RAF Serials

[MikeC]

This has never occurred to me before, but now it has, I'd be rather interested to know, if anyone can come up with an answer:  why do RAF serials not use the letter "Y"?  Take a look: http://www.ukserials.com/

 

There's no Yxxxx series; no VYxxx; no WYxxx; no ZYzzz.  It lists some in the "XYxxx" range, and shows them as changed to "XZxxx".  My copy of this https://www.amazon.co.uk/British-Military-Aircraft-Serials-1878-1987/dp/090459761X   shows those in the "XYxxx" range as "allocated in error" and changed.   It appearsthat the military aircraft register is deliberately avoiding the letter "Y".

 

Does anyone happen to know why? (Sorry, a genuine question, but pun intended!)

[Max Headroom]

I think it’s as simple as avoiding a mis-identification with ‘V’, probably why there’s never been an ‘O’ being confused with ‘0’. Ditto ‘C’ with ‘0’. Having said that there is at least one photo somewhere of a Wellington in the HCxxx range.

 

Trevor

[MikeC]

That seems reasonable, thanks Trevor.

[Rickoshea52]

Similarly the British car registration system does not use the letter I or Q to avoid confusion, Q was only used on vehicles with an indeterminate age etc. Until the most recent registration system was introduced the letter Z was also not used in case of confusion with the number 7...apparently. 

[Graham Boak]

Same with squadron codes, until they ran short of combinations when the US started pouring units into the UK.   They did not use C,I, or O, but did use Y, possibly because the larger letters made confusion less.  Or possibly because the rotation of staff members meant someone different was in charge and didn't recognise or accept any possibility of confusion.

 

Relevent here is the Japanese use of a C (strictly an open circle) on the fuselage of their ASW aircraft with MAD devices.  They would fly in formation and when the C looked like an O they were the optimum distance apart for a sweep.

Edited October 2, 2019 by Graham Boak

[MikeC]

Thanks Rick and Graham.

 

I'm aware that the car system avoids some letters, just never occurred to me that "Y" (and I've had more than one car with a "Y" on the plate) would be confused with "V".   Still, live & learn ...

Edited October 2, 2019 by MikeC

[XV107]

From an article by Ray Sturtivant in Flight, 21 October 1955:

 

Serial Z9999 was reached soon after the outbreak of war, and it was decided to continue with a similar system which, employing two letters and three numbers, began at AA100. In order to avoid confusion, the letters C, G, I, O, Q, U and Y were not used. Exceptions were that the letter G was used as a second letter, and that the combination NC was employed.

[MikeC]

7 hours ago, XV107 said:

From an article by Ray Sturtivant in Flight, 21 October 1955:

 

Serial Z9999 was reached soon after the outbreak of war, and it was decided to continue with a similar system which, employing two letters and three numbers, began at AA100. In order to avoid confusion, the letters C, G, I, O, Q, U and Y were not used. Exceptions were that the letter G was used as a second letter, and that the combination NC was employed.

That seems pretty definitive - thanks.

[lasermonkey]

I have been wondering what happens once we get to ZZ999. Three letters and two numbers?

[Rabbit Leader]

7 minutes ago, lasermonkey said:

I have been wondering what happens once we get to ZZ999. Three letters and two numbers?

Does anyone know what’s the latest RAF serial allocated so far? 

Cheers.. Dave

[Steve Coombs]

The ZA range started to be allocated about 40 years ago, and the new Lightnings are in the ZM range. At this rate, it's going to be at least 2060 before the Z* series runs out!

[Romeo Alpha Yankee]

16 minutes ago, Rabbit Leader said:

Does anyone know what’s the latest RAF serial allocated so far? 

Cheers.. Dave

The P-8s are using ZP, followed by 800 series numbers

 

[lasermonkey]

31 minutes ago, Steve Coombs said:

The ZA range started to be allocated about 40 years ago, and the new Lightnings are in the ZM range. At this rate, it's going to be at least 2060 before the Z* series runs out!

But we have started using the ZZ range already. I have to admit, I have no idea how serial numbers are allocated, but I can see it happening sooner than one might imagine.

[stever219]

In recent years the system has changed but, predictably, not for the better.  

 

The first incidence if this that I can remember is the C-17 purchase: initially the aeroplanes were leased and, for reasons best known to someone at the Misery of Disarmament who felt that he/she had to make their mark, there were allocated serials from ZZ171 onwards.  At that time the ZHxxx range was in use with the last of the RAF Tornado fleet and the C-130J purchase going through.

 

A similar situation exists with the A330 Voyager fleet which MoD wanted kept “off the books” which have serials starting at ZZ330, however the A400 Atlas fleet is an outright purchase (by comparison with the 330s) and their serials start at ZM400.  The F-35 fleet starts at around ZM135 but it’s highly unlikely that we’ll buy enough of those aberrations to impinge upon the A400 range.  Some serials have been compromised in the past, i.e. the same number has been allocated to two airframes, for example MP469 IIRC which was allocated to the prototype Mosquito NF. XV and an Airspeed Oxford.

 

Another recent anomaly is the use of serials lower than 100, e.g. ZK020 for one of the Hawk T. Mk. 2 fleet and ZK038 for a Typhoon FGR. 4.

 

During World War II large blocks of numbers were reserved for lend-lease acquisitions that never happened and large numbers of cancelled orders at the end of the war were never reallocated; somewhere in the middle of that lot were six Avro Lincolns, SS714 to ‘719, the only aircraft with SSxxx serials to be taken on charge.  The book referred to by MikeC gives a very simple but concise coverage of these aspects.

 

[Selwyn]

57 minutes ago, stever219 said:

In recent years the system has changed but, predictably, not for the better.  

 

The first incidence if this that I can remember is the C-17 purchase: initially the aeroplanes were leased and, for reasons best known to someone at the Misery of Disarmament who felt that he/she had to make their mark, there were allocated serials from ZZ171 onwards.  At that time the ZHxxx range was in use with the last of the RAF Tornado fleet and the C-130J purchase going through.

 

A similar situation exists with the A330 Voyager fleet which MoD wanted kept “off the books” which have serials starting at ZZ330, however the A400 Atlas fleet is an outright purchase (by comparison with the 330s) and their serials start at ZM400.  The F-35 fleet starts at around ZM135 but it’s highly unlikely that we’ll buy enough of those aberrations to impinge upon the A400 range.  Some serials have been compromised in the past, i.e. the same number has been allocated to two airframes, for example MP469 IIRC which was allocated to the prototype Mosquito NF. XV and an Airspeed Oxford.

 

Another recent anomaly is the use of serials lower than 100, e.g. ZK020 for one of the Hawk T. Mk. 2 fleet and ZK038 for a Typhoon FGR. 4.

 

During World War II large blocks of numbers were reserved for lend-lease acquisitions that never happened and large numbers of cancelled orders at the end of the war were never reallocated; somewhere in the middle of that lot were six Avro Lincolns, SS714 to ‘719, the only aircraft with SSxxx serials to be taken on charge.  The book referred to by MikeC gives a very simple but concise coverage of these aspects.

 

The original system  used before WW1  Started  at "A1" for Army (RFC) aircraft,  up to A9999, RNAS aircraft  started at "N1." The  Army system was continued through B,C etc. On formation of the RAF Naval operated aircraft  stayed with the "N" system until it was used up, and then they moved to the  "S" prefix. The N numbers were used again in the 1930's IIRC, in the build up to ww2 but for RAF aircraft.

 

Selwyn

[Romeo Alpha Yankee]

11 hours ago, Steve Coombs said:

The ZA range started to be allocated about 40 years ago, and the new Lightnings are in the ZM range. At this rate, it's going to be at least 2060 before the Z* series runs out!

The A400s also use the ZM range

[EwenS]

This should give you all the answers you need. Serials are being routinely allocated to drones (Reaper ZZ2??), targets (Meggitt Voodoo ZZ42?) and simulators (Atlas ZM398 and 399) nowadays. Also sales to foreign air arms often get a UK serial first. I suppose it makes the accounting easier!

 

http://www.ukserials.com/

 

The highest serials issued so far seem to be for the 3 RC-135W ZZ664-666.

 

As for what happens when we get to ZZ999? I think that is a long way off, given how few aircraft are being bought these days.  We seem to have gone ZR, ZM and started ZP with the Poseidon with ZZ thrown in for good luck. So ZS, ZT, ZV, ZW, ZX, ZY are likely to be used = 6000+ serials still available in theory.

Edited October 4, 2019 by EwenS

[MikeC]

24 minutes ago, EwenS said:

This should give you all the answers you need. Serials are being routinely allocated to drones (Reaper ZZ2??), targets (Meggitt Voodoo ZZ42?) and simulators (Atlas ZM398 and 399) nowadays. Also sales to foreign air arms often get a UK serial first. I suppose it makes the accounting easier!

...

This has been standard practice for a long time.  Have a look at the "XS" and "XV" series, there are a whole bunch allocated to Northrop Shelduck drones, many of which are marked cancelled.  And often aircraft were allocated a serial for initial flying and/or ferrying while they were sold to another user.

[Rickoshea52]

I also read somewhere that the MOD does not allocate serials in a way that can easily identify the number of aircraft on inventory (not that it makes much difference) hence the reason serial prefixes maybe varying in a way that doesn’t make sense in the issuing sequence. 

 

More here - http://ukserials.com/

[Max Headroom]

When we get to ZZ999 my hunch is that they’ll flip the letter/number sequence and start with 100AA in the same way the DVLA did with car registrations, prior to the current sequence.

 

Then you have instances of single examples being allocated a serial from a previously issued block, such as the Qinetic Mi-17 ZB698, which it ‘took’ from a Northrop Chukar D.2. Quite why this was done decades after the block was first allocated, goodness knows, unless there was some sort of stupid attempt to bury the evidence? Quite why there are now serials in the sub 100 range is beyond me, when whole blocks are being skipped.

 

Also consider the first batch of F-35’s whose serials echo the first Lightning F.1’s (XM135 etc) and the three Rivet Joint R.1’s. who’s numbers mimic the three original Nimrod R.1’s (XW664/5/6). Is there someone in the MoD playing the knowing, nerdy historian?

 

It appears to me that serial allocation is now a free-for-all.

 

Trevor

[pigsty]

21 hours ago, Max Headroom said:

Is there someone in the MoD playing the knowing, nerdy historian?

Possibly.  But ZP801 for the RAF's first (P-8) Poseidon shows they're not just doing history.

[KevinK]

30 minutes ago, pigsty said:

But ZP801 for the RAF's first (P-8) Poseidon shows they're not just doing history.

The Nimrod was the H.S. 801, so it is a very clever, knowing, nerdy historian who is perhaps making a point!

[Max Headroom]

35 minutes ago, KevinK said:

The Nimrod was the H.S. 801, so it is a very clever, knowing, nerdy historian who is perhaps making a point!

I love this!

 

And there was me playing around with the serials to see if there was a clue 

 

Trevor

[Ossington 2]

The Air Min would deliberately break up number allocations to make it difficult for a foreign power to calculate how machines of a particular kind were in service. Whole sequences ("blackout blocks") would be omitted to make precise calculation problematical, it being difficult to prove a negative. In peace time the practice was abandoned because it suited government to advertise numbers ("the RAF is to receive a further batch of XXXXX in the next decade. This secures jobs at*****") and I can't see future wars lasting long enough to design and build a new fleet in sufficient numbers to warrant its return.   

[Truro Model Builder]

On 10/5/2019 at 7:42 PM, pigsty said:

Possibly.  But ZP801 for the RAF's first (P-8) Poseidon shows they're not just doing history.

ZP801

ZP802

ZP803

etc

 

All logic has gone out of the system, that's for sure.

 

On the subject of aircraft produced for overseas nations, they are allocated military serials to facilitate flight testing in the UK. Similarly, a number of ex-DHFS Squirrels and Griffins are in use at Newquay with Cobham Flight Academy for training overseas military helicopter crew. Owned by Cobham, they retain military serials to allow them to undertake flight profiles civilian helicopters cannot.