Pelican's Perch #61:
Test Pilot School
After years of dreaming, AVweb's John Deakin became an instructor at the famous Test Pilot School at Edwards AFB. Well, for a short time, anyway! Only mildly intimidated by the idea of head-to-head air combat, John's greatest challenge turned out to be teaching young, hotshot test pilots how to think and fly at the slow speed of a WWII trainer.
When I was young, I had fantasies of becoming a test pilot. I'd done some test flying in the F-51 and lesser airplanes, but with no college at all, no money, and very poor high-school grades, it seemed an impossible prospect. Then I joined Air America in 1963, and the money started flowing into my formerly anemic bank account. (I was down to $3.95 in my checking account, and owned only the contents of one suitcase when I showed up in Laos.)
One day, I read an article in Aviation Week about aircraft manufacturers paying for their test pilots to attend the famous TPS (Test Pilot School) at Edwards AFB. Pay for it? The thought had never occurred to me. So I wrote to them and confessed to my dreams, asking if it might be possible for me to pay my way. My god, I was naive!
The commanding officer, a colonel, was nice enough to write me a very gracious personal letter, telling me that only companies with a very serious need were permitted to send their pilots to the TPS, and that the cost was very, very high. In any event, a full four-year college degree was a requirement for entry, and it had to be a serious degree in math or the sciences.
Since I had barely managed to graduate from high school, that let me out.
Now I find myself an instructor at that legendary institution!
Well, sort of. At least that's the way I like to think of it. OK, OK, so it's only for a week! Well, five days. Four days, if you count the first day of indoctrination, local-area checkout, and evaluation by an instructor. C'mon, give me a break, and leave me a little of the fantasy, OK? For just a few days, I got to swagger around the famous base and be a small part of the TPS. I even had a personal call sign, "Cobra 70," and missed no opportunity to use the common parlance on the radio, "Eddie Ground," "Eddie Tower," etc. (I have this niggling little feeling that the tower operators don't really care for this informality, for they always respond with the more formal "Edwards Ground," and "Edwards Tower.")
After years of avoiding R-2515 and associated areas, it's a real kick to be inside, looking out — legally.
How It All Came to Be
It seems that when the trainees are about 3/4 of the way along in their yearlong course, they are tasked with doing test flights and test-pilot reports on "unusual" aircraft, working with them as if the USAF were thinking of buying them for some purpose. This also broadens their experience. It's a really good idea, I think, because the more airplanes a pilot has flown, the easier it becomes to fly a new one. The trainees get to fly anything that is handy from the military inventory, but for some of the more "exotic" airplanes of yesteryear, they are forced to contract with various civilian owners. The trainees are to evaluate performance, handling and flying qualities, systems and appropriateness for various tasks.
One of the airplanes they seem to like for this purpose is the North American AT-6 "Texan." Now that there is a "Texan II" coming into the USAF inventory, there is also a bit of historical whimsy involved in having the real "Texan" around, even if only for a few days.
The CAF (Commemorative Air Force, formerly Confederate Air Force) has close ties with the military, mostly through all the military shows we do. Two very popular acts are the "Heritage Flights," and the "Legacy Flights," where we put some of our WWII fighters up with the modern jets in the same formation. A variation of this is the "Flight of the Cats," where we've had the Wildcat, Hellcat, Bearcat and Tigercat up with the Tomcat. Our Southern California Wing of the CAF is very conveniently located, only 40 minutes from Edwards AFB, so it wasn't a big surprise when the TPS folks called on us to supply an airplane and a couple of instructors. (We've done the same sort of thing for the Navy, but we didn't mention that to the Air Force!)
The Inland Empire Wing at Riverside was also chosen, so we'd have two airplanes. Jim McCabe did the duty in the other airplane, while Carter Teeters and Dave Morss also got qualified for "next time." Since I seem to be one of the few pilots at SoCal dumb enough to slither into the rear cockpit of the T-6 for training flights, I got the job on our "Yellow Peril," "Old Yaller," or "290," a 1943
Paperwork, Paperwork, Paperwork
The military paperwork for something like this can only be described as "daunting." Many forms need to be filled in and signed (blue ink only for originals, no faxing), with extensive data on the pilots, all the insurance information, etc., and much of it must be FedEx'd around the system to get the counter-signatures and data from various locations. One form had to be signed off by our insurance carrier, which developed into something of a circus. Insurance companies don't like signing paperwork invented elsewhere, and of course, the inevitable question was, "You want to do WHAT?"
One error on any of the forms, and it all must be done over again. I think we made one of those errors, in losing one or more of the forms, at one point.
Months before, the TPS sent a team of people down to Camarillo (and to Riverside) to examine the aircraft and the aircraft paperwork, and to interview the pilots. This is a real inspection, with panels pulled off the airplane so that maintenance personnel can look inside. We have a really nice T-6, and our volunteers keep it in immaculate condition, so we seemed to pass all the inspections with flying colors, no gigs.
Months went by, while the schedule was arranged and rearranged, and paperwork was rejected, modified, and finally completed. There were several postponements, and frankly, I began to think it would never happen. The week of September 23 through September 27 was finally set, and in the final few days, I began to think this one was for real, although some of the paperwork was not done until the last couple of days. Several final phone calls to various offices coordinated the final mission numbers and codes to enable our entry into the gigantic Restricted Areas, and to land at Eddie itself.
This huge base had a very humble start in about 1933. Lt. Col Henry "Hap" Arnold was the base commander at March Field, in Riverside, Calif., and apparently was somewhat frustrated by the difficulty in getting permission from "that other military service" to operate in bombing and gunnery areas in the Pacific Ocean. He looked around for alternatives, and the vast desert just over the hills from Los Angeles (from Palmdale north, and from Owens Valley east) was ideal, with little but rattlesnakes, cactus, and the occasional miner or reclusive homesteader. Perhaps even more important, there were several major dry (most of the year) lakes, which could easily serve as ready-made runways. This was then Muroc Dry Lake, later renamed Rogers Lake. A new gunnery range was born, and it wasn't long before much of the Army Air Corps testing of new aircraft was done there. Boeing P-12s, Curtiss B-2 Condors, and the hot new P-26 "Peashooter" left their tracks in the dust. Eventually, the huge tract was purchased for something like $130,000 in about 1935. Today, 68 years later, the focal point is the gigantic Runway 4/22, over 15,000 feet of concrete, 300 feet wide, plus another five miles of dry lake bed that can support the Space Shuttle. Manufacturers have test sites there, the NASA Dryden Test Center is right next to the base, and several concrete runways ("North Base," "South Base," etc.) take some of the traffic. The lakebed itself is crisscrossed with dozens of marked runways in all directions. They get flooded a couple times a year when the thunderstorms move through, but with astonishingly clear skies, bright sun, and dry desert heat, they soon dry out and return to normal.
My trusty steed coughed to life at first light on Monday morning, September 23, and we were off Camarillo (CMA) before the tower opened. I love pre-dawn flights, when everything is so cool, clean, and quiet, and there's no one else around. Well, at least it's quiet until that Pratt & Whitney starts up!
The flight was uneventful, except for a towering plume of smoke well off to my right. It could have been an erupting volcano, or even a nuclear blast, but it was, of course, a wilderness fire, so very common this year. It had just started in the hills to the north of the Los Angeles basin (I found out later it was in the Angeles National Forest), and while talking to Center, I heard airliners getting deviations around it, and complaining about the ash fallout. But it was off my right wingtip, and I was headed for the Mojave Desert, so I didn't think much about it. It is still burning as I write this, a week later!
After all the paperwork, all the codes, and all the briefing, the penetration of R-2515, and the arrival into Eddie, was a non-event. I guess they knew I was coming. I simply entered the downwind and flew alongside the monster runway, and flew alongside it, and flew some more alongside it. I began wondering if I'd need a fuel stop in the pattern. I finally gave up on trying to reach the end, and just turned in and landed long, about 6,000 feet down the runway, touching down at the 9,000-feet-remaining marker. That put me nicely at Bravo taxiway, the runway-sized taxiway to the main ramp at midfield. I would later land and stop with the "14" marker showing.
Monday was to consist of a most-of-the-morning briefing. This is some briefing! Two of the school's IPs (Instructor Pilots), and two of us ragtag civilians. They use a really neat touch-screen on the wall, perhaps five feet wide and four feet high, driven by Windows. I immediately began trying to figure some way of strapping one to the belly of our T-6 for the trip home. Surely, they wouldn't miss just one, for all the briefing rooms had them!
But, back to the briefing. The first part of it concerned the airspace "owned" by the test center. There is a lot of it, with many different functions, and some truly bizarre flight patterns. There are a couple of supersonic corridors, approach patterns for lifting-body aircraft, "Spin" areas (yes, for spinning aircraft), Space Shuttle patterns for modified T-38s, modified Gulfstreams, and, oh yes, the occasional real shuttle "drops in."
Numerous areas are for air-to-air work and test, air-to-ground practice, and close-air support, sometimes with real ammunition. All these go "hot" and "cold" unpredictably, and everyone needs to stay heads-up, as many areas overlap, or have an effect on other areas. My feeble brain was soon reeling with areas that could be hot from the surface to 60,000 feet, some others from 11,000 feet and up, with us flying around below, some corridors, some square, some round, some just odd shapes.
To cut the clutter, I reflexively started paying attention to only those areas of immediate interest to me, and I once whined, "Do we really need to know about that?" The young IP (They're all young, even the colonels!) looked at me with pity, and said, "Well, if you're on downwind or base for the long runway, and a lifting-body aircraft comes over the base at "high key" (25,000 feet) and makes one tight, steep 180 turn to the runway in under 60 seconds, wouldn't you like to have an idea where to look, and where to go to get out of the way?"
Hmm, point taken. I sat up, started paying more attention, and said, "Would you mind repeating everything after 'Good Morning'?" He thought I was joking!
The perspective is very different. These kids (hey, at my age, I reserve the right to call 'em all "kids",) learned to fly in T-38s; few have ever been in an airplane with a piston engine, and, essentially, none have time in taildraggers. It's a whole new world to them. The concept of time and distance in a T-6 is totally alien. A working "box" of airspace for them might routinely be 100 miles or more long, 50 miles wide, and 40,000 feet deep, and they'll go from one place to another at 500 knots and more. End up your airwork 60 miles from base, and you're only a few minutes away, and just right for a descent. At one point I said something like, "Where's a nice little area about 10 miles in diameter, maybe five miles from the base, from the surface (at 2,300 feet) up to maybe 8,000 feet?" They looked at me as if I was from Mars. As I said, it's all in the perspective.
Even the traffic patterns are complicated. Most patterns are on the south side of the main runway, probably to stay away from the main base facilities and housing areas. The "South Base" runway (6/24) is located roughly one-half mile south of the main runway, "only" 7,000 feet long, and is not quite parallel to the main runway. It is not controlled at all, and all traffic there remains at and below 2,800 feet. For the main base (runway 4/22), the lowest pattern for the slowest movers (like us) is at 3,300 feet, and jets are at 3,800 feet. For those entering or re-entering the pattern, 4,300 feet is the norm. I was less interested in the exact altitudes, and more interested in just staying out of everyone's way!
Straight-in approaches are usually made on the extended centerline of the main runway, but this is not a good idea in the T-6, with a 105-knot approach speed. Or even "pushing" it at 140 knots, for an F-15 or F-22 will overtake very quickly, and no one around Eddie quite has the perspective of a really slow-mover.
There is also a "Flyby" line, which got my immediate interest. It is dead parallel to the main runway, and close to the main ramp and tower, with a very prominent black line painted for several miles out into the dry lake! What a great way to show off the T-6, with a thundering, 140-knot low pass at 10 feet! Alas, they're ready for weenies like me, and very sternly said, "You MAY NOT fly over the flyby line! YOU MAY NOT ALLOW your trainees to fly the flyby line, even if they are colonels!" Shot down again!
Turns out it is for calibrating the pitot-static system on aircraft in flight (see sidebar by Major Doug Dodson, below).
Still, it sounded like fun, and surely they wouldn't mind just one pass? Seemed like the instructor was reading my mind, though. "The last guys that were here got tower approval, and flew the flyby, but they got into serious trouble." I didn't ask what the punishment was. Scratch the low flyby.
Then we got into the planned maneuvers, and they too were briefed in exhausting detail. Each flight was to be two airplanes taking off together, about half an hour of formation work, half an hour of solo maneuvering, and half an hour in the pattern for the test pilots. Test engineers (non-pilots) were to get a bit longer in the air, and were not allowed to fly below 300 feet, so they only got to see one landing.
Purpose of the Flyby Line
Ninety-nine percent of the error of installed systems is due to the pressure field around the airplane distorting the pressure sensed at the static port. That distortion varies with angle of attack. So, to calculate those errors, we fly by a tower (not the tower) and, using a simple mechanical sight (like the iron sights on a rifle), we measure the angle between the airplane and the tower. Do a little trig, and you get the altitude of the airplane if you know how far away it is. So, as long as the airplane is over the line, we can measure its altitude to within about 15 feet ... no lasers required.
Then, we take a temperature reading at the tower, and a pressure reading. We can calculate the pressure and density altitude. The crew records the aircraft indicated altitude (altimeter set to 29.92, so it's already pressure altitude). The difference is the static-pressure error. This is done at a variety of airspeeds, up to .95 M and down to 1.2 Vs to get the variation with angle of attack. This is either plotted and put into the flight manual, or programmed into the air-data computer, and voila! The airspeed can be calibrated similarly, but pitot tubes are generally pretty accurate, so any errors are assumed to be from the static port.
We do have another line on the lakebed used to calibrate the pitot-static system called the low-altitude speed course. That one runs north-south and has marks exactly one statute mile (it's as old as the T-6s) apart. We time the aircraft to calculate ground speed, then account for the wind by not crabbing (eliminates crosswind effects) and flying both ways (eliminates headwind effects). Again, we use the info to measure static errors, not pitot errors. The speed course is really never used anymore, since it has to rely on more assumptions to yield the desired results. Wind effects can never be eliminated truly, since the wind is never really constant. We can use GPS to do the same type of calibration at any altitude, but even that is inferior to the "Tower Flyby" technique.
The briefer fixed me with a steely gaze and asked, "What's your takeoff protocol for a two-ship?"
"Oh, we'll taxi onto the runway, lead takes the downwind side, number two takes the other side, lead takes off, and when there's daylight beneath the wheels, number two starts rolling."
Then, "What's the interval, in seconds?"
I sorta grin, and say, "No timing, just daylight."
"How about hand signals, or radio calls?"
"None, just go."
This was a novel concept, but we got by that.
Then we discussed power settings (manifold pressure and RPM were alien concepts), and then climb speeds. One T-6 is marked in knots, one in miles per hour, but the briefer finally heard, "105 knots."
"105 knots for a climb speed? Are you serious?"
"Well, we can climb slower, but I like 105 for engine cooling."
He only choked a little on that, then, "How long do you maintain 105?"
"To cruise altitude."
I think that's when he started losing it; he was never quite the same after that.
"Ok, after we get to cruising altitude, we'll start the formation work ..."
"Uh, maybe you want to do some of the formation stuff during the climb, as soon as we join up?"
"Well, it's a very hot day, and we'll probably only get about 500 feet per minute or less to 8,000 feet, so that's 10 minutes of climb wasted, and you could get the formation stuff done for at least one airplane during that."
"500 feet per minute is the best you can do?" (Weak voice.)
"Well, if it was a cool day, we could do a little better."
So we talked about formation. Military pilots are accustomed to moving the thrust lever(s) from idle to full afterburner during joins, and they have those great speed brakes that allow them to come booming into position, snatch the thrust lever to idle, pop the boards, stop all relative motion, then retract them, one shot of afterburner, and done, they're "in."
I knew this would be a problem, so I told them, "You cannot come back to idle in flight, it's hard on the main bearings and other parts of this old engine, and there are no speed brakes of any kind. At 8,000 feet you can go to full throttle if you need it, but mostly you'll have to use geometry and anticipation to get into formation, and to move around while in formation. Small movements of the throttle, please, well in advance."
Then we talked about "advanced rejoins." These have elements of ACM (Air Combat Maneuvering), but are a little more fixed, as the primary purpose is to evaluate how well the airplane does relative other airplanes. This is normally done at 500 knots or more.
The briefer seemed to shake off the business of a 105-knot, 500-fpm climb, and said, "OK, for advanced rejoins, first we move out to line abreast, about 3,000 feet apart, then the lead designates a shooter and a target, and calls 'turn out.' Both airplanes turn 30 degrees away, then when the lead thinks there's enough room, he calls 'turn in.'"
My hand went up, and he got that sick look again.
I said, "Due to the low speed, may I suggest we just turn out for a few seconds, then let the IP call the turn in? You'll save a ton of time, that way?" We finally settled on 1,000 feet apart, line abreast to start, then turn out, then turn in. In the end, we all agreed that was still "too much" for the low-speed aircraft.
He continued, "Each aircraft passes the other on the right, or 'left to left,' and on passing abeam, the fight is on."
He had my full, undivided attention, now!
"You mean we're going to turn and fly at each other, nose-to-nose?"
"Okay, we can do that, but I want to know exactly what your protocol for that is. I can tell you right now, I'm the chicken, let's not play that game! Who's the shooter, who's the target, and which side do we use to pass?"
But they were way ahead of me, and the "left-to-left" is well-established, along with calling the shooter. With that settled, I went back to my usual semi-stuperous state.
Working in the Vertical
"OK, when the two airplanes pass, the target has his choice, he can either do a 360 in the vertical, or either direction horizontally ..."
I'm sorry, I got a case of the giggles; I just couldn't help it.
He patiently waited for me to get control of myself, and I was finally able to say, "Ahh, you do know this airplane won't do a loop from level, cruising flight?"
From the look on his face, you could tell that he just assumed every airplane in existence would do that little trick with ease. It took a little convincing that we'd really need to dive at full power for a few seconds, build the speed from 140 knots to 160 knots (180 in the mph airplane), and then be pretty careful to get through a loop without pulling too much at the top and spinning out of it.
(The airplane is placarded, "No Intentional Spins," but I figure unintentional ones are OK.)
"OK, OK, scratch the vertical, then, we'll just do the horizontal." But you could tell he didn't really believe it. Can't loop from level flight? Who ever heard of such a thing!
"Look, you're welcome to try anything, vertical up, vertical down; just don't pull over 4g positive, and not less than 0g ..."
"WHAT? You mean we can't do negative g?"
"Well, you can, but the engine quits because the fuel won't feed, and the engine gets starved of oil, which isn't good. You wanna glide around inverted with no engine, be my guest, but leave the canopy closed so we catch all the accumulated trash in the floorboards, I've lost some money and stuff that's probably still down there."
You could tell, he was learning some very new concepts, but what the heck, that's why we were there!
Anyway, the idea was for the "target" to do 360 turns in any direction or plane, while the "shooter" maneuvered for the "kill." The "target" was not supposed to do anything but change the direction of the circle.
(In all fairness here, all this was not just the fellow who did our Monday briefing; it's a composite of the reactions from everyone, including those in that briefing, in individual briefings, and in a "T-6 Academics" class I gave late Monday, as well as in the airplane.)
The briefing had taken a little longer than I think they'd expected, so we moved on to the solo maneuvers. These went normally, except it was hard to get across that we'd have to dive a bit to pick up speed to do most anything. Airwork was to consist of normal and aggravated stalls in various configurations, loops, aileron and barrel rolls, and hammerheads, after which we'd "roll in" on a ground target, and do some "low-level" work. My interest was up again. Then they set a hard deck of 500 feet. I whined piteously about that, saying that was only for fast movers, but it did no good at all. Others mentioned 300 feet for test engineers, and 200 feet for pilots, but I went back to sleep.
I did warn, "Be sure to do all the stuff you want to do at altitude first, because you won't want to climb back up there."
"Remember that 500 foot-per-minute climb?"
"But can't you use energy to get back up to altitude?"
"Yeah, for about 500 feet, then you're back to slogging your way back up to altitude, on a hot day."
(I don't even want to know how far above 100 ºF the temperature was, and the T-6 has a thin firewall with no insulation. With that hot, desert sun beating down, the black glare shield is hot enough to raise an instant blister. Not to mention the hot NOMEX flight suit and gloves, and flight helmet. The next person who tells me, "But, it's a dry heat," is gonna get a knuckle sandwich.)
It's funny; most civilians think the T-6 is really a hot, high-performance airplane, even after they fly it. It's amazing how the perspective changes when you learn to fly in a twin-engine, Mach 2.0 trainer, capable of a 15,000-fpm climb — with one engine out!
(Yeah, I hinted about a ride in one, but after the Navy Sub incident, that is reserved for politicians and movie stars. Maybe that'll lighten up one day. I sure hope I live long enough.)
Briefing done, we paired up and headed for the airplanes. A quick walk-around, and we stopped at the tailwheel for my usual demo of the tailwheel lock. Like most Mustangs (for which the T-6 was, and remains, the trainer), pushing the control stick fully forward unlocks the tailwheel, leaving it fully castering, 360 degrees. Moving the control stick to any other position than the forward inch or so of travel locks the tailwheel to the rudder, giving wonderful, positive control during taxi. The trick is to get the tailwheel and the rudder aligned so that the lock can engage, but that's pretty easy.
What is really tricky is unlocking the tailwheel inadvertently. If you manage to do that while in a turn, with the tailwheel lock holding the airplane nicely in that turn, then it's an instant ground loop when it unlocks.
"Ground loop?" On hearing that, several asked me, "What's a ground loop?" So I've added an explanation for that, too.
Something on the order of, "A ground loop is an unintended rapid rotation or high-speed yaw in the horizontal plane while on the ground, usually through 360 degrees or more."
Being test pilots and all, they understand the words perfectly, but they don't quite get the concept that arises from the center of gravity being well behind the main wheels, and what happens when the CG is going one way and the wheels are going another. You can see them thinking, "Geez, I'd never do that!"
So they take the front seat, and the first thing they notice is that they cannot see over the nose.
"Yeah, you have to make s-turns all the time, to see where you're going."
"What's an s-turn?"
Remember, it's a new world. Or an old one, depending on your perspective.
"An s-turn is where you perform a sine wave on either side of the taxiway centerline, with the amplitude just less than the edge of the taxiway. During the time the longitudinal axis of the airplane is not aligned with the taxiway, you can see ahead."
See, ya jus gotta talk like a test pilot, they'll get it.
"No ejection seat?"
"No ejection; you bail out the way real men do: Throw away your headset, release the belt, and dive for the trailing edge of the wing. If you really try to hit it, you won't, but you won't get hung up in the tailfeathers, either."
I'll give him credit, he didn't quiver a bit.
"Prop control? What for? MIXTURE???" I manfully refrained from telling him of the gigabytes I've written about mixture control!
The airplane briefing took a bit longer than any of us expected, too. I explained that he'd do the start while I stood on the wing, and that he'd have to wobble the wobble pump with his left hand, while priming with the old-fashioned primer with his right hand, and to ignore the dribble of fuel on his fingers from the primer.
He looked at me in puzzlement, and I realized that, once again, I'd lapsed into perfectly normal jargon, incomprehensible to him.
"Sorry, I meant you'll use this manual hand-pump here to pump up fuel pressure. We call it a wobble pump, because your whole shoulder wobbles when you do it; that way the ground crew knows you're about to start."
"Ok, but why the dribble of fuel?"
"So you know when it's working, of course!"
For the first time, I put a testy tone in my voice, and he looked up, startled. The twinkle in my eye must have given me away, because he really laughed at that, and maybe relaxed a bit. (The old primers sometimes leak when the leather seals dry out.)
The old, old "barrel DG" was new to him (as it is to most current GA pilots!), as was the concept of gyros that tumble during aerobatics. He was a little nonplussed when I suggested that he just cage both of them for the whole flight. No inertial platforms, either, but by this time, that was no surprise.
At Last, Flight!
The flights went well enough. All the guys (no women! I was so disappointed!) did well at the flying, crisp and sure, especially the formation stuff, once we broke them of major throttle movements. All had trouble with rudder coordination, but learned very fast, for people who normally fly with feet flat on the floor. All were astounded at the "lack of performance," and how the wingman couldn't catch up to the lead aircraft if he fell behind a little, or below. We played around, swapped leads, and crossed over and back, while the IPs pointed out the local landmarks to us. The big, dry lake is impossible to miss, even for me, and all the landmarks are very, very obvious.
The advanced rejoins are fun! During the final turn-in, there is one heart-stopping moment when you really wonder if the other guy is going to make the turn properly, but we pass in opposite directions close enough to see the smiles. In higher-speed aircraft, there is a lot more separation required.
Most targets turned into the other airplane at the passing point, most shooters pulled high and tight, and most were "in" within a full circle. During one, the pilot in my airplane needed to remove his earplugs to hear the radio better, so I suddenly got to do the maneuvering as the target. The shooter went high, but showed me his belly for a second, and my meanness kicked in. I hauled it around hard under him, staying in his blind spot as he rolled, then rolled hard the other way, coming up behind him. As briefed, he called "blind" the instant he lost us, and we sorted it out for another try. I so felt bad for not sticking to the pattern, but I get these uncontrollable urges ...
Everyone got good loops, with a couple of them getting high-speed stalls coming down the backside, which was new to them. All did passable rolls, but needed more rudder, not surprising. Many noted the need for rudder during the loop, something most trainees miss. These guys are completely at home in unusual attitudes with a lot of things going on, so they'll make good test pilots and test engineers. None had ever seen a hammerhead before, and all got a big kick out of it.
(A hammerhead is a pull to the vertical, hold it there until just before the airspeed drops too low, then full rudder (left is better in the T-6) and full opposite aileron. The airplane gently rotates about the vertical axis until the nose is straight down. Full opposite rudder, timed right, will stop the nose from swinging too far through, and the airspeed will be showing almost nothing. At that point, I pull the power off, and in the T-6, I pull the prop all the way back to keep it from overspeeding as the speed comes up. If you try to pull out of the dive too early, the airplane will snap into a very violent spin. A little later and you'll at least feel the buffet from a high-speed stall. A little later yet, it will recover nicely to 140 knots or so, at the same altitude you started. Still later, you'll go into the yellow, and burn a couple thousand feet of altitude below the starting point. Delay too long, and the old girl will go right through the redline, where too much pull will break something, if you don't run into the ground first. Don't try this without a good instructor, please!)
Then come the landings. All the pilots made good landings, starting with wheel landings, and most getting three-pointers on the second or third try. The T-6 is a joy to fly, and to land, but the instant the wheels meet the runway, she turns into a rattlesnake. Without prior tailwheel training, no one, civilian or military, test pilot or not, has the foggiest idea of how much rudder is needed, how active you have to be with rudder to keep the airplane straight, and how eager the airplane is to go both ways at once. In test-pilot terms, the airplane is catastrophically and instantly unstable in yaw on the ground.
In most airplanes, I think all pilots try for the "nice" landing, a "squeaker," when the tires just kiss the runway and start rolling. All attention is focused on that part of the maneuver. No matter how that turns out, whether a "greaser," or a "drop-in," or a skip, everyone relaxes a bit for the subsequent landing roll. In a nose-dragger, no problem.
In any tailwheel airplane, when the rubber meets the runway, the fun is just starting, and the most critical phase is coming. In the T-6, it's worse, because of the narrow gear and the top-heaviness. The Pitts Special and some other small airplanes are worse, but the controls are pretty quick, too. Once the T-6 begins to swerve, you're in deep doo-doo. However, it's not usually the first swerve that gets most nosedragger pilots trying on the T-6. It's the second. They'll sometimes recognize and catch that first swerve, which starts from a zero rate, and they'll correct before it gets too bad. Then they'll relax a little, thinking they've cured the problem. But now the nose swings through the centerline with an increasing rate, and all is lost.
Each pilot was allotted only 1.5 hours "block time," and each time, it was over all too quickly. All wanted more, and I had to shut 'em off. During the long taxi in on taxiway Bravo, I reminded them to set up the long, easy sine waves of the required s-turn. During one of those, at about five or ten knots, I usually just quietly suggested, "Say, would you move the stick full forward for a second?"
Not even remotely thinking of the tailwheel lock, they would, and suddenly that nice positive tail-wheel steering was gone, and the swerve started. It immediately turns into an all-out ground loop, for at least 360 degrees! As one put it later, "It'll make your eyes water, even at five knots!" I guess I forgot to tell them about differential braking, darn. I'll have to include that, next time.
For the final part of this very mild ground loop, the force vectors sum up, and the airplane actually rolls backwards! I used to park a C-46 that way, backing it up about 50 feet into the spot (until the chief pilot caught me one day). The old Stearman does this wonderfully well, too.
In spite of my abusing their trainees so badly, the TPS treated me royally. They even put us up in the "DV" (Distinguished Visitor's) quarters on base. Two of us went to the "Muroc Club" for dinner, just in time for the Wednesday-night special, steak for two at $9.95 for members, $12.95 for non-members. That's $12.95 for both dinners, $6.475 each! Pretty good steak, too, baked potato (Quayle style), salad and coffee. True to form, I instinctively asked for the usual airline discount, then for the AARP discount, but it didn't work. Oh well, win some, lose some.
There was only one downside to the whole thing, and that was communications. My communications. My cellphone wouldn't work. The base phones wouldn't work, either; all were on the military system, and without the codes, they might as well be dead to me, at least for Internet use. The phone in my quarters was unique: If I dialed the hotel operator, I got her OK, but at the same time, I got the main-base switchboard automatic answering machine with a long voice-menu, and some random conversation between two other users, all at the same time, and all at the same volume! The hotel operator thought all that was perfectly normal, and was surprised when I mentioned it!
If they ever invite me back, we have to talk about Internet access, with my computer!
Be careful up there!