Radar contact based on SSR

[JohnnyEagle]

Hi,
how do you interpret the "check" that shall be done prior to identification according to Doc 4444? Since it says the code has to be "set", is a readback of the squawk when its given good enough?

DOC 4444 chapter 8

8.6.2.2.2 When a discrete code has been assigned to an
aircraft, a check shall be made at the earliest opportunity to
ensure that the code set by the pilot is identical to that assigned
for the flight. Only after this check has been made shall the
discrete code be used as a basis for identification.

[Inverted81]

The way it reads, i assume it is basically telling you to see the squawk change ASAP rather than allocating a squawk and not looking at the radar for some time to see the squawk is displayed correctly........

[JohnnyEagle]

So when the aircraft is given clearance and squawk prior to departure.. how do you do this check?

[Inverted81]

It reads as if it refers to an aircraft in flight. If it does indeed refer to squawk allocations during a clearence, then it could only be cross checked at airports such as heathrow who have a modeC/S surface surveilance (sp??) radar, but whether this is something they do i do not know. Usually in most instances, the first time it is seen that an incorrect code has been dialled in, is when the aircraft first appears on approach radar....

[Quincy M.E.]

So when the aircraft is given clearance and squawk prior to departure.. how do you do this check?

Check on the ATM that the squawk is correct before binning it to APP.

[reportyourlevel]

(This is in the UK)

For a departure I would identify using a primary method (normally the departing aircraft method) and then validate the mode A and verify the mode C before giving to radar/area. If you've missed the primary identification, then it's a case of using the squawk ident before validating and verifying.

[JohnnyEagle]

Thanks for all the answers! I have one more question though. The verb "set" in this setting, should it be interpretated as "will be set", "being set" or "is already set" ? or all of the above English is not my native language

In our national regulations it has been translated to "has been set".. And we dont have a PSR where I work..

[reportyourlevel]

No PSR? Scary! Nice clutter free picture though, I suppose.

Your national regulations have it correctly, I think. It must be to check that the assigned code has been set correctly, i.e. look at the radar and check that the numbers (or code/callsign pairing) are correct. The radar we use shows the callsign, but if I select the target with the ERBM it will show the four digit code as well.

[ferris]

Johnny; yes, in this context, it means "has been set". You cannot check something that will be set! Regarding your first question:

a check shall be made

Everywhere I have worked defines how the check shall be made, so there is no ambiguity. eg. "the aircraft is squawking the assigned code (code/callsign correlation) at the correct altitude in an expected position" or words to that effect. Some places say that code/callsign correlation is nota sufficient check.