Harrier replacement
If the old girl thought that the F35 "Flying Wheelie Bin" was Fugly, what did she think of the Harrrier?!!
I always compared the 2:
Oh well, off to the Tower for me then...
LJ
I always compared the 2:
Oh well, off to the Tower for me then...
LJ
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Al R
The Harrier was never the prettiest of things either, mind. I rather like the ungainly look of the F-35.
The Harrier was never the prettiest of things either, mind. I rather like the ungainly look of the F-35.
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Nut,
Actually, it did. It was called a very large engine with an oversized front fan. It also carried a lot of additional structural weight to locate the engine in the middle of the fuselage.
There were other penalties, but these were overcome by brilliant design and detailed engineering so as to make it a viable combat aircraft.
You might also note that the F-35B's lift system is used for STO as well as vertical landing, slightly useful if you want to operate from a ship, or short runways.
The point I'm trying to illustrate is that getting a powered lift aircraft to work well enough to be an effective military combat jet is 'crazy hard'. It always involves compromises, clever engineering and significant risk. The Harrier was the only successful one of many attempts to develop such an aircraft - my opinion (and that's all it is) is that the F-35B will be the next. Many think it won't - that's fine too.
Hope this helps, best regards as ever to those making function meet requirement
Engines
Actually, it did. It was called a very large engine with an oversized front fan. It also carried a lot of additional structural weight to locate the engine in the middle of the fuselage.
There were other penalties, but these were overcome by brilliant design and detailed engineering so as to make it a viable combat aircraft.
You might also note that the F-35B's lift system is used for STO as well as vertical landing, slightly useful if you want to operate from a ship, or short runways.
The point I'm trying to illustrate is that getting a powered lift aircraft to work well enough to be an effective military combat jet is 'crazy hard'. It always involves compromises, clever engineering and significant risk. The Harrier was the only successful one of many attempts to develop such an aircraft - my opinion (and that's all it is) is that the F-35B will be the next. Many think it won't - that's fine too.
Hope this helps, best regards as ever to those making function meet requirement
Engines
At least the Harrier never carried a load of dead weight everywhere that was only utilised on the landing phase...
LJ
(sent from the Tower of London)
F35s on ships
Why didn't they think of some sort of catapult device on ships to save the weight of heavy lift fans and maybe have cables and things to stop aeroplanes from falling off the end of the deck when they land? Or is that too far in the future. Sorry.
Engines,
Actually, the "oversized fan" made the RB Pegasus a very efficient (medium bypass) engine in the Harrier role and in achieving its hover power requirement. I would also suggest that the placement of the engine in the middle of the fuselage of a combat jet like the Harrier probably MINIMIZED its structural weight! Placing engines at the extremities of an aircraft structure can increase structural weight due to the extra strength needed to be built into large parts of the aircraft that do not need to be so strong for aerodynamic or other loads. Weight penalties of tail mounted engines on large-ish narrow body aircraft spring to mind.
You are right though, compromise, and the RIGHT compromise, is the key. Trouble is, maybe they have got the cost/effectiveness compromise of the F35 badly wrong?
OAP
Actually, the "oversized fan" made the RB Pegasus a very efficient (medium bypass) engine in the Harrier role and in achieving its hover power requirement. I would also suggest that the placement of the engine in the middle of the fuselage of a combat jet like the Harrier probably MINIMIZED its structural weight! Placing engines at the extremities of an aircraft structure can increase structural weight due to the extra strength needed to be built into large parts of the aircraft that do not need to be so strong for aerodynamic or other loads. Weight penalties of tail mounted engines on large-ish narrow body aircraft spring to mind.
You are right though, compromise, and the RIGHT compromise, is the key. Trouble is, maybe they have got the cost/effectiveness compromise of the F35 badly wrong?
OAP
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OAP,
I apologise for not being clearer - by 'oversized' I meant that the engine had to have a very large diameter - this led to a fairly fat fuselage and a basically subsonic design. That was a challenge looking at the UK's firm requirement for a next generation supersonic STOVL aircraft.
For a combat jet, LM's view was that the right place for a single engine is down aft. This minimises jet pipe losses, allows more options for intake placement, and frees up the central structure for stuff like weapons bays (if you are going for stealth) as well as fuel. I am inclined to agree, but I know others might differ.
The British preference for aft mounted engines on airliners was driven in part by a desire for very clean wings to attain high cruise speeds and long range, with quieter passenger cabins as a useful by product. This layout was structurally inefficient, and led to substantial extra weight (which reduced the range). The situation is very different with combat aircraft like the F-35. The engine thrust mounts are closed to the main wing spar and also the undercarriage attachments - making for what should be an efficient structure.
The Harrier design solution included multiple small fuel tanks built into the fuselage to replace larger but fewer fuel tanks - they worked, but could never be very weight efficient. They also leaked. The UK's many efforts to design a supersonic ASTOVL design with a centrally mounted engine never delivered a feasible design - and I got that opinion from a senior BAES designer.
You are spot on that the right compromise is the key. My answer to your question 'have they got the compromise of the F-35 badly wrong' is 'no, I don't think so'. Again, I know others will disagree.
My view is that the design has concentrated on high end sensors and information capability, and systems integration with the weapons. I think that's a key attribute. They have gone for an 'LO' design, not a 'VLO' design, and have not pursued the highest end of the manoeuvre spectrum. Again, I'd back that call.
Most importantly for the US, they have produced a common family from one aircraft that replaces many legacy platforms. The savings are planned to come downstream as the production lines roll and the support systems are delivered to reduce through life costs. That's the plan. Again, I know others think it's a rotten plan.
Hope this helps a bit,
Engines
I apologise for not being clearer - by 'oversized' I meant that the engine had to have a very large diameter - this led to a fairly fat fuselage and a basically subsonic design. That was a challenge looking at the UK's firm requirement for a next generation supersonic STOVL aircraft.
For a combat jet, LM's view was that the right place for a single engine is down aft. This minimises jet pipe losses, allows more options for intake placement, and frees up the central structure for stuff like weapons bays (if you are going for stealth) as well as fuel. I am inclined to agree, but I know others might differ.
The British preference for aft mounted engines on airliners was driven in part by a desire for very clean wings to attain high cruise speeds and long range, with quieter passenger cabins as a useful by product. This layout was structurally inefficient, and led to substantial extra weight (which reduced the range). The situation is very different with combat aircraft like the F-35. The engine thrust mounts are closed to the main wing spar and also the undercarriage attachments - making for what should be an efficient structure.
The Harrier design solution included multiple small fuel tanks built into the fuselage to replace larger but fewer fuel tanks - they worked, but could never be very weight efficient. They also leaked. The UK's many efforts to design a supersonic ASTOVL design with a centrally mounted engine never delivered a feasible design - and I got that opinion from a senior BAES designer.
You are spot on that the right compromise is the key. My answer to your question 'have they got the compromise of the F-35 badly wrong' is 'no, I don't think so'. Again, I know others will disagree.
My view is that the design has concentrated on high end sensors and information capability, and systems integration with the weapons. I think that's a key attribute. They have gone for an 'LO' design, not a 'VLO' design, and have not pursued the highest end of the manoeuvre spectrum. Again, I'd back that call.
Most importantly for the US, they have produced a common family from one aircraft that replaces many legacy platforms. The savings are planned to come downstream as the production lines roll and the support systems are delivered to reduce through life costs. That's the plan. Again, I know others think it's a rotten plan.
Hope this helps a bit,
Engines
