Selcal/Squawk and Database

[Horsham Spotter]

I know that we can see the squawk ID of aircraft on RB but can we access the selcal of a aircraft. Also are they the same. I know that the squawk has four numbers and that the selcal has four letters.

Could someone please explain the difference and what they are used for.

Can't see a thing landing at Gatwick today cloud base to low and that's started me looking in to this topic.

Thank you.
Steve.

[RodBearden]

Steve - as I understand it, the squawk is allocated by ATC on a per-flight (or even per ATC sector) basis, and is transmitted as part of the Mode-C.

Selcal (selective call) code is assigned pretty much permanently to an aircraft, and is used in voice communications to direct calls from ATC to that particular aircraft, allowing other pilots to not be woken up (sorry - interrupted) by calls that aren't meant for them.

Rod

[Horsham Spotter]

Thank you Rod.

I assume that RB has non details of Selcal. It seems another good way to ID aircraft like mode S ( not a moan by the way more than happy with RB ).

I have only noticed the Selcals when looking up aircraft mode S detail on www.airframes.org when updating databases.

Steve.

[RodBearden]

Steve - as it's concerning voice, not data, it's not really anything to do with RB. And, only being a four-letter code, I guess it's of pretty restricted use in ID'ing an aircraft - I thinlk it's only used for long-haul planes.

Rod

[Allocator]

A good description here:

http://en.wikipedia.org/wiki/SELCAL

Note that the SELCAL is allocated to the operator and not the aircraft and then only when applied for.  When an aircraft is sold, a new code must be allocated to that aircraft by the new operator.

There will also be a huge number of aircraft where the SELCAL code is not required and will therefore not be applied for or allocated, so not a good way to identify an aircraft.

[nortonbeak]

but can we access the selcal of a aircraft.

AirNav do market a Selcal decoder. You will need a receiver hitched up to your PC for it.

http://www.airnavsystems.com/Selcal/index.html

[DaveReid]

AirNav do market a Selcal decoder. You will need a receiver hitched up to your PC for it.

Presumably their Selcal database is as out-of-date as their Mode S database ?

[nortonbeak]

Presumably their Selcal database is as out-of-date as their Mode S database ?

That would be a very safe bet!

[Allocator]

AirNav do market a Selcal decoder. You will need a receiver hitched up to your PC for it.

Presumably their Selcal database is as out-of-date as their Mode S database ?

Is there an easily available SELCAL database?

[nortonbeak]

Is there an easily available SELCAL database?

There is a book, but I've no idea how up to date it may be.

http://www.pwpublishing.ltd.uk/bookstore/books.html

[RodBearden]

The Aircraft part of airframes.org allows you to enter a Selcal code to decode it, and there's also http://www.selcalweb.co.uk/ which has a searchable database and a good FAQ section explaining hpow Selcal works.

Rod

[DaveReid]

there's also http://www.selcalweb.co.uk/ which has a searchable database and a good FAQ section explaining how Selcal works.

Includes a not exactly flattering review of the AirNav Selcal Decoder:

"Sadly the database has never been officially updated since and is completely useless for identifying anything you hear on the airwaves today."

[Allocator]

Dave, you seem to have a bit of an agenda here regarding AirNav databases ........

[DaveReid]

Dave, you seem to have a bit of an agenda here regarding AirNav databases ........

You mean apart from the fact that I think they are hopelessly out-of-date ?  I make no secret of the fact that I think something needs to be done - clearly all users would stand to benefit from that.

[abrad41]

DaveReid

I completely agree with your comments and something needs to be done about the process of updating the database too.

Andy