F-35 Joint Strike Fighter (JSF)

[Colin Parkinson]

True, but take away the sensors what is the technical difference of a Super Hornet and a F35? From a lay persons view does the advances in construction and repair justify the non-sensor cost difference? Is there a significant savings on maintenance hours between the F35, F15SE and SuperHornet?

Personally I think Lockheed was smart to seal the deal with the sub component contracts being offered only to those that buy the aircraft. I suspect at the end of the day that will be the major deciding factor in the political review. Unless opponents make the deal just to toxic.

 

[Loachman]

Is there a significant savings on maintenance hours between the F35, F15SE and SuperHornet?

F35 has the advantage of not being saddled with a redundant engine, therefore having fewer things to go wrong.

 

[GR66]

F35 has the advantage of not being saddled with a redundant engine, therefore having fewer things to go wrong.

LOL.  Well played! 

 

[Colin Parkinson]

oops  ;D

Furthermore, he said that a defect in the Pratt & Whitney F135 engine that powers all three variants of the aircraft was likely to be fixed by year's end. The defect caused an engine fire in one aircraft that led to a fleet-wide grounding in June. Pratt & Whitney, a division of United Technologies, has promised to cover the cost of the repair.

 

[Loachman]

That'll get fixed.

Nobody needs a second engine.

 

[RyanHealy29]

There is no doubt that having a second engine doubles the chances of something going wrong, so you can say that a dual engine set up is less reliable than a single engine set up.

But if an engine failure happens in a single engine aircraft during flight, the chances of that entire aircraft being lost are much higher than if an engine failure happens in an aircraft with a second engine capable of keeping it in the air. So you can say that in the case of an inflight engine problem, a dual engine set up is more survivable than a single engine set up.

For an air force the size of Canada's where we'll already be significantly limited in the number of aircraft we can afford to purchase (with the plan being to purchase essentially the minimum number identified as necessary to meet our responsibilities) would it not be fair to say that survivability might trump reliability?

If we can't really afford to lose any aircraft, doesn't it make more sense to go with the one that is less likely to be lost when (not if) something goes wrong with an engine?

(Not trying to stir up debate about the reliability of modern engines vs older engines, just asking about the tradeoff between total system reliability and total system survivability and how that comes into play in a situation where we're buying so few aircraft that we can't really afford to lose any.)

 

[MarkOttawa]

1) Reuters:

Lockheed, Pentagon say near deal on next batch of F-35s
...
[Orlando] Carvalho [executive vice president of Lockheed's aeronautics division] said the ninth and 10th batches of the F-35 were expected to include 154 aircraft, which would help provide stability to the company’s suppliers…
http://in.reuters.com/article/2014/09/09/us-aero-summit-lockheed-idINKBN0H41XQ20140909

2) DoD BUZZ
...

Bogdan: F-35 Engine Fix May be Ready by Year’s End
The Pentagon is currently negotiating with Lockheed to buy 43 planes as part of the eighth lot, or installment, Bogdan said. That figure is slated to increase to 57 aircraft in Lot 9, 74 aircraft in Lot 10 and 119 aircraft in Lot 11, he said...
http://www.dodbuzz.com/2014/09/15/bogdan-f-35-engine-may-be-fixed-by-years-end/?comp=1199444235793&rank=1

That's 131 for LRIPs 9/10 vice LockMart's 154.  Any explanations for difference?

Mark
Ottawa

 

[Loachman]

But if an engine failure happens in a single engine aircraft during flight, the chances of that entire aircraft being lost are much higher than if an engine failure happens in an aircraft with a second engine capable of keeping it in the air. So you can say that in the case of an inflight engine problem, a dual engine set up is more survivable than a single engine set up.

That is not the only factor.

Modern engines are far more reliable than older ones. The single engine on F35 is statistically far more reliable than the two on our F18s. So which, really, is "more survivable"? If the odds of an engine failure on any given flight are, say, 0.00000000001%, is an improvement to 0.000000000005% worth the extra space, weight, and expense?

The same arguments were raised when airliners went from four to three to two engines.

We have previously operated many single-engined aircraft (jet and piston) over the same vast expanses of wilderness that now, apparently, requires a minimum of two engines.

The US Navy flies over vast expanses of water, and does not seem to think that a second engine is necessary any more.

As I posted elsewhere on this site: "I've got over 4000 hours on single-engined helicopters by day and night, fair weather or foul, over large expanses of wilderness, water, alligator-infested swamp, major cities, and Liberal-held ridings, and not once, ever, did I see that as a problem."

I've never had as much as a hiccup from an engine. I never, ever got stuck anywhere (even when I wanted to be stuck) due to an engine problem (or any other), until I was flying a twin-engined helicopter. I'm sure that there were worse gravel pits to leave one's machine overnight, and there were perhaps worse hotels (but I cannot actually recall ever being in one).

We have lost at least one "safer" F18 due to a single-engine failure.

The USN had both engines on an F18 fail with a resultant crash into a residential neighbourhood in California several years ago.

If one flies through enough geese, even four will not necessarily keep one alive - the USAF lost an AWACS due to multiple goose-strikes a few years ago.

And engines are not the only things that can go catastrophically wrong.

 

[RyanHealy29]

That is not the only factor.

Modern engines are far more reliable than older ones. The single engine on F35 is statistically far more reliable than the two on our F18s. So which, really, is "more survivable"? If the odds of an engine failure on any given flight are, say, 0.00000000001%, is an improvement to 0.000000000005% worth the extra space, weight, and expense?

The same arguments were raised when airliners went from four to three to two engines.

We have previously operated many single-engined aircraft (jet and piston) over the same vast expanses of wilderness that now, apparently, requires a minimum of two engines.

The US Navy flies over vast expanses of water, and does not seem to think that a second engine is necessary any more.

As I posted elsewhere on this site: "I've got over 4000 hours on single-engined helicopters by day and night, fair weather or foul, over large expanses of wilderness, water, alligator-infested swamp, major cities, and Liberal-held ridings, and not once, ever, did I see that as a problem."

I've never had as much as a hiccup from an engine. I never, ever got stuck anywhere (even when I wanted to be stuck) due to an engine problem (or any other), until I was flying a twin-engined helicopter. I'm sure that there were worse gravel pits to leave one's machine overnight, and there were perhaps worse hotels (but I cannot actually recall ever being in one).

We have lost at least one "safer" F18 due to a single-engine failure.

The USN had both engines on an F18 fail with a resultant crash into a residential neighbourhood in California several years ago.

If one flies through enough geese, even four will not necessarily keep one alive - the USAF lost an AWACS due to multiple goose-strikes a few years ago.

And engines are not the only things that can go catastrophically wrong.

All true of course. But the question of single engine vs double engine doesn't need to take into account all of the other catastrophic things that can go wrong since both single and double are equally susceptible to those.

It also isn't really fair to compare the JSF engine to the engine on the legacy Hornet. The comparison would have to be between the F-35 with one modern engine and say, a newly built Super Hornet with two modern engines (i.e. F414 or upgraded F414, not F404)

No one is going to argue that both engines can't fail or that a single engine loss in a dual engine aircraft can't cause a total loss, but the fact remains that, at least by all logic, a plane with two highly reliable modern engines is less likely to be lost completely from an engine failure than a plane with a single highly reliable modern engine. And despite what Peter McKay may think, engine failures WILL happen for one reason or another.

But I guess you nailed the real question, which is is the added survivability worth things you might have to give up in order to gain it. I could see an Air Force like the U.S.A.F. not being quite so concerned due to budgets, but for Canada, where even a loss of a single F-35 would be a very significant event from a financial perspective, I just wonder if the added survivability of a second modern engine would carry more weight even if the gain from one engine to two wasn't a huge one.

 

[MarkOttawa]

Further to this post on LRIPS 9/10,
http://milnet.ca/forums/threads/22809/post-1328089.html#msg1328089

there's a breakdown of LRIPs through 8 at end here:
http://www.lockheedmartin.com/content/dam/lockheed/data/australia/documents/F-35FastFactsNovember2013.pdf

Mark
Ottawa

 

[Loachman]

I could see an Air Force like the U.S.A.F. not being quite so concerned due to budgets, but for Canada, where even a loss of a single F-35 would be a very significant event from a financial perspective

They're buying, what, 20ish times as many as we are, so they'd expect to have twentyish times the losses, statistically, right?

Do you really think that they'd not be concerned about that effect on their budget?

The engine non-issue is just that: a non-issue. It's being driven by competitors and media with agendae.

It's more of a way to blame the Harper government for something than any concern about Pilot's lives.

 

[RyanHealy29]

They're buying, what, 20ish times as many as we are, so they'd expect to have twentyish times the losses, statistically, right?

Do you really think that they'd not be concerned about that effect on their budget?

The engine non-issue is just that: a non-issue. It's being driven by competitors and media with agendae.

It's more of a way to blame the Harper government for something than any concern about Pilot's lives.

But are they buying what has been identified as the bare minimum number of aircraft necessary to meet their domestic and international obligations? Not to mention that they have other highly capable fighters sharing the load (F-22, F-15E to be in service past 2025).

If Canada is buying the bare minimum, as all reports seem to point to, then we won't have the luxury of being able to shrug off even a single loss. So what happens when those inevitable losses occur? We lost, what, 43% or so of the CF-18 fleet over the course of 30 years? And aside from buying some replacement chunks for repairs, as far as I know, there was never a subsequent order of new legacy Hornets put in to replace losses. With the minimum number of F-35s, what happens when losses occur? Do we simply let the numbers drop below minimums? Redefine what 'minimum' is? Or will we have to replace?

I just don't think a parallel can be drawn with the US and Canada. The scale of their buy is so much larger and the willingness of their government to spend as necessary on defense is so much greater than ours is in Canada.

You hear a lot of people saying "it's a non-issue", "it doesn't matter", "it won't be a problem", engine failures "won't happen", but what no one has yet explained is what is going to happen when they DO happen?

If 65 is the minimum we need, and 65 is all we can afford, then what will happen when we lose an F-35?
And alternately, if 65 is the minimum number we need, but the Super Hornet will either allow us to buy more, or potentially add survivability to the minimum number we acquire, how can that be written off as a non-issue?

Is it better to have an older design and slightly less capable aircraft and have enough to do the job and deal with losses and problems, or is it better to have a newer, more capable aircraft but potentially not have enough to do the job with if losses or unanticipated problems arise?

 

[Loachman]

So the number of engines is the overriding factor in the selection process?

Other aircraft may be more vulnerable to detection and attack, not be as responsive due to less-capable information sharing, more expensive to operate and maintain because fewer and fewer people are using them and production facilities were shut down a couple of weeks after ours were towed out of the factory.

We lose aircraft due to a variety of causes. Most of those are human factors - fatigue, complacency, disorientation, distraction, inexperience, poor judgment, illusion, and a bunch of others.

There are also design shortcomings and manufacturing defects that may not appear for years or decades, because design, testing, and quality control, no matter how good, will not pick up everything.

Fatigue problems will show up. Lines will chafe.

Focussing on the number of engines over everything else that could go wrong, when the odds of an engine failure are so statistically low, is silly.

While I have no direct interest in this selection, I do have a strong desire to see an honest and impartial evaluation and selection done, without media or political interference, and the best choice made based upon valid factors. We do not need a repeat of the Sea King/Cyclone fiasco.

 

[RyanHealy29]

So the number of engines is the overriding factor in the selection process?

Other aircraft may be more vulnerable to detection and attack, not be as responsive due to less-capable information sharing, more expensive to operate and maintain because fewer and fewer people are using them and production facilities were shut down a couple of weeks after ours were towed out of the factory.

We lose aircraft due to a variety of causes. Most of those are human factors - fatigue, complacency, disorientation, distraction, inexperience, poor judgment, illusion, and a bunch of others.

There are also design shortcomings and manufacturing defects that may not appear for years or decades, because design, testing, and quality control, no matter how good, will not pick up everything.

Fatigue problems will show up. Lines will chafe.

Focussing on the number of engines over everything else that could go wrong, when the odds of an engine failure are so statistically low, is silly.

While I have no direct interest in this selection, I do have a strong desire to see an honest and impartial evaluation and selection done, without media or political interference, and the best choice made based upon valid factors. We do not need a repeat of the Sea King/Cyclone fiasco.

No one has said that the number of engines is the overriding factor in the process. That is a strawman. All that I've said is that I don't see how it can be treated as a non-issue, as you've suggested, which seems as silly to me as making it the overriding priority.

All of the things you mentioned come into play as well as many others. Some favour the F-35, some don't. Survivability is just one of those factors. However, in my opinion, it should be considered a factor, not the complete non-issue that some make it out to be. Especially to an absolute minimally small fleet where even one less could drop us below operational needs.

 

[a_majoor]

Single engine vs dual engine is a straw man argument.

Many air Forces the world over use versions of the F-16, which is another single engined aircraft, with few complaints. The F-16 serves from arctic to tropical to desert conditions (depending on which air force flies it) and has been used in long range missions (such as the Israeli strikes against the Iraqi nuclear reactor back in 1981) or more much recently by one of the Gulf States to strike Islamic militants in Libya.

And the F-16 uses a much older engine than the F-35 as well.

 

[McG]

If the odds of an engine failure on any given flight are, say, 0.00000000001%, is an improvement to 0.000000000005% worth the extra space, weight, and expense?

Are those realistic numbers for modern engines?

 

[Good2Golf]

Are those realistic numbers for modern engines?

Far too small.

The CF-18's F404-GE-400, for example, has a 0.0154% 'event' rate (the % analogue to a 6,500 hour MTBF).

The JSF Joint Project Office doesn't publish such figures for the F135-PW-100/400/600, but some math of published flight test hours and reported engine failures (some info at link) would indicate an 'event' rate much higher than one event per 6,500 engine hours.  Re-designs of various elements of the F135 variants appears to be increasing reliability.

Regards
G2G

 

[Loachman]

My numbers were rectally extracted as a means of illustrating the almost negligible difference between the statistical chances of losing a single-engined aircraft due to an engine failure compared to a twin-engined one, presuming that all other factors were equal.

I don't think that there is any real difference in the real world, especially given the loss rate from other causes.

The number of engines on aircraft is generally due to the lack of power in any one engine. This was true of early jets - Messerschmitt 262 and Gloster Meteor. Other successful designs reverted to one, such as Sabre, MiG-15, and later designs.

Adding engines increases size, weight, cost, and fuel requirements. There has to be sufficient gain elsewhere to make that worthwhile.

Simplicity has benefits.

 

[WingsofFury]

The number of engines on aircraft is generally due to the lack of power in any one engine.

This; part of the reason the Hornet (both Super and Legacy) has two engines is due to the fact that a single engine doesn't spool quickly enough in the event the aircraft has to bolter after a missed carrier arrest.

 

[Loachman]

A7 Corsair https://en.wikipedia.org/wiki/A-7_Corsair_II and F8 Crusader https://en.wikipedia.org/wiki/F-8_Crusader (both favourites of mine) seemed to manage alright, although the A7 was underpowered in its early versions. The A7's Skyhawk https://en.wikipedia.org/wiki/Douglas_A-4_Skyhawk predecessor was highly regarded as well.