Countermeasure buckets.

[corsair67]

Phil, as our Armourer-in-residence, can you explain how chaff and flares are fired from the countermeasure buckets - is it a mechanical or explosive system of deployment?

Also, I understand that chaff is basically very fine filaments of reflective 'tin foil', but what form do the flares take and approx. what dimensions are they?

[phil]

The chaff and flare were deployed explosively from the buckets. Each tube in the bucket is loaded in a predetermined order with either chaff or flare, and this corresponds to how you set up the CDS controller. The Controller is programmable, for each press of the chaff/flare button it will deploy a certain number of each, over a certain period of time, that is set up in the controller before the mission and depends on the specific threat expected. It is also possible to 'salvo flare' and fire them all off very rapidly one after the other.

The chaff is fine glass fibers coated in aluminium, there are a variety of lengths in each chaff tube, the lengths correspond to wavelengths of weapons radars. Not sure anymore than that when it comes to the technical side of it though. We used to wear leather gloves dust masks and goggles because the fine aluminised glass posed quite a risk, you didn't want to breath it in or get it into your skin/eyes. We also wore white paper overalls when doing chaff.

The flares were pyrotechnics, grains of magnesium compounds designed to burn rather hot. They were ingited as they were ejected from the tube by an igniter wire that ran through the middle. Basically like striking a match, as the flare was forced out, the friction of the igniter compound on the wire set off the flare grain.

Both chaff and flare were deployed from the buckets by a small explosive cartridge.

[Dave Homewood]

When you say the flares could be fired as a salvo, is that what was done during the Kiwi Red display when the soloist flew vertically upwards, rolling as he went and firing multiple flares to make an awesome visual effect like a Roman candle?

When I was based at Whenuapai in 1989 or 1990 I was in the base Cafe getting some chips one evening, and as I walked out I saw and heard three Skyhawk scream over low and one of them fired off muliple flares. In the dark of evening it was very impressive. I've no idea what they were doing, but it had to be some sort of night exercise. Maybe the flares represented bombing the base?

[Barnsey]

To get the continuous stream of flares using the HOTAS, you had to trick the system by selecting chaff against the zones that were actually loaded with the flares.

Each bucket (Left and Right) was divided into two zones holding 10 or 20 individual cartridges (giving a total of 30 countermeasures per bucket). So this gave the loading settings of L10, L20, R10 and R20, against which the armourers set what supposed to be in the zones - chaff, flare or jammer. This panel was located in the aft hell-hole. It also was where the chaff and flare programs were loaded.

The reason that you tricked the system was that the chaff program dial allowed a "continuous" setting, whereas flares did not.... (The program type required were selected on the cockpit CMDS panel). So for the vertical rolling departure, you would push the HOTAS countermeasures switchon the throttle forward to chaff, and the CMDS would dispense flares continuously!

You could also salvo all your flares by selecting the CMDS power switch all the way through to SALVO. This wasn't a player during a display as the switch was heads down, so would've been a prick to find during a 6g pull-up.

[corsair67]

Thanks for all that information, Phil and Barnsey. I certainly have a better understanding of how the system works now.

I thought that chaff and flares were probably explosively discharged from the buckets as when I've seen them in action at an airshow the flares certainly come out at a fair rate of knots when fired.

Is the positioning of the countermeasure sysytem on the aircraft critical to getting a good flare/chaff plume, or can they be installed pretty much anywhere on the airframe? I've noticed that the RAAF F-111s have theirs located near the tailplane pivot joint, but the Hornets seem to have theirs at the front of the air intakes?

By the way Barnsey: are you the pilot who had a nasty experience off the coast of Western Australia in NZ6256?

[phil]

It's quite important that wherever stores are placed on an airframe, they wont bump into other bits of airframe when they are launched/fired/dropped. Doing stores clearance tests are a big part of bringing any system into service.

I'm sure whoever was responsible for putting the dispensers aft of the hellhole thought that one through. Although with Kahu there was a lot of things that got squeezed in where ever there was space, I notice that other A4s with CDS tend to have them in a similar location. There are also C of G issues.

[corsair67]

Ah, stores separation testing: that'd be a fun job to be test pilot on - so long as nothing went wrong! :-)

Phil, have you seen the video clip of one of the pre-production Hornets releasing a drop tank(?) only to have it tumble awkwardly and clobber the TA-4 chase aircraft?

Project Kahu was a pretty incredible engineering feat, because I believe no one else had tried to cram all that equipment into a Skyhawk before. Good old Kiwi ingenuity comes to the fore again!

[Calum]

phil said:

It's quite important that wherever stores are placed on an airframe, they wont bump into other bits of airframe when they are launched/fired/dropped. Doing stores clearance tests are a big part of bringing any system into service.

I'm sure whoever was responsible for putting the dispensers aft of the hellhole thought that one through. Although with Kahu there was a lot of things that got squeezed in where ever there was space, I notice that other A4s with CDS tend to have them in a similar location. There are also C of G issues.

Pretty sure with kahu they just put them where other A-4's had them. Some A-4's had buckets further aft but I noticed with the Hasegawa A-4 models they give you an option to Chaff buckets in that spot.

Stores clearance is quite an art as Phil said

As for the RAAF F/A-18's they have added more buckets during the HUG

[corsair67]

The upgrade Hornet buckets are located on/in the outer wing pylon, aren't they?

[Calum]

Pretty sure you're right Craig

[skyhawkdon]

The original new build RNZAF A-4K's and RAN A-4G's came "fitted for but not with" Chaff and Flare Dispensers in the exact location as used post Kahu. Both the A-4G and A-4K were based on the USN A-4F which came with CDS as standard equipment. In RAN and RNZAF service the CDS Bucket housings were blanked off, but the CDS controller remained on the LH side of the glare shield on the RNZAF A-4K's for many years (not sure about the A-4G??). Eventually these were removed along with the ECM controller (I've got some cockpit photos which show these controllers so I'll post them shortly). I remember a box full of these old CDS and ECM controllers being in the Avionics Bay at 2 Sqn when I first arrived there in 1987. I wouldn't mind one now for a souvenir! While I was in Singapore last week I visited the RSAF museum at Paya Leba and they had 2 and a half A-4's on display there. The TA-4SU on display had 4 CDS buckets, 2 in the same location as the RNZAF A-4 and another 2 further aft either side of the hook. When I get my photos sorted out I'll post some here as I took lots of detailed walk around shots. Also of note was the TA-4SU had the exact same HUD and DADC fitted as the Kahu Skyhawk - they obviously copied quite a bit of the Kahu update when they did their own Avionics upgrade.

[skyhawkdon]

The chaff controller is on top of the LH glareshield and the ECM controller is underneath

[corsair67]

Thanks for that information Don. I never realised that the original A-G/K came off the production line with the CDS as a option.

The Kahu upgrade obviously impressed the Singaporeans if they've copied what the RNZAF came up with.

Is the Skyhawk still in service with the RSAF? They used to have some of their Skyhawks based in France, but I'm not sure if that is still the case.

[skyhawkdon]

TA-4SU CDS dispensers x 4. Don Simms photo

[skyhawkdon]

Is the Skyhawk still in service with the RSAF? They used to have some of their Skyhawks based in France, but I'm not sure if that is still the case.

Yes they still have a Squadron flying in France. None are flying in Singapore any more, although the guy at the Museum said they haven't been "scrapped" and could be brought back into service quickly if needed. The TA-4SU on display at the museum was 100% complete and was in immaculate condition.

[corsair67]

The RSAF is based all over the world: they have Super Puma helicopters in QLD, S-211 jet trainers in WA, and a squadron of Skyhawks in France.

I guess that's what happens when your airspace isn't very big.

[Dave Homewood]

I never realised they still used Skyhawks. Why are they in France?

I was alwayys amused at pictures oftheir two seaters, each seat with it's own self-contained cockpit. Really cool.

[Calum]

They do their fast jet conversion on the A-4's in France as they don't have the airspace in Singapore. The A-4's are being replaced with F-15SG's (F-15E's)

[corsair67]

Dave, the Skyhawks are based in France because there's not enough airspace around Singapore to be able to train pilots.

I believe that Singapore signed an agreement with France so that their pilots can train in France and use several of their ACM ranges.

[Dave Homewood]

Wow. We should lease them some of our airspace, we could do with a few squadrons of Skyhawks flying around, especially if they're paying to be here.