Maritime Patrol Aircraft - Best/Worst Features

[Running Ridges]

Evening all!

I've been assigned a Uni Project, with brief to design a clean sheet Maritime SAR / Submarine Hunting aircraft. I thought this might be a good place to canvas some opinion on what makes a good aircraft for that role. Hence my question for those who have designed / built / flown / worked on / maintained any fixed wing Maritime Patrol aircraft (P-3, P-8 & Nimrod spring to mind) :

What are the best and worst features of these aircraft? Design features & capabilities that you admired and things that made your life difficult while working on them?

I'd really appreciate any input, whatever your link to the aircraft, so thanks in advance if you can contribute.

Cheers, RR

[Sandy Parts]

There must be literally 20 odd threads on here about MPA already. Have you had a look at those? Try a search for 'MPA replacement' 'Nimrod 2000' 'P8' 'tea-pots' (the last one will surprisingly also be about MPA...)

[strontium.dog74]

Why only fixed wing?


SAR and ASW roles are also heavily fulfilled by rotary wing aircraft.


Your title says MPA but your brief states SAR and ASW, whilst MPA do SAR and ASW actual recovery of persons from the water and generally detection and prosecution of submarines in the vicinity of the fleet are generally (for the UK specifically) conducted by rotary wing aircraft.

[QTRZulu]

Sandy, so will any search for kipper, dairy cream sponge or fray bentos pie.

Come to think of it, just make up a random search and you are bound to find a MPA thread tenuously linked somewhere

[KenV]

Best/worst depends a lot on what the airplane is expected to do, and different nations have very different requirements/expectations. But I would guess that having engines buried in the wing root like the Nimrod, while not a "worst" feature, would definitely be a feature to avoid.

[Lonewolf_50]

Originally Posted by Running Ridges

on / maintained any fixed wing Maritime Patrol aircraft (P-3, P-8 & Nimrod spring to mind) :

What, no love for the Atlantique 2?

[The Old Fat One]

Hey Op,

I'll take pity on you, seems no one is interested. I have 5000 hours flying on MPA (mostly, but not all Nimrod)

Assuming your spec id for long range maritime patrol, also known as blue water ASW.

Range/Endurance - The ability to transit long distances and loiter on patrol.
Speed - to get on patrol relatively/reasonably quickly.
Capacity 1 - to carry weapons, sonobuoys and other ordnance
Capacity 2 - to carry a largish crew
Capacity 3 - to carry a full sensor fit (radar, acoustics and other stuff)
Capacity 4 - to carry a load of communications equipment (LF, HF, V/UHF, Data Link, Satcomm etc)
Aircraft Systems - needs to have electrical capacity to drive all this kit and the cooling capacity to stop it overheating. Needs system redundancy to keep the thing operating at a consistent level. Needs the ability in terms of engines, handling and avionics to operate at low level over the sea for very long periods.

that should get you started.

Other aircraft types, smaller a/c or helos as mentioned can do shorter range stuff, but at this moment in time only fixed wing large aircraft can do long range maritime patrol.

Technology might change this one day, but it aint' here yet or even close.

PS and yeah, to keep everyone happy..it needs a galley.

[PDR1]

It all flows from the Mission - define the mission, derive an operating concept, derive operational requirements, which lead to user requirements, which lead to system requirements that lead to system features. The actual aeroplane isn't at the top of the operational hierarchy - it comes a couple of steps down the tree. The following comes from a paper on the subject which started from the premise that:

"Engineering could be described as the field of endeavour associated with devising systems that provide a capability to undertake a mission"

Where “Systems” would be any combination of machines, people, skills, infrastructure and information, a “capability” would be the ability to utilise the system when required for its intended purpose and a “mission” is some activity required to meet a political or economic need, either as discrete events or a continuous activity. From this flows a view that can be visualised as a "mission pyramid":



The problem with trying to jump straight to the systems requirements stage is that you can't establish the root justification for each requirement in terms of how it contributes to (or enables) mission success. They just become rabbits pulled from a hat, and that presupposes that some has actually put some rabbits into the hat in the first place.

HTH,

PDR

[Basil]

Good thread for an intelligence service to start in the hope that someone will, inadvertently, provide a useful snippet or three.

[Wensleydale]

PS and yeah, to keep everyone happy..it needs a galley.

....and not forgetting the toilet capacity!

[KenV]

Galleys, toilets, and other crew amenities assume a large blue water patrol aircraft. But for some nations, a small austere twin, like a King Air 350LR, may the "best" feature. Even for a big and rich nation like USA, a medium turboprop twin may be ideal. Witness the US Coast Guard taking over the C-27Js USAF parked in the desert. And for a few decades a medium twin jet, the S-3 Viking, was the "best" way to go. Again, "best/worst" is totally dependent on the mission and absent a rigorous mission definition, "best/worst" cannot hope to be defined.

Mission (mis)definition is the trap the "F-35 cancelled" thread fell into for the first several years it ran. The airplane's mission was completely misdefined and misunderstood by the countless trashboys in that thread.

[EW73]

Carefully considering all the comments here, after operating P3B and P3C Update 2.5 airplanes for over 10 years (5,000+ hours), I think they are the 'ducks gutz', and I'm very disappointed Lockheed didn't go on with producing the P7.

[EAP86]

While PDR's top down systems engineering approach is sound, don't forget the constraints eg the cost/price. Most MPAs start with an existing platform as it's likely to be the most cost-effective approach. Pick your platform with care as this will probably be the most important constraint.

EAP

[PDR1]

The question pre-judges that the solution is actually an aeroplane - there's no particular reason why it has to be and artificially constraining the options too early in the process is rarely a good idea.

For example a requirement that calls for “a bridge capable of handling 500 cars per hour in each direction” would allow bidders to offer a suspension bridge, a box-girder bridge, a pontoon bridge or indeed any of many other technical approaches, but all of them must be bridges.

A requirement calling for a “river crossing capability for 500 cars per hour in each direction” would allow all of these, or a tunnel, or a ferry service, or a catapult-and-net system. It might even allow an enterprising contractor to offer a service-based solution using a fleet of surplus heavy-lift helicopters that he happened to see coming up on Ebay with 1 minute to go, no bids and a £0.99 minimum bid price. That could achieve the requirement with a totally different financial profile (minimal capital, higher revenue) whilst also adding the benefit that it could be in operation in a matter of weeks with no construction disruption rather than needing five years of construction investment and constipating of local traffic for the duration.

Focus on the mission first - never prejudge a solution. Some maritime patrol requirements can be fulfilled with remote video camera with a zoom lens. That solution wouldn't need a galley or a toilet...

PDR

[PTR 175]

My suggestion is also a 'role bay'. An area that can quickly be reconfigured to take a crate/pallet of auxillary equipment that can adapt the role of the aircraft quickly. When not in use the role bay could be fitted with Pax seats or a small rest area with a couple of bunks.

In addition make the aircraft maintainer friendly for example trim that is easy to remove and refit.

O2 on tap for all to alleviate the Kokinelli headaches.

[Wander00]

PDR1 - my argument against Concorde (don't get me wrong, a brilliant aeroplane in whose building I played a small but proud part) - but if the objective is to get from city centre to city centre as quickly and economically as possible, Concorde was just maybe the "wrong" answer

[PDR1]

Absolutely - for journey distances much below about 5,000 miles, anyway. It's like putting out requirements for ever faster carrier pigeons when someone is selling telephones!

I once read a Fast Jet URD which included the phrase "the aeroplane must be able to retract its undercarriage".

A few seconds of thought and you realise that this isn't a requirement at all - it contributes nothing to the mission objectives. It's actually a system solution to the operational requirement:

"Shall operate from CVS-class carriers"

and the performance requirements

"Shall deliver death, mayhem and Xmas presents to a target 500 miles away within 80 minutes of mission tasking"

"Shall have a mission radius (with reserves) of at least 800 miles"

and the operating constraints:

"Shall fit down a standard CVS lift"
"Shall fit in a standard CVS Hangar space allocation" [yes I made this up to keep it simple]
"Shall not require external refuelling support to achieve standard missions"

Within these constrains and requirements most of the available solutions will use a wheeled undercarriage, and it's highly unlikely that the drag of a non-retracting undercarriage would be tolerable. So the undercarriage is a system solution, not a requirement.

QED

PDR

[Lonewolf_50]

Originally Posted by EW73

Carefully considering all the comments here, after operating P3B and P3C Update 2.5 airplanes for over 10 years (5,000+ hours), I think they are the 'ducks gutz', and I'm very disappointed Lockheed didn't go on with producing the P7.

Not sure of your involvement with P7, but that program had sufficient warts on it that it deserved being cancelled (in part due to some dodgy claims LM made). Not saying the aircraft necessarily should have been, but sometimes (see also A-12) the program kills itself.

[Running Ridges]

Thanks for the feedback and tips so far

Originally Posted by strontium.dog74

Your title says MPA but your brief states SAR and ASW, whilst MPA do SAR and ASW actual recovery of persons from the water

No need for actual recovery in this case, more the "S" part of SAR

Originally Posted by PDR1

The question pre-judges that the solution is actually an aeroplane - there's no particular reason why it has to be and artificially constraining the options too early in the process is rarely a good idea.

I'm looking at long range missions, so fixed wing is probably the only way to go. In any case it's an artificial constraint of the project, so fixed wing it is!

Im particularly interested in the advantages (if there are any) that going for a clean sheet design might offer. Was there anything that the Atlantique (or the Kawasaki P-1 if anyone has any experience) is able to do better than the MPA's adapted from airliners?

[Rossian]

Ahem, the most important.....

.....component of any new MPA/MMA must be a well trained crew. Not just the execs but including all the equipment operators. They should operate together and not in little cells.
One of the worst phrases I ever heard was "Aft of the flight deck door is mission crew ****"

The Ancient Mariner