Special Information on 300C

[HeliFrank]

Moin,

 

as some of you might already know I'm working towards my European Flight Instructor. I'm almost done with the theoretical part now and I finally chose to take my checkride in a Schweizer 300C. I'm not really that experienced in it so I'd like to get to know it a little bit more detailed.

I'm looking for any kind of good hints and information (specially on the technical part...), that stuff you won't find in the books....

 

Thanks,

 

Frank

 

P.S.: Lu, I'm counting on your comments....

[Lu Zuckerman]

My only recommendation is to take several rides with a qualified instructor to get more familiar with the 300-C.  As you have indicated you do not have that much experience in the 300-C and this lack of experience may manifest itself to your detriment during the check ride.

 

:unclesam:

[HeliFrank]

Thanks Lu, great comment....lol ::

[UNDCFII]

I can give you all kinds of stuff.  We have been operating the H300C's for 20 years.  All my piston dual-given has been in that model along with most of the other instructors here at UND.  If you could give me an example of the type of information your are looking for ie. flying quirks, chart accuracy, student problems with the 300C, models changes over the years, etc. I'd love to help you out. ::

[HeliFrank]

Thanks UNDCFII,

 

I really appreciate your help. Actually, the stuff you listed below is what I'm looking for...

- student problems (tail rotor efficiency etc)

- most common and uncommon technical problems

- technical bits and pieces (e.g. travel of stick vs. CG, why is the cabin load limited to 600 pounds etc.)

 

Thanks in advance,

 

Frank

 

PS: If it's going to be a long list an e-mail is fine with me...  

[UNDCFII]

HeliFrank,

 

Here is some stuff for now:

 

1.) Common student problems - as with most piston helicopters the big one centers around maintaining RPM.  The correlation unit is usually most effective between 17 - 24 in. MP.  Oustside that range it gets pretty lazy and your doing most of the throttle work.  Where this bites the students is on the high DA days, combined with adverse winds during pedal turns and especially OGE hover checks.  This helicopter has plenty of tail rotor for typical student maneuvers as long as they maintain RPM if not she'll pick up a yaw rate on you pretty quick and your looking at either setting it down or overboosting to recover.  Like I said this is only a major concern on adverse days, most of the time this aircraft has ample tail rotor.  Also make sure they keep the cyclic well trimmed during all phases of flight.  We can always tell the guys that didn't when they transition to our hydraulic controlled aircraft.  The guys that were diligent on the trim have a much easier time transitioning to the lighter feel of hydraulics.

 

2.)  Mechanical stuff - First one that comes to mind is the main rotor dampers.  We not only do hovering autos, but all other emergencies to the ground as well.  Lots of times after a student completes a hovering auto or a full touchdown auto they sit there frozen with the collective in there armpit thanking God they are alive and praying becasue they are about to do it again.  This puts alot of wear on the elastomeric dampers.  I can't remember the TBO on those dampers but I haven't talked to an operator yet that gets TBO out of the dampers if they do alot of low rotor work.  I try to make a effort to get the collective down immediately after positive ground contact on the engine-out stuff.  Make sure those landing gear dampers are in good shape.  Ground resonance is not alot of fun, not to mention bending an aft crossbeam.  Just a side note, a slight bend in the aft crossbeam is allowed as long as it is centered.  We call it the "smile" but we don't let it go more than 1" from horizontal.  One other side note on ground resonance.....here is where RPM comes in again.  Do not let the student dump the collective after they set it down, lower it slowly even after ground contact.  Usually they do not maintian RPM either.  If ground resonance starts you will be along for the ride without the power or RPM to pick it back up.  The only times I've felt resonance start in this aircraft has been during running landings.  Oddly enough it is usually during the really soft greaser landings.  It is no big deal if you pick it back up, but we have all seen the videos of the old 269A falling apart around the pilot.  If it happens recover but don't accept it, get the main rotor dampers checked out.  Be liberal with your cool down and warm up.  We sit at 3000 RPM for 2 minutes and 2000 RPM for 1 min. after all flights and even then we will not kill the engine until the CHT is below 300 degress.  We also run slightly rich at the fuel servo.  The reason for all this was the loss of three engines in the early 90's at this school.  Two of those resulted in the loss of the aircraft.  No injuries but only because of some good instructor work.  Supposedly, there were some Lycoming's HIO-360-D1A's floating around with inadequate exhaust valve guide clearance.  Well, we got three of them.  It has been AD'd out but we still take precautions, as all should on any aircraft.

 

3.) Flying Gremlins to watch out for - I cannot stress enough the importance of keeping the ball centered during settling with power and turning autos.  One of the first "incidents" I had as an instructor happened when I let a student get the tail out to the right during settling with power.  That goofy diagonal H-stab will start flying on you and you will quickly be in a extreme nose down attitude.  Not a lot of fun to recover from and hard on the aircraft.  The same thing happened to me on a 180 auto.  The student hammered down on the pedal going into the turn and the next thing I know I'm past 90 degrees bank and quickly approaching Vne.  The guys you really have to watch out for on this problem are prior fixed pilots.  They still want to lead the turns with the pedal to couteract for adverse yaw.  Obviously we don't have that problem and they will spend the first hours skidding through almost every turn.

 

4.) Autorotations - I wouldn't call this a forgiving aircraft but it not as bad as some, and actually I enjoy teaching autos quite a bit.  I have yet to let a student get me somewhere I couldn't calmly recover from as long as I keep them to tight parameters. The magic range for a normal auto is 55-60 kts.  About 4 kts. of wind on your nose and you can get a nice zero-ground out of it.  Anything slower that and your room for error gets pretty thin.  We enter most of ours at around 600 AGL which seems to be plenty good for the students.  From personal experience I will tell you that anything under 300 AGL and 45 kts. you are going to be making it up as you go along.  From an instructing standpoint, that 190 hp up to 4200 MSL has been a nice "out" on many occasions.  I can let the student go wrong pretty deep and still save it with plenty of safety margin left.  That is why we don't operate the CB's or CBi's.  Last quick piece of advice on these....don't be afraid of ground-run.  We only do our stuff to the ground on a hard surface in this aircraft.  If the student hangs you out to dry at 25 feet with an agressive flare, a little forward cyclic goes along way to make a nice 20 ft. run-on power-off landing.  The reason I choose that over screaming the engine back to life is reality.  I want the student to have options to recover from a bad auto if it really happens and it usually touches down lighter than dropping it straight in.  Horizontal flow over the rotor goes along way in all helicopters but it seems more notieable to me in the H300C.

 

These are just a couple of the things that pop to mind right now.  But I'm sure this will start a discussion that will lead to other topics.  As more come to mind, I'll put them up.....I'm interested to see what other H300C operators have to add.