Where does the UK/JAR "twin only" mentality come from?

[SilsoeSid]

lynx-effect;
The last 3 horrible crashes have been multi-engine, multi-crew. The proof is in the pudding.. i.e there is no proof. Just more cash to be made by licensing agents.

Uuuum, just which 3 crashes do you mean? Wasn't the last 'horrible crash' single engine, single crew

[lynx-effect]

Sumburgh, Glasgow, Beccles.

[SilsoeSid]

So, you're just looking at UK incidents, whether or not an engine is involved. How very blinkered that seems considering this is a twin engine discussion thread. (The last horrible crash, your phrase, was in fact the Seattle 350)

Ok, if you want to play it that way, may I suggest you visit the UK AAIB publications webpage Air Accidents Investigation: Publications & Search Reports ... select the radio buttons to search the rotary only reports, leave the dates as 'any', press 'search' and you'll notice that of the 940 reports, the vast, vast, vast majority are single engined rotorcraft.

[John Eacott]

I think that an earlier post raised the issue that since UK legislation requires twins for many operations, the lack of single engine accidents/incidents is skewed because they do not feature in the operation anyway!

I've had engine failures in twins and in singles. A PT6 turbine letting go over the North Sea it was very nice to have the other half of the Twin-Pac to get me to the nearest suitable platform. A C20 compressor shredding on late finals to a floating pad on the Yarra River was justification in taking a steep approach to such a pad with an auto from short finals. I wouldn't have liked to have the same failure 3 minutes earlier when I was flying down LaTrobe Street at 50 feet, and retrospectively a twin should have been used for such an exposed operation.

Not UK, but certainly my experiences back up some of the demands made by the CAA.

[ShyTorque]

The twin numbers appear now to be accepted as wrong.
It is just not 2x10^-10.
No defenders.

Seems that you are beginning to clutch at straws to find something that no-one has disputed.

It really doesn't matter a jot if a mathematical calculation to predict the likelihood of engine failure was accurate or not - it's just a figure, not real life. Didn't you know that 100% of statistics are made up? You only need one engine failure in a single to spoil your day, and that of your passengers, forever.

However highly you personally rate your flying skills and abilities, you might be proved very wrong one day, if it happens to you and you aren't in an ideal situation. Night, IMC, over unknown or hostile terrain? IMC or with no visual references to the ground, or into a wood or lake? Who are you trying to kid that you are going to walk away from that?

You spouted nonsense about no-one having had engine failures on take off or in other critical flight phases. When contributors give you examples, you ignore their entirely valid responses, disappear from the discussion and come up with something else. As you keep showing here, you can keep coming up with "facts" to "prove" in your own mind anything you like, depending on the personal opinion you hold.

Point is, you are completely out of kilter with the opinions and experience of a whole raft of professional pilots who have flown both singles and twins extensively. By your strangely unusual, defensive attitude about your qualifications or experience, it appears you haven't yet done either. So far you have put forward uninformed ignorance, supposition and incorrect understanding of rules, regulations and design concepts.

I'm actually beginning to hope that you are a troll. Because If you really are an instructor, you will probably be teaching your students this guff. If so, let's hope at they are intelligent enough to see past it, for what it is.

[chopjock]

Sid

So, you're just looking at UK incidents, whether or not an engine is involved. How very blinkered that seems considering this is a twin engine discussion thread

There is a "UK" in the thread title as well. Perhaps not so blinkered eh?

[SilsoeSid]

Sid
So, you're just looking at UK incidents, whether or not an engine is involved. How very blinkered that seems considering this is a twin engine discussion thread

There is a "UK" in the thread title as well. Perhaps not so blinkered eh?

Surely if you want to use statistics and have evidence comparing single against twin, regardless of which country the discussion is about, you need to use as much data as possible and that means using statistics and evidence from every source available.

Chop, as you mention the thread title in your reply, let me remind you of it;
Where does UK/JAR twin only mentality come from?

How about from analysis of worldwide single/twin incidents

[mdovey]

I think that AnFi's hypothesis are both valid:

i) that as engines get more reliable, the advantage of two engines over one will decrease. The advantage will only become zero when engines are 100% reliable (almost certainly never) but there may come a point when the chances of engine failure is so small that the advantage of a twin is outweighed by all the other things than can go wrong.

ii) that the chances of a twin engine failure is higher than you might think (both engines will be the same age, subjected to the same stresses and impurities in fuel/oil etc.)

However, I think that AnFi is drawing the wrong conclusion. AnFi's conclusion is that a single is effectively as safe as a twin. I think the correct conclusion is that a twin is effectively as unsafe as a single.

Obviously, I'm not saying ban all helicopters - just that those flying twins should not be just as cautious as those flying singles e.g. be prepared for an auto even in a twin etc.

Matthew

[chopjock]

Sid

press 'search' and you'll notice that of the 940 reports, the vast, vast, vast majority are single engined rotorcraft.

Note also the vast,vast,vast majority are pilot error and not engine related.
So if the weakest link in the chain is the pilot, why are the UK CAA mandating twins?
Perhaps there should be twin tail rotors, twin tail rotor drives, twin rotor heads,
twin everything…
There still seems to be a lot of twins crashing so something is wrong with the system.

[SilsoeSid]

Lol, chop, keep up!
Just as the 3 crashes that lynx effect mentions in support, none of those as far as we know are engine related!

You can't throw examples into the single/twin discussion that don't actually relate to accidents caused by the engine!

Chop;
There still seems to be a lot of twins crashing so something is wrong with the system.

Mmmm, so why is it that there are more singles crashing?

[chopjock]

Mmmm, so why is it that there are more singles crashing?

Same as the Robinson Syndrome, there's more of them. Still mostly pilot error though and this is what we should be addressing.
For example, single engine CFIT could be reduced if single engine were allowed to fly IFR.

[Tandemrotor]

So, on one side of the argument, we have AnFI who refuses to tell us what his experience is. I wonder why? Added to that we have a new entrant mdovey who is currently training on a Cabri G2 for a PPL, and chop jock who tells us that the biggest threat to a helicopter is the pilot. Not a problem for him as when he's not exercising his PPL the helicopters he flies don't have a pilot on board! They are flown by radio control.

On the other side we have many enormously experienced professional pilots who have seen and done pretty much everything it is possible to imagine in a helicopter (plus a few things you probably can't imagine unless you've been there!)

Now who's opinion do I prefer???

Mmmmmm. Can I have a millisecond to think about that please!

BTW: We do of course have helicopters with THREE engines as well! Spawn of the devil I say!! Burn 'em!!!

[I-IIII]

Hi
I flow most of my life slinging with 350 B2 B3,I was like AnFI,single forever but in last few years I had a lot of TP and sling longline with 355N and Bo105.I really enjoy the Twins.What I learned and wrote in another topic is just a simple think.
Singles kills pilots like twins,the ignorance kills the pilots,the weather kills the pilots,the cigaretes kills pilots.
So........I dont care how many engines I have,I just care choose the right machines to the job.

[Art of flight]

yeh, 3 engines in a helicopter? some sort of magic? The RAF ones were so expensive to operate, that they had to 'hire' in part time soldiers in gazelles to fly the crew round their night recces! Doh! I've probably set Anfi off now...

[I-IIII]

If dont feel confortable dont do that.........captain leadership!!!!!!!!!

[Boudreaux Bob]

BTW: We do of course have helicopters with THREE engines as well! Spawn of the devil I say!! Burn 'em!!!

US Navy Mine Sweeping CH-53E's do a pretty good job of that all by themselves I hear. Something about the center engine exhaust starting fires.

http://hamptonroads.com/2014/03/navy...ngine-problems


One works, Two is fine, Three is Divine, and when Four becomes standard then it shall be Bliss!

I firmly believe One cannot have too many Engines or too much Fuel.

The problem is paying the cost of carrying them around unnecessarily.

In general terms AnFi is entirely correct.

You can do everything with a Single that you can do with a Twin, except fly following an Engine Failure.

One does not have to be a Wizard to understand the advantage of two engines but as Anfi correctly notes, sometimes the two Engines do share a common link that negates the value of both of them.

Case in point, the Main Drive Shaft on a Bell 212/412 for instance. It fails and you have two very perfectly healthy engines doing nothing but keeping the electrics supplied and reducing the amount of fuel you will crash with.

Beating up on AnFi seems to be a popular activity here but he does have some good points amongst the many.

Don't blind yourself to that in your knee jerk reaction to his posts.

Any review of Accident Statistics will show Pilots to be the greatest hazard these days. We must not lose sight of that and that applies across the board for all types of helicopters.

You folks in the UK have the Glasgow Police Crash and the London Crane Crash to use for examples and we have the Air Methods EMS Crash we can look at.

All three were had common elements and involved both twins and a single.

Texting in the Air Methods and London events, fuel exhaustion in the Glasgow and Air Methods crash. That the Air Methods crash involved both Texting and Fuel Exhaustion is especially troubling to those of us who consider the Pilot to be the weak link in most fatal crashes.

Just because the aircraft has two engines, lots of automation or just a single engine and few gadgets, it still requires a Pilot to do right in both situations.

Now do you want to argue Single Pilot or Twin Pilot Ops?

I would suggest most of you are looking the wrong way for an answer to the questions.

The 139 crash had nothing to do with Fuel or Engines (from all available information) so how does that figure into the discussion about Singles vs Twins and Single Pilot vs Two Pilots?

[mdovey]

Tademrotor,

I think you've put me on the wrong side of the argument. I was trying to say that even if you accept AnFi's argument that as engines have become more reliable the different between a single and a twin may be a little less than it was, and that a double engine failure may not be quite as statistically unlikely as some may think, i don't agree with the conclusion that just because a single may be nearly as safe as a twin that the CAA should allow singles for operations currently permitted for only twins.

The conclusion I would draw is that a twin is nearly as unsafe as a single in those operations (particularly with other factors taken into consideration) - which is just meant as a reminder to us all whether we have 20 hours or 20,000 hours, whether we are in a single or a twin, never to get complacent!

As regards, chopjock's question about why the CAA are mandating twins. Can you really see them changing it - the press would have a field day on the first crash of a single performing an operation previously reserved for twins only. And in any case, however unlikely something is statistically it is still possible - I'd not want to be the person in the CAA weighing the balance of the additional cost of a twin versus the statistical likelihood of it saving a life or not regardless of where the balance lay!

Matthew

P.S. I'm quite happy to be open about my (lack of) experience, but please read my opinions before dismissing them, thanks.

[Art of flight]

Sometimes there's plenty of everything, 2 engines, 2 pilots, and still we revisit these pages every few months, attracted by the latest tragic puzzle.
We hope to learn from the unfolding situation, some even seem to guess the answer straight away (no learning required there then). As aircraft become more reliable, we, the pilots, are being increasingly found wanting when it comes to decision making when the aircraft or weather (or customer) do not behave as advertised. We have CRM, we have simulators, we have training and testing. So, are we at the point where we say, it's the point in our evolution where the rate of attrition is just the cost of doing what we do....fly helicopters in circumstances that are at times beyond our capabilities? The statistics certainly seem to say so.

[lynx-effect]

I thought that this thread was about discussing why the CAA think that twin engine ops are safer than single. Just because you are on a faceless thread please don't feel the urge to be rude to other people with rumours and opinions.

Yes there are more single engine aircraft incidents than twin but statistics can always have tell a different story. If you decipher between general and commercial rotorcraft on the AAIB website you will have seen that there were 678 and 273 respectively. This could mean that single engined aircraft are much more dangerous than twin or it could mean that the pilots are less experienced and trained than their commercial counterparts. If said pilots could afford to run a twin then the twin accident rate might go up. It could also mean that there are more general aviation flights than commercial so with single engined aircraft being more suited to the general aviators then of course there are always going to be more incidents. Statistics are always open to opinion and opinions are like bum holes.......everybody has one.

[SuperF]

If you want to talk stats, just straight numbers and not per flying hour, then you guys should all get out of flying and let the chicks do it.

I'll guarantee that just about all those accidents you are talking about the PIC was a male, therefore females are far safer....