign language. Pilots, imagine you were in the run-up area or in a traffic jam on the taxiways and another pilot, stuck her hands out of the cockpit displaying in sequence:

The splayed fingers of one hand, plus the thumb and finger of the other

The splayed fingers of one hand, plus just the thumb of the other

The fingertips of one hand all curled to touch the thumbtip, leaving a round gap through the middle of her fist

The third gesture repeated

If she repeated this sequence a few times, would you have any idea what she was indicating?


Greybeard said...

Is this one of those, "so simple it's hard?" things?

My son just took ASL as a foreign language. He was out late last night....not yet awake, so I haven't discussed this with him.
But a quicky guess....7600?

And thank heavens, that's another of those codes I've never had to use!

Stu said...

I agree with 76, but I'm not sure of 00. Why would the 'O' touch the thumb? I don't have a better suggestion though.

Anonymous said...

What does 7600 mean?

Anoynmous said...
This comment has been removed by a blog administrator.
Kris Johnson said...

7600 is the transponder code meaning that the radio isn't working.

Another pilot who sees it might understand it, but I doubt the ground crew or anyone else who sees the sign would understand. I think a better signal might be to hold up a headset and give a thumbs-down or other "bad" sign.

Aviatrix said...

The intended recipients were company pilots in another airplane. All the fingertips touching the thumb make an O-shape, of you do it the way I do. The message was intended to be 7-6-0-0.

In aviation, 7600 means "I am unable to communicate by radio." The message is normally conveyed by setting that number on your transponder, so that it shows up on the controllers' radar display. But often when you are on the ground, or the airport doesn't HAVE radar, the code is not received, because you are below the radar, as they say.

Greybeard, wow, I can't believe you've never had to squawk 7600. Is that because all the times your radio has failed you haven't been anywhere that anyone would care, or have you really had decades of trouble-free radio operation?

Anonymous said...

From your description I read it as a radio failure. Of course, it would rely on me noticing the pilot signalling and being able to make out enough detail at whatever distance, but if there's radio chatter suggesting that somebody was having a problem, and I saw them making that signal, it'd be pretty clear to me what was going on.

Greybeard said...

There are MAJOR differences in the environments that airplanes and helicopters fly in.

Have I had radio failures?
Is it a big problem in a helicopter?
Well, that depends, but normally, no.

Airplanes, especially those flown commercially, operate mostly in a "controlled" environment.
You get instructions from clearance delivery, then ground control, then the control tower. After takeoff, you switch to Departure control for more instructions. During flight, you take instructions from one or another Center.
Approach/landing means you go back through those ATC people in reverse order.

Two weeks ago I flew a 1200 mile trip in a helicopter. Leaving L.A. I had to talk with the airport I departed from, then get clearance through airspace controlled by four other control towers.

East of Palm Springs, I could have made the rest of that flight without contacting a soul.

Helicopter pilots are a different breed. We like planning and controlling our own flights. I will sometimes avoid an airport by flying around it rather than talk to them on the radio.

The EMS helicopter I fly bristles with radio antennas. There are two VHF comms, and two medical/operations radios in it. State of the art technology today has reached a level where presented with a radio failure, the first place we look is the antenna, to see if it is corroded. Radios seldom fail anymore. When one fails, I can yell for assistance on another. When everything else fails, I carry a handheld for backup.

So the answer, surprisingly, is that in 37 years and 17,500 hours of flying, I have never had to squawk 7600!