Royal Australian Air Force [RAAF] News, Discussions and Updates

south

Well-Known Member
It is just statistics. If you have an engine with a known failure rate and 100 fighters are built with a single engine and 100 fighters are built with 2 engines of the same type, the twin engine fleet has a greater probably of having an engine failure because of the larger engine population. As has been pointed out by others, an engine failure in a twin engine fighter will often damage the other engine due to the close proximity of the engines to each other. It is also true a single engine jet that experiences engine failure always crashes whereas a twin engine design with a single engine failure might survive.
It’s easy to extrapolate that a twin suffers more engine incidents than a single (for a given engine - not all engines are created equal).I don’t dispute that.

It is a big leap to say that you are more likely to lose a twin than a single.

I’m just asking for evidence to that effect. So far I haven’t seen any.

Otherwise it’s all opinion, internet truths, etc
 

Massive

Well-Known Member
It is just statistics. If you have an engine with a known failure rate and 100 fighters are built with a single engine and 100 fighters are built with 2 engines of the same type, the twin engine fleet has a greater probably of having an engine failure because of the larger engine population. As has been pointed out by others, an engine failure in a twin engine fighter will often damage the other engine due to the close proximity of the engines to each other. It is also true a single engine jet that experiences engine failure always crashes whereas a twin engine design with a single engine failure might survive.
Have been very cautious about replying to this thread as I haven't been able to find the supporting reference.

1. Dual engine fighter aircraft have more engine failures than single engine aircraft (more engines of similar MTBF)
2. Neither type crashes more often
3. The reason for dual engines is more payload or speed, not greater safety

Happy to be told I'm wrong here but pretty sure this is the case - just can't find the reference.

Regards,

Massive
 

hauritz

Well-Known Member
Last I read the F-35 had completed around 177,000 flying hours with the loss of only two operational aircraft. I really think that having a single engine is a bit of a non-issue.
 

John Fedup

The Bunker Group
It’s easy to extrapolate that a twin suffers more engine incidents than a single (for a given engine - not all engines are created equal).I don’t dispute that.

It is a big leap to say that you are more likely to lose a twin than a single.

I’m just asking for evidence to that effect. So far I haven’t seen any.

Otherwise it’s all opinion, internet truths, etc
I am not saying you are more likely to lose a twin than a single, just that a twin will have a higher engine failure because there are more engines.(100 jets with 2 engines will experience more engine failures than 100 jets with a single engine assuming identical engines). The aircraft loss rate difference between them would be similar because even though the twins lose more engines, they may survive an engine failure whereas the single will not.
 

John Fedup

The Bunker Group
Have been very cautious about replying to this thread as I haven't been able to find the supporting reference.

1. Dual engine fighter aircraft have more engine failures than single engine aircraft (more engines of similar MTBF)
2. Neither type crashes more often
3. The reason for dual engines is more payload or speed, not greater safety

Happy to be told I'm wrong here but pretty sure this is the case - just can't find the reference.

Regards,

Massive
The other reason for twin engines is the inability to build a high thrust engine, something P&W and GE are very good at. Just as important these companies build very reliable engines with great shelf life. Russian and Chinese manufacturers can't do this and although China is pouring billions into development, their engine technology lags behind Russia.
 

seaspear

Well-Known Member
Growing Growler: keeping the EA-18G at the forefront of electronic attack
The above article goes into further developments of the conformal tanks considered for the "Growler" and likelihood of the R.A.AF adopting such ,the article also discusses the expendable dash x drone that would be carried by the growler to aid detection of low band electrical emissions.
These seem genuine capability upgrades for this platform but is there an independent view on the advantages of this over the capabilities of the F35A and its own upgrades and why you need both jets and how complementary they are?
 

hairyman

Active Member
After reading the article Single V Twin engine posted by Barney 41 on thread 6481, I am now convinced. Single engine fighter planes are best, I notice that the F35 got canned as a fighter. Maybe we should consider a few Gripen N to handle the air to air combat. Seems to be a relatively cheap option.
 

ngatimozart

Super Moderator
Staff member
Verified Defense Pro
After reading the article Single V Twin engine posted by Barney 41 on thread 6481, I am now convinced. Single engine fighter planes are best, I notice that the F35 got canned as a fighter. Maybe we should consider a few Gripen N to handle the air to air combat. Seems to be a relatively cheap option.
Who says that the F-35 has been canned as a fighter? Sources please.
 

south

Well-Known Member
I am not saying you are more likely to lose a twin than a single, just that a twin will have a higher engine failure because there are more engines.(100 jets with 2 engines will experience more engine failures than 100 jets with a single engine assuming identical engines). The aircraft loss rate difference between them would be similar because even though the twins lose more engines, they may survive an engine failure whereas the single will not.
Which is why I didn’t respond to your post initially. I initially quoted Volkadov - who said it in black and white rhat statiatically you are more likely to lose a twin to a catastrophic engine failure.

I’m only asking for clarification or evidence supporting that statement.
 

south

Well-Known Member
Who says that the F-35 has been canned as a fighter? Sources please.
I suspect he was being sarcastic. That article was full of errors, cherry picking and conflation that unfortunately detracted from the few occasional times a valid point was made.
 

John Fedup

The Bunker Group
After reading the article Single V Twin engine posted by Barney 41 on thread 6481, I am now convinced. Single engine fighter planes are best, I notice that the F35 got canned as a fighter. Maybe we should consider a few Gripen N to handle the air to air combat. Seems to be a relatively cheap option.
Which plane is best is based on CONOPS and to a certan extent affordability. In order to get the desired range and ordinance load for long range missions , larger designs are likely required so a single engine won't have the necessary thrust. From what I have read, Iwould prefer to be in a F-35 over a Gripen N.
 

Volkodav

The Bunker Group
Verified Defense Pro
It’s easy to extrapolate that a twin suffers more engine incidents than a single (for a given engine - not all engines are created equal).I don’t dispute that.

It is a big leap to say that you are more likely to lose a twin than a single.

I’m just asking for evidence to that effect. So far I haven’t seen any.

Otherwise it’s all opinion, internet truths, etc
No references at hand but it is something that has been around for a long time in discussions of single verses twin combat aircraft and twin verses more in transport types. It is also a factor of reliability of systems improving in general
Which is why I didn’t respond to your post initially. I initially quoted Volkadov - who said it in black and white rhat statiatically you are more likely to lose a twin to a catastrophic engine failure.

I’m only asking for clarification or evidence supporting that statement.
Like I said I can't lay my hands on the reference, which is why I deliberately stated catastrophic. With very few exceptions a catastrophic engine failure will take down the aircraft for the simple reason it destroys multiple systems, including adjacent engines. Having more than one engine increases the chance of one failing catastrophicly.
 

south

Well-Known Member
No references at hand but it is something that has been around for a long time in discussions of single verses twin combat aircraft and twin verses more in transport types. It is also a factor of reliability of systems improving in general

Like I said I can't lay my hands on the reference, which is why I deliberately stated catastrophic. With very few exceptions a catastrophic engine failure will take down the aircraft for the simple reason it destroys multiple systems, including adjacent engines. Having more than one engine increases the chance of one failing catastrophicly.
Sooooo I checked the USAF safety centre website here:

Air Force Safety Center > Divisions > Aviation Safety Division > Aviation Statistics

And scrolled down to the section in Engine related mishaps:

Comparing Single Engine:https://www.safety.af.mil/Portals/71/documents/Aviation/Engine Statistics/USAF Single Engine.pdf

Twin Engine: https://www.safety.af.mil/Portals/71/documents/Aviation/Engine Statistics/USAF Twin Engine.pdf

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-15/F100-PW-100 is no longer in use in the USAF

The USAF statistics would not seem to back up the claims, and are in favour of twins - less so now with modern engines but still with F-15/F-16 the stat holds.

By definition every engine failure in a single engine fighter is “catastrophic”.
 
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Volkodav

The Bunker Group
Verified Defense Pro
Sooooo I checked the USAF safety centre website here:

Air Force Safety Center > Divisions > Aviation Safety Division > Aviation Statistics

And scrolled down to the section in Engine related mishaps:

Comparing Single Engine:https://www.safety.af.mil/Portals/71/documents/Aviation/Engine Statistics/USAF Single Engine.pdf

Twin Engine: https://www.safety.af.mil/Portals/71/documents/Aviation/Engine Statistics/USAF Twin Engine.pdf

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-15/F100-PW-100 is no longer in use in the USAF

The USAF statistics would not seem to back up the claims, and are in favour of twins - less so now with modern engines but still with F-15/F-16 the stat holds.

By definition every engine failure in a single engine fighter is “catastrophic”.
It would be interesting to compare air defence roled F-16s and F-15s to strike roled same. The mission type has an impact as well. Air safety side of things show the number of take off's and landings can have greater impact on condition and failures of components than total flight hours.

Pure assumption here, but I would imagine that strike evolutions would be more stressful on airframes and engines than CAP, even air combat manuever thrown in.
 

south

Well-Known Member
T/O landings is immaterial in this case.

You can by looking at the PW F100-229 as that is solely installed on (most but not all of) the F-15E fleet as far as twin engine goes. It is still lower than All of the F-16s bar - interestingly enough - the F-16 PW F100-229 combo. It should be noted though the F-15Es have 3 times as many flight hours so only one or two F-16 PwF100-229 losses would skew that.

I’d be careful making any more assumptions!!

Anyway back to your scheduled regular RAAF news.
 

ngatimozart

Super Moderator
Staff member
Verified Defense Pro
Some RAAF News.

The Growlers have achieved IOC. Apparently the cause of the Growler crash at Nellis AFB in Nevada during a RED FLAG last year was the catastrophic failure of a fan disk in the left engine during take off.

Five of the C-130Js are going to be fitted with Ka band SATCOM capability to enable streaming of HD video and support mission planning whilst in flight.
 

John Newman

The Bunker Group
It seems that news of deliveries of F-35A for the RAAF is starting to become a bit ho-hum... Anyway...

News this week that -013 and -014 have been delivered to the RAAF, will be based in the US with the first eight F-35As until end of 2020.

Four more aircraft due by the end of the year, bringing the total to 10 based in the US and 8 based here in Oz.

Next year will be a big one, another 15 airframes due to be delivered, and the 10 US based airframes are due in country by end of next year too.

Things appear to be moving along nicely, by end of December next year we should have 33 F-35As based here in Oz!
 

Stampede

Well-Known Member
It seems that news of deliveries of F-35A for the RAAF is starting to become a bit ho-hum... Anyway...

News this week that -013 and -014 have been delivered to the RAAF, will be based in the US with the first eight F-35As until end of 2020.

Four more aircraft due by the end of the year, bringing the total to 10 based in the US and 8 based here in Oz.

Next year will be a big one, another 15 airframes due to be delivered, and the 10 US based airframes are due in country by end of next year too.

Things appear to be moving along nicely, by end of December next year we should have 33 F-35As based here in Oz!
I think a bit ho-hum is ok if all is going smoothly which at this stage appears the case.
Probably says something of the professionalism of the RAAF.
With 30 + aircraft in country late next year I'd suspect we would be close to having a front line squadron plus an operational conversion unit, or is that to premature at this stage.
Any clarity on this.

Regards S
 
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