Question...Has anyone retrofitted a late model Cessna 210 power pack on an earlier model? I have a C-210 D, which has electric flaps, but an engine driven hydraulic pump for the MLG power pack. Has enyone retrofitted a late model Electro-hydraulic Powerpack on an earlier model and recieved a One-time FAA approval (form 337)? As it turns out, the 210D has a more "modern" like system. There is no "Priority valve" to mess with (it used to work the flaps also.) and since there are no doors, the systems are quite similar. Also, through a series of 'coincidences, the pump is a 1HP pump (2000psi at 1 gpm) which is a very standard pump in aerospace circles. Since it only drives the gear, this could work (hydraulically speaking). Now, if it will physically fit, is the question. I need a look at the schematics for a 1966 or later system to see if thats possible. Im researching the possibility of an STC. Using a late model >1966 C-210 system means I dont have to work up a lot of Engineering Data for the STC. Relocating the Manual pump to between the seats I think may be the biggest issue. Answers...
Answer by Jimmbbo I was a Cessna Service Manager in the late '70s, and I have never seen that...
Theoretically it sounds "doable", but there are a dozen questions that come to mind regarding the the pump and associated components. The older airplanes had hydraulically powered gear doors and sequencing valves as well as the landing gear, and the entire gear/door mechanism is quite different and much more complex. Since the new gear system is vastly simpler than the old, I wonder if the new pump would produce the flow and pressure necessary to drive an "old" system... IMO, the power pack in the center console/instrument panel will be the major issue.. it contains many components that direct the fluid to the right place at the right time, and would either need to be replaced with a scratch built system (expensive and certainly NOT easy), or powered by a separate electric powered instead of engine driven pump.... Bottom line - I think you might be able to replace the engine driven pump with an electrical one, but the tasks associated with replacing the existing powerpack would be monumentally expensive and complex. Try http://forums.cessnaowner.org/index Good luck!
Answer by eferrell01 I also know of no one who has STCd that conversion. Why don't you try to be the first. To simplify matters, first apply the gear door removal STC.
Answer by calnickel Sounds bloody intensive. I would stick with what you got for the following reasons:
The Prestolite power packs were designed to power convertible tops in the 1940s. They are a very poor design and quite often burn out in Piper, Cessna, and other aircraft installations. Since they run off a pressure demand system and the airplane is loud, you can't hear it turning away if there is a bit of blow-by. About the time you go to put down the gear is the time you realize it has burned itself out by running continuously for the last two hours. If you installed a Power Pack for other than just basic hydraulic power, you would basically have to install a totally new hydraulic system as all the selection, sequencing, and relief valves are in the existing power pack. Compared to a simple and light engine driven pump, the Power Pack is a heavy and quite failure-prone substitute. As for gear-door removal... It eliminates a few problems like having to repair/replace door actuators and door rigging or sagging, but it doesn't solve the problem of a gear failure. The sequencing valves are still in the power pack and if they don't do their job, guess what? Removing the doors to solve a gear problem is akin to amputating a foot to fix a leaky heart valve. As long as you do proper maintenance (by the book!) and are prepared to accept what these old aircraft cost to run (there is a reason why early 210s are cheap), you won't have any problems. If you've got an opinion about this Cessna Hydraulic Pumps post, then leave a comment... Read More About Cessna Hydraulic Pumps
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