ALARM - Air Launched Anti Radiation Missile

[timmymagic]

Quite surprised we don't have a thread on ALARM...using this mainly as an excuse to upload a very good interview on YT. Retired by the RAF in 2013 but one of the most fascinating missiles in recent years...

Good write up here...

https://www.armadainternational.com/2021/03/when-they-sounded-the-alarm/
Missile

https://imgur.com/dU8RzJH

View: https://imgur.com/dU8RzJH


Rear-view

https://imgur.com/pYsQ51O

View: https://imgur.com/pYsQ51O


Missile on Tornado GR.4 - Mix of ALARM, Brimstone, tanks and Sky Shadow/BOZ

https://imgur.com/uyM1qh3

View: https://imgur.com/uyM1qh3


Tornado GR.1 Gulf War 1

https://imgur.com/NmqSu3s

View: https://imgur.com/NmqSu3s


Missile Cutaway

https://imgur.com/7TlWz6W

View: https://imgur.com/7TlWz6W


Rather good video from an ex-RAF pilot on its usage and limitations

View: https://www.youtube.com/watch?v=06R6MTsuOAc

 

[CJGibson]

A brief write-up. Its evolution (with competitors) is described in Typhoon to Typhoon.

Chris

 

[Hood]

ALARM seeker head.

 

[NMaude]

ALARM seeker head.

I think I saw that drawing years ago in an issue of Jane's All the World's Weapons.

On another note after the RAF retired the ALARM I suppose any unexpended rounds were sold to the Saudis.

 

[timmymagic]

I think I saw that drawing years ago in an issue of Jane's All the World's Weapons.

On another note after the RAF retired the ALARM I suppose any unexpended rounds were sold to the Saudis.

By all accounts the Saudi's purchased around 250.

I don't think the RAF ones were sold on, they were in need of an MLU so the energetics may have expired. I do wonder how serviceable the Saudi missiles are now.

 

[publiusr]

"Radar-seeking missile" is more apt.

When I hear "anti-radiation missile" it makes me think of something shot into a mushroom cloud that neutralizes fallout.

 

[Flame2512]

ALARM does strike me as something which would have been rather useful for the war in Ukraine, or similar situations, if it were still in service. Presumably you could launch a suicide drone or cruise missile (e.g. Storm Shadow) attack against an enemy strategic target, then fire off some properly timed ALARMs to force the enemy short-range air-defence systems offline for a couple of minutes just as the drones / missiles start arriving at the target, increasing the effectiveness of the attack.

Though I suppose the increased capability of modern passive targeting systems (IRST, etc.) would make that tactic somewhat less effective, and the 50 nautical mile / 93 km maximum range would put the launch aircraft within S-300 / S-400 range.

 

[Flame2512]

This RAF document describes ALARM II as:

ALARM II – a modified version of the ALARM missile with a so-called ‘miss-inhibit’ facility, which stopped the warhead from detonating if the weapon failed to detect any SAM radar emissions.

Does anyone know if ALARM II included other improvements, or was it just the miss-inhibit functionality?

 

[timmymagic]

Does anyone know if ALARM II included other improvements, or was it just the miss-inhibit functionality?

I don't but I presume there were some changes following the recovery of a near intact ALARM that was recovered from a soft landing in a swampy area by the Serbs after operations during Allied Force.

 

[Zoo Tycoon]

By all accounts the Saudi's purchased around 250.

I don't think the RAF ones were sold on, they were in need of an MLU so the energetics may have expired. I do wonder how serviceable the Saudi missiles are now.

Energetic’s don’t expire as such, in that they don’t suddenly stop working or become unsafe. The manufacturer has to sign on the dotted line that they’ll work and be safe for a certain period of time post delivery. To do this they rely on a bunch of testing and storage assumptions which inherently involves extrapolation which is where it becomes difficult. Adding to this is the manufacturer, indeed end user, have requirement to for an entirely new modern product at a set period, so both have a vested interest in dictating a graceful retirement.

I know of rocket motors (albeit simple double base) made for the Korean war that are still being used on rocket sled test tracks today. I’m also sure that that some of the energetic’s we’re seeing used in today world unpleasantness may have made in the seventies or eighties.

Hence if the Saudi’s are happy to accept a little more risk I can quite believe Alarms still about, …….unless the capacitors within the electronics are a bit past it….They do degrade with calendar time.

 

[NMaude]

.unless the capacitors within the electronics are a bit past it

Electrolytic capacitors do have a shelf-life.

 

[alibongo]

Energetic’s don’t expire as such, in that they don’t suddenly stop working or become unsafe. The manufacturer has to sign on the dotted line that they’ll work and be safe for a certain period of time post delivery. To do this they rely on a bunch of testing and storage assumptions which inherently involves extrapolation which is where it becomes difficult. Adding to this is the manufacturer, indeed end user, have requirement to for an entirely new modern product at a set period, so both have a vested interest in dictating a graceful retirement.

I know of rocket motors (albeit simple double base) made for the Korean war that are still being used on rocket sled test tracks today. I’m also sure that that some of the energetic’s we’re seeing used in today world unpleasantness may have made in the seventies or eighties.

Hence if the Saudi’s are happy to accept a little more risk I can quite believe Alarms still about, …….unless the capacitors within the electronics are a bit past it….They do degrade with calendar time.

KSA likes to get value for what it buys and is reluctant to ditch anything it has bought. I was on the load team for the first ALARM delivered to Khamis, it was a bugger to load

 

[Scott Kenny]

Energetic’s don’t expire as such, in that they don’t suddenly stop working or become unsafe.

If a solid rocket gets cracked, it is better described as a solid explosive.

And as the solids age and thermal cycle, they're more likely to crack and then kaboom instead of whoosh. It's why all the "clean out the arms depots" items going to Ukraine have needed some time to inspect the items, to ensure they'd be safe to attempt to use!

 

[timmymagic]

Completely missed this.....apparently a small number of (presumably dust covered) ALARM lingered in the back of a storage bunker somewhere in the UK until at least 2022....quite unlike MoD....usually they dispose of near immediately...

https://www.armadainternational.com...-alarm-missile-to-ukraine-electronic-warfare/

 

[Scott Kenny]

Completely missed this.....apparently a small number of (presumably dust covered) ALARM lingered in the back of a storage bunker somewhere in the UK until at least 2022....quite unlike MoD....usually they dispose of near immediately...

https://www.armadainternational.com...-alarm-missile-to-ukraine-electronic-warfare/

I can only assume that they were lost in the paperwork shuffles.

Much like how a pile of Whitworth Rifle barrels from the 1860s were found in a warehouse that IIRC Parker-Hale owned. In the 1980s.