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Initial questions on the purchase of a TB 20 / 21

I've a feeling this has already been discussed, but I can't locate the thread, giving advice on purchase of an a/c to be based in the UK.

I'm not particularly experienced in this area, but having prior knowledge of the questions below, and accident history could save a trip or two around Europe to go through airframe/prop/avionics and engine logs in person.

Having exchanged basic information on the a/c (airframe, prop and engine times remaining BO), could anyone suggest further questions to the owner in addition to those below? They're not in any particular order. The initial choice is TB20 or 21 (Lycoming 540), preferably, but not exclusively, EASA:

(1) Has the aircraft always been (and currently) hangared?

(2) Type of autopilot fitted fully functioning? Altitude hold?

(3) Are there any none serviceable items including avionics on the aircraft?

(4) Has the aircraft ever, to your knowledge, been used in a club environment?

(5) Has the aircraft ever, to your knowledge, been involved in any accidents/incidents, however minor?

(6) Are all the SBs and ADs complied with? Please provide a list of these.

(7) Please provide a current Component Status list.

(8) Please provide the name and address of the maintenance organisation that maintains the aircraft.

(9) When was the last annual completed and please provide a list of items, if any, that were deferred.

(10) Please confirm the date when the engine was last factory overhauled.

(11) Please confirm the date when the prop was last overhauled and by who.

(12) At the last annual we presume a corrosion inspection was done. Was a report also done of this inspection?

(13) Please provide the cylinder compressions for the last 24 months.

(14) How many hours has the aircraft logged in the last 2 years?

(15) Are all the aircraft logs available for inspection including the ones when it was previously registered as *****?

(16) Prop de-icing serviceable?

Swanborough Farm (UK), Shoreham EGKA, Soysambu (Kenya), Kenya

has the aircraft got a mode S transponder?

what kind of GPS is installed? is LPV possible (WAAS enabled) ? is a GPSS aboard?

what about a moving map ?

are the radio channels 8,33KHz spaced?

does it have an engine monitoring instrument for all six cylinders (EGT/CHT) e.g. EDM 700 ?

has it got a three blade prop? a bit less noise but looking stylish ...

just my 2 cents

EDxx, Germany

Many thanks for the suggestions, Nobbi. This particular a/c has mostly King avionics, and my current knowledge is mainly Garmin, but I'll double-check the avionics set-up and other points.

Swanborough Farm (UK), Shoreham EGKA, Soysambu (Kenya), Kenya

For a TB20, I suggest you give Peter a call. You may, though, come away with a binder full of questions and suggestions ;-))

I am away travelling but basically you need to do a proper prebuy inspection anyway, Stuff like cylinder compressions will be done at each Annual.

Those questions are all reasonable. However note that if somebody wants to withold something they will just give you a false answer...

I would also ask about any avionics approvals. For example a GNS530 which was just put in without a BRNAV AFMS is not legal for IFR except Class G, and that is really common. There is a tendency for UK avionics shops to install stuff and leave the customer responsible for approvals, and I've had quotes for 5-figure work with that disclaimer in the small print, which is outrageous.

And same with checking logbooks for work done. Much maintenance work is covered with logbook inserts which the aircraft owner is supposed to glue into the logbook, but if the insert is likely to reduce the aircraft value he can just not put it in. For example I am aware of a certain aircraft which had many issues with a certain item, which were rectified by a firm known to me, each time, and which was sold to somebody who turned out to know nothing about it. Presumably the owner just chucked away the logbook inserts... This is why AD compliance for example needs to be checked visually. With avionics, check full functionality on a test flight, especially the autopilot.

I have done some informal prebuy checks on TBs and usually I find, within minutes, that the aircraft has not seen grease in the most obvious places - even when serviced by the most expensive EASA145 etc etc etc company. That is how nearly all GA maintenance works in the UK and from what I hear in most other places including the USA. You spray a bit of lube here and there...

I know a man who travels to do TB prebuy checks - ex Air Touring.

Shoreham EGKA, United Kingdom

I would always ask about empty weight and CoG. It would obviously tell if you can load the airplane as desired, but could also give a hint about structural repairs that have added weight. A TB-20 based here at EKRK gained more than 40 kgs many years ago when repaired after a landing mishap.

EKRK, Denmark

40kg is a massive repair.

That is practically a whole wing spar, or re-skinning the whole hull in 3mm

Are you sure the repair itself added 40kg, or perhaps the occasion was the first time the plane was weighed for many years? Many old planes have a very optimistic w&b schedule.

Shoreham EGKA, United Kingdom

I appreciate the invaluable feedback. So far, putting those questions to seller(s), the response is either a deafening silence, or totally irrelevant replies.

Swanborough Farm (UK), Shoreham EGKA, Soysambu (Kenya), Kenya

Welcome to the world of buying used aircraft!

Frankfurt (EDFZ, EDFE), Germany

We don't understand the non-response. Sure, it will take time to produce the answers, many of which would come from their maintenance outfit, and if we don't take it further, then the seller can use it to answer other enquiries.

So, are we asking too much? Surely none of you would go ahead without the information? Or does it mean an afternoon (with engineer preferably) going through the tech. logs? Doing this seriously, around Europe, isn't exactly economical.

Sent to 4 sellers (UK, Germany, Sweden, Italy), the response, so far, is zero (besides non-relevant answers - leather seats are in good condition, mostly hangared, exterior 'as new' etc.).

Swanborough Farm (UK), Shoreham EGKA, Soysambu (Kenya), Kenya
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