The Pilot's Lounge #37:
"Who, Me? Fly Upside Down?"
Summertime. Here at the virtual airport the talk in the pilot's lounge is of aerobatics, airshows and performers; who is worth going to see and which ones the faithful can miss if a choice has to be made? The other day, a group of us in the lounge were, um, discussing — yes, that's it, discussing — aerobatics. The competition crowd was again trying to "explain" that if you fly aerobatics you just have to compete, otherwise you are somehow suspect and should be investigated by the FAA, FBI, ATF and House Un-American Activities Committee (which would be re-created just for the purpose). Those of us who like flying aerobatics but don't enter competitions were trying to defend the idea that akro is pure fun in its own right without the need for some external motivator. Neither side was prevailing and each was probably about to take casualties when we were mercifully interrupted by one of the lounge regulars. He had not done any aerobatics, but was interested in learning. Not surprisingly, the factions immediately united and the conversation turned to unanimous, enthusiastic encouragement for him to start taking dual and really learning what he and an airplane could do.
Our prospective aerobatic student was interested in what kind of airplane to use for lessons, saying he knew that it could be expensive and money did matter; he was concerned about safety, where to get information, where to take lessons, whether he would get sick while cartwheeling through the sky and whether he was being foolish even thinking of taking aerobatic dual. As I'm wont to do when there are knowledgeable pilots about, I sat and listened, figuring I'd pick up some information.
From Classic Airplanes...
I learned that there is a surprisingly large choice of airplanes for aerobatics in this country. At the most basic level, some post-World War II airplanes are legal for aerobatics, largely because of the rather odd certification regulations of the time. Some of the Cubs are included (but not all — be sure and check before you go), the Globe/Temco Swift (although it is placarded against spins because it did not meet the then-existing recovery requirement), Luscombes and others.
The feeling I got from the discussion among those who knew what they were doing was that stressing half-century-old airplanes is probably not the brightest thing a pilot can do, especially those not approved for spins. None of the assembled pilots was willing to do aerobatics in those airplanes without first checking to make sure the airplane in question was legal for akro and then, if so, doing a very serious inquiry into the structural integrity of the bird. One pilot asked the others when the last time was that they'd looked over an old airplane and had not seen some corrosion. He also mentioned that he wasn't sure he could even get out of a Cub to use his parachute after a structural failure when it was gyrating madly and maybe some large chunk of airplane was blocking the door.
The group pointed out that even if a classic airplane were structurally fit for akro, the associated small engine means that getting the weight of two people and parachutes to altitude takes a long time. There can be a temptation to start maneuvers a little low. As a result, it was pretty much unanimous that, for training, it was best to either use one of the purpose-built airplanes made in the last 30 years or so, or, assuming it is in good condition, one of the purpose-built, World War II trainers.
...World War II Trainers...
I was interested to hear the group speak well of the World War II trainers. They did quickly add the caveat that even with 220 hp on something like the Boeing Stearman and Waco UPF-7, the airplanes are so massive that they tend to have very modest performance and are ponderous when looped and rolled. All said they were very enjoyable airplanes and surprisingly easy to fly, although some were a handful on landing. Everyone who had ever flown a World War II trainer encouraged our prospect to fly one if the opportunity presented itself.
...Cessna 150/152 Aerobat...
As to the more modern airplanes, I was interested to hear the Cessna 150/152 Aerobat get pretty good reviews. I was expecting a certain amount of aerobatic snobbery, for lack of a better phrase, but one of the more experienced pilots attacked such provincial thinking. He smiled and said that you have to start with a certain understanding: Any airplane that can do aerobatics is a great airplane; it's just that some are greater than others. All of the pilots said that the modest powerplant meant it took time to get to altitude in an Aerobat, but they praised its ability to do snap rolls and behavior in a spin. Apparently, because the wing has a bit of sweep starting a few feet outboard of the fuselage, it enters and exits a snap roll or a spin very cleanly, with a pleasantly fast rate of roll when in the maneuver. They were not particularly complimentary about control wheels instead of sticks, and one pilot mentioned that to do an aileron roll it is necessary to turn the control wheel completely upside down to get full aileron travel.
As is the case in all but the most powerful aerobatic birds, the Aerobat must be dived in order to get the necessary entry speed for most maneuvers. Therefore, altitude loss during a maneuver (including the entry) is usually about 300 feet, so it's wise to start high, particularly if one is going to string together a series of maneuvers. They also pointed out that the Aerobat has a carbureted engine. It quits if any negative G is induced (no big deal as it instantly restarts when positive G returns).
Interestingly, while it is certified in the aerobatic category, the airplane is only approved for a range of specific, positive-G maneuvers, such as the aileron, barrel and snap rolls, (not for the slow roll, which briefly involves about 1 negative G) as well as the loop, Immelman, Cuban 8 and a few others.
Someone mentioned that in the late '60s or early '70s, Cessna got together with noted instructor and author William K. Kershner and put out an aerobatic training manual for the Aerobat. It shows each maneuver from both inside and outside the airplane. It is one of the best basic aerobatic books ever written, so, no matter what type of airplane our prospect wound up flying, if he could find a copy of Kershner's book for the Aerobat, he'd be glad he did.
The closing comment on the Aerobat was made by our avid competition pilot who remarked that to do good aerobatics in an Aerobat a pilot has to do everything right, aggressively maneuver the airplane, be willing to put the controls clear to the stops, plan ahead and exercise energy management. However, once he or she learned to do that in an Aerobat, she or he could do it in any other airplane because it will be easier.
I asked what the group thought about the fact that seating in the Aerobat was side-by-side as opposed to tandem where the pilot sat more or less on the axis of rolling maneuvers. No one was critical. Each said that tandem versus side-by-side seating was an issue without significance. They noted that the very capable CAP-10 is also side-by-side. The French Connection flew those in incredible airshow performances for years and folks that have learned in tandem and side-by-side airplanes are able to step from one to another effortlessly.
The Citabria series caused mixed reactions from the pilots. All said very good things about them as trainers for aerobatics and for their honest handling for tailwheel checkouts. They especially liked the 150-hp model, which has an inverted fuel and oil system so the engine keeps running when upside down. They compared the performance of the 115-hp Citabrias to the Aerobat. While they liked the Aerobat for snap rolls they said they did prefer the 115 hp Citabria. One pilot mentioned that she had flown one of the early Citabrias with only a 100-hp engine. Her flight had been on a hot day and she came away from it less than impressed. She said that if she had her choice between a 100-hp Citabria and an Aerobat, she'd take the Aerobat.
The instructors in the group had some negative comments regarding the very high stick forces in roll in all Citabrias. They noted that, especially in the rear seat where the stick is shorter, rolls to the right almost require both hands on the stick. They said that the addition of "spades" (aluminum plates that hang down below the ailerons and look remarkably like little shovels) help a great deal by reducing aileron forces from awful to merely too heavy. The instructors were critical of the visibility from the rear seat when teaching akro in areas where there was any concern about other traffic and said that they were constantly maneuvering so that they could see whether other airplanes were around.
Our soon-to-be-an-aerobatic pilot asked about starting aerobatic instruction in the higher performance airplanes. The experienced pilots said that it was just fine, the only issue was money. The more sophisticated airplanes are very good aerobatic trainers, except that some were so responsive that they made basic aerobatics almost too easy.
All of the pilots in the group liked the Decathlon. It is essentially a Citabria with a lower aspect ratio, symmetrical airfoil, wing. There are two versions, one with 150 and one with 180 hp. Both have constant-speed propellers, which greatly simplify flying aerobatics. (With a fixed-pitch prop, the pilot has to add the tachometer to the scan so as to keep the engine rpm under redline, something most pilots simply aren't used to doing.) Both versions of the Decathlon do all of the inside (positive-G) maneuvers well, although the ailerons, even with spades, are uncomfortably heavy. It also does outside (negative-G) maneuvers reasonably well, and is an adequate trainer for negative G work. Years ago I noticed that a 150-hp Decathlon in which I instructed indicated a knot or two faster during inverted flight than when right side up. I never did do a side-by-side comparison with another airplane and have always wondered if it was an airspeed indicator error or whether the airplane really was a bit faster inverted.
If our prospective pilot has the money and can find a place to take dual in a Decathlon, it combines the decent tailwheel handling of the Citabria series with many of the capabilities of the much more expensive akro mounts. It is also a very good personal airplane for training and long-term use, including competition, as well as being capable of making decent speed for cross-country flights.
...To The CAP 10...
The Mudry CAP 10 is the next step up. Only a few of the pilots in our group had flown one. Those who had, liked it a great deal. The bubble canopy made picking out reference points during maneuvers far easier than in the high-wing airplanes, its light controls were a hit with everyone and the only two negatives that I heard were that there weren't enough of them in this country so it was hard to find one to fly and that its tailwheel manners on the ground were less than wonderful. One pilot said that because it is a fairly short airplane, it requires complete attention any time it is on the ground and not tied down.
Beyond the CAP 10, the world of high performance akro machines gets pretty exhilarating. The two-place Pitts series are usually the first machines considered in the top level of training and tend to be available for training in a number of parts of the country. When the first models of the line were introduced they were nearly unbeatable, unlimited class, competition aerobatic machines. Now, with the Extra 300s, top-of-the-line CAPs, Sukhois and others, the Pitts line is no longer the world-beater it once was. However, for someone who is used to flying Citabrias, any Pitts is a revelation. The controls are so light and the roll rate is so fast that aerobatic maneuvers at a level of precision the pilot has been sweating and straining to accomplish suddenly are shockingly easy. The two-place Pitts series are being used for primary aerobatic instruction, although, to some, it is a little like learning to drive in a Ferrari. Nevertheless, if a pilot has the money and wants to learn from some of the best akro instructors in one of the finest mounts around, have at it in a two-place Pitts Special. However, keep in mind that a Pitts Special is a true Jekyll and Hyde airplane: delightful in the air and one of the most gawd-awful-handling tailwheel airplanes ever built when on the ground.
The last airplane that was discussed was the Extra 300. A few of the lounge loyal had flown this utterly delightful ship. All who had done so raved about it, whether it was for competition at the all-world level or simply for learning to fly upside down. The airplane is a pussycat on the ground, handling much like a Decathlon, and is an extension of the pilot's thoughts in the air. There is virtually no friction in the control system, so when moving the stick back to the center to stop a roll, the pilot has to actually allow for the mass of the stick itself. The roll rate is very nearly 700 degrees per second; therefore an aileron roll is faster than a snap roll (that's the case with a Pitts, but it only goes around once in a second). What the Extra is not well suited for is unusual attitude recovery training. It simply responds too quickly and easily. While the student learns what an aggravated unusual attitude looks like, there is no connection to the reality of how hard a pilot must push and twist the controls to return one of the airplanes we normally fly to something resembling straight and level. The only true negative portion of the review was that the controls are so light that cross-country flying isn't all that much fun; the airplane does not stay where one puts it.
Using Normal Category Airplanes For Akro?
One of the comments that got tossed in during the discussion was with regard to using airplanes that were not certified for aerobatics to do loops, rolls and other expressions of exuberance. Having heard the macho posturing over the years by some aerobatic pilots regarding rolling everything through transport-category airplanes, I was curious as to how this group would deal with the idea of doing akro in something like a Cessna 172 or a Cherokee.
I was more than a little surprised by the level of disdain I heard expressed for pilots who were either ignorant of what they were doing or just plain stupid enough to do aerobatics in normal category airplanes. I sat and listened as the group of experienced akro pilots referred to the pilots who do aerobatics in normal category airplanes with some of the most collectively disparaging terms I'd ever heard and, as a lawyer and a pilot, I've heard a lot of disparaging terms.
As clearly as I can interpret what was said (for a family magazine) was that a normal-category airplane is good for 3.8 Gs. That's just a shade more than is pulled in a properly done loop. The problem is that everyone makes mistakes. Everyone. The aerobatic airplane is made to withstand those mistakes and not come apart at the seams. Every one of the pilots present said that they had made mistakes in their initial training that took the airplane right up to red line speed and to 5 Gs (or more) in the process of recovering from the foul-up. The lasting impression on each of them was just how incredibly quickly things went wrong and, even with a very skilled instructor on board, how near the strength limits on even an aerobatic airplane things got. Each of them said that their episodes would have overstressed a normal category airplane. One pilot noted that there seems to be about one in-flight breakup per year due to some cowboy who is infected with a terminal case of macho and makes a tiny little error when doing akro in an airplane not built for it. Each of the pilots also emphasized that he or she had made mistakes after their training was completed and that they continued to make mistakes from time to time when flying akro, even now. They were able to correct those mistakes before the airspeed or G load exceeded the relevant red line; however, those mistakes would have broken a normal category airplane, and, as it was, cost a great deal of altitude in the akro machine. What was embarrassing for some of them to relate, (and was consistent with my own experience), and so very instructive, was that the screwups tended to happen in what are normally routine maneuvers, most often in the simplest rolling maneuvers. The idea of doing aerobatics, even "easy" stuff, in a non-aerobatic airplane was something these pilots would not do and more than one admitted that such refusal might be the reason all of them were still alive.
So, Am I Going to Throw Up?
Probably not, if you are honest with yourself. Every normal person who starts aerobatic instruction has a certain amount of uncertainty and fear. The reaction is a healthy response to the unknown and to stress. It gets the body's defenses programmed to be ready for anything. (I'm not sure I'd fly with a new aerobatic student who wasn't a little fearful or at least uncertain about stepping into such a new and different part of aviation.) Added to that is the new physical sensation of G-loading beyond what one runs across in normal flight operations. Toss in the new experience of very large pitch changes and the result is almost invariably some degree of nausea. If the student is honest and the whole concept of nausea is addressed frankly right up front, the problem is not usually insurmountable.
I think it should be discussed prior to the first flight and an agreement reached between the instructor and student as to how to deal with the reality of nausea. I've found that an effective basic strategy is to come back and land before the student does the Technicolor yawn. The reason is simple: If the lesson is stopped before the student blows lunch the student's tolerance will increase on the next flight. If the student heaves, the tolerance level drops and the onset will be faster next time. Yes, there are studies that confirm this. Yes, the data can be reproduced. No, I won't assist further research. It's messy.
It helps if the instructor frequently asks the student how he or she feels, ignores what the student says and pays attention to how he or she says it. That way the instructor is more likely to catch incipient nausea before it gets noisy, smelly and unpleasant. After all, this aerobatic stuff is supposedly being done for fun. The student is paying a lot of money to have fun. Why pay a lot of money to barf? I've never fully understood how a rational person could be motivated to do that, so I've always been in the habit of terminating lessons early. I've had an aerobatic student that could do no more than one loop on each of the first three lessons. On the fourth we did three loops. On the fifth we flew for half an hour before he got uncomfortable. On the sixth he didn't even get uncomfortable. Yes, the tolerance does drop off if there is a long hiatus between flights, but it increases again very rapidly.
In recent years, technology has come up with an electronic wristband device, the relief band, which has proven incredibly effective. If you feel that motion discomfort is going to be a concern, whistle over to the Aeromedix.com web site or to Woodside Biomedical and order one.
What Does the FAA Say About Aerobatics?
Amazingly, not much. There are refreshingly few regulations, and they are almost purely common sense in their approach to the subject. The regulations are so minimal and so realistic that one is almost afraid to say so out loud for fear some bureaucrat will decide to get involved and louse things up.
In general, you have to be at a minimum altitude of 1,500 feet AGL when doing akro, stay off of airways, away from over populated areas, outside of Class B, C, D and E airspace, have three-mile visibility and wear a parachute if it is more than just you in the airplane. While there is an exception for dual for the purpose of teaching spins, when taking aerobatic dual you must wear a parachute. Akro, for parachute-wearing purposes, is defined as pitch of greater than 30 degrees nose up or down or bank in excess of 60 degrees. Otherwise aerobatics is defined as acceleration not required for normal flight. The FAA does issue waivers for progressively lower altitudes for conducting akro, something you may find that interests you, particularly if you get into competition or airshow flying.
Is It Safe?
We can fight over the definition of "safe" all day. Suffice to say that the accident rate for aerobatic flight practiced by pilots who respect the 1,500-foot minimum altitude has a superb safety record. The reason is that altitude will cure a multitude of sins. If you mess up a maneuver when you are high, you have time to fix things before they go critical. If you get the nose down and get going fast you can close the throttle and raise the nose gently to slow down without exceeding the G limits of the airplane. If you do the same thing down low you may not have the altitude to even start a recovery, or, if you do, you may have to push or pull so hard that you walk the ugly line between breaking the airplane and hitting the ground.
Up high, if you do something wrong and get the airplane into some gyration you do not recognize, you have time to try a few things to see if you can get it to do something you do recognize and return to level flight, or you can make the decision to step out and join the Caterpillar Club. (If you use a parachute to save your life you automatically become a member of the Caterpillar Club, so named for the little insect that makes the silk from which parachutes are created. You get a pin to wear and your name is entered on the Club's membership roll.)
I find myself cautioning my students that in terms of low flying, the best they can do is tie the record for lowest recovery but, if they do so, I won't attend their funeral. Nature is a hanging judge; you do not get probation for violating a law of physics. Because I know I make mistakes, I tend to practice aerobatics way up high so that I have plenty of time to correct those errors. The cliché is accurate; no one ever got hurt colliding with the sky.
Above 1,500 feet, practitioners of aerobatics have an extremely low accident rate. There have been some fatalities due to in-flight breakups, but those are pretty rare and tend to fall into the freak accident category. For those who do aerobatics in the airspace below 1,500 feet AGL, it is a different story. Every year there are a few fatal accidents. Not surprisingly, the majority are pilots who have not been trained and who get carried away in the thrill of the moment while doing a buzz job and try to roll the airplane. They either don't know, or forget, that the nose has to be raised a long ways before starting the roll, and they stuff the airplane into the ground. Adding to the foolishness of such accidents is that the majority of them involve airplanes not designed or certified for aerobatics. I often wish that the idiots who pull such stunts had done so before reproducing and wonder whether the aviation gene pool is getting a little shallow.
There are some fatalities involving airshow and competition pilots each year. Most of them are the result of a simple miscalculation in an environment where there is no room for error. For those who intend to do aerobatics below 1,500 feet AGL, it is my frank recommendation that you only go into it with your eyes wide open and fully aware of the increasing level of risk.
How Do You Do That Stuff?
If you set aside the incredible tumbling maneuvers that have evolved since the Czechs figured out the Lomcovak in the '60s, every aerobatic maneuver can be broken down to the snap roll, loop and aileron or slow roll (the aileron and slow rolls are similar but do have distinct differences) or some combination of those three elements. The akro pilots mentioned a number of books and videos. They agreed that William Kershner's hard-to-find book on aerobatics for the Aerobat was especially good, and they all liked a book by Duane Cole entitled Conquest of Lines and Symmetry, that is usually available from various sources. They suggested going to Patty Wagstaff's web site for additional information and strongly recommended joining the International Aerobatic Club, part of the Experimental Aircraft Association, as it has a tremendous amount of information available.
As to where to go for lessons the issue was more difficult. The current "hard" aviation insurance market has taken a number of operators out of the business. The Citabria I have flown for some time is not currently being rented due to lack of available insurance. The pilots in the group suggested that the International Aerobatic Club would be the place to make inquiry as the folks there know pretty well who is giving instruction, where.
What's In It For You?
By the time the gathering broke up, I came to believe that our prospective aerobatic pilot would be starting lessons soon. He looked pretty fired up. As I walked out the door and down to my hangar to close it up for the day, I couldn't help thinking about him and the pilots I've known who have made the effort to at least take a basic aerobatics course. One in particular stood out in my memory as a good example of what I'd observed in pilots who took aerobatic instruction. He wasn't one of my students, but I'd known him from talking with him and watching him fly. He had been a pretty average pilot, I knew he was uncomfortable with stalls and had a tendency to overcompensate by adding too much speed when coming down final approach.
I saw him a couple of months after he had taken a basic aerobatic course. By that time, he found it was very enjoyable to go out about once a month and "cage his eyeballs," as he put it. What struck me was that he had changed. I never could put my finger on all of it, but he was clearly more confident, not cocky at all, just more comfortable around airplanes. It showed when he did a preflight and when he took off or landed, things appeared more certain and under control. It sounds a little silly to say, but it seemed to me that he'd lost about 15 pounds and was standing a little straighter. When I asked him how he liked akro, I got a huge smile in return. He told me had was pretty nervous initially, and his stomach knotted up, so his first few lessons were brief. Then he found that he enjoyed it far more than he had ever expected and his tolerance shot up. He liked the tremendous feeling of freedom he got when he did aerobatics; it was more of the feeling he had expected to get when he learned to fly in the first place. He said he came out of the lessons with a side effect he hadn't expected: He was far more confident in his ability to put an airplane where he wanted it to go. He tended to plan farther ahead of the airplane when in flight and his family had commented that he was making much better landings in the Arrow they normally flew on trips. He sort of laughed at the last, and said that a lot of it came about because he wasn't afraid of stalls anymore. He knew when the airplane was about to stall and he knew what to do about it. He wasn't tacking on an additional 20 knots of speed on the approach, so he wasn't floating and porpoising in the flare and then banging the airplane onto the ground.
Somehow I felt that our aerobatic-pilot-to-be would have much the same experience. He'd find that his overall piloting skills would improve noticeably in a short time and he'd have one heck of a lot of fun in the process.
See you next month.