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PPL in a Twin

Old 17th Oct 2011, 15:48
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The only reason I see it would be smart to do PPL in a MEP if the student owned the aircraft and it would be cheaper to fly his own twin than rent a single-engine trainer - if such aircraft even exists, which I highly doubt

As previous posts explain, losing an engine in a light twin doesn't mean you lost 50% of all your power - ~ 90% is much more realistic number. I suggest reading this article - especially look at the numbers. Flying is all about risk management, whatever the aircraft type/size/number of engines - and engine failures really aren't that common if you compare it to number of CFIT accidents.

And as IO540 states, it's nothing complex about handling a VP prop and retractable gear - it's usually the speed of the aircraft, which is why you must think much more ahead than with an usual spam-can.
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Old 17th Oct 2011, 16:53
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Why would you want to?
Without wanting to be rude, I think the goal of the thread was to get answers to the question, not questions.
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Old 17th Oct 2011, 16:57
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losing an engine in a light twin doesn't mean you lost 50% of all your power
Yes it does, its that when you loose 50% of your total power you have actually lost a much higher percentage of the excess power available.

A PPL on a MEP would of course have to be conducted at an FTO rather than a registered facility and they would need an approved course. I suspect Insurance remains the major hurdle.
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Old 17th Oct 2011, 18:12
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MEP engine failure, 50% power loss = 95% performance loss.

Without doubt all the MEP's I have flown have been the most demanding to aircraft to fly on one engine, unlike turbines that air quite forgiving , the turbine that I have flown that required as much skill to fly with engines not working was the Electra with two out on the same side.

All things considered in the hands of a low time pilot an engine faiure in an SEP is much safer that an engine failure in an MEP.
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Old 17th Oct 2011, 18:43
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Some interesting responses so far, I'm glad I started this thread, its been quite educational, even if the actual situation may never arise in reality, its nice to know that in theory it could be done!
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Old 17th Oct 2011, 19:42
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Theoretically possible but a stupid idea.

Secondly the missus is incredibly concerned about flying in a single engine plane, which also means she's terrified about me doing it! Hence, I was wondering if there was a potential way round this, as that would make her feel better,...
The missus is misinformed. Flying a twin engine is more accident prone than flying a single engine. Unless you're doing long stretches over water (to the cottage in Sweden or something) or other inhospitable terrain, flying a single is a lot safer.

You could explain her that
a) an engine failure in flight on a properly pre-flighted and correctly maintained modern aircraft is a VERY RARE event, rarer than the missus and yourself having an accident driving to the airport
b) an single engine aircraft with an engine failure becomes a glider (albeit a heavy one)
c) the main accident causes are pilot error (such as flying VFR into IMC and mid-air near an airport, neither of which can be resolved by adding an engine) and you promise to do everything by the book, always, because you love her. This might imply that you won't be home for supper on some occasions.


As Backpacker pointed out:
- probability of an engine failure is about double in a twin than in a single
and also
- inexperienced pilots are much more likely to mishandle an engine failure in a twin than in a single

Second point is insurance : unless you own the plane and/or strike a good deal with an insurance company, they won't let you solo a twin with under 250 hours TT (of which 50 on your twin). And then we are talking a BE76 Duchess or a PA23 Aztec or some other twin that only makes sense as a trainer. For a proper Cessna 310, no insurance company will sensibly underwrite your soloing under 500 hours (even if you owned it they would ask for at least half of that).

As insurance is important in your particular case (not only do you want to protect the capital invested in your plane, you want to make sure to take care of the missus in the rare event that something does happen to you), the underwriting restrictions will dictate your line of action.


Third point is learning efficiency. It is a hell of a lot easier to operate a spam can (or a warrior, katana, cheetah, ...) than a Duchess. Even with proper ground preparation, it will still take you longer to properly fly a circuit and land a twin than to do the same with the spam can. No matter how good your instructor is, you would lose precious flying time with basic handling of the duchess.
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Old 17th Oct 2011, 19:52
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The only reason I see it would be smart to do PPL in a MEP if the student owned the aircraft and it would be cheaper to fly his own twin than rent a single-engine trainer - if such aircraft even exists, which I highly doubt
I flew such an owner in a Seneca five twin for a few years. As most was SP I taught him how to fly the aircraft until the point that he used to fly the whole route from the right seat.
The owner started training for an FAA PPL in the aircraft after I left although I believe he did part in a single.

If the missues is worried about singles why not a Cirrus then you can tell her it has its own parachute system to lower you all safely to the ground in event of you having a heart attack

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Old 17th Oct 2011, 20:11
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Haha I did think about that actually!
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Old 17th Oct 2011, 22:08
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probability of an engine failure is about double in a twin than in a single
Perhaps more than 2x, because

- the control cable runs are much longer

- the engines are believed to be subject to more vibration (more flimsy mounting)

- the owners, mostly, are less fussy about maintenance, precisely because they have a spare engine (and some are quite open about it, too)
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Old 18th Oct 2011, 06:41
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"- the owners, mostly, are less fussy about maintenance, precisely because they have a spare engine (and some are quite open about it, too)"

Rubbish!. What a completely unfounded statement.
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Old 18th Oct 2011, 12:08
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Backpacker

I cannot agree with your Interpretation of the safety benefits of a twin.
Yes climb performance especially at grosse weight and high temps can be minimal or nil and yes a lot of accidents occur with pilots attempting to climb on one engine.
I had an engine failure on a 100 hr total time Seneca but still had at my guess 30 % power. I did not shut the engine down until I got up to 1000 feet.
I held one hand on the prop lever ready to pull it in event of a complete failure. At 1000 feet I shut it down flew level and landed.
Cause three broken rocker shafts!
A light twin does badly climbing on one but is brilliant flying level on one.
15 plus years ago we shut an engine down flying Bournemouth to France and didn't restart until approaching the French coast.
Not a clever thing to do but it does show that a light twin is perfectly happy flying level on one.
There is no reason at most fields why you cannot go for level flight at 500 feet rather than a climb. Then once established in single engine cruise step climb on the trim very slowly to circuit height.
At night, over fog in IMC or over water a light twin will fly well on one but in level flight.
Maybe training should look at light twins in a different light.
The light twin gives more options than purely heading for the ground as in a single. Light on fuel and PAX it will climb so yet another option.

Pace
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Old 18th Oct 2011, 12:50
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Like I said, in the hands of a competent and current pilot a light twin does offer a technical safety benefit over a single. However, what I've seen about the statistics is that that technical safety benefit is negated by having twice the number of bits that can go wrong, and by pilots going on more dangerous missions. At night, in fog/IMC and over water for example - something that only very brave SEP pilots would do.

And let me offer up another story for comparison. One of my pilot friends had a recent fATPL and was due his MEP checkride. For preparation he booked a sim session with an instructor and I was invited to sit RHS just for fun. The request he had to the instructor was an IFR flight ending in a few different approaches plus some failures. The usual workout.

After one particular missed approach, climbing away at full power, still in IMC, the instructor failed one of the engines. Three seconds later we were inverted in the field, dead, and the instructor stopped the simulator. The look in my friends eyes was something to behold.

Now I appreciate that an FNPT-II (or whatever it was) certified simulator is still not moving and does not give you the seat-of-the-pants yaw response that a real twin would give in case of an engine failure. That may offer a partial explanation why my friend didn't react instantly the way he should. But it still shows that in a twin things can go from good to hell in a very short period of time. In a single, at the very least, the aircraft would not have inverted itself in zero time flat, giving you far more (though still limited) time to figure out what to do and where to (crash) land it.

Edited: I guess the point I'm trying to make all along is that twins are not automatically and inherently twice as safe as singles - something your missus seems to believe. Yes, twins offer more safety and more options in case of an engine failure but the downside is that it requires more training, more currency and more money to be a competent enough pilot to realize these safety benefits.

Last edited by BackPacker; 18th Oct 2011 at 14:16.
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Old 18th Oct 2011, 12:52
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All things considered in the hands of a low time pilot an engine faiure in an SEP is much safer that an engine failure in an MEP
That really depends on the pilot. I would fancy someone who has just completed their MEP course's chances a lot more than someone who passed it 5 years ago, does the bare minimum of hours and scrapes through the revalidation each year. IMHO it really comes down to the pilots attitude towards currency, and seeking instruction if they aren't current enough.

probability of an engine failure is about double in a twin than in a single
Oh please, save me from this tosh. Normally it's TBM salesmen or single engine fanboys that spout this crap. We can manipulate stats all we like. One could argue that any given piston engine, well maintained, has the same chance of failure. If one does go I'd rather have a spare one on the other side.

Twin training isn't all that difficult really, and brings a whole new dimension to flight planning long trips (and a whole new planet of expense!). But insurance will always be the prohibitive factor in a situation like this. And I'm not sure I'd move away from the traditional learning sequence.

I wonder what these guys would rather have been in:
http://www.pprune.org/biz-jets-ag-fl...near-kfll.html
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Old 18th Oct 2011, 13:24
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vjmehra,

As I hope you realise, there's a lot of nonsense on this thread, but the basic economic argument is reasonable.

The underlying answer to your question is YES, you can get your PPL on a twin. I have a friend who did just that, and went on to go commercial and get various turbine type ratings without ever having SEP on her licence. Of course, there was a catch. Her husband owned a MEP aircraft, and was an instructor :-)

Without that little quirk, it really doesn't make much economic sense.
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Old 18th Oct 2011, 13:27
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Good point, well made!
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Old 18th Oct 2011, 13:52
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The problem with light twins is that they have been extensively used for commercial training looking at larger more capable aircraft in the future!
IMO that is why the accident rates are high especially in low time incurrent private pilots.
Light twins give you more options than a single but they are options!
One maybe to establish blue line and go for a climb at grosse weight!
Maybe ok till you hit sinking air and blue line has gone while you are adding more and more rudder to hold the ship together.
That training forgets you have an extra throttle connected to another energy source through the elevator. It forgets other drag you can get rid of other than flaps gear props etc.
As stated why try and kill yourself trying to hold blue line when most light twins are more than happy in level flight!
The twin doesn't know whether it's at 300 feet agl or 3000 feet !
As in my engine failure, feather the prop shut down the faulty engine!
Why? Why shut down a unit producing 30 % power when you desperately need it ? In my case it worked.
The extra engine gives you more options one which maybe to close both and take to a field.
Historically twin training has been all about blue line NOT thinking out of the box at numerous options open to you.
IMO that is the reason for bad accident stats on twins.

Pace
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Old 18th Oct 2011, 14:47
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The twin incident stats would be even worse had it not been for the fact that most enroute engine failures (which should mostly be a non-event) are bound to be unreported.

Normally it's TBM salesmen or single engine fanboys that spout this crap. We can manipulate stats all we like. One could argue that any given piston engine, well maintained, has the same chance of failure. If one does go I'd rather have a spare one on the other side.
I am no TBM salesman but I think you have a basic misunderstanding of stats. It is a fact that the fatality rate (or any other incident rate that you care to pick) of SE turboprops is around several times lower than that of piston twins - regardless of how the piston twins are operated.

Emotionally, the warm feeling from a 2nd engine is fully understandable, but the numbers do not support it.

If one went on the basis of a concurrent failure of two unconnected systems being extremely improbable (which it certainly is) then twins of any sort should never go down as a result of loss of propulsion.

Yet they do.

If one takes out fuel system mismanagement (which is arguably 100% pilot error, no matter how confusing some of them are) you are still left with plenty of ways to go down.

And if you are crossing terrain which rises above the SE ceiling of the twin (for a significant distance) then you have a 2x (min.) chance of crashing into it, than with a single. Admittedly that is an unusual case in Europe (the Alps take only ~ 45 mins to cross, N-S) but twin owners do like to use mountains as a common example of twin advantages.
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Old 18th Oct 2011, 15:00
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Agree with Pace.

I'm a pretty new twin flyer, but have already had my left engine semi-fail on my previous cross country. 2 cylinders went bad, one chewing oil rings plugging up the sparks and making damage, the other shedding a valve. I was over Iowa fields at the moment and only an hour away from my destination, Chicago. Engine ran rough but was still producing power on 4 cylinders (which I didn't know then, I though it was a magneto problem), so I opted to continue. Because I knew that flying the Commander on one is a total non-event. In my type conversion, we shut one down completely and landed with it as you should. Rudder trim for it and she'll fly all day long like that.

Aircraft has since been repaired and just end of last week I flew her back. With two new cylinders I was weary of crossing Rockies and Sierra Nevadas, so I opted for a more southerly route, via New Mexico and Arizona with lower mountains. What I hadn't counted on is how extremely barren these areas are and I felt terrible lonely and apprehensive over these huge vast forests, canyons and mountains (albeit lower than the Rockies). In those cases I was very glad to be sitting in a twin - below me there were literally zero options for a successful forced landing.

A twin is not hard to fly on one engine. And most importantly, if you ever get into control troubles with a twin, just reduce the good engine until your control problems disappear and start over. If you're heavy, trying to outclimb things and run out of rudder, Vmc, pull back, reconfigure, rethink. As Pace said, they'll fly S&L all day long at lower altitudes. It's pretty intuitive.
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Old 18th Oct 2011, 16:30
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Addendum

Just to stress I am not diminishing the importance of flying blue line before someone jumps down my throat

If you have the discipline, courage and accuracy of flying to peg blue line good for you! but that means on hot days, or at grosse, or on windy turbulent days being able to accept minimal or no climb or maybe even a descent rate of 500 fpm.

My problem with blue line is that in low powered twins the margins for error are small. Add in panicking pax and other distractions and it's only too easy to loose blue and to get into a mess!

In the right conditions and weight blue line may be the right way but there are other ways with larger margins for different situations.

For me flying light twins is about respecting the limitations of a light twin and flying out of the box considering a number of options and using them even if that's closed throttles into s field.
Remember too that a light twin will fly quite happily all day on one engine if your flying level and use that fact to your advantage !!

Pace

Last edited by Pace; 18th Oct 2011 at 17:37.
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Old 18th Oct 2011, 16:50
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but I think you have a basic misunderstanding of stats. It is a fact that the fatality rate (or any other incident rate that you care to pick) of SE turboprops is around several times lower than that of piston twins - regardless of how the piston twins are operated
With the greatest of respect and not wanting to commence the usual prune back and forth which I try to stay away from.

My understanding of stats is pretty sound. And my point stands, one can make them look however one wants to.
There are many many thousands more piston twins in the world than turbine singles. It stands there are therefore more accidents. Also the piston twin fleet is generally much older, Cessna 310 fuel system anyone? So comparing a rate per 100000 hours or any other comparison generally doen't stand scrutiny.
My post was comparing single engine pistons with multi engine pistons, and the added safety factor the second engine provides. And also an attempt to dispel the naysayers that say anyone who touches a piston twin will die a horrid death. I've flown them for years and am still about.

I hear the 'double chance of engine failure' line a lot from Pilatus and TBM. And it hacks me off every time. Generally they are comparing their new machines to turbine twins. And it really is just a play on words. At the end of the day if the singles engine quits you are going one way. And if it quits at height you are starting that journey very quickly to recover cabin alt. In the turbine twin if an engine fails it's no big deal.

My example at the end, whilst tongue in cheek is still very very valid. Which machine do you think those pax would rather have been in?
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