Thursday, 26 January 2012

Flying the T-6

One of the many good things about Attitude Aviation is the variety of exotic aircraft that you can fly there. You can fly a Pitts and even, with enough time, patience and money, get to the point where they'll let you solo it or take friends for hair-raising aerobatic rides. They also have a Waco, which is a huge, lumbering - but aerobatic - biplane of pre-WW2 design, and a Marchetti, which is a nice touring airplane that just happens also to be fully aerobatic, including inverted. Not to mention the L-39 which allows you, at eye-watering expense, to fly a jet.

And recently, they finally got their T-6 (also known as a Texan, or in the UK a Harvard) back on the line. This is another WW2 design, classified as an "advanced trainer". In those days, a 19-year old would start flying a Stearman, solo after a handful of hours, and after getting to barely double figures would find himself behind the stick of a 550 HP monster, the size of a combat fighter. A few tens of hours in that and he'd be in a Spitfire, Hurricane or P-51, in combat for real. And maybe he'd come back, too... or maybe not.

Attitude originally had the T-6 on the line a few years ago. I flew it a couple of times, partly to prepare myself for flying the P-51 - but that's another story. Soon afterwards it had a landing mishap. The saga of the repair work and repaint that followed makes for a very long story - but finally, two years later, she showed up again at Livermore airport. I felt I needed to do something to celebrate getting my commercial pilot's license, so the timing was perfect.

The first thing about the T-6 - compared to the normal small planes we fly - is that it is seriously big. The low-mounted wing is at chest height, and the canopy stands about ten feet above the ground. Getting into it involves first clambering up on to the wing, then hoisting yourself into the cockpit, standing initially on the seat before you carefully lower yourself into place. There are two beams for your feet, with rudder pedals at the ends, and underneath that a huge void. Whatever you do, don't drop something in there!  All the controls are massive. It feels truly indestructible. After all, they were made to take tremendous abuse from very inexperienced pilots.

It's also been said that they were specifically designed to embody every known defect of all the combat aircraft of the time. So no matter what you eventually found yourself flying, it would seem tame compared to the T-6. One thing to do the first time you fly a new type - especially if it's as different as this - is to get familiar with all the controls. This means sitting in the cockpit, manual in hand, making sure you know where everything is and what everything does. Maybe you even move some of the controls. But whatever you do, don't move the landing gear control. Because this aircraft has no protection against that - move it to the "retracted" position while on the ground, and it will obligingly tuck the wheels up under itself, doing a lot of expensive damage in the process.

Finally, you feel ready to go flying (with an instructor - this is not a plane that Attitude will let you solo). The first thing to do is start the engine. It's not like a car, this is not a trivial matter. First of all, the prop must be manually turned through a couple of revolutions. Big radial engines like this are notorious for getting puddles of oil in the lower cylinders. Oil being incompressible, if the engine starts like this, the cylinder will be wrecked. This would be highly embarrassing, as well as expensive.

That done, you can climb back into the cockpit, and do battle with one of the most frustrating pieces of equipment on the aircraft. Like most piston engines, this one needs priming - using a manual pump to squirt raw gasoline into the inlet manifold. But the pump is incredibly stiff, and once you're strapped in it's at arms-length. I confess to having been completely unable to unlock the pump, needing someone else to climb up and do it for me. Though not expensive, this is definitely embarrassing - a bit like not being able to release the old-fashioned parking brake on your first driving lesson.

Finally, four shots of primer, and the primer has been closed and locked again. The starter is, uniquely, operated by a pedal between the rudder pedals. As soon as the engine fires, you must get back smartish onto the pedals, to be sure the brakes are fully applied. At the same time, you have to get the engine actually running. Radial engines start one cylinder at a time, or so it seems. The first kick must be carefully nurtured, the throttle advanced very slowly, as (hopefully) another cylinder starts to fire, and another, to the accompaniment of loud bangs and the occasional flame from the exhaust. Watching someone else start a radial engine (and listening to it!) is a delightful experience. Doing it yourself is fraught, with the knowledge that if you fail you'll have to start over, including the dreaded primer.

Finally the engine is running smoothly, all cylinders firing. Now it's time to taxi. As you release the brakes and start to move, you realise just how huge this thing is. Luckily the brakes are conventional - not heel brakes, or the strange composite arrangement with a bicycle brake lever on the stick like on the L-39. But it can't be too easy. In a taildragger you want to keep the stick fully back all the time when on the ground (let's ignore quartering tailwinds for now). That locks the tailwheel within a narrow range of motion. So if you want to make a tight turn, for example to reverse direction in the runup area, you must release the tailwheel lock by moving the stick forward. But for takeoff, it's vital to have it locked. And of course sometimes  it doesn't just lock itself - you have to wiggle the aircraft to and fro, until everything is right.

So, you've been through the (long) pre-flight checklist, got the oil nice and warm, taxied into position, and you're ready to take off. This is the frightening bit - first because you have no idea how it will behave when you apply power, and second because once you've taken off, you will, sooner or later, have to land again. (A very experienced Pitts pilot once told me that it took him several hundred flights before his first thought on becoming airborne stopped being, "Oh, sh*t, now I have to land it!").

The T-6 is actually fairly docile as it rolls down the runway. It doesn't have any vicious habits. It does take some heavy footwork to keep it rolling straight, especially as you bring the nose up. And, unlike the Pitts, it rolls a long way - although it has 550 HP, it weighs a lot too. Finally it reaches rotation speed, and with a pull on the stick you're airborne.

We flew over to our usual aerobatic practise area, which gave some time to get a feel for the aircraft. The stick is quite heavy but easy to get used to. It doesn't have a lot of adverse yaw (unlike the Citabria, for example) so only modest rudder inputs are required. And it makes that wonderful radial noise as you putter along at a modest power setting and 130 mph or so. You just know that everywhere you go, people are looking up and thinking, "What's that?"

We did a few of the usual exercises with a new type, starting with turns and then steep turns. They're easy to fly, the forces, while heavy, are consistent and well balanced. Then we went on to simple aerobatics - loops and rolls. These, too, went easily enough. It takes a lot of force on the rudder to keep a roll straight, and because the roll rate is not very high, the loop finishes with the nose pointing distinctly downwards. Loops go nicely enough, diving for 180 mph then pulling round at 3.5G or so.

Once in flight, the T-6 flies fairly unremarkably. You forget its size, since it doesn't really matter up there. The panel is typical of its era - there's no six-pack, just instruments and switches dotted about at random. The landing light switches, for example, are on the left of the main panel - while all other lights are on their own panel on the right side of the cockpit. (I confess that I didn't find them in flight when I wanted them). The fuel gauges are even worse. They're purely mechanical, with sight gauges down in the void under the floor on either side of the cockpit. Before strapping in I did manage to locate them, but I found reading them in flight to be impossible. The gear lock confirmation is similar - you have to look through two tiny windows in the upper surface of the wing, to see the yellow lock pins. I said I could see them, and at the time I convinced myself that I did, but to be honest it's pretty questionable.

We did a couple of stalls, which were also unremarkable. Then it was time to go and land - with a wonderful view of Mount Diablo in the setting sun. I had an unpleasant experience landing a much smaller vintage taildragger a couple of years ago, so I get a bit apprehensive at this stage. With the T-6, the plan was to wheel-land it. Smaller taildraggers are normally landed on all three wheels at (much) the same time, but with bigger ones it's common to land with the fuselage level, just on the main gear. This means that the wings are still flying and will happily bounce back into the air if the tail drops, increasing the angle of attack. So you have to "stick" the airplane by pushing the stick forward at touchdown. Timing and finesse are everything - too late, and you bounce. Too early, and you thunk painfully hard into the runway - and then bounce. Too much, and you can ding the prop as the nose drops towards the runway.

As it turns out, the T-6 is a pleasure to land. Maintaining a steady 95 mph on final, just gently lowering the main gear onto runway then pushing the stick forward give a gentle touchdown. It's much easier than a wheel-landing in a Citabria!

The flaps on the T-6 are odd in a couple of ways. First, they're "split flaps" - all of the action happens under the trailing edges. From the cockpit the wings look solid, and when you move the flap handle, nothing visibly moves. All the action is underneath. In consequence, it's easy to forget to retract them after landing. And if you forget them until after shutdown, you have a problem. They are operated by an engine-driven hydraulic system, and once the engine has stopped, the only way to retract them is with a manual pump somewhere in the bowels of the aircraft. Guess how I know.

We did a couple of touch-and-goes, which went rather well, then we returned to base. My one real landing didn't go so well - I dropped in hard enough to elicit comment, rather than the smooth touchdown I'd managed earlier. And I'm afraid to say I was a bit heavy-footed on the rudder. I think I've got so used to the Pitts, which is very controllable and reactive on the rollout and will forgive a surprising amount of clumsiness, that the much more leisurely response of the T-6 caught me unprepared.

So, finally, it was back to Attitude, and engine shutdown. The sun was just setting as we landed, so the usual post-flight photo opportunity gave some nice sunset-type shots.

And some time, I really will have to spend some time just getting comfortable with landings. Apart from that the T-6 is a pussy cat, albeit a very big, heavy (and expensive) one.

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