country registration code "OO" ?

[veldmuis]

Something I always have wanted to know, but only now I can reach people who might know it :

The country registration codes for civil a/c can be 'logical' (eg F for France, D for Deutschland, I for Italia, etc), or ‘not so logical’ (eg OO for Belgium, PH for the Netherlands, N for USA, etc), or even be an alpha-numeric combination (eg 3B for Mauritius).

Does anyone know the origin of these codes (eg Chicago Convention 1947 ? ICAO ? IATA ?) and the ‘meaning’ behind some of these codes, especially the origin of the Belgian OO-code ?

Geert

[TheSpecialist]

I think you should start thinking by the 'old' Belgian codes, which where "O-xxxx", so only one "O", but what does the "O" mean than

[sn26567]

Frm memory, it seems that country codes started in 1920. At that time, they were of the type x-xxxx. For Belgium, it was O-Bxxx. There were only a handful of countries which had aeroplanes, hence one initial letter seemed to be enough.

Why O? Well I guess that the initial B was already attributed. To China? I am not sure. The B after the O- seems obvious for Belgium.

In 1929, most registrations changed from x-xxxx to xx-xxx. Since Belgium had already an initial O, this was maintained and a second O was added. The change was minimal for existing planes. Ex: O-BOEL became OO-OEL

One should also remember that the airplanes of the Belgian army (and I mean the land forces, not the Air force) are registered OL-xxx, xxx being one letter and two numbers. Example: the Alouette helicopters: OL-A01. The Puma of the federal police (formerly gendarmerie): OL-G01.

OT was reserved for the Belgian Air Force.

[TheSpecialist]

Well, it might sound stupid, but may be it was this way:

France had F-xxxx
Germany had D-xxxx
Belgium had O-Bxxx

May be the "O" meant "Other"

[SAB-OM]

Well, this is all regulated by the ITU (www.itu.int)
It has everything to do with the radio onboard the aircraft.
The radio callsign is used to identify a radio station (fixed, mobile, airmobile, maritime, ...) and it's origin.

The ITU publishes a table of prefixes alocated to every country.
The country is responsible for the distribution of the callsigns to the
different users/services. (for Belgium: BIPT, for the US: FAA)

some examples of the prefix blocks allocated to countries:
ON-OT Belgium
PA-PI Netherlands
W,K,AA-AL United States
G,M,2 United Kingdom

depending on the usage the format of the callsign can change:
OO-ABC = aircraft = 3 letters after prefix
ON5LL = amateur station = 1 digit and at least 2 chars after prefix
OT3L = amateur high power station = 1 digit (year) and 1 letter after prefix
OST = Oostende radio = shortwave broadcast station = 1 letter after prefix

it's difficult to find a complete list of prefixes and usage but this one is not bad:
http://daveg4otu.tripod.com/pref.html

some of you probably don't know, but for every radio station/signal you need a permit ...
is it for radio, tv, radar, broadcast, digital, ...

hope this clears up things..

Filip
ON1AFN

[sn26567]

Filip,

Thanks for your clarification. I learned a lot today, hence I did not loose my day

But what about the OL registrations of the Belgian army's light aviation? They are outside of the range ON-OT allocated to Belgium.

[veldmuis]

Thanks already for all those replies !!! Being fairly new on this Forum, I hesitated at first to raise this issue, thinking it would be a "stupid" question for which you guys had already known the answer for years by now. But apparently, it's not that simple at all...
Geert

[TheSpecialist]

Ow, I learnt something today 8O

[aerobel]

These codes aren't only used with the Land Forces, also the Navy uses similar codes... e.g. Alouette III M1 is OT-ZPA. The same with the Former Sikorsky's from the 40th SQN.

Greetz
TOM 8)