GA Flying...is it safe ?!
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I use both of them Peter. Is this a p#ssing competition? How many vac failures or alternator failures have you had? You fly IFR at high altitude (for a light aircraft) - do you have 2 vac pumps on the TB, or indeed a backup alternator? If not, why not? I'm sure a backups could be fitted, especially as its an N reg you own.
Common sense dictates if your going to fly solid IFR you would not let these items go on until failure. Prevention is better than cure don't you think? After all, as you state, being an owner is the only way you can fly a plane that's maintained to a high standard.
I'm not saying replace/inspect every 2 years, don't get me wrong. I certainly wouldn't wait until failure however on a 10 year old aircraft though.
From your own website on backup systems it would appear you agree with me...
Socata TB20 Trinidad
Common sense dictates if your going to fly solid IFR you would not let these items go on until failure. Prevention is better than cure don't you think? After all, as you state, being an owner is the only way you can fly a plane that's maintained to a high standard.
I'm not saying replace/inspect every 2 years, don't get me wrong. I certainly wouldn't wait until failure however on a 10 year old aircraft though.
From your own website on backup systems it would appear you agree with me...
Socata TB20 Trinidad
Backup Vacuum: This is a second electrically driven vacuum pump. It's not a bad idea because the autopilot requires the main horizon which is vacuum powered so if the standard vacuum pump fails, you lose the autopilot as well. It's quite bulky and heavy... an alternative approach is to replace the existing vacuum pump every few hundred hours. Vacuum pumps are cheap enough to replace at every Annual if so desired.
Does this FAA rule still apply to icing?
Does this FAA rule still apply to icing?
IO540
5th Nov 2008, 12:38
Of course there is also the TB20 or the turbocharged TB21
Not made anymore but there are a number of potentially very fine 2002 specimens on the market, and Socata remains very much in business making the TBM850.
The TB2x, with full TKS, is certified for flight into icing, but only on a G-reg, not on an N-reg (because the FAA requires two alternators, etc).
Do bear in mind that full TKS costs about 50-70kg and a turbo costs another ~50kg. While the basic TB20 (20k ceiling) has a 500kg payload, the TB21 with full TKS is really only a 2-seater albeit a highly capable one. These payload tradeoffs will apply to every other type, too, so one needs to define one's mission profile carefully. For a start, most of this mission capability is not usable without the full IR unless one just wants to takeoff from Norwich and zoom up in circles over Anglia
5th Nov 2008, 12:38
Of course there is also the TB20 or the turbocharged TB21
Not made anymore but there are a number of potentially very fine 2002 specimens on the market, and Socata remains very much in business making the TBM850.
The TB2x, with full TKS, is certified for flight into icing, but only on a G-reg, not on an N-reg (because the FAA requires two alternators, etc).
Do bear in mind that full TKS costs about 50-70kg and a turbo costs another ~50kg. While the basic TB20 (20k ceiling) has a 500kg payload, the TB21 with full TKS is really only a 2-seater albeit a highly capable one. These payload tradeoffs will apply to every other type, too, so one needs to define one's mission profile carefully. For a start, most of this mission capability is not usable without the full IR unless one just wants to takeoff from Norwich and zoom up in circles over Anglia
Last edited by M-ONGO; 11th Jan 2012 at 13:50.
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I use both of them Peter.
Is this a p#ssing competition?
How many vac failures or alternator failures have you had?
You fly IFR at high altitude (for a light aircraft) - do you have 2 vac pumps on the TB, or indeed a backup alternator? If not, why not? I'm sure a backups could be fitted, especially as its an N reg you own.
The vac pump gets changed at every 2nd annual i.e. every ~250hrs of airborne time.
The alternator gets slip rings and bearings inspected and gets new brushes at every annual. The current one is ~500hrs old and will probably be changed in a year's time.
Common sense dictates if your going to fly solid IFR you would not let these items go on until failure. Prevention is better than cure don't you think? After all, as you state, being an owner is the only way you can fly a plane that's maintained to a high standard.
What argument would you make for things like seat belts which can be inspected easily and thus life limits make no sense?
Or perhaps Teflon oil hoses, which have no engineering/technical support for life limits, which are operated at about 1/10 of their continuous working rate pressure, yet which are generally lifed under EASA.
That is why I wrote earlier that ownership gives you both options: do it well, or hang yourself.
I'm not saying replace/inspect every 2 years, don't get me wrong. I certainly wouldn't wait until failure however on a 10 year old aircraft though.
What I could add is that the bit the vac pump drives, typically a KI256 or similar, is likely to fail as often as the pump, but costs about 20x as much. Tell me what you do about that? The KFC225 STC mandates a KI256 (or some ludicrous alternatives).
An electric backup vac pump doesn't help with that, because if the AI goes, so does (on Honeywell systems) the autopilot, which is just what you want
I've had one KI256 last 200hrs, another 700hrs.
Two alternators would be a huge mod for a TB20. Even in the USA, nobody did that AFAIK despite it possibly facilitating a FIKI certification. One could fit a small vac pump drive alternator, but it would have to be at least a PMAd part, and what will you drive with it? An electric AI? That would be nice but it's a pretty significant-paperwork project. You cannot drive "electronic" avionics from such an alternator unless you have a battery also, unless it is the GAMI one which is not even PMAd. Also the chances of a vac failure or a vac AI failure and a general electric failure is miniscule (two independent systems).
Anyway, you did very well to read through that 100k word essay
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Not at all, it was an interesting read.
Outside the jet for work, I fly a twin turboprop Peter. For light aircraft the list is too long. I've lost 2 vac pumps (not at the same time) on a C310, one on a Cherokee, several whilst instructing on singles such as the TB10 and that ilk. In the region of 5 pumps over several thousand hours g/a time.
You say you change the (inexpensive) pump every 250 hours. That's my whole point. Your the one suggesting replacing parts on a pure time basis is in most cases totally pointless.
Contradiction? I take it the two items I mention come under your "mostly" part? You also self admittedly say two vac pumps are not a bad idea...
Well, thanks for the advice. I'll make sure I let our company engineers know that... 
What about the Thai aero clubs TB20 with two alternators? They base their regs pretty much on the FAR's. It must be possible.
Seatbelts? Now who's being "disingenuous"...
Oil hoses? Are they not a 10 year lifed item on your '20? if that's what the AMM suggests, then do it. But you have haven't you? I'm sure that's on the website somewhere! Personally if it was my aircraft, I would. That's regardless as to whether under part 91 it's required or not. The JAA seem to think so.
Oh no, the autopilot has failed! Declare an emergency!
Outside the jet for work, I fly a twin turboprop Peter. For light aircraft the list is too long. I've lost 2 vac pumps (not at the same time) on a C310, one on a Cherokee, several whilst instructing on singles such as the TB10 and that ilk. In the region of 5 pumps over several thousand hours g/a time.
You say you change the (inexpensive) pump every 250 hours. That's my whole point. Your the one suggesting replacing parts on a pure time basis is in most cases totally pointless.
Replacing bits on a pure time basis is in most cases in fixed wing GA totally pointless.
Replacing bits which are worn is OK.
What about the Thai aero clubs TB20 with two alternators? They base their regs pretty much on the FAR's. It must be possible.
Seatbelts? Now who's being "disingenuous"...
Oil hoses? Are they not a 10 year lifed item on your '20? if that's what the AMM suggests, then do it. But you have haven't you? I'm sure that's on the website somewhere! Personally if it was my aircraft, I would. That's regardless as to whether under part 91 it's required or not. The JAA seem to think so.
An electric backup vac pump doesn't help with that, because if the AI goes, so does (on Honeywell systems) the autopilot, which is just what you want
Last edited by M-ONGO; 11th Jan 2012 at 16:45.
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You say you change the (inexpensive) pump every 250 hours. That's my whole point. Your the one suggesting replacing parts on a pure time basis is in most cases totally pointless.
Replacing bits on a pure time basis is in most cases in fixed wing GA totally pointless.
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Dublin
The ambiguity comes from the:
The above fact is rather obvious, don't you think? As no parts were mentioned, who knows?
This obviously was not highlighted when I copied and pasted it or am I missing something? (ref post 59)
The ambiguity comes from the:
Quote:
Replacing bits which are worn is OK.
Replacing bits which are worn is OK.
This obviously was not highlighted when I copied and pasted it or am I missing something? (ref post 59)
Quote:
Replacing bits on a pure time basis is in most cases in fixed wing GA totally pointless.
Replacing bits on a pure time basis is in most cases in fixed wing GA totally pointless.
Reference for the UK figures:
www.caa.co.uk/docs/33/RegReview.pdf
1.3 fatal accidents per 100,000 flight hours for the UK:
(over a decade ending in 2004)
As an aside, the really interesting statistic is for gyroplanes - over 40 fatal accidents per 100,000 hours. I think I understand where the naysayers for statistics are coming from, and I know the numbers should also be interpreted with caution due to the relatively small number of aircraft. But I think when you get differences like that, they're trying to tell you something.
1.14 fatal accidents per 100,000 flight hours for the US:
Fact Sheet – General Aviation Safety
(2010 figure)
To be honest, it wasn't hard to find. '1.3 100,000 caa' and '1.14 100,000 faa' in google work fairly well.
www.caa.co.uk/docs/33/RegReview.pdf
1.3 fatal accidents per 100,000 flight hours for the UK:
(over a decade ending in 2004)
As an aside, the really interesting statistic is for gyroplanes - over 40 fatal accidents per 100,000 hours. I think I understand where the naysayers for statistics are coming from, and I know the numbers should also be interpreted with caution due to the relatively small number of aircraft. But I think when you get differences like that, they're trying to tell you something.
1.14 fatal accidents per 100,000 flight hours for the US:
Fact Sheet – General Aviation Safety
(2010 figure)
To be honest, it wasn't hard to find. '1.3 100,000 caa' and '1.14 100,000 faa' in google work fairly well.
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This obviously was not highlighted when I copied and pasted it or am I missing something? (ref post 59)
when you copy and paste on this forum it doesn't copy the formatting.But we know that io540 didn't go and add the underlining after you post because if he edited his post after someone posted another post, then pprune tells us that he did so and the time that the last edit was made. For example we can see that you edited your post 59.
It doesn't show any editing of io540's post so we know that the underlining WA always there and you didn't notice it or failed tho take it into account.
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You learn something every day! BTW you can indeed edit a post without a time stamp as long as its soon after. Just done it on another thread.
With observation skills like that you should go for a radar validation!
With observation skills like that you should go for a radar validation!
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You also self admittedly say two vac pumps are not a bad idea.
Fitting an electric backup vac pump (which is a massive clumsy lump) is a bit like replacing an IO540 with a steam engine, and if the plane doesn't fly with it, fitting a second steam engine.
The reality is that when you fly a typical IFR single you accept a lower level of redundancy than when you are flying a twin with both engines fully loaded with accessories. Unless the single is a Cessna 400... or a TBM, etc. And even a twin with two totally separate buses (with crossbars) is unlikely to have two separate pitch/roll sources for the autopilot. Unless it is a 737+
One can improve redundancy but the cost and hassle just goes up and up, because everything that's actually worthwhile safety-wise is a major mod, and sometimes virtually infeasible paperwork-wise.
99% of my high altitude IFR is VMC.
I haven't been to Thailand lately (have a very nice girlfriend, thank you) so pardon me for not knowing that somebody out there has fitted a second (full-size?) alternator to a TB. If you have access to their paperwork I would like to see a copy; it might be useful. Is it on an N-reg? No I didn't think so; I do know one pilot there and you can't keep an N out there permanently.
You seem to have some sort of agenda, Mongo, to pick holes. Have we crossed wires in some other life?
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I have a contact there (expat instructor) who may be able to help if you're interested. It's on an HS reg.
If you need to fly with an autopilot outside of RVSM levels, you simply shouldn't be flying. (not a comment aimed AT you - just in answer to your autopilot comment)
There is no cost on safety Peter. It's simply justifying that cost or mitigating the risk a la SMS.
99% of the flying I do below FL200 in Europe would certainly not be VMC, but then again I don't necessarily choose my flying days, granted I only fly down there for short periods.
BTW I'm glad you have a 'very nice girlfriend' - I can only hope she enjoys conversation topics such as egnos, gps, tcas and the like.
Oh, and yes you do:
That's from you're website.
No, we've never met Peter. No agenda - this is a discussion forum, after all.
You seem to Think you know about most other things aviation. thought that this would be on the TB20 owners/pilots forum.
If you need to fly with an autopilot outside of RVSM levels, you simply shouldn't be flying. (not a comment aimed AT you - just in answer to your autopilot comment)
There is no cost on safety Peter. It's simply justifying that cost or mitigating the risk a la SMS.
99% of the flying I do below FL200 in Europe would certainly not be VMC, but then again I don't necessarily choose my flying days, granted I only fly down there for short periods.
BTW I'm glad you have a 'very nice girlfriend' - I can only hope she enjoys conversation topics such as egnos, gps, tcas and the like.
Oh, and yes you do:
Backup Vacuum: This is a second electrically driven vacuum pump. It's not a bad idea because the autopilot requires the main horizon which is vacuum powered so if the standard vacuum pump fails, you lose the autopilot as well. It's quite bulky and heavy... an alternative approach is to replace the existing vacuum pump every few hundred hours. Vacuum pumps are cheap enough to replace at every Annual if so desired.
No, we've never met Peter. No agenda - this is a discussion forum, after all.
I haven't been to Thailand lately (have a very nice girlfriend, thank you) so pardon me for not knowing that somebody out there has fitted a second (full-size?)
thought that this would be on the TB20 owners/pilots forum.
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I have to be quick with your posts because you keep editing them...
I got kicked out of there in 2008, for upsetting the web admin, not to mention some bible carriers
thought that this would be on the TB20 owners/pilots forum.
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Hopefully the OP will have picked up on the point by now that there is little point in trying to make generalisations about GA.
Yes I'd agree, made about GA, the quote about the drive to the airport is nonsense, as a generalisation at least. The point here is that general aviation flying is very much as safe as one makes it.
I was recently perusing an article in Flying, a US aviation magazine, and in particular a discussion about how to make GA safer; one of the contributers noted that possibly one route cause of the comparatively high accident rate is that the issue of danger is not addressed sufficiently in initial training and that we should spend less time trying to convince people who want to learn to fly that light aircraft are safe and more time convincing them of the dangers yet going on to explain how to overcome them.
So I'd say to the OP in answer to his question: It depends, if one is a diligent student pilot with good instructors after a while one will get an idea of what is 'best practice', follow it, and apply it with mounting experience and by then you will probably have found your answer...
Yes I'd agree, made about GA, the quote about the drive to the airport is nonsense, as a generalisation at least. The point here is that general aviation flying is very much as safe as one makes it.
I was recently perusing an article in Flying, a US aviation magazine, and in particular a discussion about how to make GA safer; one of the contributers noted that possibly one route cause of the comparatively high accident rate is that the issue of danger is not addressed sufficiently in initial training and that we should spend less time trying to convince people who want to learn to fly that light aircraft are safe and more time convincing them of the dangers yet going on to explain how to overcome them.
So I'd say to the OP in answer to his question: It depends, if one is a diligent student pilot with good instructors after a while one will get an idea of what is 'best practice', follow it, and apply it with mounting experience and by then you will probably have found your answer...
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To be honest, it wasn't hard to find. '1.3 100,000 caa' and '1.14 100,000 faa' in google work fairly well.
, quite. In the same paragraph of the UK document where we find the ratio you dug up, we read:
Meaningful comparison of the UK data with other foreign States was not possible due to differences in the definition of GA and a lack of available information, particularly utilisation.
and a few sentences down...
However, the estimated FARs for the various classes of UK GA were found to be [...] better than the rate for most European States.
which is quite a statistical find, in view of admitting they're comparing apples to oranges and that they are only doing a survey once in a blue moon.
The UK CAA definition of GA is "anything civil that is not a CAT operation"
whereas other states use : GA = light aircraft (under 12500 lbs) or some other definition.
The UK CAA also don't say how they measure/estimate "hours flown", which is of course the denominator of your accident ratio, just that it is "constant" at 1.4 million hours. They are also not clear about counting the N-reg hours in the UK, which inevitably would drive their accident rate down.
By comparison, General Aviation in the USA had 1518 accidents for about 23.8 million hours flown in 2006, or about 6.3 accidents per 100000 flying hours. The 2006 number of fatal accidents per 100000 flying hours was about 1.1
It should be noted that the US have something out there like Alaska, which due to the harsh flying circumstances (and living conditions) distort the US result somewhat.
US references all on www.faa.gov (search) with very detailed materials on methodologies, statistical errors and a great many additional indicator...
Although the data presented doesn't statistically support it, the UK accident rate might actually be better than the continental european one if only for the existence of the IMC rating. A similar recognition was made by EASA in its introductory comments about FCL.008 (the accessable instrument rating). The same argument could then explain why the UK has a slightly higher GA (fatal) accident rate than the US.
I think that most of these statistics are a finger in the wind.
So far as I know, the only major GA countries with regular centralised reporting of flying hours are the UK and Australia.
The USA does not centrally record these hours, therefore any hours per fatal accident estimate is just that - an estimate, and could be very badly out.
The best you can do is compare fatalities per number of similar airframes. And that is also very approximate because useage patterns of aeroplane types vary a lot between countries as well.
G
So far as I know, the only major GA countries with regular centralised reporting of flying hours are the UK and Australia.
The USA does not centrally record these hours, therefore any hours per fatal accident estimate is just that - an estimate, and could be very badly out.
The best you can do is compare fatalities per number of similar airframes. And that is also very approximate because useage patterns of aeroplane types vary a lot between countries as well.
G
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So far as I know, the only major GA countries with regular centralised reporting of flying hours are the UK and Australia.
Total hours, with date valid, are available on G-INFO (and pay the CAA a few hundred quid and you can have it on a CD exportable to Excel, which makes analysis pretty easy).
I'm less sure what the Australians do, but I think it's fairly similar.
So far as I know, the USA does what they call the "Air Taxi Survey" of parts of the fleet, but it's not a whole fleet dataset in the way that certainly exists for the UK.
G
As I recall, the UK also surveys aircraft movements, the concern being that this gives the impression that hours are declining but fails to take into consideration the move towards flying from farmstrips (i.e. may understimate flying). There's another document out there (near the top of the search list) that gives more details about how the accidents were counted.
The UK and USA figures were originally posted more to argue that they were within the same ballpark, which is to say that general aviation remains an order of magnitude (or so) more dangerous than driving in a car in both countries. To really argue against this, you'd have to argue that the aviation statistics were out by an order of magnitude, or that the driving statistics were considerably different in both countries - which of course they are. Obviously arguing that they may be out by a factor of 2 or 3 weakens the argument somewhat, but there's still considerable latitude for being wrong, and still being right.
I agree that the US publishes very good statistics, but part of the reason for this has got to be simply that there aren't enough aircraft or accidents to make this worthwhile in most other countries. The UK statistic was calculated from data collected over the course of a decade, and still only covered about 140 accidents. This makes for a 95% confidence interval of about 120 to 170, without even taking into account the fact that we're not sure how many hours were flown not to mention all the other (valid) concerns about fleet composition etc.
The UK and USA figures were originally posted more to argue that they were within the same ballpark, which is to say that general aviation remains an order of magnitude (or so) more dangerous than driving in a car in both countries. To really argue against this, you'd have to argue that the aviation statistics were out by an order of magnitude, or that the driving statistics were considerably different in both countries - which of course they are. Obviously arguing that they may be out by a factor of 2 or 3 weakens the argument somewhat, but there's still considerable latitude for being wrong, and still being right.
I agree that the US publishes very good statistics, but part of the reason for this has got to be simply that there aren't enough aircraft or accidents to make this worthwhile in most other countries. The UK statistic was calculated from data collected over the course of a decade, and still only covered about 140 accidents. This makes for a 95% confidence interval of about 120 to 170, without even taking into account the fact that we're not sure how many hours were flown not to mention all the other (valid) concerns about fleet composition etc.
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And of course this is the big problem with statistics in that they can be presented and manipulated to give credence to an argument/discussion. I remember Reading not long ago that the general long term 'trend' in GA accidents was stable. i.e static at a level. This could be perceived as 'the acceptable level, although that term relevent to safety is not a good one. A bit like drunk driving, where regardless of initiatives, there will always be a base level that will be difficult to break. On reading about that trend u was concerned that it would appear despite advances in design, glass cockpit technology, the accident rate did not diminish. Statistically one would have thought that it might.