Rolls-Royce to provide propulsion system for Bell V-280 Valor

Yes but the A400 was meant to be able to deploy paras from conception not as some bonus feature.

Yes that is right – wasn’t it the case that the A400 produces some excessive wake turbulence due to its counter-rotating props that its modern design,modelling and production techniques failed to predict ?

Actually it was predicted by several engineers on the project but Airbus ignored them because it was so far behind.
The problem was to many cooks spoil the broth , trying to cram so many things into a brand new design with brand new engine designs.

Interesting fact the A400 costs France €152 million a plane , Germany €175 million and the uk €156 million and that is just for the base plane without any extras.

As the smaller and less capable Hercules C-130J costs between $110m and $160m a plane on the international market (dependent on level of military export subsidy and the other weapons packaged in the trade deal) thats still a competitive price.

€156 million euros = $175 million dollars plus you have to add in the costs of training and maintenance infrastructure for the A400 which according to the MoD answer to defence select Committee was £800 million.

Remember we already had the training and infrastructure for the Hercules and our 14 Hercules C130J cost 900 million euros .

And you neglected to mention the 23 billion euro cost development of the A400 meaning the program will never break even .

I am not anti A400 it is a stunning plane but as we have a limited budget we need to actually buy what we need not what we would like.
And in the case of the A400 it was rose tinted glasses time .
The Germans are still trying to cancel 30 planes from there order or sell the options .
The French had to order the C130J because the A400 cannot refuel helicopters .

Actually the A400M demonstrated a month ago that it can refuel helicopters, it’s just 5 or 10 years late, like the two door paratrooper deployment feature.

I read the article but it cannot refuel the range of helos like the C130J .

All these issues were pointed out by the engineers at a very early stage and totally ignored by Airbus.

Like I said a beautiful plane but it will never achieve success like the Hercules .

What?… A big corporation ignoring engineers because they’re focused on profits rather than actual safe operational use??? I cant see that ever happening……NOT!!!

For the Nth time: All aircraft suffer from the same problem. Some more than others. It is particularly acute in the A400M because of the exact symmetry of its airflow round the back of the aircraft doe to the handed nature of the propeller rotation. It increases the likelihood of paratroopers coming together behind the aircraft when jumping simultaneously from both para doors. The A400M nations actually applied higher safety standards on the aircraft than they’ve been accepting for years on the C130Js. And not just in this area, in all areas. Basically Airbus was asked to develop an aircraft as safe as the safest civil airliner with all the military attributes of all preceding military transport aircraft on top. In many areas this turned out to be an impossible brief. Anyway, problem has been resolved now. So that’s the good news. The bad news is that far from greedily racking in the profits, Airbus has lost money on this programme hand over fist.

As per normal with Airbus, everything takes yonks and costs a bomb, it’s quite frustrating but I’m proper impressed with the A-400 even though its had major problems in the “para” transport role due to airflow issues…….that’s a bit of a concern, especially if you’re standing in the doorway ready to jump.

Not only that but Air Tanker have a contract that states that A2A re-fuelling is their exclusive domain which is why we’ll never see the Atlas, in RAF colours, carrying out refuelling duties

I suspect the 16 long range chinook we plan to buy but never placed an order on will be the replacement for the Puma.

But a Chinook cannot land in confined compounds, a Puma can.

Yes this craft looks a far better all-round bet potentially than the Osprey for our forces. Though depends on how it gets on and developed for US forces first I guess so that we can indeed piggyback on those developments.

You assume the replacement decision will be based on needs rather than money. I would guess that the MOD will see that having less types of helicopter will bring down maintenance costs and that the wildcat can fill in for smaller roles.

Nope, they will be replacing the original Chinooks we bought back in the early 80’s.

Actually I think VARS entered service last year .

The Valor has been primarily designed to replace the Blackhawk and the all roles it does with the US Army, taxi, special forces long range insertion, medivac etc. The Blackhawk and Puma are comparable in size and the have nearly the same landing footprint. One of the stipulations for the Valor was to match the Blackhawk’s footprint. I think the fuselage footprint is the same, but the overall rotor diameter is slightly wider, but narrower. So it will be interesting to see how the US Army judge this, especially when you compare the Defiant’s rotor diameter footprint is actually smaller than the Blackhawk’s.

The USMC have said they want to replace their fleet of Hueys, so are looking at the two competing designs. Bell have shown a mock-up of a marinised Valor, complete with a folding main-wing and rotors. Personally, I think the best aircraft for the USMC is the Valor, as it has better range and a higher speed over the Defiant. However, for the US Army it’s slightly trickier. The Defiant, I believe will have the edge landing in tighter spots and will be nimble low level hedge hopping, but will this sway the judgement over greater speed and range of the Valor?

Not sure if the V22 can auto-rotate due to it smaller wing and higher disc loading. The AW609 has already shown that a tilt-rotor can auto-rotate, the Valor with is correctly sized wing and rotors “should” also be capable of auto-rotation landings.

Interesting reading all that GHF. Encouraging.

The US Army cancelled its further procurement of CH47F Block 2 Chinooks. It got a lot of press in the States, where the Senate/Congress foisted further buys on the Army. The US Army are currently converting a lot of the older Model Ds and Block 1 Model F to the later standard. The US Army is its own design authority for their Chinooks, unlike us where its still Boeing so they do most of the work themselves. The US Army was hoping to use the money saved for the future joint multi-role – Heavy program, i.e. the Chinook replacement.

I wouldn’t say the US Army are desperate to replace their Chinooks, but they can definitely see that it will need replacing soon. The obvious issue is that it won’t, even with the best will in world, be able to keep up with either the Defiant let alone the Valor. The other issue is that compared to the CH53E/K its vertical lift isn’t as great.

The Chinooks we originally bought in the early 80’s are going to be pensioned off and replaced with new buy Chinooks. These and the remaining fleet are expected to go to at least 2040. At which point the winner of the FMR-Medium (Defiant or Valor) will have been in production for at least ten years. If the Valor wins, there is already a manufacturing tie in between Bell and Leonardo, so could it be put together over here at Yeovil? What if the Defiant wins, would there be scope for production in the UK?

With the Puma, I fully expect to see its out of service date extended further, even though its well past its best! It WILL be replaced with one of the winners from the JMR-Medium competition. Unless Leonardo or Airbus comes up with a competing design, they will not get a look in. The aircraft that they make currently that could fit the bill such as the AW149/189 and the NH90 are no real advancement over what we have already. It’s the same with the Merlin. For the ASW role it currently does with the Navy its more than adequate. However, something like the Defiant with its greater range/duration and dash speed would be a major advantage.

We have talked before about the Army requiring a decent utility helicopter that could take over the duties done by the Gazelle and those that the Lynx used to do such as a battlefield taxi. The Airbus EC145M or preferably the EC145T2 would be an obvious choice, as its already used by the training school. Therefore the conversion to the utility variant would not need excessive training.

How expensive would it be to convert the Army’s AH1 Wildcat to the Navy’s HMA2? I know the AH1 is already marinised as part of its design spec was it had to be able to operate in the maritime climate for prolonged periods. So perhaps the idea of converting them to HMA2s wouldn’t be out of the question. So what is there that can replace the Wildcat in the reconnaissance role? The obvious answer would be one of the two JMR-Light (future attack reconnaissance aircraft) competitors. So either The Bell 360 Invictus or the Sikorsky Raider X. The Bell is the simpler design and uses a conventional main rotor plus tail rotor (fenestron) arrangement supplemented by a small wing. Whilst the Raider X is a smaller version of the Defiant. As a knife-fighter the Raider X has both the agility and speed advantage. In some respects it could replace the Apache, however the Raider X currently shown has a side by side seating arrangement rather than tandem. Which goes against the norm and is perhaps a constraint due to the size of the main rotor gearbox.

My guess is that the UK saw nothing likely to become available in at least the next 20 years to replace Chinook so that commitment was pretty easy to make. Perhaps the most likely option, as you’ve previously discussed, is an updated V-22, using learning from V-280 to significantly reduce cost and improve performance. V-22 isn’t that far off Chinook in lift capability but its just too expensive. CH-53K is the payload king but even more expensive than V-22. So chasing payload performance too far may not be the best approach, certainly for the US Army or UK forces.

The Leonardo, Yeovil technology and manufacturing base is a challenge in the scenario I outlined. They clearly have nothing competitive with FLRAA for a Puma replacement. There’s an expensive history associated with license building, but if it could be done at a low premium along with the maintenance contracts, then that might be desirable. However I remain critical of paying premiums for UK defence builds that reduce forces capabilities. MoD budget shouldn’t be used for a jobs program.

The best chance for Yeovil may be against the FARA program winner. If its Bell 360 Invictus then the performance of that platform may not be that much greater than Wildcat. It would be interesting to know how the lift from the recently developed Wildcat armaments “wing” contributes to improved cruise speed, if at all, to help close that gap. Wildcat would still have to be competitive from a purchase and operating costs perspective though and clearly Bell is aiming to be a much lower cost platform than Raider X. If the FARA winner is Raider X then the performance delta is likely to be far greater vs Wildcat and much tougher for Leonardo to offer a competitive solution.

The final opportunity for Yeovil is on the utility helicopter front. If Wildcat stays as the AAC reconnaissance platform because of “good enough” performance vs an alternative; and if Wildcat can be priced low enough for pure utility use, then that would be attractive. But those are two large IFs. Alternatively, as we discussed, Leonardo has other platforms that might counter H145M.

The new wing on the Wildcat could be used to improve its cruise speed and top end performance. But the aircraft’s flight control system and engine controls need to be more integrated together. It’s definitely doable, as the Bell Invictus is a good case in point.

One of the limiting factors of a helicopter is the rotor’s tip speed. As the aircraft flies forward and gets faster, the local airspeed at the tips gets into the transonic zone, faster still it can go supersonic. As the wing planform aerofoil is designed for maximum efficiency at subsonic speeds. The laminar flow at these speeds is broken up and small bubbles are formed leading to less lift and a proportional rise in drag. As the aircraft goes faster still, these bubbles merge and the blade starts suffering from compressibility, i.e. the bubbles cycling through a cycle of them getting bigger and smaller as the blade rotates. This causes the blade to oscillate, when the blade reaches resonance it will simply and catastrophically break apart.

To make sure the blade tips don’t suffer from this the aircraft’s rotor rpm is generally fixed with a +/- 2% margin. The aircraft will reach a Vmax and the pilot (or automatic flight control computer) will lessen the pitch to prevent the aircraft going any faster. The pilot will notice that they have to increase the collective pitch more to maintain speed as the aircraft is losing lift. Generally the aircraft will hit a brick wall in speed anyway, as the blades will loose a lot of lift and the drag balances out the rotor thrust.

Too make a helicopter go faster, one of the methods that is being used is to slow the rotor rpm down, i.e. slow down the tip speed. However, by slowing the rotor rpm down you generate proportionally less lift. Both the Defiant and Invictus go from 100% rotor rpm to about 85%. The Defiant has the large propeller for thrust, so can reduce the forward pitch of the contra-rotating blades to near zero. It also feathers the trailing blades, so its pitch is zero to reduce drag further. The Invictus doesn’t have the thrust from an additional propeller, so it still needs to tilt the rotor disc forward for thrust. However, it can reduce the angle required collectively, as the small wing will generate the lost lift from slowing the rotor rpm down. It also uses the training blade feathering that the Defiant uses to reduce drag. The Defiant uses a different method. As the thrust is now provided by the aft propeller, the thrust it generates helps increase the aircraft’s speed. It has the knock on effect of increases the airspeed over the rotors, so even though they are rotating slower, the increased airspeed over the blades balances out the lift requirement. The Defiant has the ability of a transitioning from the hover to forward speed in a flat profile, as it can use the propeller to generate the thrust rather than using a pitch input. It can still use the traditional method of tilting the disc forward, Sikorsky have given the pilot the option to use either or a combination of both.

The Wildcat would have to do the same as the Invictus, to go faster. The Flight control computer would need to tell the two engine computers to slow down the rotor rpm, whilst controlling the blade pitch and then feathering the trailing blade through the swashplate. It is doable, but, it has to be done through the flight control software and lots of trials.

Both the Invictus and Wildcat (if converted) would still be a lot slower than the Defiant. These aircraft don’t have the additional propeller for providing thrust. Therefore, all the thrust must be developed by tilting the rotor disc forward. There is a physical limit in how far a swash plate can be tilted. When the swash plate is at its extreme movement angle, it causes a significantly increased bending load to be placed on the rotor shaft, again limiting the aircraft.

Interesting, thank you.