Not to suggest that the information provided above is wrong, I would like into clarify something I continuously read in sim forums/reddit. The practice of controlling altitude is being muddled a bit, I believe, by vague descriptions. Power is there to control airspeed and the elevator is there to control attitude. The combination of the two allow us to go up and down.
There are primarily three basic regimes in flight. Level, climbing and descending. They are all handled a bit differently. When in level flight, set power to desired thrust. Depending on the aircraft type you are flying determines how you set that power. Fixed pitch aircraft, simply adjust throttle to desired RPM. In constant speed aircraft use throttle to set the desired manifold pressure and prop/pitch controls to select the desired rpm. Turbine aircraft differ depending on configuration but generally you are simply setting thrust.
Once the desired power setting is selected for cruise, leave it. Adjust attitude only to maintain your altitude. As the speed stabilizes you will find you will need to continually make very small adjustments to maintain level flight. Use trim to relieve control pressure until the aircraft flies level, hands off. As long as you do not change power settings the aircraft will stay level. As fuel burns or people wander around the cockpit, weight and balance will slowly change and you may need to make minor trim adjustments.
If you find your altitude changes you need to do two things.
- Fix it. Nothing will drive an instructor nuts faster than a pilot that can see they are 100 ft below assigned/selected altitude and just shrug or ignore it. There is no room for “good enough” in the cockpit. DO NOT adjust power. Climb or descend as required to nail that altitude, using elevator control. When the altitude has been corrected in this manner you will need to hold the altitude with pitch for a few moments as things re-stabilize.
- Tune into a nearby ATIS or when unavailable, IRL, you can call a nearby flight service. The voice on the other end will give you the local altimeter setting. Adjust your altimeter as required and if need, your altitude. Barometric pressure will likely vary thru-out your flight and it is much safer to hold the correct altitude if the altimeter is set correctly. If flying in a mountainous region at low altitude it can also save your life.
(CHEAT) - In MSFS you can tap “B” at any time to correctly set your altimeter.
The other two regimes are climbing and descending. This is different than making small adjustments to maintain altitude. Depending on where you learned to fly and what age group you are in as well as the type of flying you do, the “correct method” for dealing with going up and going down is going to be different. They all achieve the same end. Suffice to say that there are three components but the order may differ and is always a good argument starter.
Attitude/power/trim.
Lets look at a climb. I am of the ‘attitude first’ school. I have found after 1000s of hours hauling around passengers, where the goal is maneuver in a manner that the passengers can’t feel, that this is significantly smoother than power first (Just my opinion).
To climb, I pitch the aircraft to my desired climb rate. Allow the airspeed to bleed to slightly above my target climb speed and smoothly apply the climb power setting. As the speed stabilizes I trim the aircraft to maintain the climb rate and speed. Upon reaching the target altitude, I pitch the nose down to my original cruise attitude and smoothly reduce power back to cruise setting, retrim as airspeed stabilizes and carry on.
Descending is power first to go down but attitude first to level out. Some instructors will say power first at the bottom too, but a very clean aircraft can accelerate VERY quickly if power is applied in a nose down attitude.
To descend I will reduce power and allow the nose to naturally drop to my desired descent rate and adjust power to maintain the target airspeed, usually cruise spd unless I am wanting to slow down for approach. Again trim out the control pressure once things have stabilized. Once reaching my target altitude I simply bring the nose back to cruise attitude and smoothly return power to cruise setting and a minor trim adjustment has me back flying level.
As you have probably noticed, I am using attitude/pitch to control my altitude and power to control my airspeed. That is how we fly in the normal ‘power curve’. This is the region of flight where we are managing a minimum of drag and the aircraft is its most efficient. There is another side to the curve. This is what we call ‘Slow Flight’. It is the backside of the power curve where smart pilots normally don’t fly but must learn to transition.
When taking off we pass through the slow flight envelope as the aircraft lifts off. It is creating a large amount of drag and only the mill pounding out full power will keep us from falling out of the sky. We also pass through this envelope on landing. As we slow to landing speed, we raise the nose. In your 172 you keep pulling the nose up until the stall warning beeps (hopefully only a couple feet off the ground) but the aircraft keeps descending. The harder you pull the slower you go. No amount of control input will get the aircraft to climb at this point without significant application of power. You are now in the world where ‘Pitch controls airspeed and power controls altitude’.
BONUS: Extra credit…
This can be used to your advantage if you want to softly touchdown on a muddy dirt strip out in the bush one day. Just as that stall is about to chirp, add some power to hold the aircraft just off the muck then without changing pitch, gently reduce power to settle the wheels to the ground. When they touch pull the nose up to kill more spd but maintain power so the wheels don’t sink into the mud. When at a safe spd you can reduce power, settle and mush to a halt. You now have plenty of time to re-read this long post. You won’t be taking off again 'til the strip dries out.