F-35 Cancelled, then what ?
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Am I right in thinking that there has yet to be a definitive statement on what the cause of the engine fire was and hence it would seem that any required redesign of the engine has yet to start, implicitly delaying the USMC's desired IOC of May 2015?
Also is there any update on the software status, last I heard the US Army was looking at it, we in the UK need to have Software version 3F for our front-line planes not a pre technical refresh Version 2 or 3i of the software.
I am assuming that the planned carrier trials for the F35C have been delayed because of the engine problems, can anyone confirm?
Also is there any update on the software status, last I heard the US Army was looking at it, we in the UK need to have Software version 3F for our front-line planes not a pre technical refresh Version 2 or 3i of the software.
I am assuming that the planned carrier trials for the F35C have been delayed because of the engine problems, can anyone confirm?
up standard Mil-Spec runway concrete as well. On the bright side, the RAF won't need a replacement for JP233.
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Originally Posted by Maus
VLs need specially prepared landing surfaces to resist heat and velocity related damage, spalling etc. It's unlikely that Miramar has installed these yet - at least in airshow areas.
So, 35B needs dedicated surfaces after all?
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Only if you are going to perform repeated vertical landings on the same spot.
If you are doing short-rolling landings, or only an occasional VL on different spots, then normal Mil-Spec runway concrete is sufficient.
Heck, with a short-rolling landing/take-off even asphalt works, as long as you don't keep using the same patch over & over.
The special pads are for repeated regular vertical landings.
If you are doing short-rolling landings, or only an occasional VL on different spots, then normal Mil-Spec runway concrete is sufficient.
Heck, with a short-rolling landing/take-off even asphalt works, as long as you don't keep using the same patch over & over.
The special pads are for repeated regular vertical landings.
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As the B will be spending most of it's life doing completely conventional take off's and landings I don't think anywhere in the UK would need any special surfaces. The carriers are obviously getting thermal coatings but will be mostly SRVL which will spread the load out.
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Why will they be mostly SRVL?
The SRVL gives you no bolter option, a portion of the approach with no overshoot option, a second landing that's a VL in any case, a divergent reaction to failure or poor technique (as opposed to a wire which centres you up) and a total reliance on the brakes.
The SRVL gives you no bolter option, a portion of the approach with no overshoot option, a second landing that's a VL in any case, a divergent reaction to failure or poor technique (as opposed to a wire which centres you up) and a total reliance on the brakes.
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GreenKnight121, thx.
AFAIR, there have been various statements regarding this issue, so this settles them now.
On another note; did Harrier need special surface for continuous VTOL ops.?
AFAIR, there have been various statements regarding this issue, so this settles them now.
On another note; did Harrier need special surface for continuous VTOL ops.?
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F-35B only needs SRVL when heavily loaded in extreme climatic conditions that severely degrade hover performance (the USMC aren't worried about it.) It's a UK specific requirement put in based on conditions our Harriers and carriers experienced in certain middle eastern areas. The F-35B has plenty of hover performance in most conditions so I would suggest that most landings will be VL.
I'm sure SRVL will be practiced and simmed as required, it has a lot of benefits when a VL with both weapons bays full may be marginal.
I'm sure SRVL will be practiced and simmed as required, it has a lot of benefits when a VL with both weapons bays full may be marginal.
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USMC F-35Bs are only going to VL 10% of the time, or so they say ATM. This is mostly to save money on wear and tear on the aircraft's doors and swiveling parts, and to a lesser extent on fuel. They can also "save" money on fuel by cutting its predicted future cost assumptions by 10%....
Note: I had posted based on memory, and I had the savings parameters reversed...
Note: I had posted based on memory, and I had the savings parameters reversed...
Last edited by Maus92; 10th Oct 2014 at 17:13. Reason: Fixed based on LO's comments
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When they're ashore I'm sure that's accurate.
Harriers don't (didn't, if in UK) land vertically all the time either. No doubt the USMC looked at their stats from Cherry Point and Yuma to come up with that figure. A short take-off and landing still uses the lift fan though, it's not just for VL.
Harriers don't (didn't, if in UK) land vertically all the time either. No doubt the USMC looked at their stats from Cherry Point and Yuma to come up with that figure. A short take-off and landing still uses the lift fan though, it's not just for VL.
I'm not sure I understand the argument that not doing a VL saves fuel. The fuel flow during a VL is a lot lower than typical tactical cruise speeds and the time spent in this mode is pretty small.
To be correct, I think the Marine 10 per cent STOVL thing has more to do with O&S costs than fuel burn. The lift system is expensive (the B costs $13 million more than the A, URF in 2012 dollars, average across production) and cycles twice per STOVL operation, and some parts (the clutch for instance) have life limits shorter than the engine overhaul cycle.
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Am I right in thinking that there has yet to be a definitive statement on what the cause of the engine fire was....
I'm sure someone will post if they have seen or know anything different.
LF
Pratt & Whitney Says F-35 Will Be Combat Ready In July - Hartford Courant
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Reuters published an interview yesterday with NAVAIR's RADM Harrah, excerpted below:
"“We’re going as fast as we can possibly go to ensure that we
get that done quickly, but not so fast that we mess up some
critical aspect of this,” Darrah said in an interview on
Wednesday.
“It’s just a matter of ensuring that we do the right thing,”
he said. “This is an engine that needs to perform properly
throughout its entire life cycle.”
Darrah said he had never seen the underlying technical issue
- which involved excessive rubbing of two parts in the F135
engine that led to chemical changes in their composition – but
remained confident that it could ultimately be resolved.""
Note the part about the technical issue [chemical changes in the blade due to excess heating] never being experienced before.
"Darrah, who previously held leadership roles on the F-35
program and the Boeing F/A-18 program, said any new aircraft
engine faced technical challenges, but this incident was
different given the scale of the program – which will be used by
three U.S. military services – and the huge size of the motor,
the most powerful U.S. fighter engine ever built.
He said the companies and military officials involved had
worked closely together to tackle the engine issue. “This is an
all-hands-on-deck effort.”"
"Joe DellaVedova, spokesman for the F-35 program office, had
no immediate comment on when the analysis of the root cause of
the incident, and the proposed solution, would be completed, but
said officials were getting closer.
“We’re nearing the end of that process,” DellaVedova said."
U.S. Navy underscores need for 'lasting fix' for F-35 engine issue | Reuters
Darrah's tone makes the problem with the F135 appear more serious than originally reported - and downplayed - by Pentagon acquisition, program, and contractor leadership - certainly not an "one-off" incident. Officials were predicting a root cause to be determined by the end of September... and that timeframe was later than initially predicted after the accident.
The investigation is beginning to be uncomfortably long in duration....
"“We’re going as fast as we can possibly go to ensure that we
get that done quickly, but not so fast that we mess up some
critical aspect of this,” Darrah said in an interview on
Wednesday.
“It’s just a matter of ensuring that we do the right thing,”
he said. “This is an engine that needs to perform properly
throughout its entire life cycle.”
Darrah said he had never seen the underlying technical issue
- which involved excessive rubbing of two parts in the F135
engine that led to chemical changes in their composition – but
remained confident that it could ultimately be resolved.""
Note the part about the technical issue [chemical changes in the blade due to excess heating] never being experienced before.
"Darrah, who previously held leadership roles on the F-35
program and the Boeing F/A-18 program, said any new aircraft
engine faced technical challenges, but this incident was
different given the scale of the program – which will be used by
three U.S. military services – and the huge size of the motor,
the most powerful U.S. fighter engine ever built.
He said the companies and military officials involved had
worked closely together to tackle the engine issue. “This is an
all-hands-on-deck effort.”"
"Joe DellaVedova, spokesman for the F-35 program office, had
no immediate comment on when the analysis of the root cause of
the incident, and the proposed solution, would be completed, but
said officials were getting closer.
“We’re nearing the end of that process,” DellaVedova said."
U.S. Navy underscores need for 'lasting fix' for F-35 engine issue | Reuters
Darrah's tone makes the problem with the F135 appear more serious than originally reported - and downplayed - by Pentagon acquisition, program, and contractor leadership - certainly not an "one-off" incident. Officials were predicting a root cause to be determined by the end of September... and that timeframe was later than initially predicted after the accident.
The investigation is beginning to be uncomfortably long in duration....
Last edited by Maus92; 10th Oct 2014 at 17:46.
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Originally Posted by Lowe Flieger
...the root cause has not been isolated yet, but P&W expect to announce a fix by the end of October.
Engine doctors forgot Hippocratic Oath?