For other high performance airplanes I recommend the same procedure. Top it off for cross country flights of 2.5+ hours. For local flights you may allow the oil to be 2 quarts below maximum per manufacturer’s maximum level.

I know some folks don’t like to add this much oil. Those folks might say the oil is just thrown overboard and hence wasted and it just dirties up the belly. Maybe they are right, but maybe they are not. At any rate, err on the conservative side. The truth is that additional quarts of oil and airplane washes are a reasonable price to pay to keep engines healthy and happy.

Please forward comments, questions or suggestions to chiefpilot@wvfc.org.  Thank you!

Cutlass 172RG
Cessna manufactured approximately 1,190 Cutlass C172RG airplanes between 1980–1985. This airplane is a great commercial trainer and cross country airplane. The down side to this great machine was the small production number and production window which today translates into a scarcity of C172RG and parts. The parts, when you can find them, are expensive. Like all creatures the mighty bird is subject to the stresses and strains of age, use and abuse. Each year our nation’s general aviation fleet loses C172RGs to the scrap yard.

The weakest link on this piece of equipment has always been the landing gear and it isn’t young anymore. You ought to treat it as you would your favorite elder. In order to extend the life and health of the C172RG on our flight line, I am asking you to operate the airplane in the following way.
1.) A maximum of 6 full stop landings and taxi backs are permitted per training session.
2.) Be completely familiar with operational guidelines as listed in the manufacturers P.O.H.
3.) Touch-and-goes are not permitted at any time in any WVFC complex airplane, so please don’t do that.
4.) No more than one emergency gear extension (EGE) during transition training is allowed. I highly recommend coordinating your EGE gear extension with the MX department.
5.) Allow the landing gear motor to cool after each use. You can do so by traveling between local airports after a gear cycle. This gives time to promote the proper use of checklists and procedures if needed.
6.) Also, if you or your student is having landing issues, for example has unstable approaches, lands left or right of centerline, side loads on crosswinds landings in the C172RG,  please get out of the C172RG and get into a fixed gear C172’s. Once the landings become consistent and well executed then you can hop back into the C172RG.

Thanks for reading. Have fun and be conservation in your flying!
Happy Holidays and a Grand New Year To You!
Lucy

Most of the time when we get checked out in a club plane, we do the typical maneuvers to show we capable of flying it to the PTS, and that we can handle the avionics and aircraft systems.  Most of the time, the entire checkout can be performed within a few miles of the airport.  For a very good reason, that changes with the planes that are capable entering the Flight Levels.

Virtually all of these planes have two things in common, both or which are not on the other club planes. First, all have (or require) some form of oxygen systems, and second, all are turbo charged.  As a result, each of these planes requires a flight into the Flight Levels as part of the checkout.

OK, I’ve had a mountain checkout, and I’ve been to the altitude chamber at Beale AFB, why do I need to go to altitude?  Glad you asked.

First, there is a difference between knowing about oxygen systems and being able to use them effectively and safely.  Mostly, we think about oxygen systems as something we require above 14,000 feet (or 12,500 for more than 30 minutes), but what kind of system?

Did you know that most cannula systems are limited to 18,000 feet?  What if you’re flying up to Flight Level 230?  Well, you’re going to need a continuous flow mask (the kind with the bag underneath).  But where do you put the microphone?  If you want one with a microphone built it, it costs a bundle – around $600.  If you use one without the microphone, you get to lift the mask every time you speak, and put it back on when you pull the mike out of the way.  Not necessarily easy when you need two hands to do it, and you still need to fly the plane.

Of more importance, what about turbo charging?  There is a really good reason for going to altitude for the checkout.  Unless you have experienced the differences in how turbo charged engines work at altitude, you are in for a surprise.  And it might not be a pleasant one. 

First, let’s talk about how turbo-charging works.  The simple part of it is that exhaust gas enters the turbo-charger, causing it to spin, which compresses intake air and sends it (under pressure) back to the engine.  This allows the engine to operate at higher manifold pressures than it would otherwise be able to at a given altitude.  Some engines even operate at manifold pressures well above the normal sea-level pressure of 29.92.  That part is pretty straight forward, but things start getting interesting when we talk about how the manifold pressure is controlled.  At sea level, virtually all turbo-chargers produce much more turbo-charged air than the engine can use.  A waste gate limits the excess pressure.  However, it isn't’t controlled in the most immediately obvious way.  You’d think (or at least I did) that the controller would be on the turbo-charged side.  However, the controller is actually on the exhaust side (it keeps the turbo-charger from over temping and running at too high an RPM).

At low altitudes, the waste gate is open, and the engine behaves as one would expect.  You set the power, RPM and mixture during climb, and as you climb, nothing changes, because the manifold pressure is unchanged with altitude.  Until the critical altitude is reached, at which point, the waste gate is closed and the engine starts behaving like a normally aspirated engine as the climb continues.  And that means you now need to start leaning the engine with altitude.  Somehow, that probably doesn’t seem like a good reason to go to altitude as part of the checkout.

Ah, but what happens when you level off.  You’re going to reduce the power, which reduces the manifold pressure, just as you’d expect at low altitude. Then you reduce the RPM, and this is where things get weird.  In a non-turbocharged engine, we expect an RPM reduction to cause an increase in manifold pressure, but in a turbo-charged engine, the RPM reduction causes less mass to enter the turbo-charger, and the manifold pressure goes DOWN, so you need to increase the throttle to get the manifold pressure back up.  Now, lean the mixture, and there is less mass into the turbo-charger (again), and you need to increase the throttle (again).  This iterative process is worth the trip to altitude, but it gets even better,

So you are flying along at altitude and your engine quits.  If you follow the standard procedures, of mixture and throttle to max, and turn on the aux pump, you’ve just done the worst possible thing.  The mixture should actually go to idle cut off first, because when the engine quits, you’re now operating WAY too rich, but the engine will fire when the mixture is correct.  Then you can adjust the mixture to what you need.

A variation on this theme happens when you make a big power reduction at altitude, the engine can quit because the mixture, which was correct for a high manifold pressure, is now way too rich for the reduced pressure – like running sea level mixture at 14,000 feet.  The good news is that if you do nothing, when you’ve spiraled down to about 6,000 feet, the engine restarts, leaving you wondering what happened.

Having just read about this, you may be thinking that the trip up to altitude isn’t necessary, but there is an incredible difference between knowledge and proficiency.  How well did you land the first time, even though you’d read all about the approach and landing?

These are things you need to know at the gut level because you’ve experienced them.