Wednesday, August 5, 2009

Chapter 14: Warbird Restoration

The SNJ of John Collver is impressively large as it sits on the ramp in Southern California . The 550 HP radial engine dominates the airframe. The paint scheme represents an aircraft based at nearby El Toro Marine base.

Generations of airmen were trained on the AT-6 advanced trainer during the Second World War and in subsequent years. North American built over 15,000 of them under the various designations of the AT-6: SNJ: Harvard and Texan. Across the United States many of the existing AT-6s and SNJs had been painstakingly restored. I had long wanted to fly one of these classic aircraft. Eventually I had the opportunity of flying with John Collver, airshow pilot and fellow Great Lakes biplane aficionado.

John’s SNJ-5 squatted pugnaciously on the ramp at Torrance airport. It was a large aircraft, stretching forty-two feet from wingtip to wingtip and almost twenty-nine feet from the silver dome of its constant-speed propeller to the tip of its tail. This big trainer, powered by a 550HP Pratt & Whitney R-1340-AN1 radial, was immaculately painted in 1950s - vintage Marine markings, as aircraft 90917, tail code WD. This aircraft had belonged to the training squadron VMT-2 based at El Toro, less than fifty miles away down the Californian coast. The chrome-yellow cowling and green identification bands on wing and fuselage made it a distinctive aircraft. Since its restoration it has been a frequent visitor at airshows on the California circuit, with Collver at the controls.

This aircraft had a fascinating history. Aircraft 90917 was completed at Dallas, first flying on 16 November 1944. It initially served with HQ Squadron 46 at El Toro, later moving to Fleet Air Wing 14 at MCAS Miramar, San Diego in 1946. After overhaul at the end of 1946, 90917 spent the next eight years with various training squadrons in Florida before being retired to the Navy storage center at Litchfield Park, Arizona. From there it was shipped to Japan as one of a batch of SNJs supplied to the Japanese Maritime Self-Defense Force under the Mutual Defense Air Program. The aircraft served in japan from 1957 to the mid 1970’s when it was stripped of its useful parts and auctioned off to the Kanai-Shoji Co. for the princely sum of $536.91 – for scrap.
At this point a savior appeared in the form of Dennis Buehn, an aircraft restorer from California who shipped the remains of 917 back to California, where the aircraft was completely restored by Warbirds West at Compton during 1979. It was a pristine example of the carefully restored warbirds seen so often in California.

We completed the pre-flight walk-around and I climbed aboard. The view from the rear seat was minimal, bringing back memories of many hours spent in the rear seat of the Chipmunk and Tiger Moth in England. Both of these old aircraft were taildraggers, just like the SNJ, so I knew what to expect when taxiing. I strapped into the roomy rear cockpit, while John strapped into the front seat and started to run through the pre-start checks with me.

Any vintage warbird has a fairly complex procedure to get started. In preparation I had read the Flight Manual and the cockpit was not too unfamiliar. John had just brought the aircraft in from its home base at Compton, so the engine was still warm and needed no priming.
Pre-start checks were first,” Parking brake on; mixture rich; prop lever to full decrease and throttle half an inch open; carb heat cold; oil cooler open; fuel on reserve tank; battery on, generator on…” the litany continued:”pump the wobble pump until you get four p.s.i on the fuel pressure gauge.”
Stick back for starting. Both ignition switches to the ON position, then John energized and engaged the starter.

The big radial turned over and the prop juddered round. One cylinder fired, sending a blast of blue smoke down the right hand side of the fuselage. The other cylinders fired in turn. As the engine caught the big prop spun into invisibility and the blare of the engine settled down into a steady rumble. Engine pressures and temperatures were OK and at 1,000 rpm oil pressure was satisfactory, indicating eighty p.s.i. We were ready to move. The tailwheel was steered through the rudder pedals, but remained locked fore-and –aft for takeoff and landing. John reminded me that I had to push the stick forward to unlock the tailwheel for taxiing.

I got us moving with a burst of power. Cautiously checking the brakes I turned the SNJ out onto the taxiway, swinging the nose cautiously from side to side to check the way ahead as we threaded our way carefully down a none-too-wide taxiway between rows of parked aircraft. With 5,000lb of aircraft strapped to me I could feel the inertia trying to swing the tail into an incipient ground loop even at this low speed, so I prudently kept the speed down. I could feel the tailwheel bouncing over the joints in the concrete during taxiing, amplified by my sitting well aft of the c.g of the aircraft.

At the runup area for Runway 29R we turned into wind and performed the pre-takeoff checks. A standard CIGFTPR check sufficed:” Controls free; instruments OK; gas checked feeding from all tanks, then put back on reserve for takeoff; flaps checked for operation and then selected up; trim tabs set, with elevator trim down on my left side set to eleven o’clock and rudder trim to two o’clock. Prop to high rpm…” At 1,600rpm the propeller pitch was cycled, giving the normal 200rpm drop.

Then the throttle was advanced and as the engine really thundered away the magnetos were checked at 2,200rpm. We were allowed a 100rpm drop for each magneto. We were within limits. Carburettor heat similarly checked out OK and I throttled back to 1,000 rpm to check that the vacuum was sufficient to keep our gyro instruments humming away. The hydraulic system was on and reading just under 1,000lb/square inch. We left both canopies cracked open a few inches in case of an emergency during takeoff that would require a speedy exit.
Checks completed, it was time to fly.

We got clearance from the tower and I turned onto the runway, locking the tailwheel once we were pointing straight down the runway. Releasing the brakes I progressively opened the throttle on the left hand quadrant. Full power brought the manifold pressure up to thirty-six inches. I had been anticipating a strong swing as we accelerated, but progressive application of right rudder kept things well under control. With my canopy open, the noise was deafening.
By forty knots it was time to ease the stick forward and the tail came up. At seventy knots we lifted off. A touch on the brakes stopped the wheels rotating. It was a busy time as John actuated the hydraulic power lever and raised the gear. By this time we were climbing well and I throttled back to thirty inches of manifold pressure and 2,000rpm in deference to the tender ears of the homeowners beneath our flightpath and the even more tender electronic ears of the noise monitoring stations which surrounded Torrance airport. The power reduction helped to minimize the strident blare from the supersonic prop tips so familiar to generations of airmen trained on the SNJ and AT-6.

We climbed out to the practice area over the sea. Sliding my rear canopy closed helped to shut out some of the noise. Once we were out over the Pacific I started with a few medium turns, then progressed into steep turns, being rewarded with a bump as we hit our own wake at the conclusion of the first three hundred and sixty degrees. Beginners luck.

I found that the controls were well harmonized and with each succeeding minute realized that this was a delightful aircraft to fly. The ailerons were very effective. Maneuvers in pitch were…well…different. Gentle wingovers were fun but the heavy aircraft certainly lost height quickly. It was just a matter of becoming accustomed to this. My aerobatics of late had been performed in an aircraft only a fraction of the weight of the SNJ.

“Want to try this with smoke?” said John. As a display aircraft, this SNJ was equipped with a full smoke system. So the smoke went on and I amused myself trying to draw lines and curves in the sky off the Palos Verdes Peninsula.

Smoke The SNJ makes an impressive sight in the California sky as it banks steeply during John Collver's airshow routine.

I found it really required a precise touch to fly this big trainer accurately. When we had completed this session of wingovers and rolls, it was time to get back to straight and level.
We cruised down the coast with the radial engine rumbling away, but all too soon it was time to wheel back over the Los Angeles Harbor and return to Torrance airport.

Back over the Vincent Thomas Bridge we set up on finals for the left runway. John was busy talking me through this approach as this was my first time. Gear down at 110 knots, mixture rich and twenty degrees of flap. Gently bring the speed back to ninety knots on the approach, and check again that the visual indicators on the wing upper surface ed that the gear was down. It was time to bring the flaps fully down, maintaining eighty knots on finals. Remember to put the prop pitch fully forward and watch that airspeed like a hawk. The SNJ had a violent wing drop at the stall, and generations of SNJ pilots have had accurate airspeed control drummed into them. It was a busy time for me.

The left runway was the shorter of the two parallel runways at Torrance and we came in low over the rows of hangers at the east end of the field, aiming to hit the first few feet of runway. Visibility from the back seat was of course abysmal. We touched in a normal three-point landing, stick fully back, with brisk rudder work keeping us straight. I remembered to get the stick forward to unlock the tailwheel before we exited the runway, and was more confident about taxiing back, adapting to the weight of this aircraft, but still wary of the large wingspan and lack of forward view with so many expensive aircraft parked close to either side.
Once we were back in our parking place, we let the engine cool down at 1,200rpm with the prop control pulled back to full decrease to get the oil out of the prop dome. Then mixture to lean, throttle open and fuel finally to OFF after the engine coughed into silence.

John Collver shuts down after a flight. The clamshell rear canopy of this SNJ is a reminder that back in wartime days, an air gunner occupied the rear cockpit, and swiveled the gun against banner-towing target aircraft

There was a lot to learn in flying a warbird, much more than I could hope to absorb in such a brief first acquaintance with this powerful trainer. This was not a machine for your average weekend pilot, any more than the bigger Mustangs and Corsairs which were the next step in the hierarchy of warbirds in California. Despite this, the AT-6s and SNJs which proliferated in the USA had a fervent band of followers, owners who swore by their noisy and expensive machines. They raced them, polished them and attended aviation meets in droves. One Civil Air Patrol squadron at Van Nuys, the Condor Squadron, operated a flock of AT-6s and SNJs in USAF and Luftwaffe markings, staging mock battles at airshows. At a later date I flew with the Skytypers, operating out of Long Beach and flying a quintet of smartly-painted SNJ-2s with military precision, skywriting in line-abreast formation over the southern California beaches.
These vintage warbirds were the most popular thing around.

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