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Owning and Flying a T-34 Part 2

By Todd McCutchan, WOA 23306, for Briefing

Todd's T-34

We continue this month with the second part of Todd McCutchan’s story about his T-34. The preflight and start-up of the T-34 is very straightforward and immediately familiar to any GA-experienced pilot, with no special equipment required save for a Dzus tool or flat-head screwdriver to open the engine cowl doors. The differences between the T-34 and its Bonanza cousins don’t really start to stand out until you climb up on the wing and roll the canopy back.

Flying the T-34
The preflight and start-up of the T-34 is very straightforward and immediately familiar to any GA-experienced pilot, with no special equipment required save for a Dzus tool or flat-head screwdriver to open the engine cowl doors. The differences between the T-34 and its Bonanza cousins don’t really start to stand out until you climb up on the wing and roll the canopy back. With a quick step over the canopy rail to lower yourself into the roomy front cockpit, you somehow instantly go from flying a “military Bonanza” to an honest warbird trainer.

The aircraft’s military origins quickly become apparent as the stick and throttle come readily to hand and the numerous utilitarian aspects of a true military aircraft begin to assert themselves. The start-up is basic to anyone familiar with fuel-injected engines, and the throaty rumble of the Continental engine reaches your ears through the two massive “augmenter tubes” below the cowling. The augmenter tubes are there to allow a passage for the exhaust as well as to assist in drawing air through the cowling for cooling, and provide the T-34 with its distinctive sound.

Taxing the T-34A model is a straightforward affair through its nose gear steering, and even the B model with its free-caster nose wheel is no challenge to taxi smoothly and easily. The run-up is uncomplicated. The aircraft’s military design again comes to mind as you rotate the massive magneto switch on the forward left panel for a mag check. After a few quick cycles of the prop and wiping out the cockpit to cycle the flight controls which are easy to see inside the expansive canopy and from your perch on top of the aircraft, you’re ready to go flying!

Takeoff in the T-34 is very easy. Canopy open or closed (the canopy must be closed above 152 KIAS), smoothly advance the throttle to the stop, add a little right rudder, and about 1,000 feet later, smoothly raise the nose at 55 KIAS to let the mains fly off. Best rate of climb airspeed is about 95 KIAS, and the IO-520 and 550s will yield initial climb rate in excess of 1,500 fpm. But most people cruise-climb the aircraft around 110 KIAS which still provides 1,000 fpm and affords better forward visibility and improved engine cooling. I tend to use the cruise climb of 110 KIAS, leave my throttle full forward, and reduce the rpm to 2,500 feet as I pass through 400 feet AGL where I also pull the mixture back to around 20 gallons/hour. The aircraft accelerates rapidly to 150-plus KIAS and requires left rudder trim to keep your feet on the floor. At lower altitudes (4,000 to 6,000 feet MSL) the aircraft will yield a true airspeed of 162 to 167 knots true airspeed (KTAS) on a fuel flow of 15 to16 gallons/hour (50 degrees Rich Of Peak).

T-34
AviationSpectator.com

At higher altitudes (10,500 to 12,500 feet MSL) the true airspeed slips to 157 to 159 KTAS, but fuel burn reduces to 12 to 13 gallons/hour (50 degrees ROP). My aircraft does have GAMI injectors, and I have verified that running 25 degrees Lean Of Peak will save approximately 2.7 gallons/hour but will cost about 9 KTAS in return. This relationship is pretty consistent at all of the altitudes I’ve tested it. I’ll include some real-world examples and efficiency comparisons for number-crunching geeks like me at the end, but for now we’ll continue with what the aircraft actually flies like!

The aircraft handles exquisitely with controls that are light without being touchy at normal speeds, yet stiffen up as airspeed increases toward the 219 KIAS velocity-never-exceed (Vne). The controls have very good harmony and balance with no noticeable “heaviness” or “lightness” in comparison between the ailerons, elevator, and rudder. Ailerons remain effective right to the stall, and the rudder remains effective throughout the stall. The aircraft provides lots of buffet as it gets close to the stall, and if coordinated, the nose will break cleanly straight ahead. All civilian T-34s have “stall strips” added to their leading edges.

If the stall is aggravated or uncoordinated, the T-34 will quickly drop a wing which is easily caught and brought up with the rudder. Spins in the T-34 are variable and never truly stabilize into a constant pitch attitude or rotation rate. The pitch attitude will begin to oscillate after approximately the first turn to a turn and a half, and the rotation rate will increase and decrease with the pitch oscillations.

The entry and recovery of spins, though, are predictable; recovery is within a quarter turn with the applications of traditional anti-spin controls. Speed does build quickly on the clean airframe, and care should be taken on the pullout to avoid over-g or exceeding the Vne of 219. A 2-½-turn spin results in an approximately 1,500-foot loss of altitude, and the spin rotation rate tends to increase dramatically past the one-turn point.

Aerobatics in the T-34 are a joy. And while the airframe is stressed to +6/-3g, that reduces to +4/-2g for “rolling” maneuvers. “Rolling g” is a huge fatigue inducer as anytime you’re rolling the aircraft (meaning aileron deflection) the lift being produced is asymmetrical, and the ascending wing is carrying a much higher load than the descending wing.

Prudent maneuvering and instruction dictate that one should always “pitch, then roll” or “roll, then pitch.” If your stick ends up in a corner, you must respect the lowered g limits—this should be avoided. The roll rate is an adequate 90 degrees/second, and the aircraft is very capable of doing graceful “gentleman” positive g aerobatics. A loop can be initiated as low as 135 KIAS with a 4g pull, but 150 KIAS and a 3g pull are more comfortable.
Immelmans, Cuban eights, hammerheads, and aileron, point, and barrel rolls are all well within the repertoire of the T-34. Snap rolls are approved but not recommended due to the age of the aircraft and high torque loads imposed on the engine mounts, prop, and tail section. A split-S initiated at 110 KIAS and idle power will require approximately 1,500 feet to complete with a 4g pull and provide an exit speed of 165 KIAS. T-34 is capable of performing all of its approved aerobatic maneuvers with 4g or less which provides for a nice 2g buffer below the maximum of 6g. The airframe is approved for inverted flight including inverted spins. However, the lack of an inverted fuel and oil system preclude the execution of these maneuvers, and the T-34’s airfoil and dihedral don’t lend themselves to inverted flight.

Descending to the airport, the aircraft does tend to pick up speed; if the air is turbulent, care will need to be taken to stay below the 152 KIAS yellow arc. In smooth air the aircraft will easily accelerate to 200 KIAS in a 1,000 fpm descent with power on and is perfectly capable of exceeding its 219 KIAS Vne.

T-34
Courtesy: Buck Wyndham

Anytime the airspeed is above the 148 KIAS maneuvering speed (Va), care should be taken to ensure the g limits aren’t exceeded. Slowing down illustrates what is probably the weakest area of the T-34, and that is its 109 KIAS gear operation speed (Vlo). Once the gear is extended, you can reaccelerate up to 165 KIAS (Vle), though, if you ever need to get down in a hurry or keep your speed up on an approach. The T-34 is an extremely stable and predictable instrument platform, and I have shot ILS approaches down to minimums on several occasions.

Due to the low gear operating speed, the preferred way to enter the pattern (traffic permitting) is via the overhead approach. The T-34 performs the overhead very nicely at 125 to 135 KIAS up initial to the break with a 45- to 60-degree level bank turn. This will provide 100 to 109 KIAS after 180 degrees of turn. And you can extend the gear and flaps (Vfe 110 KIAS) and continue your descent from the perch to landing as you smoothly decelerate back to 90 KIAS as you roll out on final and continue to slow to a touchdown speed of approximately 75 KIAS (90 KIAS all the way with flaps up).

Like its Beech cousins the T-34 lands easily and has no bad tendencies. Sliding back the canopy as you taxi in, you’ll have a hard time getting rid of that grin which comes from flying one of the most sought after and efficient warbirds today.

Efficiency
So what do all of these fuel burn and cruise speed numbers actually mean? To put it into perspective, here’s a real-world example.

In my T-34A with tip tanks, a Victor IO-520-BB, and GAMI injectors at 6,500 feet, I get about 1.6 nautical miles per gallon (nm/gallon) difference between 25 LOP and 50 ROP operation. This is the only real number that matters as it’s the one that actually impacts your pocketbook: nm/gallon.
Twelve nm/gallon 25 LOP and 10.4 nm/gallon 50 ROP.(This of course was pushing a 6-knot headwind.) No wind efficiency would be better than 12.4 nm/gallon at 25 LOP and 10.8 nm/gallon for the 50 ROP (mathematically derived).

There’s also a 9 KTAS difference (164 versus 155) and 2.7 gallons/hour (12.5 versus 15.2).

If you assign an arbitrary fuel cost average of $5/gallon and budget reserves for labor, parts, engine, prop, and an additional miscellaneous reserve, you get a “dry” direct operating cost for the engine/airframe of $71.94. (This amount is a best guesstimate and will vary depending on operator/aircraft). Most likely I am conservative on my reserves which translates into “high.” Better to be pleasantly surprised when the mx or overhaul bill comes!

Direct Operating Cost    

 

Fuel (average)

$5

$75

 

 

 

 

 

Maintenance cost

 

 

 

Labor/hour

$65

$32.50

 

Parts

 

$7.50

 

Engine reserve

 

$22.35

 

Propeller reserve

 

$4.58

 

Miscellaneous expenses

 

$5

 

 

 

 

 Total hourly direct operating cost

 

$146.94

Over a 150-nautical-mile en route flight, the difference would be:

150 nautical miles

25 LOP

50 ROP

Flight time (hours:minutes)

0:58

0:55

Fuel burn
(gallons used)

12.1

13.9

Fuel cost ($5/gallon)

$60.50

$69.50

Airframe cost
($71.94/hour)

$69.54

$65.94

Total cost

$130.04

$135.44

Over a 450-nautical-mile en route flight, the difference would be:

450 nautical miles

25 LOP

50 ROP

Flight time (hours:minutes)

2:54

2:44

Fuel burn
(gallons used)

36.3

41.7

Fuel cost ($5/gallon)

$181.50

$208.50

Airframe cost
($71.94/hour)

$208.63

$196.64

Total cost

$390.13

$405.14

I will let everyone interpret the above for themselves and come to their own conclusions. One thing that stands out to me, though, is just how efficient our airplanes really are! For instance, 12.4 nm/gallon = 14.3 statute miles per gallon, and when you translate this into traveling a straight line distance versus following curvy roads, you can generally add another 15 to 25 percent more!

As an example, here’s a trip I flew between Fort Wayne, IN (SMD) and Kentucky Lake (M34) on May 11, 2011. For comparison purposes, I’ve made both the flight and drive from airport to airport and used statute miles and still air. I didn’t include airframe cost as I’m not sure how to compare that to car depreciation and maintenance cost.

 

Mazda CX-7
(18 miles/gallon)

T-34 25 LOP
(14.3 miles/gallon)

Difference

Statute miles

435

331

104 miles less

Flight time

6:54

2:08 (still air)

4:46 less

Fuel burn (gallons used)

24.17

23.15

1.02 gallon less

Fuel cost ($4.25/gallon car; 4.75/gallon plane)

$102.71

$109.95

$7.24 more

Fun

0

100

100 times better!

The T-34 is the most efficient cross-country aircraft in its category with the possible exception of the SF-260B. The graph below is compiled from actual operators and “typical” cruise settings. The figures don’t necessarily represent the most efficient, nor are they all comparable (i.e. 75 percent power), but are real-world operators’ feedback.

 

T-34 (285 hp)

CJ-6 (285 hp)

Yak-52
(360 hp)

T-6

T-28A

T-28 B/C/D/F

SF-260B

SF-260C

KTAS

165

125

135

135

150

200

175

165

Fuel burn (gallons/hour)

15

15

15

30

35

50

15

15

Nautical miles per gallon

11

8.3

9

4.5

4.3

4

11.6

11

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