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RV628PV Squawk..... Never had that before!

Rosie

Rosie

Well Known Member
Coming home from Lake Havasu on Sunday, I called Los Angeles Center for flight following home to Rosamond Skypark. I ALWAYS use flight following when flying long distances.

I'm squawking 1200 as I call.
"LA Center, RV628PV, VFR Request".
"RV628PV, squawk 7701, ident and say request".

So I start turning knobs (as I've done for 36 years) and start with the first knob...I spin it to 7...I grab the second knob and start spinning it...to 3, 4...then I SEE 7400, pause...I then grab the last knob, spin it to 1, then go back to the second knob and spin it to 7.....that could have caused some momentary excitement at LA Center!!!!!

NEVER CAN I RECALL having been given a 77XX code, let alone 7701 :eek:

Sitting on the ramp in the plane, I posed this question to Victoria (knowing the answer already) and she didn't even blink; She started on the last knob (since that knob is closer to her), and using her left hand, she put in 1077 from right to left...good girl!

Has anyone else ever been given a 77XX code? Rosie
 
I have not. And frankly I can't see why they would ever give that to anyone. Almost seems like a test.:confused:
 
77 code

Hello Rosie

I don't know about domestic flying but lately it has happened numerous time while transitionning from the NAT ( North Atlantic Track System ) to the Shannon FIR where I 've been assigned squawk code like yourself (7701,7702, even 7501 ) that one sure got our attention..

I inquired with Shannon and they said those are the codes they are assigned and that they rarely have one that stay at 7700 or 7500 for more than a few seconds..

I guess it prove that we're still awake even if barely after crossing 6-7 time zone..

Good on you to catch it before putting in the last 2 numbers..

Cheers

Bruno
 
Ya that seems weird to get those codes. I guess I've never really thought about it.

Since there are only 4096 codes, who decides what to assign. I'd guess airliners squawk the same code the whole route?

If I'm just flying around locally and call for a clearance though a D or something and they give me a code are they picking from an available list or something? Do different ARTCC's typically assign a range of codes? Interesting...
 
Yes, once had a 77xx code and I queried center before dialing it in - it's what they wanted and I complied. Must have been ~25 years ago and I still remember it fairly well. I can't recall the last time I was assigned a 7xxx
 
boom3 said:
Ya that seems weird to get those codes. I guess I've never really thought about it.

Since there are only 4096 codes, who decides what to assign. I'd guess airliners squawk the same code the whole route?

If I'm just flying around locally and call for a clearance though a D or something and they give me a code are they picking from an available list or something? Do different ARTCC's typically assign a range of codes? Interesting...
Click to expand...

To the best of my knowledge whichever ARTCC initializes the flight plan pulls a random code and assigns it to that flight plan. That code will get you through the various airspaces until you enter another ARTCC, if that code is not currently being used it stays the same. Once you enter a different ARTCC where your present code is being used by another flight plan you get "N123 reset transponder squawk 7234." Airliners get code changes quite regularly.

For flight plan processing, the approach controls, class D etc are all assigned to 1 ARTCC and all flight plans pull from the 4096 possibilities. Except reserved codes such as 7500-7600-7700, or things like 1255 firefighting and others. I believe some places have a small bank of codes that they will use if a flight plan will stay within 1 facility such as a local flight within Denver class B.
 
crabandy said:
To the best of my knowledge whichever ARTCC initializes the flight plan pulls a random code and assigns it to that flight plan. That code will get you through the various airspaces until you enter another ARTCC, if that code is not currently being used it stays the same. Once you enter a different ARTCC where your present code is being used by another flight plan you get "N123 reset transponder squawk 7234." Airliners get code changes quite regularly.

For flight plan processing, the approach controls, class D etc are all assigned to 1 ARTCC and all flight plans pull from the 4096 possibilities. Except reserved codes such as 7500-7600-7700, or things like 1255 firefighting and others. I believe some places have a small bank of codes that they will use if a flight plan will stay within 1 facility such as a local flight within Denver class B.
Click to expand...

Will we still have assigned codes with ADSB?

If we are outputting a unique code is it really still needed?
 
never have but it reminds me of a short transponder story...........

flying north up thru Washington's airspace i heard center trying to give out a new code to a pilot. over and over the pilot repeated back the incorrect code. after about 4 or five attempts center responded back with 'close enough'. :eek:
2015-01-25%2017.28.47.jpg
 
Yes, Gil - even in the ADS-B world, you'll have a 4-digit squawk code. Part of the reasoning behind this is to allow non-Mode-S aircraft to continue to function within the radar environment (note the term radar, not controlled airspace, where ADS-B will be required).
 
Squawk code

Was not given 7701 but Chicago center gave me 1201 and Ident just to see where I was before giving me my en-route code. I was leaving Logansport In headed for KOSH and requested FF from Chicago Center. After that exchange the controller let me know that I was outside the Class B and I was instructed to stay clear of all Class B,C,and D airspaces but I got the FF code

Tyler
 
ALT-> SBY
Select 7701.
SBY->ALT

That's how we were all taught to do it, isn't it?

- mark
 
newt said:
ALT-> SBY
Select 7701.
SBY->ALT

That's how we were all taught to do it, isn't it?

- mark
Click to expand...
That's how I was, yes. Never change your code with your transponder in ALT or ON. You run the risk of corrupting the ATC system, at least in Australia.

From the AIP:
Pilots must select the transponder to STANDBY before effecting an SSR code change and returning the transponder to ON/ALT.

Note: This action is required to prevent possible loss of displayed aircraft position/label information and possible misidentification of aircraft in automated Australian ATC systems due to temporary selection (while effecting the change) of a code already in use.
Click to expand...
 
code subsets

We try (via automation) to preserve your code from facility to facility to reduce the need to change your code. Given the number of planes and the limited number of codes, that isn't always possible. Each center does have a subset of codes that the computer assigns as a first choice; at Albuquerque Center we often see codes 07xx, 26xx, 41xx.
Approach controls do have a set of local codes they use if you stay in the immediate facility. You will notice that if you call inside approach and request flight following outside their facility, it takes a few moments longer because they retrieve a code for you to use as you leave their facility so they can make an automated handoff to the adjacent facility.
 
newt said:
ALT-> SBY
Select 7701.
SBY->ALT

That's how we were all taught to do it, isn't it?

- mark
Click to expand...

Probably not necessary with a glass cockpit, I'd think...the transponder code entered in to an EFIS (like Dynon w/ its own XPDR) most likely doesn't take effect until the last digit is entered, unlike the old-style XPDRs with separate knobs for each digit.

At least, that's how I'd design the code.
 
Probably not necessary with a glass cockpit, I'd think...the transponder code entered in to an EFIS (like Dynon w/ its own XPDR) most likely doesn't take effect until the last digit is entered, unlike the old-style XPDRs with separate knobs for each digit.

At least, that's how I'd design the code.
Click to expand...

That is the way we would design it too.

-Robert
Dynon Avionics
 
That's cool and obvious (I think Garmin does it the same way too).

Another alternative is to have a flip-flop button for the transponder code, the same way we do with COMs. Microair does that on their T2000SFL transponder: You select the code you want on the standby, and hit the flip switch to activate it.

I have one of those, I still turn it back to SBY before changing it, out of habit :)

In any case: Rosie said he was turning dials, which makes the EFIS side of things less relevant.

- mark
 
newt said:
ALT-> SBY
Select 7701.
SBY->ALT

That's how we were all taught to do it, isn't it?

- mark
Click to expand...

Negative...Controller friend tells me that they know you are changing codes and would rather see a very short time with screwy numbers than the numbers disappearing altogether.
 
rjbob said:
Negative...Controller friend tells me that they know you are changing codes and would rather see a very short time with screwy numbers than the numbers disappearing altogether.
Click to expand...

Second that. Heard the same thing from a controller in CA.
 
VH-VRN said:
that's how I've been taught so as not to create the 7700 inadvertent scenario
Click to expand...

Bad idea...again, controllers would rather that aircraft don't disappear from their scopes for any reason.

The following is a direct quote from a controller:
Also, just to add from a controllers standpoint, I would rather see a limited data block with your callsign still associated with the primary target than seeing a primary target with no information whatsoever (as in, Squawking Standby). The time between the change is so miniscule that I do not believe it would be an issue.

Another quote I found (but this one is unofficial):
I think that the "turn to standby" when changing code is likely to have been dreamed up instructors sitting about on bad weather days who seem to like to try to turn flying into a black art.

Avoiding unnecessary steps is generally safer when piloting, also.
Bob
 
Another thing...
Almost all the newer transponders, especially the digital ones, don't change to the new squawk until the last number of the new code has been entered.

Check your manual.
 
What many folks posting against the STBY procedure is that the folks posting that are all from Australia - different country, maybe slightly different rules and customs. I am with the Americans who have never heard of doing it that way, and don't - but its interesting that it is taught that way down under....
 
rjbob said:
Negative...Controller friend tells me that they know you are changing codes and would rather see a very short time with screwy numbers than the numbers disappearing altogether.
Click to expand...

That doesn't make a lot of sense. I only see the flashing radar-paint indicator every few seconds. I can change from one code to another with the transponder off between samples and they won't even know.

- mark
 
Ironflight said:
What many folks posting against the STBY procedure is that the folks posting that are all from Australia - different country, maybe slightly different rules and customs. I am with the Americans who have never heard of doing it that way, and don't - but its interesting that it is taught that way down under....
Click to expand...

Nope, in my case it was two tower controllers from KTOA who were part of a safety seminar. They were FAA employees. I had never heard of doing it that way either until then.

Heinrich
 
newt said:
That doesn't make a lot of sense. I only see the flashing radar-paint indicator every few seconds. I can change from one code to another with the transponder off between samples and they won't even know.

- mark
Click to expand...

Cool...then they won't be able to see your inadvertent erroneous code even if you don't put it on STBY.
 
rjbob said:
Bad idea...again, controllers would rather that aircraft don't disappear from their scopes for any reason.
Click to expand...
A worse idea is an incorrectly assigned ID block because TAAATS has assigned your location to the aircraft whose code you inadvertently selected or the system has dropped the ID block on a legitimate RPT flight because you cycled through his code. this is what happens when "the system" mucks up codes.

The following is a direct quote from a controller:
Also, just to add from a controllers standpoint, I would rather see a limited data block with your callsign still associated with the primary target than seeing a primary target with no information whatsoever (as in, Squawking Standby). The time between the change is so miniscule that I do not believe it would be an issue.
Click to expand...
That is a quote from an American controller. While that may be the case for FAA Controllers it is not true for Australian controllers and presumably others. The point being, you need to know what your regulatory requirements are, not just blindly assume what should be done based on hearsay.

Another quote I found (but this one is unofficial):
I think that the "turn to standby" when changing code is likely to have been dreamed up instructors sitting about on bad weather days who seem to like to try to turn flying into a black art.
Click to expand...
Again, in the US, possibly, but it is required procedure to select standby in Australia. Why? Because:
In Australia, under the TAAATS system, cycling "live" through codes could trigger the activation of various flight plans -- nine between 1200 and 1237, for example. With TAAATS auto coupling and flight "corridor" matching, it should be less of a problem; however, certainly not outside the realms of possibility that, whilst transitioning from one code to another, that another flight-plan could be moved from "announced" to "active"; based on autocoupling; rudimentary route segment and code match.
Click to expand...

From AIP ENR 7.1.10
Airservices Australia said:
Pilots must select the transponder to STANDBY before effecting an SSR code change and returning the transponder to ON/ALT.

Note: This action is required to prevent possible loss of displayed aircraft position/label information and possible misidentification of aircraft in automated Australian ATC systems due to temporary selection (while effecting the change) of a code already in use.
Click to expand...
TAAATS is based on EuroControl, so presumably the same requirements will apply in Europe, but as I don't fly there, I can't say for sure. AIUI, a derivative of TAAATS has been sold to China so expect to see more of this "select standby" occurring.
 
Thanks for the info, KRviator.
My wife and I will be visiting Australia within a couple of years so it's good to learn some of the technique differences.
Bob
 
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