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glojo,
Can you read? If you can how many times do you need telling something? You even have a picture of the damned thing posted for you.
The F-35B does NOT have a second gas turbine engine. it is a single engined aircraft.
That's just the one engine, right?
Can you read? If you can how many times do you need telling something? You even have a picture of the damned thing posted for you.
The F-35B does NOT have a second gas turbine engine. it is a single engined aircraft.
That's just the one engine, right?
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Glojo,
To help out here - the IPP is about what the acronym means - an Integrated Power Pack. It's a fairly substantial rotating shaft machine located aft in the fuselage. It's designed to combine the functions carried out on previous aircraft by a number of items of machinery, such as power generation, starting, cooling and hydraulic power. It can run on aircraft fuel, in a turbine mode, but usually runs on bleed air from the engine. It's no more a second engine that a gas turbine starter unit is.
The heat issue from the exhaust is something I was closely involved with while on the project. The exhaust from the IPP is actually less hot and fast than that from the current APU on the F-18, and the assessment at the time was that while it posed a potential issue, it was manageable, using the same sort of techniques the USN and USMC had done for some time. If that's changed since I was on the team, I'm not aware of it.
Best Regards as ever,
Engines.
To help out here - the IPP is about what the acronym means - an Integrated Power Pack. It's a fairly substantial rotating shaft machine located aft in the fuselage. It's designed to combine the functions carried out on previous aircraft by a number of items of machinery, such as power generation, starting, cooling and hydraulic power. It can run on aircraft fuel, in a turbine mode, but usually runs on bleed air from the engine. It's no more a second engine that a gas turbine starter unit is.
The heat issue from the exhaust is something I was closely involved with while on the project. The exhaust from the IPP is actually less hot and fast than that from the current APU on the F-18, and the assessment at the time was that while it posed a potential issue, it was manageable, using the same sort of techniques the USN and USMC had done for some time. If that's changed since I was on the team, I'm not aware of it.
Best Regards as ever,
Engines.
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One v Two
With respect to the posts above as to whether one or two carriers are to be converted, the self same clarification was requested in the Commons and Fox gave a different answer to what Astor gave in the Lords:
EG
Mr Ian Davidson (Glasgow South West) (Lab/Co-op): Will the Secretary of State confirm the exact details of the announcement he made in his statement when he said, “I can therefore now give the go-ahead for the procurement of” a list of things, including “the cat and traps for the Queen Elizabeth class carriers”. Does that mean that both carriers will receive cat and traps?
Dr Fox: That is our plan, and I have agreed to my officials now getting involved in contract negotiations. They were not previously able to do so because we were not guaranteed that we would have the budget. When we make decisions of this nature we must ensure that we have the wherewithal to pay for them. Otherwise, as I have said, they are simply a wish list.
I guess we'll just have to wait and see!Dr Fox: That is our plan, and I have agreed to my officials now getting involved in contract negotiations. They were not previously able to do so because we were not guaranteed that we would have the budget. When we make decisions of this nature we must ensure that we have the wherewithal to pay for them. Otherwise, as I have said, they are simply a wish list.
EG
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Hi Engines,
THANK YOU very much indeed for taking the time to clarify the IPP issue and the last thing I want to do is appear argumentative.. ESPECIALLY when I am having the rare opportunity of listening to folks like your good self who are experts on this topic.
I have attached just one of many, many example of what has confused me when they all refer to this item as being a small gas turbine. All the similar locations refer to this IPP as being a small gas turbine, hence my posts.
Is this the IPP we are discussing?
I apologise if I have ruffled a few feathers as this was NOT my intent. I have highlighted the guilty comments that lead me to believe there was the smaller engine and hopefully folks might accept the reasons why I was, and perhaps still am confused. My bad, my fault.
I FULLY and totally ACCEPT your final comments regarding numbers and that is an end to it
I have read a number of posts that have explained how the exhaust issue was dealt with and as you say it is now not an issue
Apologies again to all those that have said there is only the one gas turbine and I guess we all move on
THANK YOU very much indeed for taking the time to clarify the IPP issue and the last thing I want to do is appear argumentative.. ESPECIALLY when I am having the rare opportunity of listening to folks like your good self who are experts on this topic.
I have attached just one of many, many example of what has confused me when they all refer to this item as being a small gas turbine. All the similar locations refer to this IPP as being a small gas turbine, hence my posts.
First flight was originally planned for late August, but was delayed when the F-35’s Honeywell-developed integrated power pack (IPP) failed qualification testing. The IPP combines the auxiliary and emergency power units and environmental control system to save weight, and is required to start the engine and power the aircraft.
The IPP is a small gas turbine that provides power to the engine-mounted starter/generator to “motor” the F135 to its starting speed. The engine then accelerates to idle speed, and the system transitions from operating as a motor to operating as a generator, driving aircraft systems including power-by-wire flight controls.
“The IPP started first time, and every time, and generated the power needed to start the main engine, which was critical,” says Doug Pearson, vice-president of the F-35 integrated test force. “The main engine was similar – the first time it was commanded, it started.” The IPP was started 20 times, motoring or starting the engine 12 times
The IPP is a small gas turbine that provides power to the engine-mounted starter/generator to “motor” the F135 to its starting speed. The engine then accelerates to idle speed, and the system transitions from operating as a motor to operating as a generator, driving aircraft systems including power-by-wire flight controls.
“The IPP started first time, and every time, and generated the power needed to start the main engine, which was critical,” says Doug Pearson, vice-president of the F-35 integrated test force. “The main engine was similar – the first time it was commanded, it started.” The IPP was started 20 times, motoring or starting the engine 12 times
I apologise if I have ruffled a few feathers as this was NOT my intent. I have highlighted the guilty comments that lead me to believe there was the smaller engine and hopefully folks might accept the reasons why I was, and perhaps still am confused. My bad, my fault.
I FULLY and totally ACCEPT your final comments regarding numbers and that is an end to it
I have read a number of posts that have explained how the exhaust issue was dealt with and as you say it is now not an issue
Apologies again to all those that have said there is only the one gas turbine and I guess we all move on
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glojo,
I can't say that your pictures look very much like the IPP as I remember it, but I could be wrong.
The heat from the IPP exhaust was all terribly exciting a year or so ago, and legions of aviation press reporters and rumour website posters were citing it as the end of the world and a reason to cancel the Program. Turns out that in this (as in most cases) they were utterly wrong. The IPP can operate in 3 modes - bleed mode when it's being spun by bleed air taken off the main engine, burn mode when it's operating similar to a good old-fashioned APU, or bleed-and-burn which is obviously a combination of the first 2. Clearly the exhaust in bleed mode isn't hot enough to worry anyone, it's the other 2 modes that caused concern. These concerns were only relevant to a -B model because the exhaust vents downwards in a -B (shorter exhaust pipework = saved weight) and straight up for an -A or a -C.
In current flight test, IPP management is a total non-issue. When we first started flying the jet we were slightly concerned about stopping on asphalt in bleed-and-burn mode for any length of time - because the testing hadn't been done to assure us that everything was going to be ok. So there's a switch in the cockpit that the pilot can use to force the IPP into bleed mode whenever he has to hold on asphalt. LM are working on a number of minor tweaks to the design (including possibly making the exhaust come out at a more acute angle to the ground) and at an opportune point in the test program the team will take the time to figure out if the effects on asphalt are in line with the worst case predictions, or if they've been over-egged (which the safety folks have a habit of doing).
Any possible issues with ship integration will be thoroughly flushed out on the first deployment to USS Wasp later this year. Anyone who's telling you otherwise is living in the world of the ppt warrior.
Regards,
Single Seat, Single Engine, The Only Way To Fly
I can't say that your pictures look very much like the IPP as I remember it, but I could be wrong.
The heat from the IPP exhaust was all terribly exciting a year or so ago, and legions of aviation press reporters and rumour website posters were citing it as the end of the world and a reason to cancel the Program. Turns out that in this (as in most cases) they were utterly wrong. The IPP can operate in 3 modes - bleed mode when it's being spun by bleed air taken off the main engine, burn mode when it's operating similar to a good old-fashioned APU, or bleed-and-burn which is obviously a combination of the first 2. Clearly the exhaust in bleed mode isn't hot enough to worry anyone, it's the other 2 modes that caused concern. These concerns were only relevant to a -B model because the exhaust vents downwards in a -B (shorter exhaust pipework = saved weight) and straight up for an -A or a -C.
In current flight test, IPP management is a total non-issue. When we first started flying the jet we were slightly concerned about stopping on asphalt in bleed-and-burn mode for any length of time - because the testing hadn't been done to assure us that everything was going to be ok. So there's a switch in the cockpit that the pilot can use to force the IPP into bleed mode whenever he has to hold on asphalt. LM are working on a number of minor tweaks to the design (including possibly making the exhaust come out at a more acute angle to the ground) and at an opportune point in the test program the team will take the time to figure out if the effects on asphalt are in line with the worst case predictions, or if they've been over-egged (which the safety folks have a habit of doing).
Any possible issues with ship integration will be thoroughly flushed out on the first deployment to USS Wasp later this year. Anyone who's telling you otherwise is living in the world of the ppt warrior.
Regards,
Single Seat, Single Engine, The Only Way To Fly
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Thank you VERY MUCH indeed for the update and I fully understand your excellent points and the first hand experience that you have..
Regarding the non heat issue, I did follow it with interest and as you say this topic is now WELL past its sell by date and should now be buried on the 'grassy knoll'
Are you optimistic about this aircraft ever becoming fully operational? (STOVL version) I am only asking as it clearly effects decisions regarding our aircraft carriers.
My personal thoughts are that we should go with the conventional version but that is me..
Thanks again for your understanding which is much appreciated.
Regarding the non heat issue, I did follow it with interest and as you say this topic is now WELL past its sell by date and should now be buried on the 'grassy knoll'
Are you optimistic about this aircraft ever becoming fully operational? (STOVL version) I am only asking as it clearly effects decisions regarding our aircraft carriers.
My personal thoughts are that we should go with the conventional version but that is me..
Thanks again for your understanding which is much appreciated.
SSSETOWF - Point of order, the exhaust vents down on the A. It was up on AA-1.
I don't recall anyone saying that IPP issues were a show-stopper. However, I somehow doubt that such a piece of kit will become standard issue on subsequent aircraft, or that the long-ago promises of weight and Mx-cost savings will be accrued.
I don't recall anyone saying that IPP issues were a show-stopper. However, I somehow doubt that such a piece of kit will become standard issue on subsequent aircraft, or that the long-ago promises of weight and Mx-cost savings will be accrued.
Are you optimistic about this aircraft ever becoming fully operational? (STOVL version) I am only asking as it clearly effects decisions regarding our aircraft carriers.
). Certainly the article here suggests so!
There's not a lot of good news for the F-35 Joint Strike Fighter in the UK review. A requirement for 138 F-35Bs has been wiped out and replaced by a smaller - possibly much smaller - number of F-35Cs.
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SSSETOWTF,
Nice post - clearer and more comprehensive than mine. The picture looks like a fairly old version of the IPP installation.
I was closely involved with the early studies into the installation that resulted in the redirection of the exhaust from up to down on the B. I believe the A went that way as well. However, a lot of people on both sides of the pond got really excited over the issue and the C stayed with an upward exhaust. For the B it was a good move - saved a lot of weight and resolved quite a few issues with the routing of that vertical exhaust.
Best Regards As Ever
Engines
Nice post - clearer and more comprehensive than mine. The picture looks like a fairly old version of the IPP installation.
I was closely involved with the early studies into the installation that resulted in the redirection of the exhaust from up to down on the B. I believe the A went that way as well. However, a lot of people on both sides of the pond got really excited over the issue and the C stayed with an upward exhaust. For the B it was a good move - saved a lot of weight and resolved quite a few issues with the routing of that vertical exhaust.
Best Regards As Ever
Engines
