Rami1988, My TB20 was not hangered as there is no hangerage available at Denham where I am based. What is the TB20 at Goodwood? I saw some messages on this forum a while ago trying to replace the wing on a TB20 at Goodwood due to corrosion. I don’t know what the outcome of that was, or if this is the same aircraft. I can’t help you with the prop or DME as mine is only a 2-bladed prop and the DME recenty failed. I think it is only the display of the DME that has failed (it was getting flakey before the complete failure) and I was planning to send it to Avionik Straubing for repair. But that was put on hold when the corrosion was found. Regarding the TKS, I think it would be good to have but I would certainly be cautious about using in anything other than brief IMC until I had more experience with it.
Peter, I was certainly rather naive when I bought my first TB20. I did have a pre buy inspection done but it was really just the engineers haveing a quick look over the aircraft and the documents. I had no idea about any potential corrosion issues at that time. I did find all your write ups about TB20 ownership very useful though, and it was partly because of those that I decided to buy it. (So it’s your fault!) The engineers have suggested that if I am going to buy another one I should have it flown to their place for at least 3 days so thay can give it a real good going over. But even so, I think it is hard to inspect all areas of the wing spar through the available access holes. Do you have any suggestions of how to do it properly or what equipment to use? Is there any special kind of borescope to use or is a standard one adequate? Also, if I do go ahead, what would you recommend for treatment or ongoing maintainance to prevent corrosion in the future? Am I onto a complete loser by keeping it outside at Denham? If the corrosion problem is due to defective material or heat treatment at manufacture then are everybody’s wings spars eventually going to rot? How often do you inspect yours? I don’t think my engine is affected by SB569. I don’t have the details to hand but I remeber looking up the serial number and it was not within the affected range.
Even the airlines struggle sometimes with rain ice etc.
Huh? Not really. Probably 0.0000000000000000001% of flights.
Snoopy wrote:
Snoopy16-Feb-24 19:44220
Even the airlines struggle sometimes with rain ice etc.Huh? Not really. Probably 0.0000000000000000001% of flights.
Snoopy wrote:
sometimes
Well, yeah, I suppose it´s true if it´s put in the context of related delays and cancellations subject to winter storms. The reason would NOT be the airline(ers) as in AIRPLANES themselves though – but the airport clearing procedures (aprons, taxiways, runways) and general airport related infrastructures.
Others can opine but I do believe lack of hangerage could lead to extensive corrosion in the UK, especially given the fantastic materials used in TB20 :)
On that note, I read somewhere that the newer tb20s >1990 used different materials which were less susceptible- is that true or just a fib?
Re icing, airliners fly above the ice and avoid icing conditions like the plague. Its much more relevant for us as we can’t climb high enough so could spend extended periods in ice.
Far fewer corrosion cases with the GT aircraft, AFAIK.
It isn’t just the UK. Weather is much the same in much of the mainland. The main airflow is westerly so e.g. La Rochelle, while warmer than say Shoreham, will get the same muck from the ocean.
They did change the main spar material (mod 152), but it was about the same time as the change from G1 to GT (mod 151) so I don’t think any G1 TB20s were made with the new material. There is a thread about it (see below). The last post from Peter in that thread lists the exact serial numbers when they made the change. I’m not aware of any earlier change, although I could be wrong.
https://www.euroga.org/forums/maintenance-avionics/12679-socata-wing-spar-material?page=1
Rami1988 wrote:
Re icing, airliners fly above the ice and avoid icing conditions like the plague
Again? Yes, climbing/descending at 3’000ft/mn or more allows reduced time in icing conditions, but the common airliner of either European or American manufacture is equipped for flight into adverse wx.
A little known but quantified beneficial aspect of a faster airliner is Ram rise.
As a matter of fact, it is surprising how airliner manufacturer have dropped some of their ice protection over the years, probably thanks to increasing climb performance… looking at older stuff like DCs and Boeing of all kinds, I was surprised when type rating on the Bus that only the wings LE, and not even the whole length of them, are protected. Nothing on the tail feathers nowadays. Icing? Just add 10kts (IIRC) on the Vref “if ice is suspected”.
In some 28 years and 20Khrs of line flying there was not one instance of “avoiding the plague”….
Severe icing was seldom and very short, solved (great fun to watch the ice flying away 
) with the push of a button, easy.
Here’s a picture taken in 2013 of the “ice detector” as fitted on the Bus:
Excuse the thread drift, and back to the all mighty TB20 
Around S/N 2000 there were a number of planes assembled which had some pre-GT (pre Mod 152) features and some post-GT features.
Nobody will be told what his spars are made of but this situation is quite evident around the avionics.
There are lots of pages in the MM/IPC which have footnotes on S/N applicability, with funny stuff around S/N 2000.
Mine is S/N 2121 which is 100% GT and was built from the same pile as anything later. Socata made an internal decision to stop piston production around year 2001. They just didn’t tell anybody
The TB is a great aircraft, and the TB20/21 are especially capable machines, with no equal for ticking lots of boxes, notably range and comfort, unless you want a parachute for “family acceptance”. Unfortunately the company has been variable in its honesty e.g. the inconel exhaust on the GT which never was. At the same time their corporate hospitality has always been top-notch.
Prompted by this thread, I just looked at TB20/21 prices. It’s pretty incredible. There are people asking over 300K for them! There are plenty of pre-GT aircraft asking over 200K (€/$, whatever). Doesn’t mean they’ll get what they’re asking of course, but there must be some relationship.
That has changed even in the last couple of months. Makes me think that mine, even after spending 50K on the engine, could probably pay back close to what I’ve paid for it. Not that I’m in a hurry to sell.
The TB is a great aircraft, and the TB20/21 are especially capable machines, with no equal for ticking lots of boxes, notably range and comfort, unless you want a parachute for “family acceptance”.
Absolutely. If I hadn’t moved to twin I would’ve never sold TB20. Mine was S/N 1923, manufactured in March 2000, probably one of the last G1. In 2010 when I bought it, absolutely no corrosion and practically in mint condition with 1200 airframe and engine hours (located in Netherlands, always hangared). I sold it in same condition 2015, also always hangared. I was affected by SB569 but the purchasing price was lowered and I got good deal on new engine replacing it 2012 at 1600 airframe hours.
