Steep turns: you have to do them on every check ride all the way from private to CFI, CFII and MEI. So you might as well learn to get good at them. Here are some tips on how:
1) Becoming fixated on something
Okay, rule number one in aviation: NEVER BECOME FIXATED ON ONE THING. I put this in all capitals because it's a huge mistake I see tons of students make. They become too focused on one task or one instrument and everything else around it starts to suffer.
When it comes to steep turns, there's a lot of things to focus on. Your fast changing heading, altitude, bank angle, and looking for traffic outside at a minimum. Keep those eyes scanning!!!
If you keep your scan looking outside at your reference to the horizon and back inside to all your instruments you'll catch something as soon as it starts to change, which keeps you from letting any problem become too hard to correct.
The rate of your scan should be like they teach in CPR classes, to the rate of Stayin' Alive by the Bee Gees. I sing it in the cockpit if I have to when I teach, it engrains that rhythm and really improves your scanning method. Trust me!
2) Using the wrong visual sight cues
The key to being able to do awesome steep turns is knowing what to look for both outside and inside. Outside of the windshield, put your cowling right through the horizon as you enter the turn and keep it there. Remember that it will look slightly different on your left and right turns. Once you have the 45-degree bank established and can get the altimeter stable on your altitude take a mental picture of what it looks like outside and then work to maintain that picture. This will help TREMENDOUSLY.
3) Forgetting to compensate for loss of vertical lift
Okay, let's bring it back to basic aerodynamics here.
When you're flying straight and level, you have vertical lift (up and down). When you start turning the wings, that's transferred to horizontal lift (side to side). So, therefore you're losing vertical lift and will experience a small loss in altitude.
So what's this mean to you? The more bank you add, the more back pressure you will need to add to compensate for that loss of vertical lift so you don't lose altitude. On a check ride your altitude on a steep turn is limited to +/- 100 feet of your starting altitude. To keep yourself from even getting close to that margin, the SECOND that you add a lot of bank and your nose starts to fall, pick it back up. Don't let the problem get worse and worse before you fix it, fix it right then and there. That's one reason you have to demonstrate steep turns, there's a lot of multitasking and flying skills that go into the maneuver itself.
4) Being uncoordinated
This one speaks for itself. Don't be uncoordinated. Keep that ball centered on the turn coordinator always. In steep turns, you're closer to the margin of stalling (read why on the next bullet point) and remember that if you're uncoordinated and you stall, these two factors are the ingredients for a spin which you WILL begin to enter unless you counteract it properly.
Whether you're flying a Cessna 172 that is approved for spins versus a Piper Cherokee that's not approved for spin recovery....don't even get near that area. Be a good pilot, add some rudder and keep that relative wind at the center of the prop.
5) Accidentally entering an accelerated stall
With any amount of bank, especially anything past 30 degrees, your load factor increases and therefore so does your stall speed. I think of it as the plane being more sensitive, so I need to have good controllability and be smooth (not aggressive) with my control inputs.
I'm harping on load factor because being in 45 degrees of bank you have a higher load factor and your nose can start to feel heavier, so it's very easy to lose altitude. If you lose a lot of altitude then try to hurry and yank the nose up, you'll likely hear the stall warning system start to go off. This is an automatic failure in steep turns because you're not performing a stall, therefore you shouldn't get near one.
So go back to bullet point one, keep your visual scan moving and catch an altitude loss before it becomes too big. And if you feel the nose is too heavy and you can't stop the descent...take out some bank! That's what made the nose feel heavy in the first place. Take out bank, bring your altitude back up, then add it back in. Magic!
Hopefully, these tips help the next time you perform steep turns. Remember to get better at something keep practicing and practice diligently, use a good method for performing maneuvers and come up with your own tricks too if that helps. Study the maneuver on the ground (don't expect to learn everything in the air, you're flying so your brain can't take in as much as you'd think) and then go try and fly it. And if you're having a lot of trouble with it, take a break for a few flights then give it a shot the next time. You may have reached a learning plateau and just needed to break away from it for a bit.
Keep flying and happy landings everyone! Happy Fall!