Pelican's Perch #38:
AIRSHO 2000 — The Agony and the Ecstasy
What's it like to fly a 25-ton WWII-era round-engined twin to, from and in the Confederate Air Force's big annual warbird airshow? It's a tough job, but somebody's got to do it. AVweb's John Deakin was elected to shepherd one of CAF's two flying C-46
The Confederate Air Force (CAF) does the granddaddy of all warbird airshows every October, in an unlikely place called Midland, Texas. The airport is located between the towns of Odessa and Midland, and while it is a superb location to fly an airshow (flat, no obstructions, no noise complaints except from armadillos), it's a million miles from anywhere across the sere desert that is West Texas. It takes us about six hours to fly there from Camarillo, Calif. In the old Curtiss-Wright C-46, and it probably takes more than that for folks to drive there — from the nearest town.
I exaggerate, of course. It really takes us only five hours to fly there.
Flight to Mecca
Be that as it may, if your thing is warbirds from the WW-II era, or big round radial engines (and a few "hot water 12s"), then for a few short days Midland becomes "Mecca." In principle, all of the 140 warbirds belonging to the CAF are supposed to fly in from wherever they are assigned for the big show. FINA Oil Company donates the gas for the show, including that used to get there and back, so the only acceptable excuse for not making it is an unflyable aircraft. About 20 are still in restoration and obviously cannot make it, a few more make one excuse or another, but most do show up.
The main show is on the Saturday and Sunday, but there is a warm-up show for "special people" on Friday. Our C-46 is achieving some fame as a camera platform, so we make the trip to Midland on the Wednesday before the show, which gives us all day Thursday for press and publicity flights, and some photo work.
"AIRSHO 2000" (hey, don't blame me for the spelling, that's the way they do things in Texas!) was to be really special this year, as the Speedvision folks were supposed to come in and do a special on the show and the CAF, a one-hour TV show to air sometime in January, 2001.
Seats are always at a premium to and from Midland, as insurance is very expensive, and we're limited to just 14 people, including crew. Seats are usually taken months in advance, and generally go to volunteers who have done the most for the CAF and the Southern California (SoCal) Wing, where the C-46 is assigned.
We launched from Camarillo (CMA) on time this year, at about 8 a.m. on Wednesday, October 4th, the redoubtable Kerry Bean in command, yours truly as SIC. Kerry is also a licensed undertaker, a training manager/pilot for a major US carrier, and a real hoot to have around. Don't get him started on the undertaker jokes, or you'll soon be incapacitated from laughter.
The C-46 has no autopilot, so one of our favorite pastimes is to get the volunteers forward, one at a time, and give them a little stick time. The resulting curves and parabolas probably don't add too much to the overall time, and it's a lot of fun. Of course, we pilots hog the real fun part, the takeoff and landing.
It's always a scramble arriving at any airshow, and Midland is no exception. Everything seems to happen at once, then everyone involved runs to the next arrival, and if you didn't get everything done, you're out of luck. Transport, fuel, lodging, location of the nearest beer and pizza ... that sort of thing.
Early the following morning, we were scheduled for the largest photo flight ever undertaken at Midland. We assembled at 0700 in the CAF "Pub," a large room with all the crews, all the photographers, and a few onlookers.
Air-to-air photography is a big thing for many photographers, and we like to cooperate with them as much as possible. The pictures they take will be used extensively on calendars, posters, advertising, and in magazines for years. That helps us get our message across, brings in more members and donations, and gives great pleasure to our volunteers. In short, a win-win situation.
The C-46 is particularly well-suited for this sort of thing, for the waist (overwing) hatches can be taken out, the paratrooper jump door on the right side can be taken out, and we can open the "man door" on the left, leaving nothing but air between the photgrapher's lens and the target, and plenty of room for up to 12 photographers to work. With cargo netting stretched tight across the openings we can keep most of the photographers from falling out, and for those who do, well, they get some even more interesting pictures!
The Speedvision crew were to occupy the jump door on the right exclusively, and the B-25 also had a camera in the tail for "nose-on" shots of each aircraft, once they were done with us.
I was a little bit awed, because as the camera ship pilot, it fell to me to organize the flight, and to brief it. These are fairly complex events, because everyone needs to know exactly what they're doing, where and when they're doing it, and how to get in and out of the big formation. Formation and photo flights are among the most dangerous flights we do, and while fighters are bad enough, the big bombers and transports are even more difficult because of the dissimilarity in performance and drag, and the inertia is far greater than fighters. Essentially, we agreed that the C-46 would orbit the "Maybee Ranch," a prominent airstrip about 15 nm north of Midland, while maintaining a very steady, very constant 15-degree bank. That's important, because when three or four large aircraft are trying to fly formation in a turn for pictures (more dramatic, that way), the slightest change at the camera ship results is a real "crack the whip" effect, and warbird pilots are not shy about screaming on the radio at the incompetent fool driving the C-46 (ask me how I know).
We took over an hour to set this all up, and then headed for the airplanes. I was busy getting the C-46 started, and didn't think too much about what we were doing as I taxied a couple miles north along the taxiway to the primary runway, 16R. Then I turned into the runup position, and had my first look back down the long taxiway we had just traversed. The sight brought goose bumps, and a choking feeling, for it appeared to be a throwback into history. Following me were the B-25, B-17, the only flying B-29 left in the world, a Bearcat, Hellcat, Hornet, three Russian Polykarpovs, and assorted other aircraft. All with huge props spinning in the sun, all living, breathing, roaring dinosaurs from the past. What a sight! What a sound!
Getting myself under control again, I proceeded to the runup. The usual 1700 RPM, prop check several times, feather check on the right, feather check on the left, one more prop check. Right engine up to 27" (field barometric manifold pressure), and it showed right on 2,300 RPM, a perfect power check. Mag check on the left, both, right, both, and throttle back. Man, this is fun. I can even hear the roar of the other engines through the open window when we're at low power.
Throttle up on the left engine to 27", and uh, oh, we're about 100 RPM short. I don't even like to proceed to the mag check with that, because I can be pretty sure it's going to bang and pop, even if only from fouled plugs, and that's hard on the big old R-2800. So I left the power at 27", leaned it out manually for a slight rise, and left it there for about 30 seconds. Back to auto-rich, and we're still 100 low. Haven't had plug fouling in ages, and I can't remember the last time that burnout procedure didn't work.
I pulled the RPM back to about 1700 again, then held my breath, and checked the mags. Left one ok, back to both, then the right, and BANG, BANGETY BANG, pop, pop, pop, and the engine died. I pulled the throttle to idle, waiting for the RPM to coast down to under 1,000, then switched both mags back on.
I was sweating blood now, for the other pilots were starting to signal "ready." I ran it up to a much higher power setting (36 inches of manifold pressure) and did the burnout again, knowing that it was probably futile. Sure enough, still dead on the right mag.
I sat there for a very, very long 15 seconds, thinking, wondering if I could get away with flying with a dead mag. I knew I shouldn't, but all those airplanes! All running expectantly, all the pilots, eager to get pictures taken! But then reason kicked in, and I thought of the headlines if the other mag fizzled out with the Speedvision crew (and others) on board. It just wasn't worth it, risking a priceless airplane. Something we might have done in wartime without much thought became a no-go situation, no matter how important the flight was to us.
It was one of the most difficult radio calls I've ever had to make. Groaning aloud, I pressed the button and said, "The C-46 has a dead mag, the photo flight is cancelled, everyone back to the ramp." Oh, did that hurt!
By the time everyone was secured, the morning was pretty well shot. Someone brighter than I said, "What about Tinkerbelle?" (the CAF's other C-46, based at Midland).
A quick check with the people on Tinkerbelle revealed that she was fully operational, and even had fuel! Everyone went into high gear to transfer all the equipment and people from one C-46 to the other. Meanwhile, we were on the phone, arranging for a fresh mag to be shipped in from Camarillo, overnight FedEx.
This flight went off without a hitch, although several of the target airplanes were unable to make it. After that, it was too late to do much on China Doll, so we made arrangements for some maintenance stands, and went to bed.
In general, the Midland weather is limited to "hot, cold, windy, dusty, or rain," often several of those together. "Blowing Mud" would not surprise me. The airport may be ideally located for an airshow, but that weather!
It was "abnormally gorgeous" Wednesday and Thursday, and we had hopes it might hold for the weekend. Ha! Friday morning dawned in the 40s, with a 30-knot wind, and occasional rain was forecast. There was no help for it, we had to get the airplane fixed, or 14 people were going to have to buy very expensive seats home on Monday, if they could buy them at all. We also were supposed to participate in the show with both C-46s, and we wanted to do a couple photo flights, as well as finish up with the Speedvision folks. We decided to open up the left engine and get that mag off, all ready to put the new one on when it arrived at 9 a.m.
Of all the decisions I made that trip, the smartest one was to take the lead, get my hands dirty, and do as much of the work as I could. Good guy? Nope, I figured out right away that was the only way to keep warm! Besides, I like working on the old beast.
The Pratt & Whitney R-2800 engine can have at least two distinctly different magnetos and distributors. China Doll has the Bendix mag, which is a large, single unit mounted on top of the nose case, one shaft driving both mags, one above the other. A single wire (the "primary lead") comes out of the lower (right) mag through a conduit, to the right distributor, which is a large can, mounted at approximately the 2 o'clock position. Another "primary" wire comes out of the top part of the dual mag, to the left distributor, mounted at the 10 o'clock position.
(Tinkerbelle, on the other hand, has two GE mags, separate from each other, each containing the mag and its own distributor, mounted at the 10 and 2 o'clock positions, with the center pad closed off with a plate.)
We first popped the cover off the big distributor, and everything there appeared normal. Rotor in good shape, everything nice and clean. We pulled the primary lead out of the mag, and checked continuity. That meant our problem was most likely in the mag itself, probably the coil, but it's easier to change the whole dual mag than to change one coil, so it was "off with the mag!"
We were well into removal when someone asked, "Wasn't the new mag supposed to be here by now?" Well, yes, as a matter of fact, it was.
Checking revealed that the home front had shipped it UPS because it was easier and cheaper. UPS had not the faintest idea where it was, or when it would arrive, so we started scrambling around, trying to find another mag. First thought was to steal one from Tinkerbelle, but with different mags, they were safe (hey, if the crew isn't there to defend their airplane, what can I say?)
But the Tinkerbelle spare parts room did turn up a freshly-overhauled Bendix! We finished up pulling the old one off, and got the new one installed about 2 p.m. Friday, just as UPS delivered the one from home. The sky cleared (temporarily), though the wind continued at 25 to 30 knots as we did a runup, confident that we had done the job well, under difficult conditions.
Wrong. No change whatsoever, the mag was still dead! COLD, tired, hungry, dirty, and discouraged, we couldn't think of what it might be. A second dead mag? Very unlikely. It was late Friday and getting colder, so we knocked off.
The next morning, grasping at straws, we pulled the rotor off the end of its drive shaft, and found evidence of arcing and burning between the inside of the rotor and the end of the shaft. Perhaps that was the problem? We cleaned that up, painted the inside with fingernail polish, cut a small square of silicon out of an Adel clamp, and glued that in to act as an insulator.
We put that all back together, and fired it up again. Checked the mag at 1,000 RPM, and it worked! 1,700 RPM, and it worked! Ran it up for a power check and mag check at 2,300, and ... no good, same old same old. Checked again at 1,000, and no good again. Bad news, but at least we thought we knew where the problem was, we figured that rotor had burned through again.
We sent a team to find a rotor at any cost, and pulled the old one out again. But there was no sign of arcing at all. Strange.
Then, thanks to a fellow from the Colorado Wing named Merle Bingham, we started the troubleshooting process that I should have done from the start, which would have saved us a mag change. Merle's suggestion was to pull the system apart at key points, and turn the engine with the starter to see if there was a spark. Any lawnmower mechanic knows this trick, but I had become so focused on the mag from the outset, I never thought of it.
At this point, I had unhooked the primary lead at the distributor, and pulled it right out of the conduit, so we tested that, and got a good, solid spark. That meant the mag was good, and we thought it meant the primary lead was good (wrong).
Fished the primary lead through the conduit again, hooked it up, and checked for spark at the plugs. None. Everyone retired to the nearby van for a warmup, and scratched heads. Pulled the distributor cover again, and hooked up a jumper from the center post and checked that. No spark. That meant it HAD to be the primary lead, shorting out WITHIN the conduit! Pulled it out again --
-- and sure enough, a close examination revealed cracks in the insulation, and evidence of arcing, where the spark was jumping from the inner core to the conduit itself. In the previous test, the primary lead was out in the open air, with no place to short out, so it worked fine!
We'd found a replacement rotor by then, so we installed that, replaced the bad primary lead with a length of equally old wire, put it all back together, and the runup was fine. By this time, it was Saturday afternoon, and we'd missed the big show. Hate that.
Sunday we made the show, both C-46s, Stan Musick and Walt Atkinson in Tinkerbelle, Kerry and I in China Doll, as a formation flight. These are fast-paced and intense, usually several passes as part of a larger act, then a photo pass or two, approaching the crowd line from one side and behind, flying a curved path in front of the crowd in a slipping bank so as to show the crowd the top of the airplane, and exiting show center at the other side, climbing. There are up to 30 or more airplanes in the immediate airport area, and everyone has to know what to do, and where to go. It's all under the wonderful direction of the best Airboss in the business, Ralph Royce.
After the show, we did another flight for the media with the Bearcat, Hellcat, and Hornet moving around in various positions for photos, and the next morning, Monday, we did another Speedvision flight. Most of the photos you see here were taken by Paul and Sam Koskela, our official Wing photographers, on the various flights we made.
Heading for Home
Once the Speedvision crew was done with us late Monday morning, we left for home. It was one of those days when the briefers were yelling "No flying, not even IFR!" All kinds of icing forecasts, still not much above freezing on the ground, etc.
We don't fly hard IFR in the old girl, so we launched VFR to take a look, and maybe just get to a better airline airport, so our people could get home. We stayed at about 1,500' agl for the first four hours, picking our way along between hills. We just about froze, for the heaters were removed from China Doll years ago. We all wore just about every bit of clothing we could find, clean or dirty. Too bad shivering can't be used for power somehow, we'd have been doing Mach 1!
But the flight itself was no problem, we never saw less than 20 miles of visibility, never had any precipitation, and had a very smooth, if cold, flight for the first four hours. But the solid gray overcast above looked awful, very dark and wet. I wouldn't have wanted to climb into it in anything but a jet.
Near Phoenix, the clouds started breaking, and we started to see patches of sunlight! Glorious, warming sunlight! Soon we were able to pick our way up between the clouds to "on top," and with the sunlight warming the airplane's skin, the interior temperature jumped a good 20 degrees. I usually hate sunlight in the cockpit, and put up sunscreens, but not this time! In fact, for about two weeks after this trip, I found myself seeking out sunlight, and basking in it, very rare, for me!
During the letdown, with Camarillo in sight, the left engine stumbled a bit. I reached up and checked the mags, and sure enough, that right mag was dead, again! A couple days later I came out and pulled out that scruffy old wire we'd used for a temporary fix, put in some nice new stuff, and it ran fine.
Gosh, airshows are fun!
Be careful up there!