Would that be suggesting that a MEP (land) rating covers any MEP (land) aircraft regardless of systems (EFIS/Turbo/Press etc)? There is a high chance that I am reading it wrongly but initially that is the way it reads to me.
Looking at table 10 here (http://www.easa.europa.eu/certification/experts/docs/oeb-general/ListofAeroplanes--ClassandTypeRatingsandEndorsementList-12062013.pdf) I think you are right. The distinction between various levels of complication that exists with singles and which requires differences training is omitted from the list of twins. In the referenced document there is only one type (the Diamond DA42 on top in table 1) that actually requires differences training!
1) Turbocharger does require differences training
2) differences trainings do require flying with an instructor (as opposed to familiarisations)
3) within the SEP and TMG classes, differences trainings don't have any recency requirements (for MEP, there are)
These are the various "differences" according to Part FCL:
1) Turbocharger does require differences training
Only for SEP! Once you have flown your first MEP type, you can fly al the others as well with just a familiarisation. With or without turbocharger. Which really isn't a big deal. You just can't advance the throttle to the stop but have to look at the manifold pressure while adding power.
Right you are. Only SEP. Sorry for not bering entirely clear in my post above. The table says it all.
It seems really arbitrary. Why did they draft the rule that way?
It seems really arbitrary.
And incomplete. I think the MEP section will need to be rewritten ASAP. There is absolutely no point in getting a multi-engine rating in a fixed-wing fixed-prop unpressurised Partenavia and then flying an old Cessna 421B without differences training. Enough people have got killed because of that already.
Why did they draft the rule that way?
The usual compromise when 24 representatives of 24 (or whatever number) countries think they alone know how things need to be done.
But isn't the whole world of "differences training" (etc) stuck hopelessly in the Dark Ages?
One can keep it simple, or one can force a formal type rating course for every different type of major glass cockpit component.
In large jet aviation, the latter is essentially what happens i.e. there is type specific training.
The general view in light GA is that would be overkill. I tend to agree, even though I am not happy with the fact that so many people who fly behind G1000-type panels don't really know how much of it works.
EASA's problem was "eloquently" expressed by a Mr Seebohm who said, with a completely straight face that only a Eurocrac could muster, that there are areas in European aviation where there is no regulation, so EASA must go and create some...
There are turbocharger installations which are normalised so you don't need to watch the MP. You can just fly with the throttle all the way forward. The TB21 is one example.
If you do that you will waste money, etc, but you won't contravene the POH 
I have to say it seems a bit strange to me also. I feel like it's all a bit muddled misshapen. I am sure I have read a reference (possibly in CAP 804) that says that doing differences training in a single for lets say a turbocharger installation would not cover you for the same thing in a MEP, which doesn't seem to agree with much since you don't differences training for it in the MEP. Similarly, if I fly a MEP with a turbocharger (to keep it consistent), having not done any differences training, merely familiarisation - can I then fly a tc SEP without the differences?
Probably all irrelevant at the end of the day for the large part of it anyway. With regard to what Peter is saying about people flying around behind G1000 panels with little knowledge of it, there is a book full of differences training stickers at my local club which operates a couple of G1000 172s as well as some conventional ones. I don't think any of these have ever been used, and actually a few years ago when I was doing my IMC rating I recall one day having to use a G1000 aircraft due to a tech issue, and the experienced (ATPL, lots of instruction and regional stuff) instructor start to look a bit perplexed when he couldn't quite work out how to display VOR1 and 2 on the HSI when moving on to VOR tracking in a lesson.
Regardless of the regulations, I worry about people who need regulations to know when they need differences training.
Regardless of the regulations, I worry about people who need regulations to know when they need differences training.
Exactly. It reminds me of a woman I knew 20 years ago who told me she felt safer driving now that they'd passed a seat belt law.
Pilots aren't typically as stupid as that, and I think this kind of thing arises with an aviation culture that isn't based on ownership, and therefore assumes people want as little investment in flying a given aircraft as they can get away with. Its a vicious circle wherein over regulation makes ownership harder, which then creates the 'need' for more regulation because people aren't invested in what they're doing.
Just my observation.
