Seminole Checkride Question

[starchkr]

I can see and understand why some have come to say the prop is hydraulic, but i still stand by my previous posts above.
The technicalities of it all point to what can be considerred hydraulic, but it is not refferred to as being hydraulic.
I will look for my old -44 poh and double check what they list as hydraulic and get back to everyone...or someone who has it handy can do the same.

 

[stingray]

Yes the props do move due to oil pressure (engine oil) and counter weights.
In Hydraulics work is being done by the motion or pressure of fluid!In that since some may think of it as a hydraulic system. Are you going to be putting hydraulic fluid anywhere near that propeller or engine? I hope not, or you would be in serious trouble!!!!!!!!!!!!!!!!
But as to what is considered a hydraulic system in a airplane it is not. No hydraulic fluid is used here. There are only 2 hydraulic systems on the semihole. Brakes and gear.

 

[tarp]

hy·drau·lic (h? drôÆlik, -drolÆik), adj.
1. operated by, moved by, or employing water or other liquids in motion.
2. operated by the pressure created by forcing water, oil, or another liquid through a comparatively narrow pipe or orifice.
3. of or pertaining to water or other liquids in motion.

I would smile at the examiner (this is fun) and answer there are either 2, 3 or 5 hydraulic systems on the airplane depending on your definition. They are the Gear, the brakes, the props, the oleo shocks and the shimmy damper. Which would you like to hear about? (PS: oleo struts and shimmy dampers perform their function by forcing oil through a small orifice and hence are considered hydraulic!)

 

[Bluto]

Starcheckr,
What sends the props on a Seminole to low pitch? Oil, water, fuel, and hydraulic fluid can all be utilized in a "hydraulic" system. Most, if not all, hydraulic systems have some mechanical components like the spring and counter-weights in the Seminole. In the Emb-145, the CVG (comressor variable geometry) system uses fuel as a hydraulic fluid. Now, whether the prop is part of the "hydraulic system" of the Seminole, I won't say. I would argue that it doesn't really have a a hydraulic system in the conventional sense. It has a number of independent systems: gear, brakes, propellers, oleo struts, shimmy damper, that use hydraulic principles of operation. The props on a Seminole are sent to low pitch by oil (or hydraulic) pressure. Does this make it a hydraulic system? Who cares? I think that is completely missing the point of this type of checkride question. If you understand the system, and can explain it adequately, no examiner, Fed or otherwise, should have a problem with your definition of a hydraulic system. Assuming they understand what a hydraulic system is.

 

[Tref]

I guess my bit of advice would be to know your stuff, but don't try and show off. I would guess that the examiner is probably most interested in hearing about the hydraulic gear system, but you can always ask for clarification, "Do you mean the hydraulic gear system?" Don't go and answer a bunch of questions that weren't really asked.

A fairly general rule with orals is to answer the questions well enough so that you don't sound like a big dummy, but don't give them enough rope to hang you. If you start to go into a bunch of unnecessary detail and you start to seem unsure of yourself then you know you're going to get more questions on that subject.

I wouldn't get into numbers/details unless I'm asked. I would make sure I knew them, just in case, but I would keep my answers short and simple. If they want to know more detail, they will ask. And if you don't know an answer at least know where to find it in a reasonable amount of time.

Also, alot of times these examiners are really good guys/ladies and they want you to do well, but many of them are very experienced and they are happy if you can learn something from them. Sometimes they will ask questions that seem ridiculous like "how many bolts connect the wing spar to the cross over box?" They're probably just having some fun with you, but you might actually be able to learn something from them.

Never make them look dumb, or your oral will become much more difficult. Remember they are supposed to be old and crusty and you are still wet behind the ears. If you are confident but humble and don't seem arrogant you will score big points.

Above all it's their job to make sure you're safe. There's nothing more scary than a pilot who thinks he/she knows it all. No one does. And just when you think you do, you'll realize that you forgot the first half of what you learned. I think it's true when the crusty old guys say "I've forgotten more than you now know." It doesn't mean that they just have bad memories.

Good Luck!

P.S. I suppose you could design a hydraulic system that uses maple syrup if you really wanted. Probably wouldn't work too well, but it'd make the walk arounds alot more fun. "Hey you! Quit licking that airplane!"

 

[Mickey]

I think Tref has hit the nail on the head. Know and understand the systems. Stingray points out how wording can change interpretation. Stingray states that the prop system isn't hydraulic because it uses oil instead of "hydraulic" fluid. This is interesting because the brakes don't use "hydraulic" fluid either, they use "brake" fluid. It's not what you call the fluid, it's what you do with it that matters. Tref has the right idea.

 

[A1FlyBoy]

Speaking of Seminole checkride questions,

Tell me how many fuel pumps are on the aircraft AND the aircraft's anti-ice features.

 

[FSIGRAD]

As far as fuel pumps the answer I would give is 5. 2 engine driven, 2 electrically driven and one for the janitrol heater. I did have a pilot try and tell me once there was 9, including 2 carberators and 2 fuel primers. (how he passed the drug test for his medical I don't know)

As far as anti-ice, the electrically heated pitot mast, carb heat, anti icing design of the fuel tank vents, and the windshield defroster.

Off the top of my head that should be it. I haven't looked at Seminole systems in a few months so I may have missed something.

 

[bobbysamd]

PA-44 Systems

I second FSIGRAD's answer in its entirety. It's the same answer I heard and taught at FSI and at Riddle ten years ago, almost word for word.

I also heard the same malarkey about a carb and a primer being fuel pumps. The more things change, the more they stay the same . . . .

 

[DC9stick]

I have taken a lot of checkrides and never have I heard of a prop being part of or a hydraulic system. Light aircraft generally have 1 or2 hydraulic systems, on the Seminole it would be 2 separate systems, gear and brakes. Both are operated by Mil-H-5606 hyd. fluid (red in color) and is generally what is used in defining hyd. systems, otherwise we get into all those little things that just don't matter.