Slow Rolls & Hammerheads HOBBS 1457.0 hrs

Lesson #4 in the Pitts was all about slow rolls, Immelmans and Hammerheads. We started out doing some more dutch rolls like we did in lesson one. Its always good coordination practice with aileron and rudder. Rudder as you roll into the bank to offset the induced drag...and then switching back to the other side, quickly, and doing the same the other way.

The reason for this, other than the practice was Dagmar wanted me to do these inverted during this lesson. This was preparation for doing slow rolls. Slow rolls are a competition maneuver and the name is somewhat confusing. They can be done at any roll rate...not necessarily slow. The key to these is, unlike aileron rolls which start with a pitch up before rolling, these are done with the nose stationary on the horizon...no pitch up. So, as you roll to knife edge...top rudder, continuing to inverted, forward stick...around to knife edge, and again top rudder...and finishing upright with probably a little aft elevator depending on your airspeed. The goal is to do the entire roll with no loss or gain of altitude...always looking for straight lines in aerobatics.

I describe this process as being mechanical, but to do it smoothly you are gradually feeding these controls in and out during the roll..its far from mechanical, its a "feel" manuever. Its very much a control coordination exercise and let me tell you its plenty difficult the first few times. But gosh, what a great stick and rudder exercise...if all pilots could master this, we assuredly would be better stick and rudder pilots.

Now that you know what a slow roll is, lets talk about my experience trying this. Dagmar says, check your seatbelts (should always do this before doing negative G maneuvers), I check and reply, "good to go!" Inverted dutch rolls here we come...roll inverted, then proceed to roll left and back right...ah, but the difference...and difficulty is its left aileron coupled with right rudder. Yes, it sounds cross controlled, but its not. And its difficult to get past the mind trying to do what it thinks is "correct"...it takes plenty of concentration...my head hurt. Of course, I botch it pretty badly and we end up all over the place. The nose swinging wildly with my clumsy rudder inputs.

Next we do knife edge flight...roll 90 degs to our side. Short durations since the oil system doesn't like knife edge flight...upright or inverted it can handle just fine, knife edge, it is not set up for. This was an exercise in learning to use "top rudder." When in knife edge flight, the rudder becomes your elevator...and since we are now using the inefficient fuselage as our "wing"...it takes quite a bit of top rudder to hold altitude.

Now lets combine these and try a slow roll. Wowza, my first attempts were plenty ugly...I was rolling too fast...trying to cheat my way around. Dagmar says, "slow down until you get the hang of it...we can do them faster later." I was losing altitude like a gambler hemorrhages chips playing craps on a bad night in Vegas! I struggle with the control inputs as we roll, I'm constantly behind the airplane...get back to upright, and Dagmar says..."ok, you lost 1000' on that one." Ouch, are you kidding me?!! Its not easy boys and girls. At least I can only get better I think. We do several, and I did improve, but Dagmar says its a maneuver that usually takes a couple sessions to grasp...I shall sleep on it and try again.

Next up is the Immelman...a half loop followed by a slow half roll to upright at the top...again, without losing altitude. Its an energy management maneuver, as you get to the top, you are slow and low on energy...near stall speed. We need to roll...efficiently, so as to not rob that critical energy from the airplane since we don't have any to spare. All the while, not stalling and entering a spin. I've done a few of these already and not had too much trouble. But now, actually trying to do it correctly...i.e., hold altitude...it was much harder. I did several...they were sloppy, but mostly I did ok on these.

Now for the best part of this lesson. Dagmar says, "lets try some hammerheads". Giddy up! I've been itching to do these since we started this adventure. I've always been fascinated with this maneuver since I was a small boy and couldn't wait to see what they were like from the cockpit. You may remember, I had done a hammerhead entry...followed by a torque roll and inverted spin...in a previous lesson. Now we were going to do them correctly.

Again, pull 4G's into a vertical upline...hold it, as our airspeed decays...feed in some aileron and rudder to counteract the left turning/rolling tendency. There is a slight shudder as all forward motion almost stops, then its this, mechanical, control sequence: full left rudder, full right aileron, slight forward elevator...as we pivot, right rudder to stop the nose on our downline...then neutralize all controls, pick out a point on the ground and straight down we go...screaming back toward the earth! Woohoo! Hold the downline, now pull out with another 4G pull. Dagmar says in my headset..."good job, now go right into another one"...well shoot, alright, why not...this is a kick. I had read enough about this maneuver beforehand and really nailed these right from the get go. That made me smile...finally felt like an aviator again, as everything else had been pretty humbling up to that point. They are actually pretty easy...and boy, a ton of fun...I could do these all day!

After quite a few successful ones, Dagmar again wants me to intentionally botch one...see a pattern here? She says...do one, but instead of pivoting...just hold the vertical upline and lets see what happens. I had done this before with her, so I knew what to expect. We slow...the aileron finally loses all effectiveness and we start torque rolling to the left...followed by a tailslide when we run out of energy. Of course, this induces a spin...ah, but that's the goal with this! haha!

Again, it worked perfectly...another lesson learned...let me explain. I did remember to cut the power like I learned previously...that was good. Ah, but this time I hauled back on the stick too hard and too soon...entering a secondary stall. I continued to do this until Dagmar chirps, "get the nose down, you're stalled!" Duh I think...why didn't that register in my brain until she said it? Again, panic...its a common reaction to pull back on the stick. Pay attention to what the airplane is telling you, because it was talking and I wasn't listening...get past the "brain lockdown" mode and actually THINK. Its not easy to override your survival instincts. Does this scenario sound like a common accident? We see it all the time. So, this was my takeaway from this lesson. I try to have at least one thing from each lesson.

The other takeaway was this. As we got into doing botched Hammerheads, Dagmar says..."if you miss your pivot and find yourself at the top with no airspeed and a pending spin coming, cut the power. It will remove the energy out of the system." Think about it, you are at zero airspeed, pointing straight up, with a 260hp engine screaming at full tilt. All kinds of things going on...torque, spiral slipstream, gyroscopic precession...with no control authority to counteract it since we have no forward airspeed. Chop that power and the airplane gets more manageable immediately. Worked like a charm as the Pitts turned from a rabid pit bull clawing for altitude to a purring kitten in the flash of a second.

The unintentional spins are great learning experiences, I like the fact that Dagmar forces me into them. If you are the "perfect" pilot right from the get go...flying every maneuver perfectly, how will you ever know how to recover when you finally screw up. Better to learn this now with Dagmar, than later solo.

This lesson was by far the most G's I had pulled in one session. The Immelmans and Hammerheads (we did quite a few) all require that 4G entry. It wears you out...I was physically drained at the end of this lesson. Still having a blast...until next time.