Top ARM missile

We either do the same as the French & send off a general-purpose PGM (preferably with an imaging seeker) towards the identified location of a SAM system, or hurriedly buy something from someone else if we ever need it.

That MBDA Spear III thingy might have something to do with the RAF decision of not acquiring a direct follow on (AKA “anti radar specialist munition”) replacement for ALARM (that or i am being too optimist and the actual answer is “no money”).

Cheers

Despite saying that the missile was retired almost two years ago.

Looks as if either it was worked out that they’re not all time-expired & they’ve not all been thrown away, or someone’s been replacing the propellant & anything else that’s too old.

See the post I made in the missile news thread.

The RAF are still training to use the ALARM on GR4s.

IIRC the missiles in stock were reaching the end of their lives, & neither re-starting production nor refurbishing the existing stock was thought worth paying for. We either do the same as the French & send off a general-purpose PGM (preferably with an imaging seeker) towards the identified location of a SAM system, or hurriedly buy something from someone else if we ever need it.

Why did the RAF get rid of ALARM? Was it rubbish? It seemed on paper to be a very clever system and leaves an obvious gap in capabilities. Do they just plan to throw Storm Shadows at SAM sites from now on?

With a bit of help from the editor of ‘Jane’s Air-Launched Weapons’, and from the Imperial War Museum, I have tracked down a definitive answer to the question of how the ALARM missile operates.

Following the 1999 Gulf War, Bob Bartlett, at that time the programme manager for ALARM at BAe Stevenage, gave an interview to the Swiss aviation magazine ‘Interavia/Aerospace World’, and described how the missile works. The single-burn motor has conventional boost and sustain phases, and the missile’s diving attack is unpowered.

The published version of the article was heavily edited to reduce its length, but yesterday I saw a draft of the original text. This contains a lot of fascinating material that it is still unpublished. (If I may paraphrase the style of the late Dr John Watson of 221b Baker Street, ‘The Case of the Terrified Secretary’ has yet to be placed before the public.)

Given that the missile must be coming to the end of its service life, I wondered if the IWM already had an ALARM in its collection. I checked, and it has. The museum’s notes on the missile state “Once the target has been acquired, the missile releases the parachute and falls under gravity to the target.”

So there we have it – the missile behaves just as I had described.

Bayern Chemie was right.

Jane’s was right.

The Federation of American Scientists was right.

Mercurius was right.

The Wikipedia entry for ALARM was wrong.

The Flight International news story that the Wikipedia entry had cited was wrong.

Lukos was wrong.

I did my best to explain the missile’s operating principles back in mid-November, but Lukos preferred to expound his own opinions. Despite his determination to defend these in the face of evidence to the contrary, his opinions are now shown to be completely wrong (and about as valid as his criticism of my analytical skills).

I suppose that he could try to argue that the ALARM programme manager was a mere undergraduate or even a work experience student (just like those chaps at Bayern Chemie), or perhaps that the man was so senior that he did not understand how his own missile worked. But as far as I am concerned, the programme manager is about the most reputable source you can ask for.

Case closed.

Sorry for ridiculous bump – but great info, thanks Mercurius.

Meanwhile, the myth continues:

https://en.wikipedia.org/wiki/ALARM

Su-25, Su-34 has also been successfully used Kh-31P and Kh-25, to disable enemy air defense forces in Kuwait, Iran and Georgia

I did not find any statistically significant achievements of HARM, positive as the air defense system of Iraq and Yugoslavia were paralyzed by rain bombs from F117, B2 and Tomahawk not by HARM

great result! another myth laid to rest.

I cannot speak for engineering students, but this thread it is a good illustration for the forum in general of the problems created by over-reliance on questionable data.

A common part of any discussion here is the demand for ‘links’. To some people, ‘links’ = proof.

But what we had here was an instance where some websites said one thing, and some said another. Since both could not be right, it was a matter to trying to find which was likely to be the more reliable.

Unfortunately, the skills needed to analyse evidence are not too strong on most aviation fora. It often boils down to “a source that agrees with my beliefs is right; one that disagrees with my beliefs must be wrong”. I think this principle was being used by Lukos when he dismissed information published by the motor manufacturer as perhaps being the work of undergraduates or even work-experience students.

The situation with ALARM soon escalated ‘behind the scenes’, since Jane’s needed to know whether its description of the missile in ‘Jane’s Air Launched Weapons’ was correct. So finding an answer has involved a significant amount of work for several individuals over a period of several weeks.

But we got there, and the myths of a second motor burn or the existence of a secondary rocket motor can now be laid to rest.

So Jane’s can refine its ALARM description, and anyone who researches this subject in future will be able to find this thread.

The only correction I would make to what I wrote earlier in this thread is that since an ALARM round recovered by the Serbs shows only a single efflux pipe, the “twin nozzle arrangement” (Doppeldüse) described by Bayern Chemie may not have been of the concentric form I had suggested from what I remembered from photos of the Serbian example seen more than a decade ago.

With a bit of help from the editor of ‘Jane’s Air-Launched Weapons’, and from the Imperial War Museum, I have tracked down a definitive answer to the question of how the ALARM missile operates.

Following the 1999 Gulf War, Bob Bartlett, at that time the programme manager for ALARM at BAe Stevenage, gave an interview to the Swiss aviation magazine ‘Interavia/Aerospace World’, and described how the missile works. The single-burn motor has conventional boost and sustain phases, and the missile’s diving attack is unpowered.

The published version of the article was heavily edited to reduce its length, but yesterday I saw a draft of the original text. This contains a lot of fascinating material that it is still unpublished. (If I may paraphrase the style of the late Dr John Watson of 221b Baker Street, ‘The Case of the Terrified Secretary’ has yet to be placed before the public.)

Given that the missile must be coming to the end of its service life, I wondered if the IWM already had an ALARM in its collection. I checked, and it has. The museum’s notes on the missile state “Once the target has been acquired, the missile releases the parachute and falls under gravity to the target.”

So there we have it – the missile behaves just as I had described.

Bayern Chemie was right.

Jane’s was right.

The Federation of American Scientists was right.

Mercurius was right.

The Wikipedia entry for ALARM was wrong.

The Flight International news story that the Wikipedia entry had cited was wrong.

Lukos was wrong.

I did my best to explain the missile’s operating principles back in mid-November, but Lukos preferred to expound his own opinions. Despite his determination to defend these in the face of evidence to the contrary, his opinions are now shown to be completely wrong (and about as valid as his criticism of my analytical skills).

I suppose that he could try to argue that the ALARM programme manager was a mere undergraduate or even a work experience student (just like those chaps at Bayern Chemie), or perhaps that the man was so senior that he did not understand how his own missile worked. But as far as I am concerned, the programme manager is about the most reputable source you can ask for.

Case closed.

Very interesting dialog…good story for engineering students.

With a bit of help from the editor of ‘Jane’s Air-Launched Weapons’, and from the Imperial War Museum, I have tracked down a definitive answer to the question of how the ALARM missile operates.

Following the 1999 Gulf War, Bob Bartlett, at that time the programme manager for ALARM at BAe Stevenage, gave an interview to the Swiss aviation magazine ‘Interavia/Aerospace World’, and described how the missile works. The single-burn motor has conventional boost and sustain phases, and the missile’s diving attack is unpowered.

The published version of the article was heavily edited to reduce its length, but yesterday I saw a draft of the original text. This contains a lot of fascinating material that it is still unpublished. (If I may paraphrase the style of the late Dr John Watson of 221b Baker Street, ‘The Case of the Terrified Secretary’ has yet to be placed before the public.)

Given that the missile must be coming to the end of its service life, I wondered if the IWM already had an ALARM in its collection. I checked, and it has. The museum’s notes on the missile state “Once the target has been acquired, the missile releases the parachute and falls under gravity to the target.”

So there we have it – the missile behaves just as I had described.

Bayern Chemie was right.

Jane’s was right.

The Federation of American Scientists was right.

Mercurius was right.

The Wikipedia entry for ALARM was wrong.

The Flight International news story that the Wikipedia entry had cited was wrong.

Lukos was wrong.

I did my best to explain the missile’s operating principles back in mid-November, but Lukos preferred to expound his own opinions. Despite his determination to defend these in the face of evidence to the contrary, his opinions are now shown to be completely wrong (and about as valid as his criticism of my analytical skills).

I suppose that he could try to argue that the ALARM programme manager was a mere undergraduate or even a work experience student (just like those chaps at Bayern Chemie), or perhaps that the man was so senior that he did not understand how his own missile worked. But as far as I am concerned, the programme manager is about the most reputable source you can ask for.

Case closed.

Funny, but in my experience on this forum its the engineers who enjoy rubbing people up the wrong way and have to be right all the time. I have one particular 1990s vintage computer in mind but there are others and lukos I can’t see what you are getting out of this exchange now…

And I don’t see what else there is to gain by showing us pictures of you doing the ironing…..:angel:

The feeling is mutual, I assure you.

And just for the record, anyone who writes factual material for a living is by definition either a primary, secondary, or tertiary source. There is no level below tertiary. Most of my writing is secondary source material, with the odd bit of primary to the degree that the provisions of the Official Secrets Act allows.

I only write primary source material for a living because I’m an engineer. Given your analysis on range, probably best if you stop writing primary source material altogether.

So that makes it a secondary source, just like all the other defence magazines. The only thing ‘special’ about it is that it is widely trusted by knowledgeable insiders in industry and elsewhere.

Who can’t disclose any more than the OSA allows them to, so really nothing ‘special’ at all, they get their water from the same well as everyone else in that field.

Whenever I read that “everyone knows…” I confidently assume that I am about to read BS.

In this case, it is clear that you cannot perceive the difference between a weapon that loses height during its flight to the target, and one whose mission requires it to maintain height.

I have done my best to try to explain how Alarm works, but if you wish to believe an alternate theory, then be my guest.

Consider me your guest.

Well guess what? You aren’t a primary, secondary or tertiary source and I don’t care what you think..

The feeling is mutual, I assure you.

And just for the record, anyone who writes factual material for a living is by definition either a primary, secondary, or tertiary source. There is no level below tertiary. Most of my writing is secondary source material, with the odd bit of primary to the degree that the provisions of the Official Secrets Act allows.

Jane’s is also, at best, a secondary source despite the credence people place in it. It gets its information from similar sources to every other military magazine.

So that makes it a secondary source, just like all the other defence magazines. The only thing ‘special’ about it is that it is widely trusted by knowledgeable insiders in industry and elsewhere.

Ranges? You’re kidding me right? Everyone knows….

Whenever I read that “everyone knows…” I confidently assume that I am about to read BS.

In this case, it is clear that you cannot perceive the difference between a weapon that loses height during its flight to the target, and one whose mission requires it to maintain height.

I have done my best to try to explain how Alarm works, but if you wish to believe an alternate theory, then be my guest.

I am not sure that Wikipedia constitutes a ‘reputable source’! It is at best a secondary source, and more often a tertiary source. Nor do I think that Flight had any missile specialists on their staff when that late 1980s news report you cited was written.

Well guess what? You aren’t a primary, secondary or tertiary source and I don’t care what you think.

Jane’s is also, at best, a secondary source despite the credence people place in it. It gets its information from similar sources to every other military magazine, or simply reprints press releases from elsewhere, so no, there’s nothing special about it and I don’t see a link. The undergraduates point is also an absolute fact. I see incorrect stuff on BAE’s site all the time as a result of it.

Ranges? You’re kidding me right? Everyone knows range is a hairy-fairy figure, heavily dependent on launch altitude, speed and trajectory. An SDB has no motor at all and still manages a range of over 100km, even a 1,000lb JDAM brick can manage 45km with a supersonic launch. Last I heard the latest MLRS developments were aimed at lobbing 90kg warheads 120km with 4m-long, 227mm-diameter rockets with far less aerodynamic surface area. I don’t even know what your 45km figure refers to? Confusing Skyflash with ALARM perhaps? Oh well, there goes your attempt at an analysis. Good day.

I am not sure that Wikipedia constitutes a ‘reputable source’! It is at best a secondary source, and more often a tertiary source. Nor do I think that Flight had any missile specialists on their staff when that late 1980s news report you cited was written. In the 1960s and 1970s, the magazine employed at different times Gunston, Hewish, and Richardson, but when the last of these left the magazine, he was kept under contract to write their annual missile surveys and some of their major missile articles. So there must remain a possibility that an inexperienced reporter got it wrong, and that his error was picked up by other secondary and tertiary sources.

Let us consult the reference book ‘Jane’s Air Launched Weapons’. What does it say?

“The ALARM has a solid-propellant dual chamber, boost and sustainer motor. This gives the missile a range of about 45 km when launched from high altitude.”

It elaborates:
“In direct, dual or loiter modes, following launch, the ALARM climbs to altitude and coasts towards the target area.”

So how does Alarm coast for tens of kilometres without sustainer power? You will not get 45 km range or more from just a boost burn. A weapon with a short burn would have a range of less than 10 km. The Genie air-to-air missile could only manage around 10 km at altitude.

A look at the specification of heavy air-to-surface rockets will show ranges of only a few km. So that sustainer burn is needed to provide Alarm’s coasting range.

Describing the loitering mode under the parachute, Jane’s states:

“If a target is detected, then the parachute is jettisoned and the missile dives down onto the target.”
There is no mention of this dive being under power.

I have a reasonable experience of both receiving and giving briefings, so you can be assured that Alarm’s mission and operating modes were explored in some detail during my early 1990s briefing. I no longer have my notes from this, while the computer file containing my subsequent report is now missing a major part due to a computer problem. But both would have still been available for consultation several years later when I wrote a more general report on anti-radiation missiles. That text described how after releasing its parachute, the Alarm missile makes an unpowered dive on the target. So it is reasonable to assume that this reflects what BAe Dynamics had told me.

It is not particularly useful to dismiss facts that do not support your opinion as perhaps having come from “undergraduates and even work experience students”. I do spend a lot of time at air shows visiting stands and chalets and talking with the company engineers, and my office is a near-impassable maze of boxes containing the technical literature I have gathered.

The high degree of motor turn-down reported by Bayern Chemie is well-matched to the task of proving high-altitude cruise power, but not the task of powering a final descent phase. Since target-detection could come at a relatively late stage of the parachute descent, a short burn time would be more desirable for such a late burn.

So you have the choice of believing Flight (which by the late 1980s was a shadow of what it had been in the days when Gunston and Hewish did their missile reporting), or of believing the company that manufactures the rocket motor in question.

I’ll put my money on what Bayern Chemie statement – a single-pulse boost/sustain motor.

Also, I had a long briefing on Alarm soon after its combat debut, and the manufacturer made no claim of a second delayable burn.

What has probably confused some people is that the motor has two concentric nozzles – one optimised for the boost phase and the other for the sustainer phase. The reason for this arrangement is that the motor was required to deliver a level of sustain thrust that was very much lower than the boost thrust. This turn-down ratio was probably pushing the state of the art at the time the motor was designed.

Or maybe you are just plain wrong about everything and its motor can be stopped and started exactly as my Flightglobal link states along with the original link I posted to the article in Wikipedia.

Company websites are often done by undergraduates and even work experience students, so don’t place too much trust in them having all their facts straight, especially when you have 2 reputable sources to the contrary. All discussions I’ve had with people inside MBDA suggest burn-stop-burn operation.

Also – don’t confuse the absence of a claim with a claim to the contrary. Commonsense should also tell you that in such a time-critical situation free-fall would be less effective.

So you have the choice of believing Flight (which by the late 1980s was a shadow of what it had been in the days when Gunston and Hewish did their missile reporting), or of believing the company that manufactures the rocket motor in question.

I’ll put my money on what Bayern Chemie statement – a single-pulse boost/sustain motor.

Also, I had a long briefing on Alarm soon after its combat debut, and the manufacturer made no claim of a second delayable burn.

What has probably confused some people is that the motor has two concentric nozzles – one optimised for the boost phase and the other for the sustainer phase. The reason for this arrangement is that the motor was required to deliver a level of sustain thrust that was very much lower than the boost thrust. This turn-down ratio was probably pushing the state of the art at the time the motor was designed.

You’re incorrect in your assertions regarding post loiter operation.

http://www.flightglobal.com/pdfarchive/view/1987/1987%20-%201575.html

Once a target has been
acquired the parachute is
jettisoned and the motor
restarts, boosting the missile
to its target.