Transponder question

I was reading somewhere today that when you are setting your transponder code that you should never have the first two digits of the transponder set to 75, 76, or 77 because it will transmit as 7500, 7600, or 7700 regardless of the last two digits. Is this true?

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Never heard of this before, Do you remember where you were reading this/

yea I was reading this in one of my private pilot books. I tried looking this up but I really was not getting anything. @anon93248082 you can try this next time and tell me what happens lol :).

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Lol I can go try it probably doubt anything will happen, but @DeerCrusher any idea?

Well the fact that the VFR code is 1200 and if you get a 75,76.,77 code you should prob chnage the last two numbers first

No what I read was regardless of the last two numbers if your first two numbers are 75, 76, 77 it will be transponded as an emergency squawk.

I think I found the answer

From the AIM

1. When making routine code changes, pilots should avoid inadvertent selection of Codes 7500, 7600 or 7700 thereby causing momentary false alarms at automated ground facilities. For example, when switching from Code 2700 to Code 7200, switch first to 2200 then to 7200, NOT to 7700 and then 7200. This procedure applies to nondiscrete Code 7500 and all discrete codes in the 7600 and 7700 series (i.e., 7600-7677, 7700-7777) which will trigger special indicators in automated facilities. Only nondiscrete Code 7500 will be decoded as the hijack code.

So I guess it can!

EDIT: Re-Read this still doesn’t answer the question lol

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what did you mean by the edit?

Means I added it

Oh I see. Yea that does not answer it.

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What did you mean by the 7600-7677?

That info Came from an Old AIM trying find 2019’s

give me a few as I am landing (in IF) and then I will look too

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Ignore that comment I just said, Time to find out what those codes are for yeah.

Okay so this is what I’m getting from the AIM

Yes - You shouldn’t trigger the first two numbers 75, 76 or 77 reason being is this is the emergency code. So if you’re squawking 2314 and you have a lost comm situation, you go down and change it to 76 and that’ll inform tower you have lost comms.

Oh ok that makes sense. Thank you!

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Yeah welcome! I just asked a facebook group some one just said this so I’m probably wrong lol



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