There should be no mystery…
A quote from the NTSB’s 2017-2018 most wanted list of transportation safety improvements: From 2008 to 2014, nearly 48 percent of fatal fixed-wing GA accidents in the United States resulted from pilots losing control of their aircraft in flight. They want that fixed.
The sad thing is that this has been forever true. It was one of the factors that drove the founding of AIR FACTS in 1938. The low altitude, low speed loss of control has always dominated and back in the good old days this was often dismissed with the comment: he ran out of airspeed and ideas at the same time and he spun in.
Do pilots know enough about spins?
Spins were a part of private pilot training until 1949, when they were dropped. Several reasons were given: Spins scared new pilots, we’ve done spins for years and pilots still spin in, and if an airplane is easy to spin intentionally (as is good for training) then it is also easy to spin accidentally.
I started learning to fly in 1951 and my instructor, Rudy Peace, included spin demonstrations before first solo and spin training before I was sent out to practice stalls solo. Rudy said that I could accidentally spin while practicing stalls and he wanted me to know how to recover. Most instructors felt the same way so while no longer required, spin training remained the norm for a while after 1949.
There was a lot of local recreational flying done at the airport where I learned to fly, in Camden, Arkansas. When our hangar or rental customers would show up we’d ask if they were going for a spin. In some cases, that just meant a local flight but it was often literal because spins were, to many pilots, a fun thing to do when out boring holes in the sky. We all did loops, too.
Most of the airplanes were two-seaters, with J-3 Cubs the most numerous. A good one could be had for $750 and the operating cost was low. Our blue-collar friends could and did afford Cubs. The Cub was a good spinner and was especially fun to spin when the weather was warm and the door was opened all along the right side of the cockpit. In a spin I think I remember the bottom half of the door moving up and down some, like the Cub was wiggling one of its ears in delight.
The Champ did a cleaner spin than a Cub and the Cessna 140 was even better. The 140 spun more nose-down than the others and rotated more rapidly but you did have to be mindful of the airspeed on the recovery from the dive after the spin was broken. It was a cleaner airplane than the others and a good 140 spin recovery was one that kept the airspeed well within limits. That took more Gs than a Cub or Champ recovery.
Luscombes were good spinners, too, and we had one customer who liked to do many-turn spins. I think I remember him doing a 10-turn spin. I never like to do more than two or three.
A friend, Jack Donnell, who I taught to fly, wound up winning the spin championship, though. He had bought a Porterfield 35-70, built in 1935 and powered by a 5-cylinder, radial LeBlond engine. It was a jaunty, tandem, two seater with unorthodox wing struts: Instead of being in a V, they were parallel.
After he bought the airplane, he asked if I would do spins with him in it. He had spun a Cub but he wanted to see the Porterfield spin before trying it solo.
As an aside, I had the thought that the Porterfield was within two years of being as old as I (at 20) and I wasn’t used to flying airplanes that old. Now the average age of the fleet is a lot older than a hot shot 20 year-old instructor.
The Porterfield was nice to fly and it spun well nose down and rotated almost as rapidly as the 140. The recovery was clean and easy, too.
Jack started spinning the Porterfield regularly and one day got it high enough to do a 14-turn spin and still have plenty of room for recovery. I don’t think anyone believed him so he told us to watch and he would do it again. We did and all agreed that he did many turns but nobody felt like they made an accurate count because it was hard to keep up with the turns because of the high beginning altitude. Maybe he counted better from within, maybe not. We still crowned him spin-king.
My first airplane was a Piper PA-12 Super Cruiser. It was a neat three-seat airplane as long as the two in the rear were not broad of beam.
I used this airplane for my flight instructor rating (this was before it became a certificate) training and check ride and, in the 1953 scheme of things, precision spins were a requirement for an instructor. They were done three ways: straight ahead, out of the bottom of a turn and out (over) the top of a turn. To this day I am not sure exactly how you are supposed to mark the beginning of a spin out of a turn so you can count the number of turns in the actual spin. I passed, though, so my guess of how to do it was apparently okay.
The spin over the top was the most difficult. For some reason, most pilots usually spin to the left and my spins out of the bottom of left turns were pretty simple. I used about 45 degrees of bank, slowed to the stall in the turn and, at the stall, gave it full left rudder and full right aileron. Into the spin it went.
To do it over the top, the same left turn, the same slowing, but a different technique was required as the airplane approached the stall. The stick had to be brought back smartly as full right rudder was applied. The result was a sort of a snap roll out of the top of the turn followed by a spin entry. If I did it any other way, the airplane just rather wallowed into the spin. I didn’t use full opposite aileron because it didn’t seem a natural thing to do, sort of like patting your head and rubbing your tummy then changing hands.
If that sounds like a dizzying amount of spins, it was. It was also fun.
The interesting thing about our spinning in the early-50s was that we knew the airplane would spin and we knew how to spin and recover, but, we really didn’t know why the airplane would spin. Aerodynamic knowledge was in short supply at that time.
I guess we did know that it took stalling and yawing to make the airplane spin and that the corkscrew motion was caused by the angle of attack on the bottom wing being greater than that of the top (outside) wing. What a lot of pilots didn’t know was that in some airplanes you could get enough adverse yaw out of just the ailerons to cause an airplane to spin. Most pilots thought it took full rudder to get enough yaw to spin.
The airplanes we were spinning were certified under Part 3 of the Civil Aviation Regulations and we just assumed they were okay to spin because most or all had been used for training when spins were required. Some years later I researched this for an article and found that at that time spins were neither approved nor disapproved or even mentioned in the documentation for most airplanes. I think this later changed, at least for some airplanes, probably as type certificates were reviewed when they were sold.
Now the basic spin certification requirement for singles is that they be able to recover from a one turn spin in one additional turn. If an airplane is approved for spins it must recover from a six-turn spin in one and a half additional turns. I never spun an airplane that didn’t recover instantly and would imagine that any time that elapsed between applying recovery controls (stick forward to reduce the angle of attack and opposite rudder to stop the rotation) would be uncomfortable. If other means of spin recovery, such as the airframe parachute on the Cirrus, are available the airplane doesn’t have to meet the other recovery requirement. The same thing is true if an airplane is shown to be incapable of spinning.
Twins do not have to be spun to meet certification requirements.
When an airplane is spinning, it is stalled so the airspeed is stable just below the stalling speed. Some airplanes will fly out of a spin and into a spiral, with the airspeed building. This needs to be noted quickly and a recovery started from the dive.
The location of the airplane’s center of gravity is quite important. The farther aft it is, the easier the airplane is to spin and the more difficult the recovery. With the CG too far aft, recovery will be impossible.
A good example of the CG effect on spins is found with the Cessna P210, one of which I flew for 28 years. The certified aft CG limit on the airplane is set at 52 inches. When making STC mods to the airplane, spin tests are required and to my knowledge no modifier has been successful in recovering from a spin with the CG at the 52 inch aft limit. Most have had to put the limit at 50 inches and in learning this I think that at least two airplanes were lost in unrecoverable spins. In others a spin chute (carried in the tail) was deployed and the jettisoned after it forced the airplane out of the spin.
When spinning, the nose of some airplanes seems to be quite low, others even lower. The windshield literally contains a commanding view of the rotating earth. The most nose-low spin, as in a Cessna 140, is probably not nearly straight down even though it might seem that way.
Some NASA research found that in a steep (nose-down) spin the angle of attack is 20 to 30 degrees. That is not too far from the stalling angle, which averages about 18, and what this means is that the airplane should recover quickly. In a moderately steep spin it is 30 to 45 degrees which would make recovery slower and in a flat spin the angle of attack is from 65 to 90 degrees. Flat spins are unrecoverable without a spin chute.
Piper certified at least one model of the Cherokee for spins, to be competitive with the Cessna trainers. I tried spinning one of those and while I could get it to break like it was going to spin I never got a fully-developed spin out of the airplane.
Piper designed the PA-38 Tomahawk to have more active spin characteristics than the Cessna 150/152. The company said flight instructors wanted a better platform for spins.
The Tomahawk was a fine spinner, too, and the recovery took a brisk application of anti-spin controls. Most pilots learned not to look back at the T-tail in a spin because the Tomahawk would wag its little tail in a spin. This was early lore and I made a point of spinning one and looking back at the tail. The motion was not as dramatic as some had described it but it was definitely there. I only looked once.
When our son was getting his CFI, he could not find an instructor to give him spin instruction and provide the required logbook endorsement on spin proficiency which is now the only spin requirement.
One gee dad later we were vaulting up to altitude in a Beech Skipper to do spins except it was more of a struggle than a vault. The Skipper was a sad climber with two full-grown Collins boys on board. I had never spun a Skipper but had it on good authority that it both spun and recovered well. Still, I wanted New Jersey a good distance below so the climb took a while on the warm summer day.
The POH said to use a standard spin entry except for the addition of full aileron opposite the direction of the spin on entry. I guess it needed that yaw in addition to that from full rudder for a clean spin entry.
The spins were fine but the exercise took a while because of the climb back up before the next spin. I demonstrated a couple and then let him do a few before deciding that we had met the requirement and I signed his logbook for spins. After that the FBO called me a couple of times to come do spins with flight instructor applicants, but I declined. Too much slow climbing. I might have done it in the winter.
The Cessna 172 is used a lot for training and is approved for spins when operated in the Utility Category. That is pretty well handled by just flying with the front seats occupied and with nothing in the baggage compartment. Before spinning, a 172 pilot should do a weight and balance calculation just to make sure.
I have spun a 172 many times and the old, pre-1973, ones spin better than the newer ones that have a contoured leading edge. Also, in 1981 the flaps travel was reduced from 40 to 30 degrees and I think there was a corresponding decrease in up-elevator travel which would make the airplane more difficult to spin. The later model 172s will spin, and are approved, but they just don’t spin as nicely as the old ones.
The two-place Diamond DA-20 is approved for spins and I have heard it is a good spinner, but I have no experience with it.
How much altitude is lost in a spin? Lighter wing loading means a lower stalling speed and correspondingly less altitude loss in a spin. Some say that a really light airplane, like a Cub, can be spun and recovered in as little as 500 feet. To me, that is about like saying it will clear a 50-foot obstacle on takeoff in so many feet and then demonstrating that with the obstacle a brick wall.
The altitude loss in an accidental spin would include that lost in the departure from controlled flight and as the airplane entered the spin. Then there’s the time to recognize what happened, then the altitude loss when breaking the spin, then the altitude lost recovering from the dive after the spin.
I’ve seen numbers on this ranging from 1,000 feet to 1,500 feet for airplanes in the PA-28/172 class. What that means is that if you stall below that altitude, all those stalls you practiced at altitude, and any spins you have done up high, won’t do you any good. Below that altitude, the only salvation is in maintaining an angle of attack that will not allow the airplane to stall. Keeping the ball in the middle helps, especially if you get a little bit slow. Be mindful of the ailerons, too. If it is taking a lot of opposite aileron to keep the airplane from overbanking, look at the ball and center it while reducing the angle of attack and levelling the wings. Also, beware bank angles of over 30-degrees.
In the spin itself, each turn might account for 400 to 500 feet of altitude loss but, again, the entry and recovery have to be considered. When an airplane departs controlled flight and crashes, witnesses on the ground often say it wobbled and then rolled over and dove into the ground. If it had been a little higher they would have probably seen the spin start to develop before it hit the ground.
When the question of parachutes and spins comes up, those who love to nit-pick the FARs have a field day. I have read those rules many times and do feel that they are open to interpretation but here is how I see them.
You can go out spinning solo all you want without a parachute.
If you are a CFI and you are instructing a CFI applicant in preparation for a spin endorsement, you do not have to wear parachutes.
Past that, the interpretation of the word crewmember is the key. You can spin without chutes with crewmembers on board but who is to say who and what a crewmember is? Was the writer of the rules being intentionally vague when he didn’t say required crewmember? I would say that the FAA could easily bust any pilot who spins with non-pilot passengers on board. Other than that, your guess is as good as mine.
Years ago a lot of folks called spins tailspins. This might have been because to a layman the tail appears to be spinning around the airplane. An aviation adventure comic strip about a young pilot was syndicated to a lot of newspapers from 1928 to 1942. The pilot’s nickname was Tailspin Tommy. Spins were just what pilots did.
I always enjoyed spins and think that all pilots would benefit from an exposure to spins. That’s the best way to learn that with enough altitude they are fun and relatively benign (in the right kind of airplane) but without enough altitude they are a really quick way to snuff out your lights.
The whole time I was composing this post on spins, I was thinking about and looking for a note on this subject from my father. I just found the note and will share it here.
On Jan. 26, 1931 I became the only pilot I know who got into an inadvertent spin at 500’ and did not hit the ground. I had 20’ to spare in my pullout. It was at Jackson, Miss. and I was giving Lance Minor’s girlfriend a flight around the pattern. In the climb out she asked me to do some tricks. I told her I didn’t know any but in my first turn to the right I would show her how an extra g felt. It was gusty and when I levelled off at 500’ and banked steeply to the right and tightened the turn next thing I knew was that I had made three-fourths of a turn in a power spin to the right. The flight was being observed as a line boy had left off a gas cap. When I got back to the airport the airport manager told me they had a D of C inspector who came through there who would have me walking for ten years if he ever saw me doing something like that. I thanked him and checked all three caps before a hurried departure for LIT as it was late in the day and I had no electrical system in my 5 cyl. 90 h.p. LeBlond powered St. Louis Cardinal.
After the spin the young lady said “do it again.” Oh, me.
I would add all these years later that in effect he saved my butt too. That happened in January, 1931 and I wasn’t born until November, 1933.