Entering transponder codes?

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necoflyer

Well-Known Member
When a plane is told to "squawk 4-1-1-4" and the pilot stats flipping through the codes, what does that look like on the a controllers display? Does it cause any trouble, or any inconvience?

Reason I ask, I had a CFI that always wanted to put the transponder on standby mode when putting in codes. Never heard of this before, and can't find anything else about it. I suppose the biggest reason would be so one doesnt squawk one of the emergancy codes unintentionally.

Trying to figure out if this is an old wives tale or something that has some merrit.
 
There are 10 or 12 seconds between radar sweeps depending on the facility, so interim codes are not usually picked up. I think there is some guidance somewhere that says to avoid momentarily squawking any emergency codes, however.
 
Bernoulli Fan said:
There are 10 or 12 seconds between radar sweeps depending on the facility, so interim codes are not usually picked up. I think there is some guidance somewhere that says to avoid momentarily squawking any emergency codes, however.
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Right, I have heard that, like not having 7 as the first digit while flipping through codes. I think I remember a thing about only the first second digits are reconized as an emergency, the last digits are irrelevant as far as that is concerned.
 
Actually on terminal radar the sweeps are more frequent so the target will go into "Coast" for a sweep or two while the computer tries to re-acquire the target. Not a big deal really.
 
necoflyer said:
When a plane is told to "squawk 4-1-1-4" and the pilot stats flipping through the codes, what does that look like on the a controllers display? Does it cause any trouble, or any inconvience?

Reason I ask, I had a CFI that always wanted to put the transponder on standby mode when putting in codes. Never heard of this before, and can't find anything else about it. I suppose the biggest reason would be so one doesnt squawk one of the emergancy codes unintentionally.

Trying to figure out if this is an old wives tale or something that has some merrit.
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Alot of guys do that technique, but as mentioned by others here it really isn't doing anything productive.
 
If you cycle through the numbers with the transponder on, there's a remote chance that your transponder will get interrogated while it's on a code assigned to another flight plan in that facilitiy's or ARTCC's system and it could activate that flight plan. By remote chance, I mean something on the order of maybe one in a hundred bazillion. I'll leave it to the math geniuses to figure out what the chances actually could be.

If you cycle through the numbers with the transponder in the standby mode, the chance of something like that happening is zero.

With that said, I agree with my colleagues from Potomac and formerly from O'Hare... it ain't a big deal.
 
If you take someone else's code it will say DB, but that is if you are switching to your actual code at a snail's pace...
 
Thanks guys, good stuff here. Just another one of those things seem to perpetuate itself, but doesn't have any real basis for which it is done.
 
Want to go old school? While on the jet penetration for a HI-VOR IAP a couple years ago, ATC requested "Ghost 12, Squawk LO, present code" to me. I hadn't heard that since the mid-80s, and even then only one other time in my career.
 
MikeD said:
Want to go old school? While on the jet penetration for a HI-VOR IAP a couple years ago, ATC requested "Ghost 12, Squawk LO, present code" to me. I hadn't heard that since the mid-80s, and even then only one other time in my career.
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I had forgotten about Squawk LO. I do not think either of the two airplanes I fly now have that option.
 
ATC RET 2003 said:
I'll leave it to the math geniuses to figure out what the chances actually could be.
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I thought it had 4096 different possible beacon codes or is that something that has been passed down without somebody checking the math?
"It's a 4096 Mode C transponder, because that's how many codes there are."
"Sounds good to me"
 
You don't need to be a mathematical genius to determine that eight (zero through seven, so eight choices) raised to the fourth power (four blanks), is 4,096.

SteveC said:
If I don't do it within about 5 seconds I forget the new code.
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:yeahthat:

I usually wind up reading it back and dialing it in simultaneously..."Squawk, uh, four wun zeero tree..."
 
Douglas said:
I thought it had 4096 different possible beacon codes or is that something that has been passed down without somebody checking the math?
"It's a 4096 Mode C transponder, because that's how many codes there are."
"Sounds good to me"
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Yes, that's correct. 8 X 8 X 8 X 8 = 4096
 
Because our software cycles radar hits every 5 seconds, we quite often can "see" pilots flipping codes.

Coming off the ocean we've on more than one occasion had it "catch" the transponder on a code 7500.

It's almost universally assumed to be an error in code change, but when you have a 767 heading to JFK it still normally requires a bit of checking into.
 
canadian_atc said:
It's almost universally assumed to be an error in code change, but when you have a 767 heading to JFK it still normally requires a bit of checking into.
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I notice a lot of 2XXX transponder codes coasting in.

Any truth to the "OMG NEVER squawk 0000 because they'll think you're a drone!"
 
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