Hello
Is there anybody in Europe who has an operational experience with an S-TEC 55X A/P installed on a Socata TB20, eventually coupled to an Aspen 1000 Pro?
Peter mentionned this A/P as a possible and STC’d alternative to legacy TB20 A/Ps, but so far nobody in France has it installed.
Thank you for any feedback
Edouard
ESN wrote:
Is there anybody in Europe who has an operational experience with an S-TEC 55X A/P installed on a Socata TB20, eventually coupled to an Aspen 1000 Pro?
I have the exact same setup in a TB10. It works very well, especially in GPSS mode tracking a GPS flight plan. It sometimes struggles in heavy turbulence (only when its really bad though – in light/moderate turbulence it’s fine). It flies an ILS very cleanly. I have no complaints apart from the cost of installation.
Thank you “J” for the feedback. I heard some complaints about a tendency to porpoising. Hence my question. My TB will be ready by the end of the next week. The moment of truth arrives!
I will post the first impressions.
Edouard
I have never flown in a TB with an STEC but STECs do have a tendency to be unstable (mainly in pitch but also in roll) on some airframes.
IMHO this is because STEC grandfathered their STCs one onto the back of another without doing much flight testing, back in the good olde days when this certification stunt was possible. The worst I recall was an SR20 with a 55X which in light turbulence was snaking all over the place.
Most older TBs have the KAP/KFC boxes and after about year 2000 they (the GTs, except for the earliest GTs) had the KFC225 which flies superbly but has some big reliability issues.
It will be interesting to see how well a TB20 flies with the 55X because it is the only option – if very expensive – for dumping the KFC225. I don’t know of anybody who has actually done it though. The KFC225 owners I have known either sold their plane (and bought an SR22 which is the only other real option 
) or they take out the Honeywell extended warranty and then their avionics shop loves them.
Peter wrote:
but STECs do have a tendency to be unstable (mainly in pitch but also in roll)
There is a STEC modification that completely cures this but it does need to be sent back to the factory (the autopilot, not the aircraft).
As my s-tec has been delivered one month ago, I suppose it includes the latest modifications.
I will share with you the information and experience during flight tests and thereafter
To whom it may concern!
After months of installation and setting works, tuning, testing, resetting and retesting, my refurbished and retrofitted 1985 TB20 was out for flying in July. The new installed instruments are:
- An Aspen 1000 Pro PFD
- A PMA 450 audio panel
- A Garmin GTN 650
- A S-Tec 55X A/P with FD and autotrim.
The A/P is coupled to the Aspen with the newly interface software and, of course, to the GTN 650.
A few trips in France and Spain showed no major problems, yet some fine settings are still neded and will be carried out in September.
Back in April I have promissed to share on this site this experience .
As I started to discover the whole “complex” since a few weeks only, I will try to bring the information on a Q/A basis. For those interested, please feel free to ask any question and, bien sur, to comme with any suggestion or comment.
