There are counters with a differential pressure switch, i.e. that count whenever the pressure differential between ram air and static air is above a certain threshold.
Works great and really only counts flight time (except when maintenance does a static port check, obviously).
I think the only rational reason to legally require a 'journey log' is if the plane has no recording tach or Hobbs meter - they were invented to eliminate the need to record every flight. I think 70 years ago it was common for people to keep such a log in the US, unheard of now including for international flights.
It's fun to look back through many decades of entries in my aircraft and engine maintenance logs and see how the style changed. Now the mechanic makes up a sticker on his home computer for anything major. In the past they were all hand written, and often very abbreviated. That didn't stop one of my aircraft reaching over 500 hrs in the first summer after it was built.
It hadn't occurred to me that the Socata revcounter would stop counting if you turned the electrics off in flight.
I hope none of our group are doing that!
... but when I used to rent out my TB20, 2002-2006, I saw all kinds of stuff you would never believe ...
I also remember that from renting out a Seminole. Stuttgart-Hamburg in one hour twenty minutes, when even two hours twenty minutes would be sporty with a 150KTAS aeroplane. But that got clarified with three phone calls: One to Stuttgart airport to verify the departure time, one to Hamburg for the landing time and a third one to the renter ... "Oh, I'm so sorry, I must have confused UTC with local time...". Of course he paid for the extra our never flew that aircraft again. Of course this only works with fairly recent flights, verifying years old log entries can be next to impossible.
That makes me laugh 
A really crafty renter could play the system by reporting a flight time which - when viewed on the downloaded EDM700 data - is just plausible by climbing to 500 feet and setting the power to about 40% which is somewhere vaguely around 110kt (18" and 1800rpm, IIRC). I had one chap "fly" all the way to France and back like that, though I am sure he managed it entirely by accident because he didn't know about the EDM700 log. I kicked him off without even phoning the airport.
I would swear the latest EDM700 firmware compresses the data, because (a) the PC software I had can no longer open the downloaded file and (b) it seems to hold a lot more. JPI won't discuss it, possibly because they didn't like this.
I use savvyanalysis.com to view the JPI log files. Very well done and free of charge.
It would be almost impossible to sell a PH aircraft if the complete journey log was not available.
Why would that be?
no journey log means no record of maintenance checks - would you buy a used aircraft with incomplete documentation?
no journey log means no record of maintenance checks - would you buy a used aircraft with incomplete documentation?
I must be missing something here, because if I was buying a plane I would want to see the logbooks for the airframe, engine and propeller. That's 3 logbooks.
Where the pilot flew it, is less important. If I really cared I would ask to see his personal logbooks.
I would also want all the work packs from the maintenance company. They are legally required to deliver them (if they still have them!) although they can make a reasonable copying charge.
The problem is that almost any plane of any age (say 20+ years i.e. the bulk of the GA scene) will have incomplete service records. That doesn't necessarily mean there was missing work, but usually it does suggest that. In fact I don't think I have seen a single plane which was bought by somebody I know which didn't have some fairly major ADs or lifed items not complied with.
The problem is that almost any plane of any age (say 20+ years i.e. the bulk of the GA scene) will have incomplete service records.
Just like my 'new' aircraft, my older aircraft has maintenance logs from manufacture, 67 years ago. Originally it had only one logbook from the factory, no separate engine and airframe logs, and I have that one and all subsequent ones. Only one problem, there's absolutely nothing to guarantee its the same plane... The data plate is and was held in with generic rivets and like almost all airframes, the data plate has been removed and replaced for airframe painting. Also, the currently installed wings were made at least a month after the factory test flight in the logs. They made about 6000 of them, most have gone to the scrap yard, and it's doubtless convenient on occasion for one aircraft to become another. Or a collection of parts to become an aircraft for which complete logs were available.
For a simple aircraft, there's no need to get fussed about it. What really matters for most aircraft is what it is now, by inspection, plus the ability to obtain paperwork (CD) on existing mods needing approval, i.e. any 337s or equivalent. Almost nothing with old light aircraft is life limited and while its nice to feel you know the score for decades in the past, that's not the real world.
This one keeps coming up, in connection with EASA and its alleged implementation of an old ICAO requirement.
After 12 years, I have just filled up my journey logbook for the TB20…
That “CAA approved” logbook was originally supplied (2002) with the G-reg TB20 by Air Touring. It doesn’t seem to have ever served any purpose, other than duplicating entries in the pilot logbook, and summarising maintenance detailed in the airframe logbook. I’ve never been asked to show any logbook at any airport, and when I had to prove non-pilot maintenance for the UK CAA IR test (2012) I brought the three maintenance logbooks (airframe, engine, prop).
Does anyone have any views on what (if any) journey log may be expected by some N European airport policeman?
