ASW aircraft - what is needed?

[Jackonicko]

Can a 2.2 g aeroplane, cleared to no lower than 250 ft, with underslung big fan engines and no MAD do the job?

I know that if you don't have a MAD, then you don't need to fly those gut-wrenching cloverleafs (or vomit inducing MAD compensation runs), but isn't a MAD still a useful secondary sensor?

And don't the Nimrods and P-3s pull more than 2.2 g? And don't they go below 250 ft to prosecute an ASW attack?

My memory's not what it was, and it's a very long time since I flew on a Nimrod (nearly 30 years since I flew on a succession of sorties, then 20 years since I flew on a single trip) and my recollections are hazy.

Input from current/recent Nimrod or Orion blokes would be VERY much appreciated.

[x213a]

If it could discharge sonobuoys then whats the problem?

[Jackonicko]

There always seemed to be more than that to ASW, didn't there?

[x213a]

Disregard my last, posted in haste:uhoh:

[Flight Detent]

Errr...where did the 2.2g and minimum of 250 feet come from?

anyone...

Cheers...FD...:confused:

[roush]

ASW aircraft - what is needed?
A requirement for one.

The ability to find a company that can build one.

[x213a]

Are we talking organic or carrier carrier borne?

[ORAC]

But, if you're carrying a MAD equipped, air-drop, sub-tracking, ScanEagle UAV (http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=defense&id=news/SCAN060908.xml) - which can stay on station for up to 24 hours after launch, why carry around another one of your own? :cool:

[BEagle]

ASW aircraft - what is needed?

Firstly, a credible threat.

Or rather, sufficiently credible to justify the enormous expense of Nimrod '2000'.....

Which is emphatically NOT the same as the need for a multi-sensor air platform to replace the Nimrod in its current OOA applications, of course.

[tucumseh]

A Group Captain once reminded me that, as the Hercules has an Active Dipping Sonar and a full passive Sonics suite, then I should withdraw my objections to him wasting RAF money buying equipment for it.

On the assumption I was wrong (as he was supported by my 2 Star) it would seem the solution is more C130s. Er, can we have them without the sonics please?

[Jackonicko]

Flight Detent,

Boeing's own figures for their P-8A.

They seemed like drawbacks to me.

Are they?

[x213a]

Ah this...

http://www.boeing.com/defense-space/military/p8a/index.html

Just as long as all the bells and whistles are able to synchronise and relate to the kit used by the rest of the asw task group. No point being all shiny with link 16 if you cannot simulcast and tx to a ff that's on link 11.

[ORAC]

Ya gotta think system rather than platform.

Unless you know how it networks with the planned Global Hawk ocean surveillance platforms, ScanEagle, surface and space platforms - and the capability of the systems on board - it's a question that can't be answered.

I would, however, suspect, that any seeming obvious omissions or because we have no visibility of the other systems which fill the perceived hole.

Dummies they aint.

[Jackonicko]

Not every export customer will have the whole ASW 'infrastructure' that the USN has (eg India, who are buying theirs with a MAD), so looking at the P-8 on a platform basis is valid.

And while dummies they ain't, they are cash-strapped - especially on this programme, and there are some surprising omissions weapons and kit-wise.

And I remain fascinated to know whether this platform could do 'traditional' ASW in the way that Nimrods and P-3s do. Am I wrong in thinking that a "not below 250 ft" clearance and a 2.2 g airframe limit would inhibit this?

They're simple questions, and I'd really hope that some of our Kinloss PPRuNers might put me out of my (and their!) misery.

[x213a]

Define 'traditional' ASWWhat exactly are you asking?

Multi-role is the way ahead:ok:







imo

[Jackonicko]

I guess I mean the ability (in extremis) to prosecute an autonomous engagement against a fast-moving underwater target.

Is 2.2 g enough? Is 250 ft low enough?

Do current platforms go beyond those limits?

[GOLF_BRAVO_ZULU]

A Group Captain once reminded me that, as the Hercules has an Active Dipping Sonar and a full passive Sonics suite, then I should withdraw my objections to him wasting RAF money buying equipment for it.

OK; I'll bite. Attitude + vertical and throttles to 200% RPM?

[XV277]

ASW aircraft - what is needed?
Which is emphatically NOT the same as the need for a multi-sensor air platform to replace the Nimrod in its current OOA applications, of course.

Random thought for the day - Could a suitably configured non-ASTOR Global Express do that job?

[Magic Mushroom]

Random thought for the day - Could a suitably configured non-ASTOR Global Express do that job?

Yes, but there are far more efficient, versatile and cheaper options than a large business jet for the task.

Regards,
MM

[ianp]

I think we ought to buy one of these:

http://www.airliners.net/photo/Russia---Navy/Beriev-Mermaid/0194233/L/

Absolutely no idea how good it would be for ASW but what a hoot.

[x213a]

Learjet is the way ahead, conduct a vectac/madvec safe in the knowledge that your Earl grey is only a compartment away!:ok:

[Not_a_boffin]

Should have thought the ability to carry round a substantial number of weapons might be a bit handy. Not much point in finding a sub if all you can prosecute it with is harsh language. Similarly, if you're going to be a long endurance significant time-on-task asset you never know when two might come along at once. That would put the mockers on most biz jet solutions......

[x213a]

I think the Viking has all bases covered.

The key to asw is comms and datalink.

[Jackonicko]

The Aussie aircraft that lost a wing did so at 3.4 g - which should have been OK, though the official limit was then 3 g. It wasn't doing anything extraordinary in the role.

How about Nimrod?

[x213a]

What pojnt are you trying to make or what conclusion are you attempting to come to?

[Acey ducey]

Heard a rumour that due to the withdrawl of 39 US P-3C aircraft due to life fatigue problems, the Viking could be making a reappearance. Currently sitting in warmer dusty climes but "relatively" cheap to get flying again. Biggest problem would be reinstigating the training system. I would be more than willing to spend a few years in San Diego as a training advisor!

[Charlie Luncher]

Jacko The Old chubby one hit the nail on the head with the first post, UAVs may be good at finding tuna schools, but ASW please nerds back the fxxx down :ugh:.
MMA is being pitched as a system, flawed but a system of which it is one part. As for G and heights a good crew with well placed tactics dont need to fling it around. MAD raving MAD is used to refine errors in plotting to put stingray into action or the the dumb bomb with a propellor on it that is Mk 46 update 336.
The problem is the crew, the only RN that are capable in ASW are the tgts themselves and not the bomber fags. RAF MPA used to be good as were the Dutch, Canadians and Aussies. The Kiwis were always better lucky than good and the spams woeful except for the odd reserve crew out of Brunswick via Kef. Only observed Ivan from odd occasion we met over the oggin, all the research has dried up due to the rebranding of DERA to DLST so capability moves forward at a snails pace.
Anyhow too much G and you wake the old fellas and spill their tea/curry.
Charlie sends
from 100'moa, rarely these days though

[Flight Detent]

Jackonicko..

I'm involved in the AEW&C 737NG, though it's not a low level airplane by any means, that involvement has me seeing P8 info at times.

Neither airplane has a 2.2g/250 foot limit as far as I am aware.

Oh.. the Aussie P3C didn't lose a wing, though the result was nearly as bad - actually 5 of the 6 leading edges seperated following a really violent pitch up maneuver - an aero showing-off stunt!

Cheers, and keep me entertained,

FD...:E

[Jackonicko]

FD,

The limits were as quoted by the Boeing programme manager last week, who checked the information with programme folk.

P-8 is a different airframe, as you know, built on a separate line, and built as military from scratch. They don't take a green civvy airframe and mod it like they do with the Mighty Wedgie! The limits quoted caused some confusion, as the g limit is lower than that of the basic 737-800, and the volume of questions led to the information being re-checked.

I was getting my leading edge detachment and wing coming off incidents muddled. The wing off must have been the USN aircraft, I guess? (Though I know that both were below 3.5 g).

I had a look over your No.3 Wedgetail last week (the first Aussie conversion). The Boeing folk were very impressed by the workmanship. I'd have been interested to look over the Turkish aircraft too, but that was firmly not on our agenda!

[Modern Elmo]

I know that if you don't have a MAD, then you don't need to fly those gut-wrenching cloverleafs (or vomit inducing MAD compensation runs), but isn't a MAD still a useful secondary sensor?

The USN isn't emphasizing magnetic anomaly detection for the P-8's. It could be that shining a laser of a certain blue-green wavelength into the water does as well or better than MAD at detecting submerged objects. It could be that the platform doesn't have to descend to very low altitude to operate the laser system, or to visually examine the sea using platform stabilized, telescopic optical devices.

And don't the Nimrods and P-3s pull more than 2.2 g? And don't they go below 250 ft to prosecute an ASW attack?

Unlikely.

Young man, it isn't the 1940's anymore. There aren't going to be Liberators making strafing passes with 50 cal. guns. And where did your 2.2g requirement come from in regard to ASW aircraft? I doubt if B-24's were good for 2.2g pull-ups.

Nowadays, ASW aircraft doen't have to descend to altitudes anywhere near that low to launch acoustic homing torpedos or precision-guided air-to-surface munitions.

[Yellow Sun]

Charlie L has summed it up pretty well. The only point that no one has really raised is the weapons fit. I recall a point being made at a JMC debrief many years ago, ARAR/ARAX would never sink a submarine, it needed something in the water that went bang. Airborne ASW weapons procurement has always been the preserve of MoD(N) and generally based upon the premise that whatever a helo can carry will be OK for the MPA. That's fine and easier on the budget, but we end up with lightweight weapons that are in many respects a compromise. A purpose designed MPA ASW weapon could be much larger and considerably more capable. Wire guidance via a buoy system, stand off capability to reduce time late at datum, higher speed longer endurance weapon, multiple weapons with separate search pattenrs (as long as we can stop then fancying each other more than submarines:\) There are a lot of possibilities out there.

YS

[Not_a_boffin]

"Nowadays, ASW aircraft doen't have to descend to altitudes anywhere near that low to launch acoustic homing torpedos or precision-guided air-to-surface munitions"

Errr, you know the cleared release altitudes for Stingray & Mk50 then.......

[contactin]

What makes an ASW platform

Merlin HM MK1. Although only 8 Barra/Hidar capable it can come to a hover and lower a very potent ASW sensor (FLASH)

No need to pull G in a gut wrenching turn, just a sedate engage down and lower the body.

Carried on frigates and carriers availlable anywhere in the world and very good in the littoral. Simple re-role for SAR, NEO and b echelon support. Oh in the SAR role it can rescue people too not just provide a comms link.

Fly Navy its the way ahead.

[davejb]

...but just a teensy bit difficult to task into an area 500 miles away from homeplate...unless you are willing to accept rather a large amount of time late...

(Helos)

[Modern Elmo]

This P-8/737: The Navy was calling it a Multi Mission Maritime Aircraft in earlier press releases. It might a mistake to think of it -- or at least all P-8 variants -- as a narrowly specialized ASW platform.

Also, in addition to its nose radar, I read somewhere that the P-8 -- or some P-8's -- may be getting a ventrally mounted electronically scanned radar antenna looking to the left and right. ( This would be a narrow bulge several meters long behind the weapons bay, which has apparently been moved from behind the wing to in front.)

This radar would give the P-8 a functional capability similar to what the JSTARS aircraft does. This type of radar operation implies higher cruising altitude -- in other words, turbofans instead of turbprops.

[KeepItTidy]

The Old Fat One (http://www.pprune.org/forums/member.php?u=217364)


Essential

An excellent radar
Full sonar suite - passive sonar, short range active, long range active
Excellent central processing and data fusion
A fully trained crew.
Weapons capability
Endurance
Speed
Range


Desireable

MAD - Maybe, depends on a number of factors, I'm out of touch on the latest variants.
ESM - Medium range tactical, just in case.

Biggest challenge - training the crew.


Also have to include a Galley , ASW crews cannot fly without food , its known fact

[Charlie Luncher]

TOFO
I now find a bunk comes in quite useful
George Foreman Grill - those stripes on your steak and lobster tails look good
A bloody Microwave - no acoustic god should have to wait 20 mins for a curry.
Suitable cups to play Lie Dice.
Satellite phone - to book tee off times/Hotel/massage with happy ending.
ATM - to pay for four floors activities in Singapore.
Itrip to listen to music via a good ESM when in HF black hole(Calcutta FIR).
Bomb Bay capable of holding Ride On mower across vast oceans.
Trivia questions to sort out first round on landing after transit.
Still love it
Charlie sends
from 100' moa

[daze_gone_buy]

What about collapsible buoy racks to create space for Webers and cosy coupes?

Ah happy mammaries!!

[1771 DELETE]

Two Nortons on the back of my aircraft once, thank the AEO who is down under now.
Does BBQ charcoal count as DAC, if it does we should have gone out with a bang many times.

[Modern Elmo]

"Nowadays, ASW aircraft doen't have to descend to altitudes anywhere near that low to launch acoustic homing torpedos or precision-guided air-to-surface munitions"
Errr, you know the cleared release altitudes for Stingray & Mk50 then.......

Nope, I don't know that info. However, I do know that it would be a mistake to trade off the speed and altitude advantages of a turbofan muliti-mission aircraft ( up to date high bypass fans, not Coronation-of -Elizabeth-II vintage Comet airliner engines) merely to support some legacy weapons which need updating anyway.

Wire guidance via a buoy system ...

How would that work?

[Yellow Sun]

Wire guidance via a buoy system ...

How would that work?

Weapon system comprises torpedo and bouyant link. Separation occurs on water entry and torpedo commences pre-selected search course or pattern. Connection to buoy is via wire (similar to submarine launched torpedoes) and commands to torpedo relayed via secure link to buoy. The idea was originally floated as a method of utilising larger, more capable, submarine launched weapons from aircraft. Lots of potential problems that would have to be weighed against presumed tactical advantages.

YS

[buoy15]

Sod all to do with the type of ac - you have to use lateral thinking to catch a submarine, ie (options - outside the box - chess moves etc) - it's the sensor that's important - ac alert submerged targets that they are under threat because they are forced to be in the same location at weapon release height to achieve attack criteria (MAD) or to confirm position and attack solution accuracy - even so, they can evade quite successfully

The Seawolf is nearly as quiet as your Fridge/Freezer in the same room from the same distance

Bi-statics is the only answer - that way, you can cover acres of ocean - he is in a trapped environment miles from home, and when he hears that first explosive sonar thud, he knows he's been found - he can run but can't hide - you have all the time in the world to launch an attack from a remote number of platforms which gives you total element of surprise!

Bang! - WTF was that ! - too late:ok:

[Yellow Sun]

you can cover acres of ocean

Ah, the long gone days of the LASTAC.

ac alert submerged targets that they are under threat because they are forced to be in the same location at weapon release height to achieve attack criteria

This is one of the arguments used to support the concept of the air launched stand-off ASW weapon, a sort of airborne IKARA if you wish.

Another factor in favour of both this and the long range command guidance torpedo is the remove the launch platform from the engagement zone of mast mounted SAM or future encapsulated systems.

YS

[davejb]

it's the sensor that's important - ac alert submerged targets that they are under threat because they are forced to be in the same location at weapon release height to achieve attack criteria (MAD) or to confirm position and attack solution accuracy - even so, they can evade quite successfully

Agreed re sensor, until you locate him you can't kill him. (I suppose you might eventually invent a torpedo with a well programmed 'brain' that simply cruised around for as fortnight trying to identify something to attack, mind...a sort of Captor idea taken to an extreme). I think you're wrong on the point about giving your detection away though -MAD overflights are to refine a pretty well refined acoustic datum, to 'confirm' attack criteria... equally a buoy on top is often "merely" to confirm the buoy is where you think it is, thanks to drift, assumptions about ballistics, and the price of fish. So let's have buoys with satnav built in, (ditto the ASW aircraft), so there's no need to on top, as the buoys continually pass accurate coords back to the aircraft.

Most of the opinions so far are based on what a current MPA does, and current MPA processing power is pants compared to the average PC...so first off the MPA should have a fully integrated sensor/data suite that ensures all sensor data is processed and presented - ket everyone see what they need to see, instead of having to ask for it.

Using the ESM example, you will often need an operator there to decide which of the 10 possibilities for an ESM ident makes sense - but that op should be assisted by a well thought out and programmed expert system, not a poxy toy processor that has been bastardised from elsewhere and elsewhen..... (I'm being deliberately vague here).

You wouldn't buy a car with a tape drive....

As for an earlier post describing ESM as 'desirable' (TOFO?) No - I gotta disagree, ESM and ECM should be standard fit - self defence old chap, Nimrod surevived by flying where other people don't - but when they are tasked into busier airspace it's a recipe for disaster to simply hope they'll avoid the opposition. Unfortunately the ESM fit has always been pretty crap, due to a variety of reasons, it could easily have been a huge amount better with a bit more help. Having chatted to some of the MRA4 chaps a few years back I can readily understand why the RAF gets crap kit mind, for my own part I suggested they ought to try working controls with gloves on and it was treated like a divine revelation...FFS!

Microwave - no doubt those who flew before me will have their own favourite recipes, but I regretted the passing of honkers...we cooked from scratch a great deal more at the start of my time, by midpoint in my "career" (as in 'he careered downhill') it was all TV dinners - and a guest siggie still managed to set fire to one, shutting the galley down a third of the way into the flight....how anyone could even consider the abortion that is a microwaved meal is beyond me! <g> By the end of my 'career' I think I'd have been happy to land regularly for a calorific top up - Tom Bennington used to be good for that!

Dave

[Modern Elmo]

... ac alert submerged targets that they are under threat because they are forced to be in the same location at weapon release height to achieve attack criteria (MAD) or to confirm position and attack solution accuracy - even so, they can evade quite successfully


Meaning the attacking aircraft can evade quite successfully, or what?

How is a submerged submarine supposed to detect an aircraft flying at significant altitude above sea level? Are assuming that your U-boat has a sensor poking up out of the water?

[davejb]

Aircraft do not fly at a "significant" height when releasing torpedoes, Elmo, and the sub will hear the overflight on acoustics.

[Modern Elmo]

Weapon system comprises torpedo and bouyant link. Separation occurs on water entry and torpedo commences pre-selected search course or pattern. Connection to buoy is via wire (similar to submarine launched torpedoes) and commands to torpedo relayed via secure link to buoy. The idea was originally floated as a method of utilising larger, more capable, submarine launched weapons from aircraft. Lots of potential problems that would have to be weighed against presumed tactical advantages.

Lots of potential problems, you're right. If the ASW aircraft is near maximum ASW torpedo range from the submerged target, how would the peepul in the airplane decide it's time to launch an ASW torpedo unless there were something already down in the water --e.g., a sonobuoy -- reporting a detection and (at least) approximate track on the submarine?

If there's one or more sonobuoys already reporting on the target, why not just fly closer to launch the torpedo?

Next problem: how would dropping a single passive and/or active sonar buoy of some sort along with the torpedo improve the performance of a sophisticated active acoustic homing torpedo? Please enlighten us.

[Modern Elmo]

Aircraft do not fly at a "significant" height when releasing torpedoes...

Why not, assuming they've got a state of the art air-launched torpedo?

... and the sub will hear the overflight on acoustics.

How? Assuming the sub doesn't have a microphone poking above sea level? Do you have any understanding of the acoustic impedance of the air/water interface?

[Modern Elmo]

You're on a wind-up right? Any sub that isn't bashing along the bottom as fast as he can will hear an aircraft overflying his position - even worse a turbo-prop.


"... The ability of a wave to be transferred from one medium to another is dictated by the impedances of the media. When a wave is transferred from a low-impedance medium (eg, air) to one of high impedance (eg, water), a considerable amount of its energy is reflected and fails to enter the liquid. Water has 3470 times the acoustic impedance of air, meaning that only 0.1% of the sound energy present in an acoustic signal traveling through air actually enters a water-filled medium. ..."

http://www.emedicine.com/ent/topic360.htm (http://www.emedicine.com/ent/topic360.htm)

[davejb]

Modern Elmo -

Aircraft do not fly at a "significant" height when releasing torpedoes...

Why not, assuming they've got a state of the art air-launched torpedo?

... and the sub will hear the overflight on acoustics.


How? Assuming the sub doesn't have a microphone poking above sea level? Do you have any understanding of the acoustic impedance of the air/water interface?


-----------------------------------------------------------------------
Edited this bit in, having read your follow up as I posted -

With all due respect to your trawling of the internet, you are currently arguing about acoustics with people who do/did it for a living. Part of 'doing it for a living' involves becoming very familiar with sound propogation, and recording and analysing the signals gained from sonobuoys. Having seen a recording, from a submarine, of an aircraft that overflew it, and a number of recordings from sonobuys of aircraft overflights (the sonobuoy microphone being several hundred feet below the surface) I can assure you that despite your internet 'find' aircraft engine noise is far from difficult to detect on subsurface sensors.

By the way, I no longer chase subs - now I'm a physicist - and whether waves reflect or refract depends on angle of incidence.
-----------------------------------------------------------------------

Air launched torpedoes aren't dropped from 10,000 ft old chap - I have no desire to accidentally drop myself in the poo discussing weapon characteristics, but the Mk46 and Stingray torpedoes are dropped from a lot closer to the surface.

Submarines do not, generally, power around at high speed - they amble very gently along, for the most part, when on patrol so that they can make full use of their passive acoustics suites. I assure you that those acoustic suites are more than capable of detecting an overflight. I can only presume from your comments (this isn't intended as an insult) that you've never actually been involved in airborne ASW, rather than this being some sort of wind up?

Regarding your other ideas - to drop an airborne torpedo you actually have to have a very good idea of where the sub is, how deep it is, and its course and speed. This info will come from acoustics, generally passive sonobuoys. (Active buoys tell him to **** off in fine pitch, which will doubtless screw up your attack solution), much better if the first thing he hears is your overflight followed by a splash, with a homing torpedo sonar to round the morning off.

It is far from uncommon, shall we say, to deliberately overfly the sub at low level to ensure optimum weapon placement. It is also quite common to release a sonobuoy with the weapon drop, this is not for the weapon's benefit - the torp will handle its own tracking and closure with the target.

Dave

[Modern Elmo]

I assure you that those acoustic suites are more than capable of detecting an overflight.

At what range/altitude from the underwater transducer?

If the attacking aircraft is close and launches an antisubmarine weapon promptly, how much time does your U-boat have to react?

If the aircraft sounds, oh, sort of like a 737 airliner airliner at cruising altitude, how do your submariners know that it's not a civilian airliner passing by overhead? Boeing sells beaucoup 737's, you know.

... I can only presume from your comments (this isn't intended as an insult) that you've never actually been involved in airborne ASW, rather than this being some sort of wind up? ...

Correct, I never was a sailor. Too bad, sure would like to wear one of those Donald Duck hats.

[davejb]

Elmo - acoustic detections of aircraft at several thousand feet can be made from a submerged submarine or sonobuoy. This isn't theory.

By the way, only the Germans have U boats.

Evasion - you are unlikely to get given a time on this, as there's too much classified info involved, and too many variables. For example, a torpedo, once dropped, has to enter the water, start up, and commence a search pattern...if it's a circular search and your torp goes on one side of the sub rather than the other the sub will gain distance on the torp while it completes its circuit. A torp has an acquisition range, the sub speed will become a factor therefore - if you drop a torp behind a very fast sub your torp may never catch it. In real life the tactical navigator determines the optimum position to deploy the weapon, if the sub is where the crew believe it is then a correctly deployed weapon will prove difficult to evade.
If the MPA ontops the sub, then provided the crew haven't just screwed up then the clock is running.


Regarding your comment about B737s, you might like to learn a little about acoustic sensors before getting funny about them - passive acoustics systems don't only detect other vessels (and aircraft) they provide frequency information that allows the operator to identify the noise source. Acoustics will tell you what class of ship you have detected, it will allow you to identify natural sources (whales, clicking shrimp, etc) and it can also, provided the characteristics of the aircraft are known, ident the aircraft that just overflew from the frequency signature of the engine noise. There's an awful lot of information in the sound. Your insistence on the impossiblity of what we actually do - and have done for decades - is touching in its naivety.

DD sailor hat - in the UK it's the airforce (RAF) who fly MPA aircraft actually, no cute hats in sight.

For unclassified acoustic training I'd recommend the computer game 'Dangerous Waters' to you, it'll give you a very good intro to airborne ASW acoustics.

[Modern Elmo]

Regarding your comment about B737s, you might like to learn a little about acoustic sensors before getting funny about them - passive acoustics systems don't only detect other vessels (and aircraft) they provide frequency information that allows the operator to identify the noise source. Acoustics will tell you what class of ship you have detected, it will allow you to identify natural sources (whales, clicking shrimp, etc) ...

So how does your Unterseeboot distinguish P-8's at cruising altitude from civilian airliners doing their normal stuff?

Dave, you're telling us another reason why the USN chose the 737 airframe.

[buoy15]

Dave
Check Elmos location - should answer your frustrations:ok:

[MAINJAFAD]

Nope, I don't know that info. However, I do know that it would be a mistake to trade off the speed and altitude advantages of a turbofan muliti-mission aircraft ( up to date high bypass fans, not Coronation-of -Elizabeth-II vintage Comet airliner engines) merely to support some legacy weapons which need updating anyway.

This guy is an idiot. The Nimrod is not fitted with 1953 spec engines, like the Comet (Try RR Speys, which are turbofans, abet low by-pass, entered service in 1964). The MRA 4 has RR BR710 high bypass fans. As for the rest, I think the people who actually do / have done sub hunting for a living do actually have a clue about what they are talking about. As for WWII, main weapon for attacking U-boats was the 250 lb Depth Charge. That weapon had to be dropped at low altitude or it broke up on impact with the water. As for fancy stand off air launched ASW weapons, Why add extra weight and cost to what is a torpedo??? Fine for a ship or a sub, not so wise for an aircraft which can get to the target fix almost as fast.

[davejb]

Yep,
I already checked the location - that's why I figured it wasn't a deliberate wind up.

Elmo - for one thing the passenger B737's* will be flying at 35000 ft or more, whilst the P8 etc will be flying (say) 30,000 ft lower...an ASW aircraft that does not wish to risk being detected acoustically will fly most of the time at (say) 10,000 ft to maximise it's ability to pick up the signals from widely dispersed buoy patterns, which will be high enough to avoid acoustic detection (although it wouldn't surprise me to find somebody once managed it). You stand to get detected either when deliberately overflying the sub (for example when trying to make your fix cast iron by acquiring a MAD mark) or when you zoom past on your attack run....both the MAD run and the weapon release run will be a much lower level, and you will be detected by the sub unless he's going too fast for effective passive sensor reception.

* I doubt you'll get 737's crossing the Atlantic, by the way, so I'd have thought that P8's would fail to benefit from any conceivable camouflage effect...they'll be the only version of the 737 out over the oggin.

Please, as a previous poster suggested, credit those of us who have done this for decades with some measure of knowledge of what we're talking about - I chased my first submarine in 1979, honestly, I really do have some idea of what actually happens, regardless of what you've read about the air water interface. For your further edification at the interface some of the sound energy is reflected off, whilst the remainder passes into the water. The lower the aircaft flies the more energy will pass into the water. All you then require is a microphone (submarine sonar array, or sonobuoy) that is sensitive enough to detect the noise. Once detected you analyse the signal to extract a variety of information from the frequencies that the signal is made up from - for a simple example of this consider a ship passing by...the frequency information you pick up will allow you to determine the number of cylinders in the ship's engine, as you hear them 'fire', and you'll know how many blades are fitted to the shaft. If you recognise the signature as belonging to a specific class then the blade count can be simply converted to tell you how fast the ship is going. From knowledge of the ship's speed and the relative bearing change you can begin to solve the problem of it's range from yourself and its course.

Dave

[davejb]

Yeah I know,
I'm an optimist - I figured 'one more go' might convince the chap....

As for acoustic footprints...I figured this was good enough considering where the discussion was being held, and yes - overflight of the sub isn't something you'd want to do accidentally.

No doubt he'll be back shortly, allowing for the timezone....think I'll go do something useful....

[1771 DELETE]

Davejb
I thought you were very understanding, informative and whole lot more tollerant of some half baked questions, than i would have been. Must have been on 236 at some time?
I like the idea of Global Hawk myself but i guess the galley isnt too big and not a lot of room for the Nortons down the back. 24 Hours without a fag would be pushing my PLE a bit too far !!

[Pontius Navigator]

...an ASW aircraft that does not wish to risk being detected acoustically will fly most of the time at (say) 10,000 ft to maximise it's ability to pick up the signals from widely dispersed buoy patterns, which will be high enough to avoid acoustic detection (although it wouldn't surprise me to find somebody once managed it).

Yup. 1977. P3 out of Kef, on topped the previous aircraft barrier and blotted out each buoy he on topped. He was at 20k, the buoys were probably deep.

* I doubt you'll get 737's crossing the Atlantic, by the way, so I'd have thought that P8's would fail to benefit from any conceivable camouflage effect...they'll be the only version of the 737 out over the oggin.

The camouflage would come from the engines not the airframe and Atlantic is of course only one pond. Perhaps more signifcant for 'not an airliner' is, as stated the height of the aircraft (engines) and hence audio strength. Also a transiting civil air liner will go doppler high/doppler low/no contact. An MPA will return and repeat the noise sequence at power settings that will be variable and different from a cruising airframe.

The lower the aircaft flies the more energy will pass into the water. All you then require is a microphone (submarine sonar array

which means that the aircraft detection may be some considerable distance from the submarine.

, or sonobuoy) that is sensitive enough to detect the noise.

which could even be one's own sonobuoys.

There is no resaon why a submarine cannot detect sonobuoy transmissions to the MPA albeit over a very limited range. There was a case of a Canadian O-boat that surfaced, located each sonobouy and switched them off to the puzzlement of the MPA.

how many blades are fitted to the shaft. If you recognise the signature as belonging to a specific class then the blade count can be simply converted to tell you how fast the ship is going.

And if the blades are damaged, as could happen with passage through an ice field, could enable an individual unit to be identified.

A sensor operator can reas acoustics like a book.

[davejb]

Hi PN,
I think that was more detail than our friend can manage <g> I'm being somewhat vague for two reasons:

1) Acoustics and MPA tactics in general isn't something I tend to blab about in any detail, just in case they take my pension off me and throw me in the slammer.

2) I'm not very good at acoustics, rank amateur although you can't help picking the odd bit up and I used to do okay on 1C. (I learned more about wet stuff during a spell in Int. It's amazing what you learn on a ground tour that you look back on and wonder why you didn't learn about it on the Sqn...)

3) I'm an ex-dry man, so you'd think I could count better, wouldn't you? ;)

1771 - only as a stude a couple of times...120, 206 and (for one sortie) 38 (I think it was)...a taceval sortie in the SWAPPS against Battleaxe, which was then a brand new ship on workup...I had Dougie Wheatland for my Ld Dry that night, but it wasn't all bad :}

[Lazer-Hound]

P8 will not need to come close to the surface to drop torpedoes:

http://www.spacewar.com/reports/Navy_Selects_LockMart_For_MK_54_Torpedoes_High_Altitude_Laun ch_Capability.html

[Pontius Navigator]

DaveJB,

I reckon its safe as even SOSUS was written up by the Russians. In the early 80s we did our famous Bear impersonation and landed at Alconbury with Russian material flitched from magazines (probably be done for copyright infringement). One piece in my pocket had a full page on all the NATO acoustic equipments.

For those that could not read Russian it had a helpful ray path diagram with each RP annotated 1C, SSQ41, etc to Sosus. Even the lofar buoys were shown with convergence zone RP.

As a Dry Man you will have been into dentollogy then?

[Pontius Navigator]

P8 will not need to come close to the surface to drop torpedoes:

http://www.spacewar.com/reports/Navy_Selects_LockMart_For_MK_54_Torpedoes_High_Altitude_Laun ch_Capability.html

LH,

Is this an industry initiative or a user requirement?

The greater the distance from release to splash point increases the time late at datum.

At 300 yards per minute a 9 kt submarine could double the error distance from splash point for a glide delivery from 20000 feet. A powered glide would reduce the time late but increase costs and complexity.

Not saying it can't be done but it is not simple.

I have seen crews lose a sitting target as they tried to excessively define the datum. OTOH a crew that gains a contact and prosecutes within 3-4 minutes often gets the kill. Minimising time late is every thing.

[Mad_Mark]

Oh come on Elmo, please post again - we need a good laugh at work this morning :D

MadMark!!! :mad:

[Wader2]

MM,

How about taking him through an LCL or the merits of a 350 foot or 700 foot Codar plant? :}

Oddly there are any number of novels with far more precise info than discussed here. Patrick Robinson's , as mentored by Sir Sandy Woodward, for one.

Digressing, what the uninitiated would consider secret is the info in Eight Lives Down by Major Chris Foster. It is an absolute page turner and faster paced than a novel. There is some artistic licence as no one would remember conversations with the accuracy with which Chris writes.

[nimby]

What makes a good ASW aircraft ... ask a submariner!

Even the UK Crews beg for 20 minutes to get hidden when there's a Merlin about.

... But of one of you kind chaps could deliver fuel, chow and replacement buoys.

[davejb]

Understood,
Whilst I'd agree a lot is out there there are a few areas I'm less blabby about. I appreciate others may quite reasonably feel happy going into more detail - I wouldn't want to accidentally add things that are perhaps not on general release so I try to err on the side of caution.

Anyhow, in the case of Elmo I think going into more precise detail would add to the confusion!

Dentology - yes, I did a bit of that...it used to be one of the first things we did once the purple had gone and the photos arrived. (Provided food hadn't just arrived, of course).

[Razor61]

* I doubt you'll get 737's crossing the Atlantic, by the way, so I'd have thought that P8's would fail to benefit from any conceivable camouflage effect...they'll be the only version of the 737 out over the oggin.

The US Navy and US Air Force both operate the C-40 of which is the airframe the P-8 will be originating from i believe.
The C-40's cross the Atlantic everyday replacing the old C-9 in the VIP transport role.

Also, a few other nations use the BBJ (Of which the C-40 derived from i think) and this is a VIP/Private Exec variant of the B-737. Again flown everyday over the North Atlantic on the NAT Tracks.

However most of the C-40s are bright blue and white (or white) unlike the P-8 :E

[davejb]

Well, you learn something new every day - although I'm a bit surprised that the C40 (737-700C) has the legs for it, with a range of 3000 nm I'd have thought US mainland to UK would be a bit of a stretch. (Maybe the great circle chops more off than I thought <g>).

I rather took Elmo to be suggesting that the P8 engine noise would be disguised by the commercial 737 traffic, and whilst I've finally managed to convince myself that a twin engined 767 is okay for a trip across the pond it DOES have a teensy bit more range...I still don't think the P8 will find a great deal of 737 traffic masking it.

[Modern Elmo]

Thanks for that link, L. Hound:


Navy Selects LockMart For MK-54 Torpedoes High Altitude Launch Capability

Currently, P-3s (pictured) must descend to a low altitude to deliver the MK54. The HAAWC concept improves the delivery accuracy and shortens the engagement time of the MK54 torpedo.

by Staff Writers
Orlando FL (SPX) Jun 14, 2006

The U.S. Navy awarded Lockheed Martin a 12-month, $3 million contract for its High Altitude Anti-Submarine Warfare Weapons Concept (HAAWC). The program will demonstrate delivery of the MK-54 lightweight torpedo from a P-3C aircraft operating at high altitudes (approximately 20,000) feet.


Lockheed Martin's HAAWC concept employs the Lockheed Martin LongShot(R) Wing Adapter Kit to allow the launch of torpedoes from high altitudes and long standoff ranges. This technology enables P-3C aircrews to launch from outside the range of enemy air defenses.


"This is a significant operational enhancement over the P-3C's current method of launching MK-54s from close to the surface against submarine targets," said Alan Jackson, director of the HAAWC program at Lockheed Martin Missiles and Fire Control. …

http://www.spacewar.com/reports/Navy_Selects_LockMart_For_MK_54_Torpedoes_High_Altitude_Laun ch_Capability.html.

[1771 DELETE]

M Elmo
Your Navy quote for high level torp drop is still below the Nimrod Stingray clearance.
As for the accuracy of a high level drop, the aircrafts ballistic prediction takes care of most of it, including the target movement while the torp is in flight, this all assumes a constant wind on the way down and no change of MLA from the target, both of which are very big assumptions to make.
The bottom line is that, generally speaking, the lower the better, a lot less variables to worry about.

[Razor61]

davejb

You're quite right regarding the 737 masking over the N.Atlantic.
My point about the C-40 and BBJ didn't show the fact that these flights, although everyday, amount to just one or two (C-40) a day/night so hardly enough to mask the P-8 into the "background noise".

The C-40 Clipper has enough range to enable a flight from Andrews AFB to Germany.

How much endurance does the MRA4 have over the MR2 with the more efficient engines?

[Modern Elmo]

As for the accuracy of a high level drop, the aircrafts ballistic prediction takes care of most of it, including the target movement while the torp is in flight, this all assumes a constant wind on the way down and no change of MLA from the target, both of which are very big assumptions to make.
The bottom line is that, generally speaking, the lower the better, a lot less variables to worry about.

Compare to:

Navy Selects LockMart For MK-54 Torpedoes High Altitude Launch Capability


by Staff Writers
Orlando FL (SPX) Jun 14, 2006

...

"Currently, P-3s must descend to a low altitude to deliver the MK54. The HAAWC concept improves the delivery accuracy and shortens the engagement time of the MK54 torpedo.

This new capability will also increase the survivability of both of the aircrew and the aircraft by providing safe standoff. The standoff capability could potentially opens up the possibility for future of using MK-54s against surface targets by allowing the aircraft to launch [ torpedos ] from outside the range of a ship's air defenses."

...


No aircraft modification is required to deploy a LongShot equipped munition. The system is completely self-contained, including a flight control computer, a GPS-based navigation system and power sources and does not require an electrical interface with the aircraft.


http://www.spacewar.com/reports/Navy_Selects_LockMart_For_MK_54_Torpedoes_High_Altitude_Laun ch_Capability.html

[davejb]

MRA4 v MR2 - Like you, I'd have to rely on 'tInternet these days for that sort of info...eg Wiki has MR2 range up to 5755nm and MRA4 at 6910 nm - having said that I always just looked at sortie length (it told me how long my working day was going to be, once I'd added 3 hrs preflight and at least an hour after). 10 hr 15 the longest unrefuelled I 'enjoyed', of course AAR could make for rather longer.....

Wiki also says MR2 ceiling 44000 ft - anyone been anywhere near that in practise? I vaguely recall getting to 400-410 once, but my memory of that is very faint.

[Rossian]

A looooong time ago a certain co-pilot on CXX was able to claim the High Altitude Irish jig playing record at FL410+ a bit, in the middle of the night, in mid Atlantic, on the way home from Canadia. It was certified by the (Irish) Shanwick controller who when asked
"Did you get that?"
replied very slowly "Just what are you fellas DOIN' up dere?"
Followed by a "Please can we go down a bit?"
The Ancient Mariner
PS I never did like the pressure breathing practice at North Luffenham on the avmed course.

[Pontius Navigator]

davejb, I remember an air test in a Mk 1 to 410. Really wallowing then. Buy why fly at 410?

Radar horizon at 400 is 240. As an ASW platform it was no advantage being 7 miles from the action. For ASuW it just put you into the EW bracket earlier than need be.

As for the range, the BBC was always interested in how far we had flown and always noted the air mileage flown for their travel claims.:}

[davejb]

PN - Why 410?
While extracting that range info from Wiki (the source of all planetary knowledge - some of it correct) I noticed the MR2 ceiling was quoted as 440, which seemed a touch higher than I expected. I could just about dredge 410 from my memory, but I'm pretty sure that was a one off event.

AVMED - first time I went there they blew one of my ear drums in, I was stone deaf in the left ear for several days...it popped back out into fully working order as I went underwater from the back of the launch on the 'floaty dinghy puke regatta' part of the welcome package.

Oh, and to add to the theoretical debate on the ASW aircraft...something that didn't require gymnastics down the back would be nice, so how about a dispenser system for buoys that simply fed the buoys out automatically, with electronic setting from the nav station for life, depth (hey, let's add buoy type into that...click the buttons and you get any flavour you want).

To make it easier for the nav, all buoys have collapsible steel rods on top - on landing in the sea they extend their rods and lock onto each other, thus ensuring that they maintain the pretty buoy patterns on the tac screen rather than being blatted out of shape by time and an inconsiderate sea!

I remember a very old idea that sounded just the job for ASW - large floats with **** off great huge ginormous magnets on, attached to gas filled balloons by cable. You watch for one of the balloons to start moving, and drop the torp underneath it.

[1771 DELETE]

In the old days, i can remember getting to F420 once but certainly made F410 many times but it takes so long to burn off enough fuel to get up there that it isnt really worth it. Once they removed the ability to pressure brathing from the oxygen system that curtailed all high level flights.
If you really want to stay up for a very very long time, then go to F120 -F130. It sounds low for enduring but in reality its the best height, i think i once managed just short of 11 hours on a Link trial at that height. I does need very smoothinputs from the driver. It was easier on the MK1 to achieve longer endurance, i think the MK2 got a bit heavier or something.

[Charlie Luncher]

1771
I thought you always quoted the worst height for endurance to get back for a fag early, I mean siggie , no mean smoke.:eek:
Picking up the silver beast after LHR paint removal always made for a bit of malarkey in height vs mach number.:sad:.
I remember the weapon of choice that meant even Bruce Robb and his mile wide crew could get a kill:eek:.
Elmo design engineers and scientists have very little practical experience and will float many suggestions to solve solutions, without state based research and development it is left to us to make the best we can with the tools we are given by the lowest bidder, that is why we still fly in old aircraft that have evolved and can actually do the job well. The crew of the platform being well trained and experienced will get it done. I am convinced a update 3 or even AIP P3C could do a better job if the US Navy system allowed it.:(
Charlie sends

[davejb]

Bruce Robb,
Diplomacy's loss, maritime's gain....
(Or something like that :))

[1771 DELETE]

Charlie
Your right, those long trips were a real killer, or maybe a life saver, depending upon your opinion on smoking. I always enjoyed it when the drivers forget to put the airbrakes back in. Dont have to worry about endurance on my John Deere, theres even a holder for a beer can built in.

Bruce the Scottish diplomat???

[Pontius Navigator]

I'd start it, but I don't know how to spell autolocus (has it got a "Y" in it...I bet PN knows)

Sniff, sniff, no, before my time.

How about Martel, Deer, On Top Drift Sight, AS12?

In fact the Mark 1 Nimrod could almost be likened to a kid in an arms verything off the shelf.

Or Containers, Lane Equipment?

When I eventually ordered up two loads for a pair of Nimrods to cover a Royal Flight it turned out we only had 3 or so. How many hours were wasted teaching every nav and crew, and customers as well I guess, about kit we didn't have?

[Rossian]

Autolycus was a figure in Greek mythology described as "the picker-up of unconsidered trifles"
- in this case fast ions from combustion processes. There is absolutely NO charge for this bit of utterly useless triv.
The Ancient Mariner

[Yashin]

Charlie, you old scrote! You must have learned stacks since your exodus down South. Most on 201 recall that you simply ate a lot and got beaten up by the Deaf Dumb and Blind kid! ;)

As for stand off weapons, I want to become rich by suggesting that we build a series of huge catapults around the coast that are capable of hurling everything from torpedos to hand grenades, oh and big rocks into France too! That way we can do away with the RN and withdraw into our own safe island!

Bugger, some clever salesman from Boeing is going to steal my idea now! :bored:

[shack]

You really are a lot of girl's blouses!! There was only one aircraft, it was big and grey and had four mighty Griffons , a galley to make honkers in and all sorts of clever bits fitted (which worked sometimes). 15 hour trips were not unusual my longest was a few minutes over 24 hours but then it was different in the 50s and 60s.

Retires behind sandbag!!

[circle kay]

Has anyone here ever been to Majunga?

[Rossian]

O_K Put the lid back on that can of worms, right now d'you hear? Right now.
The Ancient Mariner

[davejb]

Ah yes....
15 hour trips were not unusual my longest was a few minutes over 24 hours but then it

Let's see - the 15 hr trips would be to 807, and the 24 hrs to 609 then?

[buoy15]

Is that the Malagassi (Madagascar) Majunga, where it cost you an empty jam jar to get in to the cinema, and you had to take your own pllow to sit on ?

[Pontius Navigator]

DaveJb,

Indeed, but we only managed 17 hrs with John Elias so didn't get south of Aberdeen.

Any time we passed south of the border always involved a night stop or 3.

[davejb]

Yes,
I think it was Pip Witts who once told me of a Shack jolly he was on from Kinloss to Gibraltar. Having flown all day against a touch of a headwind they landed at St Mawgan, slightly short of the intended destination.

Mind you, Norman could be a bit slow at times - it was very noticeable on airways that everyone else seemed to overtake us....

[1771 DELETE]

PN
John Elias is a name to cunjure up some memories, a gentleman for ever.
One one air display at homeplate St Mawgan, he rotated and turned all in one movement, the video from the tower was taken away quickly, apparantly there wasnt any sky under the wing tip, just grass.:=

[shack]

Wonder if the Mighty Hunter could have done the same as we did at Suez time ie. carrying 33 passengers and a reduced crew of 6, The only way to get down the back for a pee was to walk on slumbering bodies!
6 hours UK to Malta, refuel, 6 hrs to Nicosia no refuel (to save the Islands fuel resources), 12 hours off then take the next available aircraft back to the UK, 12 hours off then the same again. I was on 120 then and we were changing from Mk1s the Mk2s so took the next aircraft Mk1 or Mk2, by the end of the airlift out and back aircraft were all in the wrong places and as I remember it took until mid-January for each Squadron to get it's own aircraft back.
For "The Old Fat One" we used to do "fighter affil" as we still had the top turret---a corkscrew in a Shack was an arm wrenching experience and as for nearly drowning we had a siggie drown in Loch Neagh. There was a forward escape hatch in the nose floor and people had a habit of jumping down into the nose compartment onto the hatch, unfortunely one day it gave way and the said siggie dropped into the Loch. The captain was sitting up front in the nose cinema seat and had to stay there 'cos there was this bloody great space between him and the cockpit. After that a wooden cover was fitted to the escape hatch to prevent similar happenings.
John Elias was at Kinloss when I went through what was then the Shack OCU (I did the MRS at St.Mawgan on Lancasters) and when I went back to Kinloss as a QFI many years later he was still there. He used to drink a horrible red bitter concoction called as I remember Cinzano.

Happy days----------retires hurt.

[Wader2]

He used to drink a horrible red bitter concoction called as I remember Cinzano.

Except when flying when it was TNSVLM.

Everyone, except me, interpreted this as Weak Tea, no sugar. I knew he meant VST NS VLM - tea as black as ....................

I remember one Shack trip with John. We had lunch on the lawn, rugs, plates, sandwiches, listening to the birds in the quiet of a sunny Leicestershire afternoon.

John, hours hog? Never. Except that he counted the hour and half on the ground (engines stopped) at Bitteswell as flight time.

[Modern Elmo]

More maritime patrol gadgets:

UAV in a Tube Could Keep P-8s Up There

Posted by Graham Warwick at 6/27/2008 9:49 AM CDT

Bill Sweetman blogged from the recent AUVSI show about U.S. Navy interest in UAVs that could be air-launched from its P-8 Poseidon to avoid the modified 737 wasting fuel and airframe life by dropping to low altitude to ID surface targets. One of the ideas being looked at is Lite Machines' coaxial-rotor Voyeur, an expendable UAV designed to be launched from standard sonobouy tubes.


Video: Lite Machines

Lite Machines plans air-launched flight tests of the 24in-tall Voyeur under the recently started third phase of its U.S. Navy small-business research contract. The battery-powered UAV will be launched from the sonobouy tube to parachute down, deploy from the canister, start up its rotors and descend to ID the target at close range.
It will have an endurance of 60-90 minutes, after which it will ditch in the sea and scuttle itself, says Lite Machines. The UAV will carry a camera that will tilt up 10-15deg and down 90deg, and pan through 360 degrees by rotating the vehicle using differential rotor rpm. ...

Ares Homepage (http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3a0a5fba13-96ba-4be5-8245-6ca2d4b9d24d)

Also:

Air Launched UAVs Extend Poseidon's Reach

Posted by Bill Sweetman at 6/11/2008 1:10 AM CDT

When the US Navy picked the 737-based Boeing P-8A to replace the P-3C Orion, some wondered whether the jet would match the P-3's efficiency at low altitude. The answer - it doesn't. Dipping to low level uses a lot of fuel and eats into endurance. As a result, the Navy has two projects going that use air-launched UAVs to complement the manned airplane. They're on show this week at the AUVSI convention in San Diego.
One program is looking at expendable UAVs that can be launched from standard sonobuoy tubes. Three designs are being funded for tests out of the Navy's Patuxent River flight test center, starting with launches from a Raytheon C-12 and continuing with trials from a P-3 later this year. They include Lite Machines' Voyeur, a design from L3 and the Advanced Ceramics Research Coyote. These vehicles are electrically powered and expendable, and the initial configuration would carry an electro-optical or infra-red sensor, mainly for positive visual ID of ships below a cloud deck.


Advanced Ceramics Coyote

More complex requirements are the goal of the Wing and Bomb Bay Launched (WBBL) UAV program. The Navy has Small Business Innovation Research (SBIR) contracts in this area with Piasecki, for its Turais UAV, and Acuity Technologies, with the AT-3 Owl. The WBBL-UAV systems are bigger, weighing up to 1,000 lb, and carry multiple payloads (including up to ten sonobouys), and have an endurance of up to eight hours. They are also designed so that they can recover to a land base after a mission.

( My comment: Why not launch a bigass propeller-propelled maritime patrol UAV from a land base as well as recover to a land base, then? Maybe the thing could fly in ground effect in milder sea states. )

AT-3 Owl

The Owl, for instance, has a large weapon bay and a 36 hp UEL rotary engine driving a ducted fan. The UAV could be used to expand a patrol airplane's surveillance area, or could be a gap-filler if the manned aircraft had to return to base because of an equipment problem. Phase II contracts, including tests of full-scale mechanical demonstrators, were awarded in May.

pics by Bill Sweetman

Comments (9) | Permanent Link

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[ORAC]

GAO Denies Protest, Gives Northrop Nod for BAMS (http://www.defensenews.com/story.php?i=3675619&c=AME&s=AIR)

Published: 14 Aug
The U.S. Navy's decision to give Northrop Grumman the contract to build a new unmanned surveillance aircraft was upheld Aug. 8 by the Government Accountability Office (GAO), which denied a protest filed by Lockheed Martin.

The decision clears the way for Northrop to begin work on the RQ-4N Global Hawk Broad Area Maritime Surveillance (BAMS) aircraft.

The Navy announced its selection April 22, choosing Northrop over proposals from Lockheed Martin-General Atomics and Boeing-Gulfstream. The system development and demonstration contract initially is worth $1.16 billion, but the service plans to buy more than five dozen aircraft, priced at about $55 million apiece.......