Methods for altitude changes

writes:

In a real airplane with a real engine that generates real heat and
costs real money to overhaul there are conciderations beyond how
fast you go.

I guess that's a problem for real pilots. It's not a problem for me.

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Mxsmanic wrote in
:

writes:

In a real airplane with a real engine that generates real heat and
costs real money to overhaul there are conciderations beyond how
fast you go.

I guess that's a problem for real pilots. It's not a problem for me.


you're not even an unreal, pilot, djikkhedd.


Bertie

_Always_ rich for a climb? At altitudes above a few thousand feet MSL, it
seems that a rich mixture just slows me down.

When you're climbing, airspeed is less and engine power is higher,
generating more heat in the air cooled cylinders. A rich mixture
helps keep cylinder temps under control because more fuel is
evaporated than is burned. Nothing is automatic with these old
engines, though Teledyne has developed a single lever Fadec system
that supposedly takes care of this with electronic monitoring. Still,
even Fadec should enrich the mixture in climb. Pilots with engine
monitors (JPI, EI) may not go to full rich when climbing since they
can monitor cylinder temps in real time.

If you want a good education on piston engine management, read through
John Deakin's articles in Avweb.

In rec.aviation.piloting Mxsmanic wrote:
writes:

Pilots in real airplanes learn to fly using the yoke to control the
airplane and the trim to remove yoke pressure.

That is only one of several ways to trim.

In real airplanes making "gross" maneuvers, that is the way you trim.

For example, if you transition from climb to cruise, you use the yoke
to lower the nose, establish and maintain the altitude, stabilize the
airspeed, make any power adjustments, and once everything is stable,
trim off the yoke pressure. You may be making some trim adjustments
in the middle of it all to trim off pressure, but you are always
trimming off pressure.

In a stabilized mode, you may make minor trim adjustments if required.

Since simulators that simulate yoke pressure cost as much as real
airplanes, you will never be able to do it.

See above. It's important to be flexible.

See above; it is how real airplanes are flown.

In a real airplane that burns real gas that costs real money, you climb
to a cruise altitude that allows for all the terrain and stay there.

That does not seem to be the consensus here.

What makes you think that?

Unless you are in an ultralight chasing jackrabbits over sand dunes,
or something like pipe line patrol, you climb to a cruise altitude
and stay there in VFR flight.

--
Jim Pennino

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In rec.aviation.piloting Mxsmanic wrote:
writes:

In a real airplane with a real engine that generates real heat and
costs real money to overhaul there are conciderations beyond how
fast you go.

I guess that's a problem for real pilots. It's not a problem for me.

Then why bother asking how real airplanes fly?

Just go play with your simulator and do what you want.

Flying a real airplane requires concidering a pile of factors such
as aircraft performance, equipment and condition, weather, temperature,
density altitude, center of gravity, airspace types, pilot health and
general disposition, maneuvering speed, fuel burn, costs, engine
health, etc.


--
Jim Pennino

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Paul kgyy wrote:
Nothing is automatic with these old
engines,

Many carbs actually go beyond the mixture lever's full rich at wide open
throttle.

writes:

In real airplanes making "gross" maneuvers, that is the way you trim.

In many; not in all.

See above; it is how real airplanes are flown.

Some airplanes, not all.

What makes you think that?

Because I'm getting lots of different answers. Obviously not everyone has the
same opinion.

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writes:

Then why bother asking how real airplanes fly?

I know how real airplanes fly. The question in this case was which methods
pilots prefer for changes in altitude, since there are several ways to change
altitude.

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Paul kgyy writes:

When you're climbing, airspeed is less and engine power is higher,
generating more heat in the air cooled cylinders. A rich mixture
helps keep cylinder temps under control because more fuel is
evaporated than is burned.

But if you are, say, at 9000 or 10000 feet, don't you risk losing a lot of
power just when you need it most if you set a rich mixture?

The POH for the Baron I fly in the sim says "full rich or as required for
altitude," IIRC. Unfortunately it's not very specific about exactly how to
determine the correct mixture at higher altitudes.

If you want a good education on piston engine management, read through
John Deakin's articles in Avweb.

I think I have; I recall it being quite good, albeit complicated.

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I try it sometimes, on the theory that the more precise changes possible with
tiny bits of trim might prevent me from overcorrecting, whereas gross movement
of the yoke seems more likely to take me past the correct adjustment.

I'm guessing this is a simulation artifact... The level of precision
control offered by the yoke is equal to that of trim in most
aircraft... But barring that, I can see how you might need to use a
simulated trim mechanism to 'fill in' and provide that precision.

If the period becomes long enough, the oscillation is gone for all effective
purposes.

Can I take back what I said? the period of the oscillations is totally
airframe dependent. Like any damped function, however, the
oscillations, even at low amplitude, can and will persist for a
surprisingly long time unless pro-damping actions are taken by the
pilot. Again, these are fairly minute, subconscious control inputs
that depend highly on precision - so there might be an input
constraint with your simulator.

Sometimes I cheat and turn on the autopilot to trim out the oscillations.

Yes, this is cheating... but again probably a simulation work-around.

I also sometimes use the autopilot to trim and then adjust power until the AP is
giving me neutral trim (which gives me more trim authority and hopefully
reduces drag, although it also means that I can't necessarily fly at high
speeds).

Wow... that's actually kinda funny... You must get great simulated gas
mileage

'Neutral trim' is a false concept (an would be akin to saying that
there is a 'neutral airspeed' or more correctly 'neutral AOA'. The
only pre-defined Trim location on any aircraft is takeoff trim, which
is usually somewhere around Vy (not exactly because of variations in
atmospheric conditions and takeoff weight). The SOLE purpose of
takeoff trim is to make sure the pilot feels relatively consistent
forces on rotation/climbout.

What you are saying then is that you're getting to cruise altitude,
and then backing off until your flying near Vy airspeed... definitely
an efficient way of doing things, but generally not preferred by those
of us who lack time compression

There is no drag penalty for flying with forward trim, in general, the
aircraft will fly with forward trim whenever you are flying faster
than Vy, and back trim (nose up trip) whenever the aircraft is slower
than Vy, or 'behind the power curve'. In reality, you simply set the
aircraft up with your yoke for whatever configuration you want, trim
off the yoke pressure, and never pay attention to the actual.

See above. I've also tried setting neutral trim (in steps or in one
adjustment) and then using power to find a setting that will keep me at the
desired altitude with that trim. It seems to be more difficult but the
aircraft is very stable once in that configuration.

Again with the neutral trim... get away from that mindset.

As for holding an altitude... Its a rate-based control, so control
actions need to be very precise, but its really not that hard once you
get used to it - I suggest this would be a very good practice. I
would go ahead and try it at a range of speeds from Vy on up.

Again, the advantage is that you have a wide leeway to control the
aircraft's altitude while not inducing any harmonic instabilities...

That sounds like a plan. I don't know if I've tried it (I may have done so
unconsciously, but I'll have to try it explicitly).

Its fun to practice, I just don't remember enough when I'm up there.

Refined to perfection, the general idea is that you arrive at cruise
speed between 0-50 feet below target altitude, so that its all one
fluid motion.

I've ridden with several experience pilots who make this practice
second nature, and it really is the smoothest transition to level
flight I've ever experienced. Beats the hell out of my previous
practice of pushing the yoke forward to arrest ascent, letting the
ship accellerate, then fiddling for a minute to get everything in
order.

I suppose it depends to some extent on how much time you have on your hands.

The goal would be to make it second nature such that it doesn't
distract you from your other cockpit duties.

If you're going to be in cruise for a long while, it's more practical than if
you know you're going to have to change altitude regularly

Again, the goal is to make it so that every time you transition from
climb/descending flight to cruise, you trim out and stabilize on
altitude automatically as a matter of second nature...

(as over terrain of widely varying elevations at lower altitudes).

If you're changing your cruise altitude to account for variations in
elevation, you're not flight planning very well.