Nimrod MRA4 In Service Date?
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New Nimrod airframes...only if the jigs and machine tools and plans were still intact and available. There was talk of getting rid of them in the mid 80s, but I don't know what actually happened.
New P3? One of the plans was to reverse engineer a P3. Utterly bizarre! Another to take redundant P3 airframes; not sure how this would in truth be better than old Nimrods.
It's not a clear cut argument. Pros and cons each way.
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We mustn't forget that from SR (Air) 420 emerged a specification for a an aeroplane with 4 fanjet engines (low noise fatigue for the crew, high altitude capability for search range, fast patrol station transit time, etc). Whatever other aeroplane was chosen would have to have been a converted airliner, then. The Treasury, being simple but devious folk, would have found the idea of recycling an existing machine quite attractive (their understanding of a Through-deck Cruiser springs to mind). So here we are.
......As a minor point, though, I don't think the villagers of Bramhall would appreciate Woodford being placed next to Wilmslow.
......As a minor point, though, I don't think the villagers of Bramhall would appreciate Woodford being placed next to Wilmslow.
as ASR400 was for the Nimrod AEW, no wonder it got off to a bad start. ASR 400 was the most comprehensively useless document I've ever read with an engineering purpose in mind. Utterly vaccuous. Perhaps the poorest piece of staff work to float off the old OR desks.However, unlike the Nimrod AEW, the MRA4 did actually have much promise of getting off to a half way decent start. The requirements were well and widely advised by good technical and ops folk; it's just that the advice didn't all come through into the spec as it should. I could hardly believe the advice I'd given - on performance characteristics, isolation needs of some data, and standards management - had been almost totally omitted. That was DPA's fault, not BAE's; and it took quite an argument to put it back on track, plus severe budget.
In the end with all the lost requirements it's a miracle we didn't get a biplane Hudson with turboprops, two observer platforms, semaphore and morse comms and no bomb bay.
But - rant over - that's life acquiring big and complex systems. Bear in mind that no one (whoever they are, whatever their loyalties) comes to work with the intention of doing a bad job. No one gets everything right and in the end it comes down to what you can argue against a contract (where you will never win every last point) compared to what you 'must' have - and horse trade the rest. DPA knows it and so does BAE and every other supplier. And I'm sorry to have to say it guys, the military is/are the world's worst at stating requirements and sticking to them - and that bu
ers up everyone on all sides.
On the serious point re Woodford's location. Nuts! I like Wilmslow and remember it from the time it was a quaint old town where I lived in the 60s (at the RAF camp...long lost). And anyway I knew and regularly visited every pub within a 10 mile radius of Woodford - to ensure community relations were maintained to best modern standards and practices of course - so the good burghers (no, not Wimpy or McD's!) of Bramhall can jolly well be grateful I kept the pubs profitable and open for them.
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So, lets take a Comet, with all those 1940's design interconnected hydraulic servodynes and a minute circumference fuselage and make a 21st century jet? The only thing more stupid would be the Atlantique. Fond as I am of the old beastie, its like Ford putting a Cosworth engine in the Anglia and expecting... now hang on a minute
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GlosMikeP
You will be familiar with the Thieves' Neck, then, opposite Woodford Church. Reputedly, many a design problem has been solved in there.
Alas, the name has become the Davenport Arms, yet again. PC did take a short holiday, though.
Digressing to the AEW3, do you remember how the specification grew like Topsy after the airframes had been modified? How the computer power and cooling requirements exceded the size of the aeroplane?
You will be familiar with the Thieves' Neck, then, opposite Woodford Church. Reputedly, many a design problem has been solved in there.
Alas, the name has become the Davenport Arms, yet again. PC did take a short holiday, though.
Digressing to the AEW3, do you remember how the specification grew like Topsy after the airframes had been modified? How the computer power and cooling requirements exceded the size of the aeroplane?
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GlosMikeP
You will be familiar with the Thieves' Neck, then, opposite Woodford Church. Reputedly, many a design problem has been solved in there.
Alas, the name has become the Davenport Arms, yet again. PC did take a short holiday, though.
Digressing to the AEW3, do you remember how the specification grew like Topsy after the airframes had been modified? How the computer power and cooling requirements exceded the size of the aeroplane?
You will be familiar with the Thieves' Neck, then, opposite Woodford Church. Reputedly, many a design problem has been solved in there.
Alas, the name has become the Davenport Arms, yet again. PC did take a short holiday, though.
Digressing to the AEW3, do you remember how the specification grew like Topsy after the airframes had been modified? How the computer power and cooling requirements exceded the size of the aeroplane?
I recall having lunch in the pub on many occasions before an afternoon or evening flight - better than the Woodford diner! It was there that someone bought me a lager "I can't drink that you plonker! I'm flying later." To hear "Oh yes you can, you plonker - it's non alcoholic". My first introduction to beer with no %.
We digress.
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The Nimrod that didn't work!!
Nimrod AEW did just evolve - it was not meant to be built. As I understand, when the decision to split from the NATO AEW Component was taken in the early seventies (24 E-3A at Brize or Fairford) and we decided to go it alone, everybody in the know accepted that the UK would buy 6 x E-3A as our contribution to the NAEWF. However union power was rife at the time, so a small amount of money was dangled in front of the UK manufacturers to come up with a home-built solution before we bought the American system. GEC pocketed their share of the money, rolled out a Comet fitted with a bulbous nose radar used to test the "Blue Circle" FMICW radar which was being developed for the (then) F2, and stated that this was the best AEW platform in the world. This Sop to Union power was fine until a change of Government brought Harold Wilson to power. The result was "we are not buying from abroad - we will buy British". GEC was left with a contract, no solution and egg on their faces - hence the AEW radar with absolutely no performance. Any Sqn Sh*g on day 2 of a radar course would realise that the parameters chosen for the radar would not be suitable (Low PRF, inappropriate clutter notch etc).
Those of use who flew both AEW3 and E-3 certainly know which we would rather have had. A very sad and state of affairs for our aerospace industry!!
Those of use who flew both AEW3 and E-3 certainly know which we would rather have had. A very sad and state of affairs for our aerospace industry!!
Re Nimwacs - when the various options were shown to 8 Squadron S**gs the elements of disbelief were quite interesting:
Option 1 - A bastardised Andover (just being withdrawn from service so plenty of airframes) with bigger wings, extra jet under each wing (think Shack MR3) and tons of extra fuel - and requiring an 11000ft runway!!!!
Option 2 - An updated Hawkeye. The Gannet guys loved the idea but would probably have needed a carrier to go anywhere
Option 3 - Nimrod with the radar developed for (but never flown) a Blackburn design to go on the new RN super carrier (which had been cancelled). On the face of it a good idea but unproven
Option 4 - E3
Needless to say the Sqn (almost to a man) said go for E3, but the decisions were being taken by the OR lot at MoD, which (if I remember) didn't have any AEW guys in it at the time, or if they did he was too far down the pecking order to have any real input.
I was only surprised we didn't get the Andover variant!
It was a shame they ended up destroying so many good Nimrod airframes which would have been available much sooner (and with fewer hours) for MR4A.
Option 1 - A bastardised Andover (just being withdrawn from service so plenty of airframes) with bigger wings, extra jet under each wing (think Shack MR3) and tons of extra fuel - and requiring an 11000ft runway!!!!
Option 2 - An updated Hawkeye. The Gannet guys loved the idea but would probably have needed a carrier to go anywhere
Option 3 - Nimrod with the radar developed for (but never flown) a Blackburn design to go on the new RN super carrier (which had been cancelled). On the face of it a good idea but unproven
Option 4 - E3
Needless to say the Sqn (almost to a man) said go for E3, but the decisions were being taken by the OR lot at MoD, which (if I remember) didn't have any AEW guys in it at the time, or if they did he was too far down the pecking order to have any real input.
I was only surprised we didn't get the Andover variant!
It was a shame they ended up destroying so many good Nimrod airframes which would have been available much sooner (and with fewer hours) for MR4A.
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Nimrod AEW did just evolve - it was not meant to be built. .....decision to split from the NATO AEW Component was taken in the early seventies (24 E-3A at Brize or Fairford) and we decided to go it alone, everybody in the know accepted that the UK would buy 6 x E-3A as our contribution to the NAEWF.
The Nimrod decision was driven by indecision at NATO over what they wanted to do. UK decided we couldn't wait any longer because of the time it takes to develop new systems - then 10 years, now about the same or longer. When NATO did finally make its mind up, we'd gone for Nimrod so it was too late to do anything about it without massive embarrassment and cash penalties. Oh dear!
High clutter levels were driven by the poor decision to use the twist cassegrain antennas - brilliant idea on paper, less so in practical use - that gave a massive height line coupled with typical N Sea ops being within LOS of land, where vehicles - valid targets to a radar - swamped the system. These were not helped, however, by the decision to go for a very low design value for the minimum velocity notch - which in fact was and would remain today extremely important, to prevent loss of valid targets as their radial velocity (R Dot) towards the AEW reduces. Remember radial vel isn't a linear relationship - it's a Sine curve. After that it comes down to computing power, and there were some issues there too.
Tracking was in fact excellent for the periods before a range/velocity hole was encountered. At least it was wholly truthful by not misleading operators into believing it was tracking something when it wasn't: when it said TQ=0, it meant it and dropped the track straight away.
After the offset parabolic antennas were fitted the height line fell massively, so range and vel ambiguities improved accordingly; but of course by then so little development had been achieved and so many tempers had frayed, the end result was all but inevitable.
I wonder if, had we spent as much on the radar development as we did on the airframes, the result would have been different. Moot point now, no point worrying about it.
What is important however is we learnt a lot of lessons that got fed into the MRA4 procurement, difficult though it has been....and with more lessons learnt I suspect.
Without a clear and unambiguous set of User and System Requirements for the AEW, the PE didn't know what to buy and the contractor didn't know what to deliver - and everyone on all sides got a bad deal. This is why it's so absolutely important to get the Requirements right at the beginning, and not leave them to chance and evolution. Hopefuilly the MRA4 will come through in the end.
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Nim AEW
GMP,
Reason for NATO delay in go-ahead for NAEWF was caused by MONEY - who should pay for what. The result was RN pressure for UK to go alone because of the decision to scrap the big carriers and the loss of the AEW Gannet (Falklands showed the wisdom of that decision). The base was to be in the UK - either Brize or Fairford - although I am not sure if that decision was taken. Needless to say, if we pulled out then the base had to go elsewhere. The only possible location was in West germany (Benelux not wanting high value targets on their soil and the rest either too north or south for operations. Therefore, once the UK had stated that it would pull out if costs could not be agreed then the Germans knew that they would get the base and the financial benefits that that bought. Once we pulled out, the germans tactfully waited for a couple of months then signed up for what was to become the NAEWF at Geilenkirchen. (The cash for which, under German law has to go through a German bank - I wonder who got the interest. Rumour has it that the TCAs were allegedly funded by the "fine" levied once the rest of NATO found out how much the Germans were raking in).
My statement of "low PRF" is of course relative - I don't want to go into the current system in this forum. However I must take issue with you about the performance of the "Offset Pair of Bo****cks" - sorry Parabolics. You have fallen for the GEC line about road traffic. If this is the case then the Shetland Islands have a huge number of articulated trucks driving over them. The problem was the very large first sidelobe which painted land as moving targets due to the too small clutter notch. Hence the UK coastline and oil rigs being tracked as huge formations of aircraft doing 47 Kts. This is the reason that we could not directly illuminate the coastline within 120 nmi without crashing the computer.
I also disagree about the tracker which gave appaulingly short track life if the aircraft turned. I refer the Gentleman to the results of the final trial before the decision to scrap where the AEW 3 was trialled against a common datum (E-3A flown the day after). The results are classified so I cannot say too much, however the results were damning.
There is a book waiting to be writen about the whole episode - as you rightly say, we learned a lot from the whole mess.
Reason for NATO delay in go-ahead for NAEWF was caused by MONEY - who should pay for what. The result was RN pressure for UK to go alone because of the decision to scrap the big carriers and the loss of the AEW Gannet (Falklands showed the wisdom of that decision). The base was to be in the UK - either Brize or Fairford - although I am not sure if that decision was taken. Needless to say, if we pulled out then the base had to go elsewhere. The only possible location was in West germany (Benelux not wanting high value targets on their soil and the rest either too north or south for operations. Therefore, once the UK had stated that it would pull out if costs could not be agreed then the Germans knew that they would get the base and the financial benefits that that bought. Once we pulled out, the germans tactfully waited for a couple of months then signed up for what was to become the NAEWF at Geilenkirchen. (The cash for which, under German law has to go through a German bank - I wonder who got the interest. Rumour has it that the TCAs were allegedly funded by the "fine" levied once the rest of NATO found out how much the Germans were raking in).
My statement of "low PRF" is of course relative - I don't want to go into the current system in this forum. However I must take issue with you about the performance of the "Offset Pair of Bo****cks" - sorry Parabolics. You have fallen for the GEC line about road traffic. If this is the case then the Shetland Islands have a huge number of articulated trucks driving over them. The problem was the very large first sidelobe which painted land as moving targets due to the too small clutter notch. Hence the UK coastline and oil rigs being tracked as huge formations of aircraft doing 47 Kts. This is the reason that we could not directly illuminate the coastline within 120 nmi without crashing the computer.
I also disagree about the tracker which gave appaulingly short track life if the aircraft turned. I refer the Gentleman to the results of the final trial before the decision to scrap where the AEW 3 was trialled against a common datum (E-3A flown the day after). The results are classified so I cannot say too much, however the results were damning.
There is a book waiting to be writen about the whole episode - as you rightly say, we learned a lot from the whole mess.
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GMP,
....
My statement of "low PRF" is of course relative - I don't want to go into the current system in this forum. However I must take issue with you about the performance of the "Offset Pair of Bo****cks" - sorry Parabolics. You have fallen for the GEC line about road traffic. If this is the case then the Shetland Islands have a huge number of articulated trucks driving over them. The problem was the very large first sidelobe which painted land as moving targets due to the too small clutter notch. Hence the UK coastline and oil rigs being tracked as huge formations of aircraft doing 47 Kts. This is the reason that we could not directly illuminate the coastline within 120 nmi without crashing the computer.
I also disagree about the tracker which gave appaulingly short track life if the aircraft turned. I refer the Gentleman to the results of the final trial before the decision to scrap where the AEW 3 was trialled against a common datum (E-3A flown the day after). The results are classified so I cannot say too much, however the results were damning.
....
My statement of "low PRF" is of course relative - I don't want to go into the current system in this forum. However I must take issue with you about the performance of the "Offset Pair of Bo****cks" - sorry Parabolics. You have fallen for the GEC line about road traffic. If this is the case then the Shetland Islands have a huge number of articulated trucks driving over them. The problem was the very large first sidelobe which painted land as moving targets due to the too small clutter notch. Hence the UK coastline and oil rigs being tracked as huge formations of aircraft doing 47 Kts. This is the reason that we could not directly illuminate the coastline within 120 nmi without crashing the computer.
I also disagree about the tracker which gave appaulingly short track life if the aircraft turned. I refer the Gentleman to the results of the final trial before the decision to scrap where the AEW 3 was trialled against a common datum (E-3A flown the day after). The results are classified so I cannot say too much, however the results were damning.
PRF rating isn't relative, it's absolute. There are clear definitions for what constitutes a low, medium or high PRF system. No ifs ands or buts. Low is range and velocity unambiguous; medium is both range and velocity ambiguous; high is range ambiguous velocity unambiguous.
MPRF resolution in range is achieved by examining the modulo of PRF event. If you haven't an engineering degree you won't have come across modulo - it's a part of mathematical number theory. (Stay away from it unless you're an insomniac).
I saw first hand the results of the offset parabolics compared to the cassegrains, in design and test reports, independent assessments, and from my own observations in flight. They made a huge difference. If we'd started with them, as GEC was advised at the outset to do, the outcome might well have been completely different. The lessening of the height line was not large - it was utterly immense, measured in tens of dB.
I'm afraid the rest of your analysis is simply wrong, save for the fact that there were massive numbers of vehicles on UK roads that were picked up by the radar in main and sidelobes. I flew a number of overnight flights using the TWT drivers only (not using main power) and the road map of UK emerged from 2am and by 6am the whole of the landmass was alive and the radar unusable.
Back to the MRA4 please.
Last edited by GlosMikeP; 24th Oct 2006 at 14:18. Reason: dB
One of the development aircraft is undergoing cold weather trials at the moment http://www.flightglobal.com/Articles...w+zero+in.html
Apparently, according to the article, BAES are hoping to freeze the design. Well thats one way of getting it into service....
Apparently, according to the article, BAES are hoping to freeze the design. Well thats one way of getting it into service....
Didn't the MRA4 project used to be called Nimrod 2000? - Is it running six years late or do they consider that they still have 94 years left before it has to be called Nimrod 2100?
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ISD for Nimrod?
Newcomer - small point is that MRA4 was doomed from the beginning when it selected the most unlucky aircraft in the fleet as PA01 believe it was 47 landed at its home base post bolthole with all wheels locked also considered by groundcrew as the most unlucky aircraft as all numbers added to 13 and one engineer went down the intake plus numerous other issues. MR2 has been relifed till 2010 maybe now we should consider a new aircraft and new role no point hunting for ruskie subs?
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The linked article about the extreme temperature tests at Eglin referred to a max temp of +44°C. Assuming that the aircraft will pass those tests, I hope it isn't then going to be operationally limited to +44°C at sea level.
Of the many Nimrod & MR4A threads, the title of this one seemed most appropriate for the Flight International update on what seems to be real progress.
The article also contains information on the flight test programme (hadn't I read somewhere that there had been issues with longitudinal stability?)
BAE Systems has achieved the power-on milestone for the first of nine Nimrod MRA4s on firm order for the UK Royal Air Force, and says the surveillance platform is on track to enter service in 2010.
Aircraft PA4 is now 93% complete at BAE's Woodford site in Cheshire, and is expected to make its first flight early next year, following the installation of mission system equipment, the company says. The power-on test was performed "without a glitch", it adds.
Aircraft PA4 is now 93% complete at BAE's Woodford site in Cheshire, and is expected to make its first flight early next year, following the installation of mission system equipment, the company says. The power-on test was performed "without a glitch", it adds.
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How many ? !!
That Flight International report is encouraging, until you read this bit...
"The Royal Air Force is now expected to field nine MRA4s, with the programme's three development aircraft not under contract to be converted for operational use."
Still, look on the bright side chaps. In the past it has been rumoured that aircraft have been bought without an adequate spares package for through life support. This has now been solved by buying nine airframes for ops and a further three can be for spares
I thought it was bad that a maritime nation was only going to have 12. Does this mean that it might be realistic to only plan on having six immediately available after allowing for various levels of mainrtenance?
A very sorry state of affairs, almost on a par with the Chinook debacle.
"The Royal Air Force is now expected to field nine MRA4s, with the programme's three development aircraft not under contract to be converted for operational use."
Still, look on the bright side chaps. In the past it has been rumoured that aircraft have been bought without an adequate spares package for through life support. This has now been solved by buying nine airframes for ops and a further three can be for spares
I thought it was bad that a maritime nation was only going to have 12. Does this mean that it might be realistic to only plan on having six immediately available after allowing for various levels of mainrtenance?
A very sorry state of affairs, almost on a par with the Chinook debacle.
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Don't worry the MRA4 will have increased endurance and greater serviceability, therefore we don't need to replace the MR2 one for one.
Well that was the excuse a few years ago when 21 erm, 15 oh no, 12 were on order. Great spin until one goes u/s and leaves a bigger gap in cover, and it can't be in 2 places at once.
It now seems that the only driving force for numbers is cost, but how many do we really need? Why did they need 3 prototypes for 9 production aircraft, seems rather a lot?
Still good news that it's progressing, looks like we will see the MRA4 in a museum and as a gate guard before the MR2!
Well that was the excuse a few years ago when 21 erm, 15 oh no, 12 were on order. Great spin until one goes u/s and leaves a bigger gap in cover, and it can't be in 2 places at once.
It now seems that the only driving force for numbers is cost, but how many do we really need? Why did they need 3 prototypes for 9 production aircraft, seems rather a lot?
Still good news that it's progressing, looks like we will see the MRA4 in a museum and as a gate guard before the MR2!
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It now seems that the only driving force for numbers is cost,