This is a discussion on Canada's next Jet Fighter? within the Air Force & Aviation forum, part of the Global Defense & Military category; Originally Posted by south
I know RAAF Pilots are/have been on exchange but the intention is not that they are ...
I know RAAF Pilots are/have been on exchange but the intention is not that they are going to be deploying on carriers. Their exposure is extremely limited to USN at sea ops.
not even remotely suggesting that - its the issue that RAAF is closely tied in with the USN - and I'd argue that we have a closer relationship with USN than USAF.
USN has greater impact on our future doctrine, so we stay close for a number of reasons. the exchange program is not for pilot jollies, its for them to understand and come back with input on interoperability issues.
________________ A corollary of Finagle's Law, similar to Occam's Razor, says:
"Never attribute to malice that which can be adequately explained by stupidity"
5 cents worth here on modern jet engine reliability. I don't recall where I saw the point made - probably on another aviation related forum I frequent. This same argument is often made on why airlines are trusting big twins (777, A330's etc) on long haul overwater flights (ETOPS certification) whereas you'd think that 747's A380's and A340's would be the safer option as they have 4 engines, not just 2.
One of the pilots pointed out that you could have had 12 engines on that BA flight that went through the ash cloud and flamed out all of the 747's engines - it would not have made a difference - all 12 would have flamed out. That was a perfect demonstration that the 4 engines are safer than 2 argument was fallacious.
Apparently modern jets are so reliable that despite the incredible number of hours an airline pilot is likely to do over a 30 or 40 year career, he or she will have only a 50% chance of ever experiencing an engine failure necessitating an in flight shut-down (as opposed to a precautionary shutdown). Powerplants have come a long way from when the Lockheed Constellation used to be jokingly referred to as "the finest 3 engined airplane in the world".
OT: Additionally (and this is in a comercial airliner context - something to make those who are nervous a little more comfortable) an airliner must be able to continue its takeoff run if it loses one donk after V1 (that's the speed when it is safer to take off than to try to abort the takeoff in the runway space remaining). So, in a 747, that means that when the jumbo loses 25% of its thrust it must be able to still perform the fully loaded takeoff (MTOW) with its remaining 3 engines. This is one of the reasons the A340-300's takeoff roll is usually so long that the joke goes the only reason they take off is due to the curvature of the earth - the runway 'falls away'. In a 777, the one remaining engine still must be able to do this - hence many of the big twins are very much overpowered - to allow for the engine out scenario. More thrust is always a better bet than less when you are taking off - particularly if the conditions are hot and high at high gross weights - ergo it has been pointed out that it is probably a safer bet taking off on a long overwater flight in a twin, than a 4 engined airliner. /OT
The whole one engine / two engine fighter discussion is a complete waste of time.
The Canadian Air Force (and every other service) intending on operating F-35's has studied the issue of the aircraft's reliability and are clearly satisified with it.
NONE are concerned about the aircraft only having 1 engine or they wouldn't be looking to acquire it. Just like anyone who looks at buying F-16's, Gripens, Kaveri's, JF-17's, Mirage 2000's or whatever.
Why is it that suddenly their competence is no longer valid? If the professionals recommend a twin jet they're competent but if they recommend a single they've somehow lost their competence?
That sounds more like YOUR issues, than their's...
Edit: ("Your" in general terms, not directed at any specific individual).
One of the pilots pointed out that you could have had 12 engines on that BA flight that went through the ash cloud and flamed out all of the 747's engines - it would not have made a difference - all 12 would have flamed out. That was a perfect demonstration that the 4 engines are safer than 2 argument was fallacious.
No, that is a perfectly isolated argument to say that if you fly into an ash cloud the engines are going to stop....
MARC - comparing a military fast jet engine to a commercial transport engine is like comparing a V8 Supercar engine to a Kenworth Road train. Yeah they both use the same means to get the job done but they are pretty dissimilar.. The fast jet engine gets put under a lot more cycles for one in something like BFM where it getting a lot more throttle abuse / slam accelerations deccelerations, where your modern commercial engine is never even really set to full thrust even for takeoff, maintains the same power setting throughout the climb, sits at cruise power for 8 hours and then sits at idle for the descent.
I do agree with what AD has said, and yes the technology has off course moved on, but the point stands.. In a single engine jet, when that engine craps the bed for whatever reason (and yes, jet engines are more reliable but it does still happen ), unless you happen to be within gliding range of an airfield (good luck) you are stepping out and hopefully get to wear a nice martin baker tie.. If you have a twin engine jet, you still have an option.
Dislike what I'm saying all you like but if you look at the links that I provided earlier for the Class A mishaps from the USAF the F-16 is having engine related class A's at about three to four times the rate of F-15's. Will we suffer increased attrition because of this... Probably. Is it going to be like the Mirage III where we lost 40 or so out of just over 100. No, of course not.
To myself fact of the matter boils down more to the roles the aircraft is designed for anyhoo. Aircraft designed to go a long way and carry more load are going to be bigger to carry the fuel and stores. And until now they have had two engines to do this. The F-35 is the first fighter in its weight class that has had a sufficiently powerful engine to do what it is trying to do with one engine, as opposed to having two smaller engines. The fact that it has two vs one widgets I dont care about as long as what it can do what they say it will on the box....
south, after multiple posts....it may be time you did some research and show us the comparison between single and twin engine crashes per flight hours over the last 10 years to prove your point
If you can show me that the f-16 has sufficiently more crashes because of engine failure, I will agree with you, change my mind and conclude what I have read was wrong
Jack, have you tried looking at the links I posted on the previous page?? Alternatively how about you tell me anywhere where I have been significantly in error.
Notes:
1. "Engine-related" excludes mishaps caused by FOD, birdstrike, or failure of support systems external to the engine (ex. fuel starvation)
2. Aircraft flight-rate producing mishaps only.
3. Rates are Class A mishaps/100,000 Engine Flight Hours (EFH) by calendar year
4. F-16/F100-PW-200 is no longer in use in the USAF
eg a twin on a jetfighter is not the same as dispersed multi's on a large jet
colocated twins on jets like BAC-111's, B-52's OTOH are a fairer comparison, but still not relevant as the engine management systems are of a different generation.
apples with apples etc.....
________________ A corollary of Finagle's Law, similar to Occam's Razor, says:
"Never attribute to malice that which can be adequately explained by stupidity"
south, yes I have, you have an accumulative and a 6 quarterly, the 6 quarterly/18 mths shows no air crashes by engine
using data from the accumulative 80's isnt relative, is it. Which is why I suggested the last 10 years using the most reliable engine data
And from one POV and according to those charts, we don't actually know how safe F-16's running F100-PW-229's are, because they haven't yet had a single Class A mishap, whereas the F-15 with 2 of the exact same engine has...
Oh yeah, those 2 engines are keeping our pilots alive...
south, yes I have, you have an accumulative and a 6 quarterly, the 6 quarterly/18 mths shows no air crashes by engine
using data from the accumulative 80's isnt relative, is it. Which is why I suggested the last 10 years using the most reliable engine data
using the F-15/F100-PW-220 to the same engined f-16, the f-16 is safer
which kind of puts a big hole in your argument
Although I reckon you could be trying to talk about the 229 engine variants.... So there you have it folks, for the F-15/F-16 types with similar engines, the 229 is the choice to make if you are a F-16 driver (all other types have a significantly worse incident/100000EFH ratio, including the GE-129 which is the parallel type to the PW-229. Oh btw if you have a single F-16 PW-229 Class A you are near enough to the same ratio that it doesnt matter... )
There are a couple of other things that I will note here, one is that FOD/birdstrike are not counted in Engine related mishaps however if that was the cause of engine damage / failure it certainly supports the argument for having two engines. The second is that if you cook one of these engines, that is going to cost $1M US and hence you have a class a incident. It does not necessarily relate to the loss of the aircraft and unfortunately that data does not seem to be available.
Secondly their are a myriad of issues and differences that appear with a single/twin in GA, and you are correct in that it is completely irrelevant and in no way supports your position. I fail to see why you included it?
All that I am saying is
1) you cant compare civvie jet engines to mil fast jet as much as you cant compare a F-18 to a 787.
2) it is rare in a twin engine type that it will let go and frag the other, more frequently you know you have a problem so you shut the sucker down before anything happens. You don't have that option in a single.
3) fuel starvation or volcanic cloud ingestion is not a valid argument either way.
4) if you have two engines and one is ferked, you at least have a chance to get home.
5) Statistically in the long term attrition during training favours twin engine types.
6) we will most likely lose a couple of JSF during our operation due to engine failure.
WRT 6) is it a big deal to lose 2 JSF over a 25-35-50 year life of type, nah not really?, might be a big deal if you are the guy in the seat...
as a case in point I know of a couple of RAAF FA-18 drivers who would have a nice tie and a sore back if they were driving F-16's.
sorry, I copied the wrong engine from the article, that was an early one but it does show the lower reliability of the earlier engine, doesnt it, the later is the F100-PW-229
F100-PW-229 is the one that has a higher safety record on the f-16 than the f-15 per flight hour flown
with modern engines, engine failure isn't a big enough issue to get in a huff about, what is it, about 1 in 1,000-1,500 flight years for the f-15 and the better f-16 rate
statistically you have to fly a fighter for at least a 1,000 years before you have a class A
edit...
f-15, 859,542 hrs 4 class A
f-16, 244,846 hrs 0 class A
total,1,104,388/4 = 276,097 hrs per class A / 220 hrs year av fighter pilot = 1254.9 flight years
ps there would be more cooked engines than crashes in the class A, dont you think ?
so to try and say the f-35 is at severe risk because it has one engine is straight out rubbish, isn't it
Last edited by jack412; September 27th, 2011 at 04:51 AM.
I do agree with what AD has said, and yes the technology has off course moved on, but the point stands.. In a single engine jet, when that engine craps the bed for whatever reason (and yes, jet engines are more reliable but it does still happen ), unless you happen to be within gliding range of an airfield (good luck) you are stepping out and hopefully get to wear a nice martin baker tie.. If you have a twin engine jet, you still have an option.
Dislike what I'm saying all you like but if you look at the links that I provided earlier for the Class A mishaps from the USAF the F-16 is having engine related class A's at about three to four times the rate of F-15's. Will we suffer increased attrition because of this... Probably. Is it going to be like the Mirage III where we lost 40 or so out of just over 100. No, of course not.
....
Sorry to suggest these losses were mostly due to the single engine as a main factor is just wrong. Another major cause was under carriage failure (which was more frequent than engine failure) and pilot error. The fate of each can be found here
Hopefully not F-35. Canada should make an indigenous fighter and name it Arrow II
Good luck with that. although it could take a while as you would need to develope the technology and infrastructure to produce a modern front line air craft and I suspect this would make your proposition both very expensive and time consuming.
Good luck with that. although it could take a while as you would need to develope the technology and infrastructure to produce a modern front line air craft and I suspect this would make your proposition both very expensive and time consuming.
Too expensive from scratch but if we build the Gripen NG in Canada then we will develop all those industries for next time.
What happened to layered defence anyway? I said in another blog we should have 80 Gripen NGs to defend Canada and if the CF really want stealth for third world adventures / layered defence they can buy 15 or 20 F-22s. This single platform thing everyone seems to be into these days locks everyone into a jack-of-all-traits, master of none situation.
Gripens to defend Canada and F-22s to blow up third world country radar installations. Or how about just Gripens and our international fighter obligations won't be performing front line door crashing roles.
