This process has a long history but it seems to fail in just about every case I have ever heard of.
For Socata TBs, there was an attempt at getting about 10 owners to fund a Tornado Alley turbo STC, to in effect turn a TB20 into a TB21. The STC was quoted at ~$200k. The TB21 GT is very rare, its very rare TIO540-variant engine costs way more to overhaul, and in most cases where somebody wants to make the move and their TB20 is not a can of worms which they want to get rid of anyway it would be smarter to just install a turbo.
The autopilot options topic seems to be going nowhere too. Nothing actually exists, other than what it came with, or the now ancient STEC 55X.
There is the long saga of the Robin (and a search on “robin” digs out countless cases of near-desperate and totally-desperate owners).
I know the above three cases are all French but wonder if perhaps the common factor is the fleet size: around 2k or less. The operational patterns differ greatly between Socata and Robin, with the former used for a lot of IFR but with the latter having a vast majority in the French VFR club scene and with little or no interest in fancy avionics. Yet both have similar STC funding issues – except where the AML route is available and that is mostly limited to FAA-TC which excludes the Robin fleet.
Manufacturers obviously initially go for the low hanging fruit which is the Cessna / Piper / Cirrus / Mooney / Beech etc populations. These are all bigger than the French planes in fleet sizes, and they self-fund these. I wonder if 2k is just too small a population? By the time you have a rough guess at the real market, it may be in 2 digits only.
Socata did the G500 STC a couple of years ago, didn’t they ? Was this market-driven ?
The G500 STC for the TB was driven by a French military requirement for upgrades to a training fleet. It was published in the EU Journal and several companies including at least one from the UK went after it. It became apparent very quickly that it was always going to be given to the OEM.
Do you mean given for free to Garmin? Socata developed it. I met the people who did it.
It was much more than 2 years ago. They quoted me €48k+VAT for the installation, including 1 × GNS430W
Don’t Garmin have an STC for the old G500, whose AML covers the TB range?
The Socata STC pre-dates Garmin’s validated FAA AML, as do the multitude of individual Piper, Cessna and Rockwell STCs produced by three European Garmin design partners. Once Garmin achieved validation (a massive step forward for the AML appoach) all of our European STCs became nothing more than waste paper.
Garmin told me at Friedrichshafen that their G500txi can be used in a Socata TB20, as it is covered by an AML STC.
He double checked the list at my request, and confirmed you can install the 500txi in a Socata.
Sure, although none of these were owner-group funded. In fact I don’t think any AML STC was thus funded; the manufacturer was going for a big market.
Can anyone think of any successful owner-group-funded STC projects?
Recently Trio or Trutrak were doing something similar with autopilots, going forward with an STC application only if they get more than x firm sales.