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Barrows Bearhawk 260

A Case Study in Refinement
by Budd Davisson, courtesy of www.airbum.com

Nasty! That's the only to describe the wind, as I lined up on Winter Haven's long runway. Nasty! It had to be gusting 15-25 knots and snapped from slightly in front of the right wing to behind it. Yeah, this was a great kind of day to fly a new airplane for the first time. NOT!

On the one hand, it was a shame the day was so bad, because I'd been looking forward to this flight for a long, long time....for five years, to be exact, since I last flew the 180 hp version of the same airplane, the Barrows Bearhawk. This was a new prototype with lots of subtle refinements and, more importantly, 260 hp driving through a three-blade prop. The up side to this kind of day was that the nasty conditions would let me see the airplane at it's worse. There's no tougher condition than a sometimes-quartering tailwind to find out how evil a tailwheel airplane can be.

First, some background. The first time I flew the airplane was for a pirep in EAA's Sport Aviation. At the time, editor Jack Cox and I agreed that the four-place, straight forward airplane made a huge amount of sense. 1200 pounds of useful load, good cruise speed, even better good looks and it could be scratch built, which would allow a builder to get into the finances of the project at a rate he could afford. That's one of the downsides of the kit approach: bigger chunks of change are required to make it happen. With a scratch built airplane, such as the Bearhawk, you can squirrel away a couple hundred bucks, spend it on tubing and have enough to build the tail surfaces at your own speed. Of course, now that AviPro Aircraft, Ltd. has introduced complete kits for the airplane, a builder has the option of building fast or building cheap.

At the time the first report came out in October of 1995, the designer, Bob Barrows (for more of his background, go back and read the first report), had sold exactly 12 sets of plans. Once the word went out on the airplane, it appeared that many others felt the same way Jack Cox and I had; the airplane scratched enough aeronautical itches that plans sales really took off. As of this writing, May, 2000, Bob reports they are closing in on 500 sets of plans sold.

The airplane is fervently supported by the several hundred builders who are convinced they are building the most practical airplane in the homebuilt catalogue, and they may be right.

If there is a frustrating aspect to scratch building any airplane, rather than kit-building (a situation that may change for the Bearhawk in the near future, more on that later) it is that it takes a longer time for the first airplanes to start showing up at fly-ins so very few builder/pilots have had a chance to fly the Bearhawk. They are building it on faith. In fact, many report they are building it based on what we said in that first pilot report. That's a pretty heady responsibility and it was lurking in the back of my mind as I sat at the end of the runway watching the windsock whip back and forth. Would this new version of the airplane live up to my memory of the first one and would it justify the enthusiasm of the rapidly growing group of Bearhawk builders?

Since Bob had only one set of brakes in the airplane and a centre throttle, I opted for the right seat, when we saddled up. When taxiing out, I was pleased to see the tailwheel ratios (he even built the tailwheel itself) was dead on the money and the airplane reacted "just right" to rudder input. Not too slow not too quick. And the visibility over the nose was great. If I'd had a one inch cushion, the entire taxiway would have been in view. Without brakes, however the residual thrust of the smoothly idling 0-540 driving through a Hoffman hub with Bob's homebuilt composite blades, was enough that I had to ask Bob to poke the brakes from time to time to slow us down. Oddly enough, even with the hard wind, I didn't need brakes while taxiing crosswind. At the time, I didn't think much about it, but now, after the flight, I realize the airplane was telling me that it had plenty of rudder even when slow.

Time to go flying! I smoothly started the power in being mindful of what the wind was likely to do to me. I had purposely hunkered down a little so the side of the runway cut the edge of the cowling which gave me a definite reference so I'd catch the nose if it tried to move even a little. The instant the throttle started in however, I nearly forgot about the runway reference because the acceleration was absolutely amazing! It really was a rush and almost instantly I felt the tail getting light. Amid the clamour of an airplane that was obviously gathering momentum much faster than I was thinking, I unloaded the stick intending to gently lift the tail off the ground. Then, just as the tailwheel started to leave the ground, the airplane lunged into the air clawing upwards at a truly ridiculous angle. The takeoff actually surprised me by happening long before I expected it. Bear in mind, I make an average of five takeoffs a day in my Pitts, seven days a week, yet this airplane surprised me, which is saying a bunch.

I glanced over at the airspeed and we were already blasting through 90 mph with the nose pointed up at an almost scary angle. Bob has said rate of climb is 1700 feet per minute, but that must be with a full load, because we were well over 2,000 fpm with two guys and full fuel. On top of that, I doubt seriously if we rolled much over 250 feet. Maybe much less. This is where the nasty day worked against us: I would have loved to have played with short field techniques on a more normal day. I'd be willing to bet the ranch that using a three-point takeoff and half flaps, that thing would leap off the ground in some unbelievably short distance, especially with the wind down the nose instead of coming down the wing tip. I'm certain that as the throttle went forward, I could feel the prop blast "blowing" the mid section of the wing and that most of the wing came up to flying speed as soon as full power was in. The rest of the takeoff roll was just waiting for the rest of the wing to catch up.

The instant the airplane launched itself and we were rocketing upwards, I threw a thumbs-up signal over at Bob and yelled, "Fantastic! Absolutely fantastic!" To say I was loving it was an understatement. Now, THIS is the way airplanes are supposed to takeoff

During the takeoff roll, I wasn't conscious of making any rudder movements. This might have been because the right crosswind was cancelling out any torque induced turn. In a straight wind situation, I would expect the right foot to be keeping the airplane straight with a slight, constant pressure.

We hit 3,000 feet in nothing flat and, as I pushed over and reached overhead to roll in the trim, I yelled at Bob (he doesn't believe in intercoms, or electricity or any of the other "luxuries" most of us do, which is why his airplanes are so light) that I was going to set up a 23 square cruise. He shouted back (it's really noisy in the cockpit and ear plugs are a must) that he'd like me to see his normal cruise first.

Before we get into the "normal cruise" thing, you have to understand Bob Barrows. Bob doesn't think speed is worth anything, which considering how little effect it has on time actually spent enroute, he's probably correct. He does, however, think money IS worth something, so he doesn't think a pilot should spend any more than is absolutely necessary. This includes keeping the airframe cost down by eliminating anything costly (he makes his own tail wires out of turned down and threaded 1/4" 4130 rod and eliminates the clevis forks by threading thick wall tubing. See the detail shot. Very effective!). He also eliminates cost by eliminating anything that uses electricity and by keeping the fuel burn down. Simplicity and low cost are his commandments in everything he does.

When he set up the "Bob Barrows Low Buck Cruise Configuration" he had to fiddle with the prop a little as it didn't want to immediately adjust itself. This later proved to be a couple of blocks inside the hub that were dragging. His final setting was 19" manifold pressure and 1900 rpm. This is somewhere well under 50% power, which, as a by product, brings the noise level way down because it feels as if the engine is at idle. The speed stabilized at about 117 mph indicated for about 125 mph TAS. This isn't exactly lightening fast, but, Bob grins his characteristic grin and defends it by saying, "Yeah, but I'm only burning 7.5 gallons an hour."

Considering that a 180 Lycoming in cruise burns about 9 gallons/hour this is something worth thinking about. I later measured its 23 square cruise (approx. 60%) at about 155 mph TAS, at which point it's burning about 13 gallons/hr. Over a 300 mile trip, the speed difference would save about 25 minutes but the fuel burn would be 8.6 gallons more. At $2.30/gallon that's $19.78 more. In other words, it cost $1.32 for each minute saved. Translated into hours saved, that's $79/hour saved. Put in those terms, it's hard to fight Bob's logic. Using the big 0-540 gives him unreal takeoff and climb capabilities but lets him run the engine so far back on the power curve while still putting out plenty of thrust that he's doing as well as, or better than, a smaller engine in fuel economy. At high altitude, where the drag comes down but the engine still has power, the differences would be even more dramatic. Like we used to say back in my drag racing days, "The only substitute for cubic inches is more cubic inches."

As I brought the power up to a more real world power setting of 23 square, a couple of things happened. For one thing, the noise built up considerably. The other is that as the airplane went through about 135 mph indicated (145 mph TAS), the airplane began assuming a nose down attitude until at a stabilized 145 IAS (155 TAS) the wing was easily 2 nose down, which means, with the 2 angle of incidence added in, the fuselage was 4 tail high.

There's been a lot of conversation about this and it's an excellent example of how airplanes are nothing more than one compromise layered on another. If you want short takeoff and landing capabilities, the cruise speed is going to be compromised and vice versa. Obviously to take advantage of the Bearhawk's power at cruise, the angle of incidence needs to be reduced, this would bring the tail down 2 which would result in much less drag and a higher cruise. At the same time, however, it would hurt the visibility in short approach because the nose would be higher and, when landing on a short, short runway, the ability to see and hit the spot is more important than the actual speed. It would also hurt the takeoff performance unless the deck angle was also increased.

Changing the angle of incidence would have no effect on the wing's nose down cruising attitude. That is a factor of coefficient of lift which is a function of the airfoil section. Going to a lower lift airfoil (less camber) would flatten the wing out and give the airplane much higher cruise numbers but it would raise the stall speed and lengthen the takeoff and landing roll, which is also undesirable. Clipping the wing a foot or so would have the same pros and cons.

After a lot of bantering on the e-group, it looks as if the best Band-Aid would be to reflex the flaps slightly, as Maule does. With the huge flaps on the Bearhawk, stowing them at a negative 3-4 would probably do the trick as it would have the effect of reducing the camber on a huge section of the wing during cruise, but would still have its high lift available on takeoff and landing. I'd suggest a method of adjusting the amount of reflex a degree at a time to match the load and power available. It could be nothing more than a sliding ring on the flap handle that bears on a slightly tapered ramp on the floor. The entire reflex mechanism could be very, very simple. Quite recently a builder in New Zealand reflexed his flaps 5 and is claiming a ten knot increase. This seems high, but five knots seems quite obtainable.

I wanted to play with the stalls, so the throttle came back and the nose went up. Clean, somewhere down around 50 mph, the controls went soft and the nose nodded slightly down. I kept the stick back to see what would happen and nothing did. It let me use both aileron and rudder to control it. With full flaps, the number came down closer to 40 mph with only a slightly sharper edge to the stall itself. This time, just for the heck of it, I added a little power and played with slow flight. It took very little power to hold altitude and keep the needle nipping at about 45 with nothing in the controls loosening up or indicating the airplane was about to do anything stupid.

One of the most noticeable refinements from the first airplane was in the control harmony and feel. The ailerons, which had been a little stodgy, had been lightened up by moving the hinge point back. The result is a nice, responsive, Beechcraft-like feel with a little higher roll rate. I'm an aileron freak and I've got to say that I wouldn't change a single thing in that area. They are perfect. Ditto the rudder and elevator.

It's overall stability profile is very much in the middle of the envelope, meaning, if displaced on any axis it returns to neutral. It isn't quite as positive as some airplanes, but it is much better than most homebuilts and compares favourably with most factory Spamcans.

In level cruise, you're looking down over the nose with terrific visibility. In turns, however, you're a fair amount behind the leading edge and it's really not convenient to lean forward to clear for traffic. However, because your eyes are so far below the wings, you only have to pick up the inside wing a little bit to clear for a turn. If (actually, when) I build a Bearhawk, it'll have a tinted sky light with a shade that pulls forward. With no headliner, you could actually sit higher for short field work and you'd be able to see over the down wing in turns.

The cockpit area, for those who don't know, was sized to be slightly bigger than a 172. However, the panel is quite a bit lower and you sit higher so all around room and visibility feels much better than a Skyhawk. Also, with the cargo door option in the right side of the airplane, you can put a huge amount of stuff in or, roll out an air mattress in the back and you have your own three-dimensional camper.

Again, keeping to his goal of simplicity, the airplane has no boarding steps. Bob has a method of boarding in which he puts his right leg in the airplane past the control stick, then sits on the seat edge and brings the other leg in. Bob is also tall and all legs. Those of us who are crotch-challenged would appreciate a step. I think it could be nothing more than a simple peg or wedge on the back side of the gear leg which would allow you to grab the tubing overhead inside, put your left foot on the peg and pick yourself up to put your leg and butt inside. That might not work, but it needs something, as I refuse to wear high heels just to board an airplane.

At some point, we both knew we were going to have to go back land the airplane. I wasn't too worried, but then it wasn't my airplane.

As I turned final at 70 mph to cover the gust spread with only half flaps, we could see the wind had gotten worse. I could also see that Bob was getting nervous and I didn't blame him. The turbulence and gusts were beating the crap out of us but it wasn't until we were on short final and we could see how serious the wind really was that Bob, using the most tactful voice he could muster, shouted, "Do you want me to land it?"

By that time I was zeroed in on the edge of the runway and I shouted back without turning my head, "What ever you think you want to do, Bob." Inwardly I was grinning because I could see both of his hands nervously hovering around both the stick and the throttle. He wasn't enjoying this. But, I was. And it was too late for him to interrupt the process safely and still land.

There comes a time in transitioning into any new airplane, especially in a condition like this, that you suddenly sense the airplane's complete character and it either does or doesn't work for you. In this case, while Bob was vacillating about whether to knock me off the controls and go around or not, I was looking the Bearhawk right in the face and I was loving what I saw.

The wind was the kind that is absolutely dangerous in a taildragger; hard, sharp gusts and quartering from the rear. But at no time did I feel as if the situation was coming even close to the edge of the airplane's envelope. I was having absolutely no trouble flying the line I wanted; going for a three point (don't ever wheel land in a tailwind and I almost never wheel land anyway), cancelling out the drift, keeping the tail behind the nose. The airplane let me do it effortlessly (depending on your definition of effortless).

As the speed bled off, it took only a little more wing down to keep us centred and straight. Then the airplane painted itself onto the runway in a single, flowing motion, right main and tailwheel first, and stayed there. The airplane squatted over on all three and it wasn't until we had slowed way down that I had to call for some left brake because the wind had overpowered the rudder and we were slowly turning right.

Absolutely no sweat! I'll take luck over skill any day!

A note here: very few airplanes would have given me the control authority or response to handle that kind of wind as easily as we did. If we would have had a better day, I would have never seen that corner of its character and wouldn't have learned as much about it as I did. I would have liked to have done some sneaking-over-the-trees short fields, but I have no doubt it excels in that, because I did those in the other airplane. It's very comforting to know the airplane can handle bad environmental situations as well as it can.

I'm more convinced now than ever that the Bearhawk, with any engine, is the airplane more people should be building. It offers tremendous utility and comfort in an excellent handling package. Lots of airplanes are faster, but how many of them are carrying four people and lots of stuff? And how many can be built as inexpensively? If you scratch build, the steel and aluminium will cost about $3,500 and that will give you a complete airframe ready to start bolting the expensive stuff on. Also, you can buy that material at the rate your money comes in. And then there is the kit route: the quick build is $25,500 which whacks about three years off your building time for an estimated 1000 hour build time.

Do I think the airplane is worth building? I would think that should be obvious by now.

Bearhawk Kits
An obvious question has to do with kit availability. AviPro Aircrarft, Ltd. is now in full production of kits for the airplane ranging from complete, quick-build airframes to complete wings, wing components, etc. Go to www.bearhawkaircraft.com for more information.

Bearhawk Structure
The Bearhawk is a steel tube fuselage and welded tail with aluminium, single strut wings.

The fuselage has doors on both sides with fold up windows and a cargo/back door on the right side. The structure is such that you tack weld the top and bottom trusses first, jig it up and put the side pieces in, rather than doing the sides first as with most tubing fuselages.

The tail uses bent up sheet ribs with tubing spars. The landing gear has a uniquely simple oil shock assembly for each leg that minimizes the amount of machine work, but works really well.

The plans have no specifications for seats, but the most popular seems to be the Tripacer seat for the front with a variety of possibilities for the rear. In truth, almost any kind of seat could be adapted because the tubing structure would let you mount any kind of track.

The wings use folded up "C" shaped spars with multiple-strap spar caps on the main spar. Almost all of the skin rivets are flush and the struts are shortened C-182 units, although a custom extrusion is available from Bob Barrows.

The ailerons and flaps are fabric covered aluminium and are actuated through a combination of cables and push rods, with a minimum of push rods. There are a number of steel tubing parts in the wings including the aileron mounts and pulley mounts.

The tail wires can be either streamlined stainless steel with clevis forks or, a much less expensive alternative, is to turn down steel rod as shown in the accompanying detail photos. Bob is big on building everything, including the tailwheel illustrated.

The engine can be nearly anything, but Bob likes Lycomings. In fact, building Lycomings is part of his main business. A Continental would work just as well but would require building a bed mount for it. A number of builders are using automotive conversions including the Ford V-6 and Mazda units. It is entirely practical to build the airplane with something as small as a 160 hp Lycoming, although the aircraft would have to be kept light. Flown as a two place airplane, 160 hp performance would be surprisingly good. That would put the airplane at less than 2000 pounds with full fuel (55 gallons), for a power loading of 12.5 pounds per horsepower which is significantly better than a C-172 at gross (15 pounds/horsepower). The 260 hp airplane at the same weight is 7.7 pounds per horsepower which is right up there with Pitts Specials. Yeehah!

A note about the airplane's useful load: Bob's 260 hp airplane came in at a little over 1100 pounds and he's certain an airplane with full electrics would come in under 1200 pounds. This gives it a useful load of 1200 pounds. Four FAA sized people weigh in at 680 pounds. 55 gallons of fuel is about 350 pounds. So your baggage/cargo allowable with full tanks and seats is 50 pounds. You should know one thing right up front; no one builds an airplane as light as Bob Barrows. His finish is thin, his upholstery is painted Ceconite and he has no radios. It would be very easy to add 100 pounds with upholstery and radios which will cut down your useful load.

You didn't hear it from me, but I wouldn't worry too much about that. The airplane will carry anything, but, as long as you stay somewhere in the neighborhood of 2400-2500 pounds gross, you'll be okay as the airframe is strong enough to handle an extra few pounds. Just don't abuse that margin.