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The main undercarriage legs retract inboard
and each one has a large no-nonsense sturdy door. Brake discs are best
inspected from behind, so it is necessary to duck down behind the wing
to view them from outboard of the trailing edge root. In board of each
leading edge, by the end of the black walkway, is a fuel cap, each one
covering a 21 Imp gallon (25 US) tank. Two large and very prominent exhaust
augmenter tubes exit from under the engine bay by the belly. They were
not discoloured, as you might expect a normal exhaust tube to be. These
are outer shrouds that accelerate the air within the cowling and aid cooling
of the exhaust manifold, doing away with the need for cowl flaps. However,
climb speed of at least 110 knots is required to prevent the engine from
overheating.
Three large catches secured the cowling on each side, with the oil inspection
carried out from the left. The large cowl and nose focus on a clean two-bladed
propeller. The nose leg retracts rearwards, with two doors neatly covering
the activity when not required. The starboard wing has a small stall strip
on the leading edge, directly in front of the join between the flap and
aileron. Each wing has a large tie-down ring on the underside. Differential
ailerons are fitted, with the trailing edge of the ailerons aligned with
the flaps. Static vents are located in the middle of the fuselage, three
small holes on both sides. The fin, rudder and elevators have those elongated
stressed dimples and both rudder and elevators have small aerodynamic
balances. Both elevators appear symmetrical and have trim mechanisms fitted.
The tail cone is the only non-metal external part of the fuselage being
constructed from fibreglass and housing two tail lights.
COCKPITS
The rear tandem cockpit is entered easily from the port wing, and the
immediate feeling is one of size and space. The seat is comfortable, feet
falling naturally on the rudder bar, right hand on the stick and left
to the throttle, pitch, mixture and trimmers. There is ample headroom,
even with the seat adjusted as high as it will go (although I didn’t
need it) and the width would not embarrass an overweight Texan. The view
from the rear seat, the instructors perch, is outstanding, especially
forward – the best I have yet seen in a piston-powered tandem trainer.
Jon’s cockpit is what antique dealers would describe as “original
and weathered”, with 5 inch instruments and all absolutely ‘stock’.
There is no suction gauge as the artificial horizon (or attitude indicator
if you prefer) is electric, along with the needle and ball. All radios,
etc, were located in the front cockpit and according to Jud consisted
of “two tin cans and a piece of string tied between them,” –
actually a single King KX175 nav/comm and a transponder. With Septic secured
in the front seat, I ran through the start-up drills, reading from the
checklist. On starting, the propeller turned clockwise as we viewed it,
the engine fired and the blades whirled quickly to a disc with the tachometer
showing a purring 1,000rpm. With oil pressure, electrical systems and
flap function checks completed, attitude indicator caged and then uncaged,
Jon’s head and shoulders moved indicating the areas of attention
as he double-checked my actions. Jud called on the VHF for the formation
to taxi. Nose wheel steering was positive and the brakes, mounted on top
of the rudder pedals, felt natural and effective.
AIRBORNE
At the hold, brakes on for pre take-off checks followed. The tank selector
was changed to the left tank, as the excess fuel sent to the engine is
returned to the left tank. On the small engine it returns about 5 US gallons
per hour. If both tanks are full and you select right tank you would be
pumping fuel overboard! Oil pressure was a steady 58psi with the temperature
just under 50º. Brakes held as manifold was increased to 1,700rpm.
The prop was promptly cycled to 1,500 with the attendant rasp as it rose
and fell. Manifold pressure and oil pressure needles danced in their gain
and loss, and then settled back to where they had been. At 1,700rpm the
magnetos were flicked to check the plugs, the drop was a minimal 50 on
each side (a drop of 75 is the maximum allowable but plugs can be cleared
by cycling the prop lever, which raises the manifold pressure and so ‘cleans’
the fouled or dirty plugs).
All engine checks were completed quickly and efficiently, followed by
the pre take-off checks as specified on the checklist. Boost on; neutral
flaps; trim set 4° nose-up; rudder trim 0°; aileron 0°; throttle
friction; mixture rich; full increase (fine pitch for the prop); Ts &
Ps were good. The stick was waggled around the extremities of the cockpit
to ensure full movement and the polished control surfaces responded with
the correct choreography and glinting light. The canopy was closed and
locked, harness tightened and locked and we confirmed our readiness to
the formation leader with the appropriate hand signal.
With Jud’s signal from the lead aircraft our engine increased power
and then, with the nod from his head, brakes were released and both aircraft
were running down the runway. The acceleration was smooth, a very slight
jockey of the throttle and we were glued into position despite the fact
that Jud has a bigger engine/propeller combination in his 300hp ‘hot-rod’
T-34A while Jon’s ‘stock’ T-34A has the smaller 225hp engine
and two-bladed prop’. At 68 knots, we rotated gently in just 18 seconds
from the glance across to the other ship and the leaders nod for the application
of power.
We climbed with 2,500rpm and between 28-29 inches. At 200ft I missed the
signal of thumbs up, jerked higher, for the gear up and the nod for the
actuation (for gear retraction) as I jotted the figures down. All three
yellow and black line vertical gear indicators sprang to horizontal bars
as the undercarriage settled into their wheel wells with a positive clunk.
Soon after take-off I was handed control and we continued the formation
climb up to the designated 2,000ft for the photographic detail. It was
a joy to be flying formation with two aircraft of a similar type. The
roll and pitch rates feel the same, the inertia the same, the drag the
same. I just like an easy life and although you always devote your complete
attention and concentrate fully on keeping position, it was a delight
in the T-34. Join-up speed was 110 knots and even though the powerplants
are different, the 135 knots chosen for the photographic detail was ideal
in giving us as number two sufficient power to manoeuvre on the outside
of the turn. Straight and level, gentle climbing turns, break-aways, gear
up and down, smoke on or off occasionally punctuated with short relaxation
breaks while cameras were reloaded with film. This always gives a chance
for a check inside the ‘office’ at the healthy gauges and fuel
quantities, before rejoining the tight formation, grinning and squinting.
AEROBATICS
With the pictures over, we cleared right. I broke away up into a wing
over, not too high though as I didn’t have much energy. I didn’t
let the wings go over the vertical and the rudder wasn’t required
to help ‘tilt’ (technical term that!) the nose at the top. The
nose dropped and the speed was allowed to build. A large rushing gait
towards a high arcing, slowly rolling barrel roll. Pitch and roll together,
wing check half way around parallel with the horizon and nose high, but
with the ball still in the middle. I complimented Jon on the quality and
ease of the control co-ordination. “Why thank you old bean”,
he responded while mimicking a London ‘toff’. He half turned
around with his head cocked up, against the headset over his baseball
hat worn back-to-front and grinned. “Top hole to you too,” he
laughed through the intercom!
I continued the aerobatics with a Cuban – what harmony; a slow roll
left; aileron roll right; half-reverse Cuban and then a stall turn. “What
speed do you kick her over?” I enquired of the front seat. I think
he shrugged his shoulders round about the time I should have kicked. With
a quick “thank you” I deftly applied rudder and around she went.
Holding the vertical down line and a brief moment of level flight before
raising the nose up 30º, a 3/4 roll to 90º and a steep turn;
a Canadian break.
At this point it was time to slow things down and explore the stability,
which I was sure would be good, why else would the world’s greatest
air and naval power have chosen such a trainer for nearly three decades?
A 10-knot increase above trimmed cruise speed and a 10º pitch down
clearly showed the T-34’s stability in pitch, the oscillating phugoids
dying within three rise-and-fall cycles. There was a small amount of aileron
drag evident on aileron application in both directions and, as is always
the case, a further roll in the opposite direction magnifies the nose
swing away from the applied aileron. The turn and slip demanded gentle
rudder application.
From a slipping glide with the left wing low and
right rudder applied, I released the control column and the wing rose
as expected. Lowering it again I then released the rudder and the nose
yawed to the left demonstrating good directional stability. I repeated
the process with controls crossed with the right wing low and again the
results were the same.
I tried this again with power on. For some reason I played a little bit
more with crossing the controls, keeping the wings level and yawing the
nose to the right. The indicated speed decayed by 10 knots and I released
the control column and rudder. The nose described a circle as it swung
back to straight-ahead and the faster outside wing rose slightly, straight
away without allowing the speed to increase. I applied cross controls
in the opposite direction, wings still held level but left rudder yawing
the aircraft away from the aircraft’s direction of flight. Just as
I released the controls, the nose pitched down promptly, which surprised
me! I pondered the situation. I had only met that reaction once before,
when uncrossing the controls in a Harvard from a slip that was both low
and a bit slow.
I later discovered the FAA had mandated that all
civilianised T-34s had an interconnect between aileron and rudder, worked
by way of a rubber bungee. This was supposed to prevent the controls from
being crossed. Most rubber interconnects should still be in situ but many
have been over-stretched, thereby not doing their job effectively and
have since been replaced by the small stall strip on the leading edge
of the starboard wing. Later, I was given the Aircraft Manual and found
that the cross control departure, or stalls, of the left wing didn’t
meet FAA Part 23. In section IV of the NAVAIR 01-90KCBI it stated: “the
stall in a skidded turn (right or left) in this aircraft is characterised
by an extremely fast stall unaccompanied by the usual pre-stall indications.
The post stall characteristics generally carry the aircraft through 90
to 360 degrees of roll depending on entry configuration, air speed, and
the amount of control pressure applied. The high rate of roll is also
accompanied by an extreme loss of altitude with the possibility of disorientation.
An immediate execution of recovery procedures is necessary to the rapidity
of the stall/post stall sequence and the potential for an extensive loss
of altitude. Stall recovery will be as follows:
1. Immediately apply full throttle while neutralising
the controls.
2. Roll the aircraft as the shortest direction to the level flight attitude.
3. Raise the nose to stop the loss of altitude.
Warning; failure to neutralise the controls prior
to an attempt to stop the roll may restart as a secondary stall and roll
in the opposite direction.
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