The 450 HP Stearman
These pages are all about flying the
Boeing Stearman Model 75 fitted with the famous
Pratt & Whitney Wasp Jr., R-985 450 horsepower engine.
Flying the 450 Stearman:
First, a disclaimer. I am not a CFI. I do not profess to know everything about the 450 Stearman, or the standard Stearman. I do not have thousands of hours in this airplane. You should learn to fly one of these with an experienced CFI, who does have hundreds if not thousands of hours in type. I only offer these thoughts on flying a 450 Stearman to share what my experience has been.
I begin and end the preflight at the baggage door. First I check and make good
the oil level (the oil tank is in the baggage compartment). I give the compartment
a good once over for loose stuff, and check the ELT security and switch.
Grabbing the fuel drain and screwdriver, I'm into the rear cockpit, and turn on the fuel, then double check that the master switch and magneto switches (I have one L and one R in my airplane) are in the Off position. If the plane has been sitting for a while, or I've just topped the tank, I check the left sump drain, then look over the front cockpit security.
Back on the ground, I look over (and under) the left aileron, and check for movement. I open the two inspection panels on the wing and look for trouble, then begin walking around and looking up at the upper wing attachments, and handle the flying and landing wires to check tension. I check the pitot static after removing the cover, and move to the cowling to remove the air intake covers. I check the cowling fasteners with the screwdriver, and drain fuel from the gascolator at the bottom of the cowling, while also checking for fasteners there.
After inspecting the inside of the engine cowling and the propeller, I hand prop at least 9 blades, feeling for hydraulic lock, and listening for anything unusual. A visual inspection of the wheels, brakes, and any inspection door, combined with feeling the tension on the wires is accomplished as I walk around the right wing, climb up to check the right sump drain, and then down the fuselage. I check antennas, and wires at the tail, and rudder attachment. Making sure the tailwheel has sufficient air, I open the trim machine inspection door, and move up to the baggage compartment, where I replace the fuel tester and screwdriver while removing the flying gear needed for the flight. Then the baggage door is secured, and we're ready to get pulled to a starting position.
Inside the cockpit, I secure the five belts, and pull the seat belt lock off.
I lean forward against the shoulder belts, and check my head position against the
windshield. If the top of my head is just inside the windshield and above the panel,
then the seat height is good. I check for full movement of the rudder pedals.
Noting the Manifold pressure reading and the altimeter, I then plug in the headset cords, and check that the fuel is on. With mixture full rich, and the throttle set at about 3/16" forward of full back, I begin stroking the primer. Allowing the primer to fill completely at the end of each stroke, on a cold first start, I will give a full 14 strokes of the small Parker primer.
I give a last look around the airplane for anyone trespassing, and give a hearty "Clear Prop!" yell. With this airplane, you cannot see if anyone is near the front of the engine. As a matter of fact, you could easily hide a small car there and I would never see it due to the engine and cowl being in the way. I give anyone near a few seconds to scatter clear.
As I look out the right side of the airplane toward a warning light I have installed at the cowl to show the starter is engaged, I flip the master switch up, and press the starter button. I wait for at least 2 blades to pass by, giving a little momentum, before I push both magneto switches up to engage the mags.
If the engine does not get beyond one or two pops, then its off the starter, re-prime, and do it again. If I get a backfire while the engine catches, then I've over primed. With a little luck, I've done no damage, but I'll be extra careful during runup and taxi. One big no-no with this engine, is to NEVER pump the throttle. There's just no reason to do so, and catching fire, and causing a serious backfire are two reasons to not do it.
If all goes well, one or two cylinders catch and I take hold of the stick, and listen for the other cylinders to chime in. After checking the starter warning light to make sure the started is disengaged (it's impossible to hear a hung starter over the engine, and a very expensive accident that my little light prevents) I watch the oil pressure build, and the tachometer climb to no more than 1,000 rpm. As the oil pressure gets above 75 psi, I advance the prop control to fine pitch/high rpm. Idling between 800 and 1,000 rpm, I check the oil pressure again, and listen for all 9 jugs to be firing smoothly. With the pressure in the green, and all 9 firing, I set the radio to on, and adjust the intercom. The brakes have been held all this time, and I release them just a bit to make sure they will release, and we are ready to taxi.
Taxi for Runup
Taxi time is difficult and requires that you pay full attention all the time.
If you taxi too fast, then turn, the momentum can swing you around and cause a wing tip to dig in. You can also get going fast enough that an emergency stop will bring the nose over the top and down to the ground, causing a few thousand dollars damage in seconds. At times a stiff wind may cause you to be unable to turn away from the wind, and you may have to make a 270 degree turn instead of a 90 degree turn. And you'll not forget that forward visibility does not exist with this airplane. An old hand at the Stearman would make a bet with an ATP rated non-tailwheel pilot that he could not even taxi the Stearman to the runway, much less fly it. He never lost that bet.
The top wing
is longer than the bottom. You have no view ahead. A walking speed is
too fast for many conditions, and just a bit slow for an open taxiway.
Steering is accomplished with differential rudder, unless you need to cut tightly, or have no forward speed, when brakes are used to maneuver.
I've become very accustomed to the progressiveness and the feel of these BT-13 brakes, and feel very confident in them. Sometimes if I get a little aggressive with them, I can lift the tail slightly while smartly applying brake. I don't feel this is cause for concern, but others who see this may think otherwise.
When underway, little if any power is required to taxi smartly into position. S-turns are absolutely required when any ground traffic may be near. They are also a good way to get your head into your feet where it belongs much of the time in this airplane.
When a crosswind is apparent, good crosswind taxi habits should come into play. If the crosswind is sufficient to make good crosswind taxi habits really necessary, I think I would taxi back to the tie-down or hangar, and not go flying. Seriously. Just remember that the purpose of crosswind taxi technique is to keep the wing(s) from being lifted, as well as keeping the tail pegged to the ground. As a matter of fact, the FAA recommends neutral control positions as being the best. Bottom line here, is that if you've got crosswinds strong enough to lift a wing, you've got some nasty winds that are going to make everything uncomfortable, so I consider staying on the ground with this type of airplane in those conditions.
Once at the runup area, I position the nose into the wind as much as possible to keep the oil temp in the green arc.
On a normal day, it takes about 15 minutes of taxi/idle time to bring the oil temp
up to the bottom of the green arc, or about 100 degrees F. Before then, engine
speed is restricted to 800 - 1,000 rpm. At runup, I proceed through CIGARS. Check
controls for freedom and full movement. Set and check all instruments, confirm
fuel is on and check the tank reading on the gage. Make sure the radio is set
for the next frequency in use, and that the transponder is on "standby".
If I did not fill up before the flight, I would have checked the fullness of the tank with a calibrated dipstick, and this would be compared to the gage reading and my knowledge of the two.
Setting the trim at about 5 degrees nose down without passenger, and around 7 degrees with a passenger will set the proper takeoff attitude.
When the temp is at the green arc, then the engine RPM is brought slowly to a minimum of 1500 RPM, and the prop is cycled at least three times. I turn off the right magneto and check the RPM for a maximum drop of 100 RPM, turn it back on, and turn off the left magneto, check for drop and for a difference of no more than 50 RPM to the right mag. I reach forward and pull the carb heat, and see a reduction in RPM to indicate functionality, then while holding the brakes hard, I bring the MP up to 30" to check for full ground power. Bringing the power back to 1,000 RPM quiets things down a bit, and I check my seat belts for security, and lock them in place.
Now we are ready to go flying.
I set the airplane up dead on the centerline. I figure I may need the room, so take
it when I can. As I slide my feet down from the brakes, I advance the throttle
smoothly, but not fast. It will take about 4 to 5 seconds to go from idle to
As soon as power is fed in, pressure on the right pedal is used to counteract the torque. I bring the stick forward until I feel the tail get light, and when I perceive it to be about 6 inches off the deck, I keep the stick right there.
At about 3/4 throttle, we are off the runway at about 65 mph and by the time full throttle is in we are climbing smartly and fast. If I were to look, I'd see 2,000 feet per minute plus, 36 inches of manifold pressure, and about 2,200 RPM, while climbing at 70 MPH. I lower the nose a little, while bringing back the RPM close to 2,000, and the power is pulled to 30 inches. When I get to 30 inches, and RPM is back at 1,900, I'm ready to turn crosswind at around 500 feet and 75 MPH.
Takeoff is a lot of fun happening very fast in this airplane.
Occasionally, I will take off differently. Rather than leaving the ground tail low, I will lift the tail to level flight before rotating at around 70 MPH. This gives me a clear view of the area, especially if in formation flight takeoff. I can also keep the power down to a maximum of 30 inches and 1,900 RPM on takeoff. This yields a much lower climb rate, and keeps me from running past slower traffic, such as when flying in formation with a standard 220 HP Stearman.
Climb, Cruise, Airwork
Generally I'll climb to cruising altitude using 27" and 1,875 RPM, and about
80 MPH. If I want to climb a little faster, I increase to 30" MP. An en route
climb is accomplished with 90 MPH and 27 to 30" and 1,875 to 1,900 RPM. At
cruising altitude, 27" and 1,875 RPM will give me 120 MPH. Pulling the power back
to 22" will give me a 105 MPH cruise and burn about 11 GPH. Fast cruise speeds,
or light aerobatics with climbing thrown in will get the fuel burn up to around
20 GPH, and aggressive power will result in 25 GPH rates.
The airplane is very responsive and crisp in all controls, and the ailerons feel heavy when you try to push the airplane around alot. You need to be coordinated in turns, and in no way is this a feet on the floor airplane. Those who don't use their feet will make themselves sick on no time.
A stall series shows no bad tendencies, and since I have no stall/spin strips installed as on other Stearman, I get a gentle break, with just a burble at the elevator when everything stops flying. In power off, level attitude, both wings will stop flying at about 55 MPH. Dialing in 25" at 60 MPH with a tug back will result in a break without a wing dip, and easy release-the-pressure recovery. At a 60 degree bank with 27" of power, a tug back will stop the flying, but won't initiate a roll or spin as long as everything is coordinated. Most all 450 Stearman are illegal to intentionally spin, so I don't do that. The 450 has so much excess power, the stall recoveries are really just a lower-the-nose affair. If your pullback is slow, when power is in, you may find yourself hanging on the prop rather than dropping the nose in a stall.
Most everything you've heard about a Stearman on landing is true. The 450 Stearman
differs from the standard Stearman in two ways. When a landing is not looking so good,
you always have plenty of power to go around, and should. Also, 450 Stearman are
heavier than the 220 HP variety, and don't glide well at all, and sort of Plop onto
the runway rather than Plunk.
Every pilot's a little different, but here's what I do. On downwind, I set up close to the runway, with the runway just off the tip of the lower wing. I'm of the school that does not ever want to not be able to land on the runway if an engine goes out, while I'm in the pattern. My downwind speed is 90 MPH. Abeam the numbers, or when cleared by the tower past the numbers, I pull the power back to about 1,400 RPM, and move the prop control full forward. My target is to get the glide speed to 75 MPH prior to the turn to base. On the base turn, I should be about 200 feet below pattern altitude, and completely aware of any wind compensation I'll need. On base I've committed to my intended landing point, and type of landing, either wheel or 3 point. If I'm going to 3 point, I want to exit the turn to final at 70 MPH. For a wheelie, I will exit at 75 MPH. On final I'll then adjust power from 1,400 to establish my nose in relationship to my intended touchdown point. Naturally I won't be able to see the point of touch or much of the runway at all. By using peripheral vision and looking to both sides of the nose at the same time, I can center the airplane, or do a mild S turn to set the nose where I want it. Speed on final is critical, and I don't want to build or lose any speed at all. As I get closer to the runway, more of it is obliterated by the engine, and I am using my peripheral vision to stay aligned and check my relative height.
For a wheel landing, I'll keep the speed at 75 and a mostly level attitude, which will let me glide to a touchdown. At that point, I center the stick, pull all the remaining power, and basically drive the plane straight until the tail lowers on its own. At that point, full stick back nails the tail down as I slow with light braking for the turnoff.
For a nice 3 point, I'm maintaining 70 MPH over the threshold, and checking my height above the runway against the sight picture in my mind of the point for rounding out. At the correct height, I'll be losing airspeed, as I gently bring the tail down for the 3 point position. If the nose exhibits any tendency to rise, I'm too fast and must adjust. At the time of roundout, the throttle will be closed just as the 3 wheels are touching, and all flying speed has bled off. Once all three are down, some gently braking will slow us, while rudder will keep us straight as we slow for the turnout.
Writing this makes me want to go out and fly!
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