I lost my paper map on open cockpit (too crap to open & fold with wind in a crampy single seater) somewhere near Eastbourn coast had to fly north, follow M20, then M25 at 1500ft amsl to get back !
Now, I have an old paper edition cut in small pieces, nothing to be taken granted 
I haven’t read all the posts, but I would summarize by saying there are two dimensions: regulatory and common sense. On the level of fixed gear SEP, there is little/nothing demanded in differences training on a regulatory level. Clubs will demand a check out because they assume (often rightly) that the guy who wants to rent is not current.
I remember, not having flown in a long time, how easy it was to fly a low wing Rallye, even though most of my experience was in high wing 172s. But it were were essentially no new avionics involved. So transitions can be easy.
Even so, I would definitely want the first flight to be with someone familiar with the type. Little things, like the location of the flap switch, can be distracting. Avionics can be a major issue, even between identical aircraft models.
I am always more focused on reality than regulatory demand, which means I am usually more conservative than the rules on this sort of issue. But my experience is more in low level planes.
Ibra wrote
tricycle conversion from tailwheel
That’s me! No one has ever asked me for a nosewheel difference training sign off
On the other hand, the club where I learned to fly did difference training internally, e.g. this pilot can fly these planes (usually all planes unless a student). I had problems later on as one of the planes had a CS propeller, but I didn’t have the logbook entry… luckily one of the instructors kindly wrote a letter swearing on his honour that I could fly CS/VP. Stressful at the time, but in hindsight petty and unnecessary.
Cobalt wrote
supreme silliness, these rules means that nothing you do in a twin carries across to a single
The same instructor had bureaucratic problems with SE night: “I know it’s only 4h59 but I’ve got 3,000 hours ME night”… you can guess the answer.
Noe wrote
So what happens when you lose your logbook?
I try to scan my logbook every time I finish a page; sometimes I forget/can’t be bothered but I’m never more than 2 or 3 pages behind. It only takes a minute and preserves instructor signatures etc. It would be easy enough to print if necessary.
Two planes I fly, the DR.221 and DR.250, are identical except for engine size, number of fuel tanks, and very annoyingly the (identical) alternator & fuel pump switches are transposed. A bit like which side of the steering wheel the windscreen wiper control is, but a bit more serious. No difference training required, obviously.
WhiskeyPapa has it right: it comes back to common sense.
The one that I can’t understand in our world over regulation is why there isn’t differences training for operating aircraft are anti-ice equipped.
I’m sure there is a CAA approved 10 hour theory course plus 5 hours flying all to be done at an ATO in there somewhere.
Most of my flying has been tailwheel. Have I been flying illegally by not seeking tailwheel training when we came under EASA? I was flying 50 hours+ in a tailwheel over those years. Very few nosewheel hours since 1990.
(Last instructor tailwheel sign-off was early 1965. My biennial is always a Pa38/28 check out at the local school.)
If you have logged hours in a logbook well before the year 2000 and can show it, you are more or less grand fathered. :)
Capitaine wrote:
That’s me! No one has ever asked me for a nosewheel difference training sign off
I wouldn’t ask for that either. But some of the other “reverse difference trainings” are not so trivial.
Last year I gave the first checkout to classic Piper PA-28 for a pilot that had only flown a Thielert diesel converted Piper with FADEC, which to “normal” pilots requires the Single Lever Power Control diff. training.
I found that I had to teach and train fuel planning (different density, more contingency fuel, no fuel flow meter, start-up (the art of priming), fire hazard (much greater risk, what to do in case of the not-so-unlikely engine fire during start-up), mixture (overwhelming if you want to give the full course), carb heat (new habits, suspicions and procedures, dependency on engine heat, weather conditions), mags and mag checks, engine instrument interpretations, how do you set 65% without an %-power indicator and how do you know the power setting during climb and descent? – engine trouble procedures, leaning habits again because it was never trained during PPL training, and the general attitude about flying an engine that is much more “by feel” because it is not digitally controlled and its instrumentation is not very precise, and even the fixed pitch prop makes for different feed-back to the pilot.
The pilot’s training for non-SLPC was duly entered in his logbook as a difference training.
Did you also enter non-turbo differences training in his logbook?
huv wrote:
Difference training is very poorly described in the regs
I think it’s described very well. Necessary training differs a lot based on knowledge, aptitude, experience, intelligence of a student and design of the system at hand, and it is a good thing, the content is left open by the regulator.
In the olden days there was no need for regulations about what differences training was, and when it should be done. In those days pilots just had to get “checked out” or otherwise taught how to do things by someone who knew how. Remember, years ago you could fly a King Air on a PPL with a Group B rating, no type ratings, differences training, etc. It worked for me.
