Britain told "No Access" to F-35 Software codes

[FourWheelDrift]

F-35B listed as 60,000lbs max take off weight with a combined jet/lift-fan thrust of 39,700lbs.
Sea Harrier listed as 26,200lbs max take off weight with thrust available of 21,500 lbs.

I guess that's one reason why the Queen Elizabeth class has to be so long for a SVTOL carrier, to give the F-35 enough of a run up?

[Sylvaforever]

You gotta wonder about that lift fan dooor arrangement y'know.

Apparently 21 Items have to move, indicate and lock correctly for the landing.

That's a whole bunch if stuff to go wrong. Engines that bend. Weight issues being addressed by the bulkhead cracks so that's "fine" at the moment but redesign add more weight.

One thing I’ve never found out was if there is a fire containment system fitted like wise power distribution protection both deleted during the weight saving program. Likewise ballistic testing of inlet duct/fuel tanks [bet they were glad avoid that!!]

There's so much weirdness about the jet it's like aviation engineering rule book has been thrown out on the alter of mediocre performance.

[MartG]

Sylvaforever said:

You gotta wonder about that lift fan dooor arrangement y'know.

Apparently 21 Items have to move, indicate and lock correctly for the landing.

That's a whole bunch if stuff to go wrong.

I suspect a lot will be lost due to being unable to land back on a carrier thanks to some relatively minor failure and having to ditch when they are out of range of an alternate land airfield. Maybe when they've lost a few this way they'll be restricted to land use only, and have all the VTOL gubbinry removed to save weight and maintenance cost

[FourWheelDrift]

MartG said:

I suspect a lot will be lost due to being unable to land back on a carrier thanks to some relatively minor failure and having to ditch when they are out of range of an alternate land airfield. Maybe when they've lost a few this way they'll be restricted to land use only, and have all the VTOL gubbinry removed to save weight and maintenance cost

Which worries me about Italy's procurement procedures, they have only ordered 30. 8 for the Cavour and probably 8 for the Trieste, doesn't leave many for training and spares (RN ordered 138 and USMC ordered 340).

[Mave]

Sylvaforever said:

Y'all do realise the AUW of the '35B?

Y'all do realise the max take off weight of the '35B? It's a much bigger aircraft so it's heavier.

[Tango13]

Dr Jekyll said:

How difficult would it be make a 'continuation' Harrier to use instead of the F35? Might it be cheaper than converting the carriers to have catapults?

From an engineering perspective it would be a very straight forward job, it's all proven technology.

If you gave BAe and Rolls Royce a large enough order Monday morning and told them to get a fking move on as the carrier is on sea trials you could have aircraft flying inside a couple of years at a very good price.


This will never happen for a few reasons...

The F-35 program has been allowed to become too big to fail and now has to succeed regardless of cost.

Dumping the F-35 would involve politicians growing some balls and making a decision

BAe would propose all sorts of improvements and upgrades adding both cost and timescale to the program.

[FourWheelDrift]

The vectored thrust Bristol Siddeley BS100 jet engine of 1960 designed to go into the supersonic VTOL Hawker Siddeley P.1154 could produce 35,900lbs of thrust which is more than the 25,000lbs of the F-35B (without the extra 18,000lbs of the additional cold air fan it needs for VTOL).

https://en.wikipedia.org/wiki/Bristol_Siddeley_BS1...

Why didn't Lockheed-Martin go along the same route design-wise, instead of the cold lift fan double engine (extra weight) method? Or do we have a patent on that design?

[Dr Jekyll]

FourWheelDrift said:

The vectored thrust Bristol Siddeley BS100 jet engine of 1960 designed to go into the supersonic VTOL Hawker Siddeley P.1154 could produce 35,900lbs of thrust which is more than the 25,000lbs of the F-35B (without the extra 18,000lbs of the additional cold air fan it needs for VTOL).

https://en.wikipedia.org/wiki/Bristol_Siddeley_BS1...

Why didn't Lockheed-Martin go along the same route design-wise, instead of the cold lift fan double engine (extra weight) method? Or do we have a patent on that design?

I don't think the BS100 ever worked properly. There was some issue regarding using afterburners at the hover because hot gas would get back into the engine, which is apparently A Bad Thing. No doubt Eric and Ginetta can give us the gen.

[Ian Lancs]

Tango13 said:

BAe would propose all sorts of improvements and upgrades adding both cost and timescale to the program.

You've missed the most usual event - the Customer changing their mind post contract signature as every 2-2.5yrs there is a new requirement manager who has seen something shiny on some other aircraft that they now want, and won't accept the aircraft without it. Oh - all for no extra cost....

[davepoth]

Tango13 said:

Dumping the F-35 would involve politicians growing some balls and making a decision

Trump would do it. And he's already complained about the cost of the F-35, asking Boeing to look at an update to the Hornet.

The Harrier (in AV-8B form) is a Boeing product, and I bet they'd be quite happy to dust off the jigs and get into the fighter jet game again, especially at Lockheed Martin's cost. If RR can build the engines (Pratt and Whitney have an unused licence too AIUI) then it could be done quite cheaply.

Of course, it would never be done cheaply. You'd want variable intake ramps for supersonic flight, a more powerful variant of the engine, a longer fuselage for more fuel capacity, better stability, and better intake geometry, and most importantly avionics upgrades. It'd probably still be cheaper than the F-35 but I don't know how much.

[Ginetta G15 Girl]

The engine in the P1154 relied upon plenum chamber burning in order to generate the thrust required for supersonic flight (think vectored thrust equivalent of afterburner applied to the front [cold] nozzles), as well as for VTO, hover and VL for the heavier airframe.

Sadly RR could never make this reliable. Additionally PCB is incompatible with VTOL in that you are probably going to melt your tyres let alone the surface you are operating from, so Catch-22 really.

Edited by Ginetta G15 Girl on Friday 13th January 19:31

[Mave]

FourWheelDrift said:

The vectored thrust Bristol Siddeley BS100 jet engine of 1960 designed to go into the supersonic VTOL Hawker Siddeley P.1154 could produce 35,900lbs of thrust which is more than the 25,000lbs of the F-35B (without the extra 18,000lbs of the additional cold air fan it needs for VTOL).

https://en.wikipedia.org/wiki/Bristol_Siddeley_BS1...

Why didn't Lockheed-Martin go along the same route design-wise, instead of the cold lift fan double engine (extra weight) method? Or do we have a patent on that design?

One of the problems with the Harrier STOVL concept is that the propulsion system forces some significant trades on the aircraft.

The need to balance thrust from the cold and hot nozzles puts limits on what you can do with the engine cycle, so you end up with a bypass ratio which is much higher than usual for a fast jet. You end up with a very large frontal area, low specific thrust, and high thrust lapse rate. The F135 engine essentially acts as a variabe cycle engine, which much higher bypass ratio in STOVL operation but a lower BPR in regular flight.

The need to position the (vertical) centre of thrust on the aircraft centre of gravity means that the engine is much further forward than usual for a fast jet, which means you get a "Brontosaurus" area ruling rather than a "coke bottle" area ruling giving higher drag. It also means that you have a very short intake which is aerodynamically poor, (particularly at high angles of attack), susceptible to FOD, and hard to hide to minimise RCS.

[davepoth]

Ginetta G15 Girl said:

The engine in the P1154 reied upon plenum chamber burnin g in order to generate the thrust required for supersonic flight (think vectored thrust equivalent of afterburner applied to the front [cold] nozzles).

Sadly RR could never make this reliable.

IIRC they tried something odd with inflatable intake lips on the P.1127 to try and improve top speed without losing power in the hover - but they kept flapping around at speed so they went for a compromise fixed design. From what I can find the top speed at altitude was mach 0.98, does that sound reasonable?

Since it was never designed for going high and fast I guess the intakes would be more focussed on the low speed regimes; I wonder how much difference a modern variable design would make?

[Dr Jekyll]

davepoth said:

Trump would do it. And he's already complained about the cost of the F-35, asking Boeing to look at an update to the Hornet.

The Harrier (in AV-8B form) is a Boeing product, and I bet they'd be quite happy to dust off the jigs and get into the fighter jet game again, especially at Lockheed Martin's cost. If RR can build the engines (Pratt and Whitney have an unused licence too AIUI) then it could be done quite cheaply.

Of course, it would never be done cheaply. You'd want variable intake ramps for supersonic flight, a more powerful variant of the engine, a longer fuselage for more fuel capacity, better stability, and better intake geometry, and most importantly avionics upgrades. It'd probably still be cheaper than the F-35 but I don't know how much.

The only way would be to do it as a private venture, gambling on the F35 failing. That way they wouldn't have to worry about politicians demanding Mach 3 or an air sea rescue version.

[Mave]

Ian Lancs said:

Tango13 said:

BAe would propose all sorts of improvements and upgrades adding both cost and timescale to the program.

You've missed the most usual event - the Customer changing their mind post contract signature as every 2-2.5yrs there is a new requirement manager who has seen something shiny on some other aircraft that they now want, and won't accept the aircraft without it. Oh - all for no extra cost....

Yep. And a lack of joined up, consistent thinking between the people writing the requirements and the people using it operationally.

[Mave]

davepoth said:

Ginetta G15 Girl said:

The engine in the P1154 reied upon plenum chamber burnin g in order to generate the thrust required for supersonic flight (think vectored thrust equivalent of afterburner applied to the front [cold] nozzles).

Sadly RR could never make this reliable.

IIRC they tried something odd with inflatable intake lips on the P.1127 to try and improve top speed without losing power in the hover - but they kept flapping around at speed so they went for a compromise fixed design. From what I can find the top speed at altitude was mach 0.98, does that sound reasonable?

Since it was never designed for going high and fast I guess the intakes would be more focussed on the low speed regimes; I wonder how much difference a modern variable design would make?

Conceptually, thats where Boeing were going with the X32.

[aeropilot]

Tango13 said:

Dr Jekyll said:

How difficult would it be make a 'continuation' Harrier to use instead of the F35? Might it be cheaper than converting the carriers to have catapults?

From an engineering perspective it would be a very straight forward job, it's all proven technology.

If you gave BAe and Rolls Royce a large enough order Monday morning and told them to get a fking move on as the carrier is on sea trials you could have aircraft flying inside a couple of years at a very good price.

A couple of years......

Not without all the production tooling it wouldn't and that's all long gone, as the last full production new Harrier left the factory 20 years ago.

[Tango13]

aeropilot said:

Tango13 said:

Dr Jekyll said:

How difficult would it be make a 'continuation' Harrier to use instead of the F35? Might it be cheaper than converting the carriers to have catapults?

From an engineering perspective it would be a very straight forward job, it's all proven technology.

If you gave BAe and Rolls Royce a large enough order Monday morning and told them to get a fking move on as the carrier is on sea trials you could have aircraft flying inside a couple of years at a very good price.

A couple of years......

Not without all the production tooling it wouldn't and that's all long gone, as the last full production new Harrier left the factory 20 years ago.

It took Lockheed 2 years to get the Have Blue prototype from the drawing board to first flight and 2 1/2 years to do the same with the (under budget) F-117 and they were both new designs and radical for the time technology.

Even if the production tooling had been kept most of it has now been rendered obsolete by modern CNC machines. The days of copymills and multiple operations to machine a single part are history. Aircraft from the late 60's early 70's F-4, F-14, F15 etc were built by fitters, parts had to be reworked on the line to make them 'fit' a time consuming and expensive way to built an aircraft.

The F-22 for comparison 'clicked' together like LEGO by all accounts, everything fitted first time everytime, faster assembly, more accurate assembly, cheaper assembly.

10 years ago I was machining a part in one hit in 45 minutes on a 5-axis vertical milling machine a part that would've taken 13 or 14 separate operations and weeks using the same 1970's machinery used for Harriers and their ilk.

20 years ago the thought of machining Titanium would bring even the best of machinist out in a cold sweat, now we just let the CAD/CAM generate the tool path, press the button and walk away as the Titanium gets cut faster now than aluminium was 20 years ago.

As others have correctly posted, it's the interference at every level that adds time and cost to military procurement.

The reason F1 cars get designed and built so quick is not because the F1 engineers are much better, it's because they are managed better. Simply told what the goal is, given a deadline and left to get on with it.

[hidetheelephants]

Tango13 said:

aeropilot said:

Tango13 said:

Dr Jekyll said:

How difficult would it be make a 'continuation' Harrier to use instead of the F35? Might it be cheaper than converting the carriers to have catapults?

From an engineering perspective it would be a very straight forward job, it's all proven technology.

If you gave BAe and Rolls Royce a large enough order Monday morning and told them to get a fking move on as the carrier is on sea trials you could have aircraft flying inside a couple of years at a very good price.

A couple of years......

Not without all the production tooling it wouldn't and that's all long gone, as the last full production new Harrier left the factory 20 years ago.

It took Lockheed 2 years to get the Have Blue prototype from the drawing board to first flight and 2 1/2 years to do the same with the (under budget) F-117 and they were both new designs and radical for the time technology.

Even if the production tooling had been kept most of it has now been rendered obsolete by modern CNC machines. The days of copymills and multiple operations to machine a single part are history. Aircraft from the late 60's early 70's F-4, F-14, F15 etc were built by fitters, parts had to be reworked on the line to make them 'fit' a time consuming and expensive way to built an aircraft.

The F-22 for comparison 'clicked' together like LEGO by all accounts, everything fitted first time everytime, faster assembly, more accurate assembly, cheaper assembly.

10 years ago I was machining a part in one hit in 45 minutes on a 5-axis vertical milling machine a part that would've taken 13 or 14 separate operations and weeks using the same 1970's machinery used for Harriers and their ilk.

20 years ago the thought of machining Titanium would bring even the best of machinist out in a cold sweat, now we just let the CAD/CAM generate the tool path, press the button and walk away as the Titanium gets cut faster now than aluminium was 20 years ago.

As others have correctly posted, it's the interference at every level that adds time and cost to military procurement.

The reason F1 cars get designed and built so quick is not because the F1 engineers are much better, it's because they are managed better. Simply told what the goal is, given a deadline and left to get on with it.

It's not the airframe that's the issue, as you note manufacturing technology has moved on hugely, but the rest of the aircraft and the necessary baggage train that goes with it; all spares, documentation, training and other minutiae were binned, scrapped or sold to the USMC. All that needs to be recreated, RR persuaded to start building an engine that will not be required in large numbers and has not been built for a couple of decades, avionics fit decided, all those humdrum tier 1 suppliers lined up like ducks in a row etc. Knocking up an aircraft that can look pretty and put on a show at Farnborough is one thing, but if it's for RAF/RN service then everything needs to be planned around a 20+ year service life.

Dr Jekyll said:

FourWheelDrift said:

The vectored thrust Bristol Siddeley BS100 jet engine of 1960 designed to go into the supersonic VTOL Hawker Siddeley P.1154 could produce 35,900lbs of thrust which is more than the 25,000lbs of the F-35B (without the extra 18,000lbs of the additional cold air fan it needs for VTOL).

https://en.wikipedia.org/wiki/Bristol_Siddeley_BS1...

Why didn't Lockheed-Martin go along the same route design-wise, instead of the cold lift fan double engine (extra weight) method? Or do we have a patent on that design?

I don't think the BS100 ever worked properly. There was some issue regarding using afterburners at the hover because hot gas would get back into the engine, which is apparently A Bad Thing. No doubt Eric and Ginetta can give us the gen.

Not so much ingestion of hot gasses, although that is a perennial problem with VTOL which even F35 has not been immune to, as setting fire to whatever surface the aircraft is trying to take off from, and in the case of unpaved surfaces digging bloody holes. With hindsight 1154 would have been a good fit for our pocket carriers along with the ski-jump but no-one had dreamt that up at the time, so it died politically.

Edited by hidetheelephants on Saturday 14th January 18:30

[Ayahuasca]

Sobering to think that the designer of the Harrier was born in 1893.