Pilots don’t get disoriented; we get transitorily perplexed
Do you remember when doing spins during training for your private pilot license was common? There was a placard on the wall behind the bench seat of Cherokee 140s: UTILITY CATEGORY—that’s what they called it, and that’s what allowed you to do spins. After doing spins for the first time, I wanted more. Barrel rolls, loops, lazy eights, and more spins. Spin recovery was even part of training in the Air Force T-37. Of course, in the F-16, an unusual attitude was not unusual. Even arrogance was a normal attitude.
I eventually got to do snap-rolls in a C-150 Aerobat—never did develop a taste for any ‘outside’ maneuvers, though; no negative g’s for me, thank you. The Cherokee’s roll control with the Hershey-Bar wing was so stiff that you had to practically stand on the yolk. But then came the taper-wing Warrior. I blame the temptation on Piper: they enhanced the roll authority of the Cherokee, making it a dream to roll….. or so I’ve heard. NORMAL CATEGORY only, don’tcha know.
Many folks have rolled airplanes that aren’t supposed to be rolled. Some have done loops as well. Some with bad results. In his Shrike Commander, the late-great Bob Hoover showed a generation of pilots that, done properly through energy management, most airplanes can perform aerobatics without ‘g’-ing your lips off or spilling a cup of tea —even with both engines feathered.
The J3 Cub is the safest airplane in the world. It can just barely kill you.
-Max Stanley
A few days after I delivered a used C-150 to an FBO in Phoenix, a renter tried a loop (note: tried) and pulled the wings off. And a local pilot here in AZO crashed trying (note: trying) to do a roll right after takeoff. Aerobatics in the wrong airplane and without training can kill you. So can accidental aerobatics. How can you accidentally do aerobatics? Glad you asked.
Tail Stall
Do you know how to recognize a tail stall? What if your wing deice works, but the tail deice fails? What happens? A tail stall– and the indication and recovery procedure are exactly the opposite from a wing stall. Ever had an autopilot malfunction and rapidly pitch up? How about asymmetric speed brake or spoiler deployment? I’ve been at or beyond 60 degrees of bank, unintentionally, three times in transport category airplanes. Once was due to wake turbulence at a high altitude, another at a low altitude. I had asymmetrical spoiler deployment the third time due to a failing auxiliary hydraulic pump. I’ve talked to colleagues who have had asymmetrical deice problems as well. Lots of ice on one wing, little on the other. And while I hope to never have it in real life, I’ve trained in several different jets for inflight thrust reverser deployment, and in the sim, it’s dramatic.
Well, I Never!
If you have never been beyond 60 degrees of pitch or bank, you need to. As a part 135 or 121, two-pilot crew, the chances of being in a ‘very’ unusual attitude are slim. The odds are higher in single-pilot part 135 or part 91 operations, but it’s still rare. But don’t convince yourself that as long as you pay attention to your attitude, you’ll be okay and that upset training is just for fun. If for no other reason, it will help you recognize your condition more quickly, and more importantly, you won’t be as inclined to soil your trousers when it does happen. And with clean trousers, you can more confidently get to the task of executing a recovery.
Status quo, you know, is Latin for ‘the mess we’re in.’
Ronald Reagan
The basic thought process of unusual attitude recovery is similar to an engine failure in a multi-engine airplane: recognize the condition, verify the condition, pick a plan, execute the plan, and verify that you got the desired results.
The first thing is to recognize the condition. It’s normal to feel and hear things in your plane and react. The sound of airspeed or engine noise increasing or decreasing, a variation in cabin pressure, sudden turbulence, or the sensation of more or less g force. If you fly over mountainous terrain, the signs of mountain waves may be your warning. If it’s night or you’re in IMC, your reaction should be to check the panel. Hopefully, you’ve recognized the condition rather than getting a call from ATC. That call would be well into your deviation from level flight.
No Need To Panic!
noun – sudden uncontrollable fear or anxiety, often causing wildly unthinking behavior.
Some type of attitude indicator (PFD, MFD, ADI) is the first place to look—and look at more than one if you have several. If you find two that agree with each other, you can move on to the pick-a-plan phase. If they disagree, you must find one or more indications to determine which attitude indicator is right; a third artificial horizon, the VSI, IVSI, airspeed, and altimeter, should do. There’s no need to panic, really. You have some time. You don’t want to get this one wrong by using ‘wildly unthinking behavior,’ so take a few (3-5) seconds.
Picking a plan will depend on what you see the airplane doing. You will have the urge to ask yourself why it’s happening—fight that urge until after the wings are level. The easiest unusual attitude from which to recover is one in the roll axis, even if you’ve made it all the way around to inverted. Rolling the shortest direction upright is the accepted course of action. Depending on the plane, you may use a combination of yolk and rudder. Follow your manufacturer’s recommendation regarding the rudder, though; in some airplanes, you can break things using too much rudder or with rudder reversals (rapidly transitioning direction in yaw— e.g., AA 587 November 12, 2001).
Corner Velocity
The more dangerous unusual attitudes are extreme deviations in pitch. Usually, if you’re nose high, you’ll be slow, and if nose low, fast. However, it’s possible to have a nose-low attitude with slow speed and a nose-high attitude with high airspeed. With this in mind, you need to understand the concept of corner velocity or corner speed.
Corner velocity is used in fighters, aerobatics, and airplane racing. It’s the speed at which you can generate the highest turn rate and, therefore, the smallest turn radius. If you’re faster than corner, your radius is larger. If you are slower than corner, your radius is, again, larger. Generally, this speed is the square root of your g-limit times stall speed:
Vc = VS x √Gmax (e.g., 6g limit and 60-knot
stall = 146 corner, 4g and 80 kt stall=160).
This matters because we want to recover from this bad attitude with the smallest loss or gain of altitude. Especially if the ground is within range of a larger turn radius. It’s difficult to imagine adding power in a nose-low attitude or removing power when nose-high, but you may need to do just that. With this bit of confusion, the most likely nose-high recovery scenario will be to add power, roll smoothly to 90 degrees of bank, let the nose fall to the horizon (or below the horizon, depending on speed), and then roll wings level. More on nose-high recoveries in a bit.
Lift Vector
In a nose-low unusual attitude recovery, the first thing you do is level your wings. You need to get the lift vector going in the correct direction. Picture long arrows pointing out the top of your wings at a 90-degree angle. The lift vector points at the ground if you’re inverted (at positive g). It points to the horizon if you’re in 90 degrees of bank. The first step is to make your lift vector point above the horizon, meaning less than 90 degrees of bank.
Ideally, you want your lift vector pointing straight up, away from the rocks. The closer to straight up it is, and the closer to corner velocity you are, the quicker you will return to level flight. Learn the ‘unloaded’ roll (rolling at zero or near 0 g); remember, you want to be near corner velocity. You may have to reduce or add power. Next, gently add back pressure as required to your g limit or the edge of an accelerated stall if the rocks are near.
Dump Some Lift
A nose-high recovery is a little more uncomfortable, especially for your passengers. You may see something less than one g for a few seconds. Not necessarily zero-g, but you may get “light-in-the-seat.” Pushing straight forward would be very uncomfortable and take a long time. In an aerobatic plane or fighter, you would simply roll inverted, pull your nose down to the horizon, then roll upright. Not a good idea in your aircraft unless you are almost vertical. However, it will work fine in any airplane as long as you maintain positive g (hopefully around one or two) throughout the maneuver. The positive g is necessary to ensure your fuel and oil systems behave as designed.
The (most controlled) best way to dump lift to lower your nose is to roll left or right. The more nose high you are, the greater the bank angle must be. Anything from 30-90 degrees would be appropriate. As you roll, the lift vector points less and less away from the ground, and the nose will fall to the horizon.
The decision when to roll back level is based on a few things: how close to corner you are when the nose approaches the horizon, how fast the nose is falling toward/through the horizon, and where the rocks are. You may be able to roll out before you get to the horizon, or you may need to let the nose fall through the horizon. Make smooth, deliberate control inputs. Once again, professional upset training will teach you the nuances of the process and help in your decision-making.
Some would say that no simulator can model the disorientation of actually being upside down. Yes, and no. A simulator is perfect for experiencing and correcting an IMC or night upset. A real airplane may be better for learning day VMC upset recoveries. I recommend you do both. After which, the most challenging part of an upset event is explaining to your passengers what happened.
UFO Avoidance
Upset training will minimize the time you spend ‘transitorily perplexed.’ And so, no longer will the pax see you using ‘wildly, unthinking behavior’ or screaming like your Dachshund Lily getting a mani-pedi. So, any non-UFO explanation to the pax should work. You must also tell ATC what happened and file a NASA report. Telling ATC will prevent me and others from flying into the same crap that caused your upset if it was weather related. The NASA report will protect your ticket. The not-a-UFO part will keep you out of the tabloids and the psychiatrist’s office. We can all recover from a bad attitude, even arrogance, with training and practice. Keep the shiny side up, my friends.
Authors note:
If you are into formulas like corner velocity above, here is another fun one; it’s the speed at which tires hydroplane: 9 x √tire psi. e.g. 9 x √60 psi=70 kts. 9 x √120 psi=98 kts. 9 x √160 psi=113 kts. And your car: 9 x √35 psi=53 mph.
