Avro Vulcan flare (and other countermeasures) dispensers - any information?

[Flame2512]

I was reading this RAF Historical Society Journal and there is a section in it which talks about the Electronic Warfare Equipment on the Avro Vulcan. This part in particular caught my attention.

On paper the Vulcan had an impressive defensive suite comprising powerful jammers, a radar warning receiver, a tail warning radar, infrared flares and oodles and oodles of chaff.

I'm aware of the collection of ECM kit which resided in the Vulcan's tail, and have heard mention Vulcan's carrying large amounts of chaff before, but this is the first time I've read of the Vulcan carrying infrared decoy flares.

Does anyone have any interesting information (or pictures) about the Chaff / Flare dispensers on the Vulcan?

Here's what I've worked out so far from doing a bit more reading after seeing that: the chaff (or Window, as they were called back then) dispensers were fitted inside the wing, just behind the landing gear. They are also mentioned very briefly in both the Vulcan B.1A and B.2 flight manuals (available here if anyone is interested). The RAF Journal lists the Window dispenser on the Vulcan as follows:

ARI 18051 - WINDOW dispensers (Vulcan - Type 26 (2.8-8 GHz) & Type 28 (7.5-14.25 GHz). Short (350 packet) belt in each wing and long (1150 packets) belt in port wing, plus chaff cartridges for the Very pistol

So that comes out as the Vulcan carrying about 1,850 packets of Chaff / Window. However later on it also says the Vulcan carried 4,000 packets of chaff which is obviously a lot more. Does anyone know what the correct amount is?

Moving on, the Vulcan could dispense large quantities of chaff. It was stored within the wing, just aft of the main undercarriage legs, in what were inevitably known as ‘window boxes’, two per side. In all we had four thousand packets of chaff, each packet being about a nine inches long by three inches wide and half-an-inch thick. It was pre-cut to various lengths giving us wideband frequency coverage. It was dropped through apertures in the underside of the wing which looked rather like letter-boxes.

As for the infrared decoys I can't find much meaningful information online. Aside from a few websites (of questionable trustworthiness) mentioning the Vulcan carried flares all I've found is this US Navy Report saying that the RAF developed a 2.25" x 5.3" decoy flare for use with the Vulcan and other V-bombers under the designation Flare Type E/2/1, and later UK Mk 1 Decoy. The RAF Journal describes the flare dispensers as:

Infrared Decoys (Vulcan): 92 short belt; 172 long belt

The wording of that (the flare being in the form of long and short belts implies that maybe they take the place of one of the chaff belts?

 

[yellowaster]

Here's the Window installation. The ARI 18051 stripper/dispenser unit is the small box mounted on the top left side of the large Window magazine.

 

[Flame2512]

Here's the Window installation. The ARI 18051 stripper/dispenser unit is the small box mounted on the top left side of the large Window magazine.
View attachment 674225

So presumably the two different sized boxes corelate to the 350 and 1,150 packet belts of chaff referenced by the RAF journal?

 

[yellowaster]

Here's the Window installation. The ARI 18051 stripper/dispenser unit is the small box mounted on the top left side of the large Window magazine.
View attachment 674225

So presumably the two different sized boxes corelate to the 350 and 1,150 packet belts of chaff referenced by the RAF journal?

Looks about right. I'm confused by the reference to belted IR decoys. The Mk 1 IR decoy was a cartridge which was fired, AFAIK, from a multi-barrel discharger. I've never seen an illustration of the V-bomber fit though.

 

[Flame2512]

Here's the Window installation. The ARI 18051 stripper/dispenser unit is the small box mounted on the top left side of the large Window magazine.
View attachment 674225

So presumably the two different sized boxes corelate to the 350 and 1,150 packet belts of chaff referenced by the RAF journal?

Looks about right. I'm confused by the reference to belted IR decoys. The Mk 1 IR decoy was a cartridge which was fired, AFAIK, from a multi-barrel discharger. I've never seen an illustration of the V-bomber fit though.

The concept of "belted" chaff makes some amount of sense to me. I can imagine packets of chaff joined together and laid in the box like a belt of machine gun ammo would be. Presumably this "stripper" thing would then pull in a packet of chaff break it open and dump it's content down the chute. But yeah I'm not really sure how flares would work in that configuration. Here's one of the pilots talking about the chaff / flares (again from that RAF museum document linked in the original post).

Moving on, the Vulcan could dispense large quantities of chaff. It was stored within the wing, just aft of the main undercarriage legs, in what were inevitably known as ‘window boxes’, two per side. In all we had four thousand packets of chaff, each packet being about a nine inches long by three inches wide and half-an-inch thick. It was pre-cut to various lengths giving us wideband frequency coverage. It was dispensed through apertures in the underside of the wing which looked rather like letter-boxes. If we dropped chaff on a training flight, on leaving the area we were supposed to lower the undercarriage to create turbulence across these apertures in order to suck out any chaff that had got stuck inside. This was because our Auxiliary Power Unit (APU) was in the starboard wing just behind the main undercarriage leg; if we fired it up before clearing the stray chaff it could be ingested by our little Rover gas turbine which would do it no good at all. In practice we often left this precaution until we were approaching the circuit when we had to lower the undercarriage and start the APU anyway. Some of the residents of the Gainsborough area may have got a bit fed up with having chaff dropped on them from time to time, but they never seemed to complain. There were some people who did, however. We were allowed to drop chaff quite happily on the range at Spadeadam and the farmers would often phone in to blame us for their sheep dying because they had allegedly been eating aluminium-clad fibreglass filaments. The boffins eventually decided that the stuff wasn’t actually toxic, not, at least to sheep, and that the farmers were simply trying it on in the hope of persuading MOD to pay out in compensation.

In addition to chaff we were also well provided with flares, 192 of them in all. They were made of a compound called MTV - Magnesium Teflon Viton - which allegedly had sufficient of an IR signature to seduce a missile away from our jet pipes. Incidentally, the same material, MTV, is still used by today’s Tornados and Jaguars. A minor inconvenience with our flares was that a substantial metal pin about two inches long was ejected whenever you fired them. This sort of projectile could do substantial damage when it hit the ground; hardly a problem over enemy territory, but in peacetime we could dispense flares only over the sea and only then after carrying out a clear range procedure to ensure that we were not going to sink any ships. That did tie our hands somewhat for training purposes but I did manage to fire a couple at night, and, my word, did they light up the sky?! I can assure you that it was quite spectacular!

Based off that I can only imagine there must have been some sort of belt feed mechanism for the flares, with an internal storage box. I imagine 192 flare holes would be quite noticeable if the Vulcan had conventional flare dispensers (i.e. 1 flare one hole). Also those chaff packets sound fairly large, presumably those boxes are a bit bigger than I originally assumed when I saw the image. I will again note though that the 4,000 chaff packets he claims doesn't agree with the 1,850 listed earlier in the document.

 

[Flame2512]

@yellowaster I've managed to find an apparent photograph of the flare dispenser on a Vulcan. Not quite sure how you get 172 flares out of it though.

That image comes from Aeroguide 06 - Avro Vulcan B Mk2 & Mk 2K

Perhaps the flares being "belted" means that the flare cartridges are on a belt and once they are fired fresh cartridges are moved over then opening?

 

[TomS]

Flare chutes. There would be some mechanism behind the chutes delivering new flares for dispensing.

 

[Flame2512]

Here's the Window installation. The ARI 18051 stripper/dispenser unit is the small box mounted on the top left side of the large Window magazine.
View attachment 674225

So presumably the two different sized boxes corelate to the 350 and 1,150 packet belts of chaff referenced by the RAF journal?

Looks about right. I'm confused by the reference to belted IR decoys. The Mk 1 IR decoy was a cartridge which was fired, AFAIK, from a multi-barrel discharger. I've never seen an illustration of the V-bomber fit though.

@yellowaster Finally found out how the belted flares work. The Vulcan Flare dispenser contains two belts with flare cartridges mounted four abreast on each belt, when the flares are fired the belt rotates to move fresh flares over the opening in the underside of the wing.

This information and the first two images come from A.P. 101B-1902-1B available to view here (page 392), in accordance with the forum fair use rules I won't post any more of the document here (though you can view the whole document with a free account on that website). The large belt contains 172 cartridges and the small belt contains 92 cartridges for a total of 264. The belts can either contain infrared decoy flares or rapidly blooming window, both fired from 2.25" cartridges.

As for the window magazines (posted in the first reply for the thread); they contain paper wrapped packets of window (see third image below) attached to a long belt and laid in the magazine like a belt of machine gun ammo. The stripper units pull the belt out from the magazine and detach each packet of window from the belt as it passes through. The packet then falls through the chute and out of the aircraft where the airflow breaks the packet open and disperses the chaff. The magazines can also hold rope (long strips of metal tape used to confuse long wavelength ground radars, see fourth image) or delayed action window (instead of immediately bursting open the packet is mechanically opened after a delay from it being released). The delayed action window required a slightly wider magazine to be fitted.

Standard fitment seems to be one large and one small window magazine in the port wing, with one flare dispenser and one small window magazine in the starboard wing.

P.S. @yellowaster sorry if I am tagging you in something you have no real interest in. Just thought you might find it interesting.

 

[Fluff]

Chaff control panel on fleabay right now. Says Canberra.

 

[red admiral]

That's a lot of flares. Any idea what systems they were trying to decoy?

 

[yellowaster]

Interesting to see how the dispenser worked. FWIW, the Rapid Blooming Window was developed as a way to unlock a lock-follow radar. Idea was to provide a very large chaff cloud (ideally as large as the aircraft's echoing area) very close to the dispensing aircraft.

 

[Hood]

This switch to providing flares as well as chaff in the B.2 must have been a reaction to VVS/PVO interceptors carrying mixed SARH/IR AAM loadouts to neutralise both threats.

Presumably Victors got these too?

 

[red admiral]

I can imagine vs interceptors with IR AAMs but how do the Vulcans know when to start launching flares? Detect the AI acquisition mode from the fighter and assume its going to start launching missiles?

 

[Flame2512]

I can imagine vs interceptors with IR AAMs but how do the Vulcans know when to start launching flares? Detect the AI acquisition mode from the fighter and assume its going to start launching missiles?

The Vulcan had a tail warning radar to detect enemy aircraft. I think I read somewhere it also had a mode where it could detect a missile separating from the aircraft and fire countermeasures according.

 

[Zoo Tycoon]

For checking six there was always the rearward looking periscopes, one top and one bottom.

The lower one was also used for checking for clean weapon separation I understand….. not to mention during servicing, seeing when engineering officers were approaching, so the guys working in the flight deck would always look look very busy when he looked inside.

 

[Fluff]

For checking six there were always the rearward looking periscopes, one top and one bottom.

The lower one was also used for checking for clean weapon separation I understand….. not to mention during servicing, seeing when engineering officers were approaching, so the guys working in the flight deck would always look look very busy when he looked inside.

The 10 foot ladder, would also help.

I'm not sure in 12 years, I saw the Eng O actually outside of his office.......

 

[Hood]

I can imagine vs interceptors with IR AAMs but how do the Vulcans know when to start launching flares? Detect the AI acquisition mode from the fighter and assume its going to start launching missiles?

I presume the doctrine was that the tail-warning radar gives you warning of the threat astern, the ECM messes up Comrade Ivan's radar scope so he can't get a lock for his R-8MRs. Naturally he's going to switch to IR-seeking R-8MTs to get around that, so ideally you need flares to counter that. Plus the Vulcan is agile so can hopefully break any IR-lock on its quad-exhausts and point them towards a different piece of sky.

The R-8 variants seem to have broadly identical ranges so in theory if he can launch an MT at you, he can fire an MR (for best results though I'm sure you'd want to be closer to get an IR-lock).

The service entry of the R-8 more or less coincides with the B.2 V-bombers too.

The new question I have now is, did the switch to low-level penetration affect its countermeasures ability given that the chaff/flares are downward firing and your fighter adversary is most probably higher than you?

 

[Flame2512]

That's a lot of flares. Any idea what systems they were trying to decoy?

I gather the regular window was for primarily for use against SAM radars, the rope was for use against long range early warning radars and the rapidly blooming window was for use against airborne radars. The Flares would have been for use against IR guided air to air missiles.

According to this US Navy report it was concluded that the V bomber needed to drop flares in pairs at low altitude, and fours at high altitude, so that goes somewhat towards explaining the large number carried. Also if you want to fly deep into Soviet territory I imagine it probably pays to have a lot of countermeasures onboard. The AP document I linked to previously says the flare dispenser could be configured to discharge1, 2 or 4 flare cartridges per firing pulse (R.B.W. cartridges are always fired one at a time).

 

[Flame2512]

I've found this table in the Vulcan Servicing Manual (A.P. 101B-1902-1A) which lists four different types of window (chaff) as able to be carried in the main window dispensers. It's probably a bit of a longshot, but does anyone know the difference between Type 21, 22, 23, and 28 window? The Rapidly Blooming Window used in the cartridge dispenser is listed as "Type 200" in A.P. 101B-1902-1B, but I can't find what the types in the table refer to. Whatever the designations means the Vulcan certainly carried a hell of a lot of chaff looking at that table.


For anyone interested in what the numbers mean the table header is as follows:
Ref No. | Description | Weight (lb.) | Arm (ft.) | Moment (lb.ft.)

 

[Fluff]

Vulcan featured here, page 74

https://www.rafmuseum.org.uk/documents/Research/RAF-Historical-Society-Journals/Journal-28-Seminar-Electronic-Warfare.pdf

 

[Fluff]

WINDOW dispensers (Vulcan - Type 26 (2.8-8 GHz) & Type 28 (7.5-14.25 GHz). Short (350 packet) belt in each wing and long (1150 packets) belt in port wing, plus chaff cartridges for the Very pistol

 

[Flame2512]

WINDOW dispensers (Vulcan - Type 26 (2.8-8 GHz) & Type 28 (7.5-14.25 GHz). Short (350 packet) belt in each wing and long (1150 packets) belt in port wing, plus chaff cartridges for the Very pistol

That would suggest the type number indicates the frequency of the radar it is designed to work against (which makes sense), thought it is interesting quite how much the magazine capacity varies. I can only assume the chaff bundles are quite different sizes. The Vulcan Haynes Manual (of all places) actually has a reasonably detailed breakdown of the countermeasures that were carried. It says there was an early chaff made of metal foil (for use against DE band), a later chaff made of aluminium coated fibreglass (for use against I band), and rope (for use against long-wavelength radars). A.P. 101B-1902-1B also makes mention of delayed action window. So maybe the type numbers in the table refer to (in no particular order):

• D/E band Window
• I band Window
• Rope (Long wavelength)
• Delayed action window

The mention of Type 26 chaff makes stuff a little confusing though as that isn't mentioned in A.P. 101B-1902-1A (where the table is from). The RAF Museum document also doesn't line up with any of the quantities listed in the AP document, so perhaps they are just approximate numbers.

 

[GianVito]

I think you can find something interesting here:

https://archives.nato.int/uploads/r/nato-archives-online/f/c/0/fc0d03fbff282e3a1732b3d7a232b6baa1448c6beb124f51c0fb6cd78cfcfeb6/MC_0131_FINAL_ENG_PDP.pdf

... and in my update article:

Avro Vulcan: sistemi difensivi

I tried to collect all the data about it.

 

[TsrJoe]

Type 9422 control unit

 

[Bill S]

I have been scanning a number of negatives from the George Cockle collection and came across these yesterday. They appear to be a chaff dispenser on Vulcan XH558 during a Red Flag visit in 1981. They were carried on both wings, same pylon set up. Any ideas confirming type and designation?

 

[Flame2512]

I have been scanning a number of negatives from the George Cockle collection and came across these yesterday. They appear to be a chaff dispenser on Vulcan XH558 during a Red Flag visit in 1981. They were carried on both wings, same pylon set up. Any ideas confirming type and designation?

That's not a countermeasures pod; rather it's an air sampling "sniffer" pod; apparently it's made from an old Sea Vixen drop tank. This website has some information about it, and a nice high resolution image of one (doing a Ctrl+F for "sniffing" will get you to the right section of the page):
https://www.key.aero/article/secret-vulcan-procedures-preparing-nuclear-strike

A highly-classified role performed by the squadron was that of ‘sniffing’ particles from any above-ground nuclear tests by the Chinese, French or Soviets. Shortly after an explosion a Vulcan would fly downwind collecting particles which were then passed to scientists at Britain’s nuclear weapons research facility at Aldermaston. From laboratory tests it was then possible for the UK’s Intelligence services to determine the yield of the weapon used.

Here's another picture of one fitted to XH558:

https://twitter.com/x/status/1169487836967518208

View: https://twitter.com/vulcantothesky/status/1169487836967518208

 

[Bill S]

That's not a countermeasures pod; rather it's an air sampling "sniffer" pod; apparently it's made from an old Sea Vixen drop tank. This website has some information about it, and a nice high resolution image of one (doing a Ctrl+F for "sniffing" will get you to the right section of the page):
https://www.key.aero/article/secret-vulcan-procedures-preparing-nuclear-strike


Here's another picture of one fitted to XH558:

https://twitter.com/x/status/1169487836967518208

View: https://twitter.com/vulcantothesky/status/1169487836967518208

Thank you for the information and links. I hunted, but could not find anything resembling these.

 

[yellowaster]

I have been scanning a number of negatives from the George Cockle collection and came across these yesterday. They appear to be a chaff dispenser on Vulcan XH558 during a Red Flag visit in 1981. They were carried on both wings, same pylon set up. Any ideas confirming type and designation?

It's a Mk 3 filter duct mounted on a carrying pod. The duct contains eight filter baskets surrounding a central piston-actuated bung. The piston retracts the bung to open the duct - air is exhausted at the rear. The Mk 3 was developed back in the 1950s for use by Canberras sampling UK trials- in that case mounted on the front of wingtip fuel tanks. It's designed for large-scale debris collection and is uninstrumented. The Vulcan also carried a small Mk 10 duct inboard of the Mk 3 under the port wing, instrumented to measure airflow and activity. (I think that's the inboard duct visible in the first picture)