Bearhawkin! Planet Bearhawk

To keep this thing from rambling on I’m going to try to abbreviate it and mention high points only, although by the time you’re done reading this, you’ll find it hard to believe it’s abbreviated.

Pat took an incredible amount of time and energy to come over, do a bunch of flying, sweat his butt off and, in general, play the ambassador role for the Clan Bearhawk. Not many folks would do that and, I, for one, thank him mightily for it.

We flew about 2.5 hours together and on top of that, he hopped another five or six passengers, including the AZ Redhead who won’t stop talking about it.

*Pat Fagan of Pearblossom, CA took six years building his BH from scratc*h

Pat’s airplane
He has done a terrific job of detail work. Every little piece, like the fairing strip that captures the side of the windshield and goes under the front edge of the top door half, is perfectly straight, edges smooth and rounded, bends just right for the application. The ailerons fit in the wing with barely 1/8” gap anywhere. The engine baffles are works of art in themselves. The airplane is very, very well done without being one of those prissy, I-chromed-everything-in-hopes-of-winning-an-award airplanes built primarily for going to air shows. The airplane just feels “right” and ready to be used.

The three-blade Hartzel in front of the Bob Barrows 0-540 is impressive looking and the combination runs like a sewing machine. The vibration level is so low it’s almost scary and it starts on the first blade every time.

The interior is classic Bob Barrows (fabric inside the fuselage everywhere) but you don’t notice the sidewalls are fabric because they are so smooth and colored to match everything else.

His cooling eyeball vents, fed by NACA ducts, work really well and are among the ideas to be copied.

Cockpit
I sat with about four inches of headroom and I’m not sure I’d want to sit any higher except in serious short field work.

Several people have commented on how much the nose cuts into the visibility but no one has commented on how quickly the nose tapers out of view or how the shape of the fuselage lets you move your head to the side and almost see around the nose. On the taxiway I could see all but the middle three or four feet of the taxiway by moving my head. A very shallow turn away from me (I was on the right with the throttle and stick in the “correct” hands) uncovered the entire taxiway. I’ll bet I wasn’t turning much over ten degrees. The airplane gives the impression of being blind but it really isn’t.

Pat has flown my airplane so he now knows what “blind” means.

I was immediately struck with the feeling that the stick was a little far away from me and I had to reach for it. The seat was fairly far forward and still I felt that way. It’ll be interesting to see if others comment. We’ll monitor that because it’s an easy thing to change via linkage or the step in the “Z” of the stick.

*The entire instrument panel is machine turned and sprayed with clear lacquer*

The overall feeling of the cockpit, especially with the skylight, is one of open, spaciousness. I just can’t think of anything I’d do to improve upon the general visibility and comfort. I’m 5’10” and 185 pounds. I don’t think anyone would feel crowded until they hit around 6’4” and 250 pounds, but, if you’re that big, you’re used to feeling crowded. The two of us definitely were not intruding on the other’s space and, for you Alaskan types, I don’t think heavy jackets would change that.

Taxi
Taxiing is a simple matter of moving your feet and pointing the airplane. The ratio was just a little long so it behaves in a fairly subdued manner and is easy to keep up with. Also, there was no feeling of inertia wanting to keep the airplane turning. Very easy to taxi. At least as easy as a Citabria.

Takeoff
Wow, is all I can say! WOW!

This was truly bad day to be flight testing airplanes because we never saw temps under 95 degrees once and they were usually higher than 100. The worse part, however, was that we had a 3-4 knot quartering tailwind most of the time, which really screws with tailwheel airplanes. It doesn’t sound like much, but because of local noise abatement procedures, I operate in them a minimum of an hour a day, I’m here to tell you that they make a serious difference in both performance and handling. Still, that first takeoff stood my hair on end.

*The interior is so subtle and well done you don't even notice that the sidewalls are Ceconite.*

We did a bunch of takeoffs and played with several variations on a theme. All of them happen so quickly that you’d be hard pressed to get in trouble before you were off the ground.

I tried a pure three-pointer, holding the tailwheel in contact until lift off and it vaulted into the air, the nose going up twenty degrees and putting us at 50 feet and racing through 70 knots before I could blink.

With the tail wind, it was hard to get meaningful measurements, but after we standardized on a short field technique that put the tailwheel just a few inches above the ground, we were seeing 250-400 feet, depending entirely on the wind. Pat did one when it must have been calm because it was noticeably shorter than the rest. Barely 200 feet. Remember this is at 100 degrees (density altitude was 4,900 ft), although we were only two guys and at full tanks most of the time. All takeoffs were made at half flaps.

Oil temperatures hampered our experimentation time. In those conditions we’d easily go up to 240 degrees doing touch and goes. At altitude (OAT was 97 degrees at 4,000 feet!) they stabilized at 225-230 depending on the power setting. Cylinder head temps came up during touch and goes, peaking at 410 but most of the time they were down around 380-390. This says that the cowling configuration will work in hot weather but the oil radiator, although big, is either too small or two are needed. This is strictly an AZ thing. Even Pat’s airplane would still work well out here if you didn’t thrash it the way we were doing.

The AZ demonstrator is going to wind up with two coolers, one with a straight ram scoop and maybe a shutter.

Rates of climb never went under 1300 fpm and could be pushed over 1500 feet by pulling back to 75 knots, but the nose is ridiculously high and that doesn’t help oil temps. I kept track and found that even at 100 knots it was stabilizing on 1000 fpm, which fell to 850-900 fpm by 5500 feet.

Speeds
We did some two-way runs down a road that I later went out and measured with my car’s odometer to verify what it showed on the sectional. Assuming my odometer was right, it was a shade over 10 miles, so we had a good distance to measure things over.

The Bob gave us some power settings to use including an rpm adjustment formula for the heat. We did two-way runs at 75% and 60%.

At 75% you can really tell the airplane is going fast and is working to do so. The nose of the wing is really down. This came out to 161 mph.

At 60%, the fuel burn dropped by 5 gallons per hour, and the speed dropped to 142 mph.

At the time, I was disappointed because that didn’t match with the 135 knots (155 mph) Pat now appears to be flight planning at. Then I realized that was because we were at 4,000 feet. With the amount of power being put out by the 0-540, the drag curve of the airframe falls off faster than the power curve of the engine so at the altitudes he usually flies, 8-10,000, the airplane is much more efficient.

We’re going to continue to say the airplane is a 150 mph airplane, but it really needs some fairings to go fast low. Also, Pat hasn’t played with reflexing the flaps yet, which may yield some useful gains. To any who care, Pat has 700 x 6 tires, which are big, but not as big as Bob’s 8.00's.

*Pat used to fly fire fighting tankers for Aero Union and his BH is painted in a tanker scheme utilizing his BH plans number.*

Handling
We played a little with phugoids, rudder-doublets and some of the handling stuff and found the airplane is dynamically positive in pitch but not overly so—pull the nose off trim ten knots and let go and it’ll start back to level but is in no hurry to do so. It damps eight of the ten knots and most of the altitude gained in the first cycle and then takes another three to totally damp out, but it finally does. This was at a forward CG location.

Break-out forces (how much you initially push to make things happen) are just a little higher than I’d like (I fly a Pitts, so I’m not a good judge) but the actual aileron pressures and response are really pleasant. It does exactly what you want it to do as soon as you ask it without being too quick. The pressures are lighter than Cessna's but the response and roll rate is much higher. I tried some rapid reversals from a forty-five degree bank one way to the same bank the otherway while verbally timing it and I'd say the roll rate is around 90 degrees a second or 30-40% higher than a Cessna. Trim it up hands off, and you can go to sleep it is so stable.

The rudder on Pat's airplane felt noticeably different than on Bob's two prototypes. As I understand it, Bob redrew the aerodynamic balance on all the plans and reduced the size of the balance. Originally the rudder was extremely light with little break-out force, but Pat's is perfectly matched to the ailerons and rudders. In fact, the controls are as well balanced as you'll find on any airplane of any type.

Stalls
I did a lot of messing around at stall and sub-stall speeds. Clean it bobbles a little and mushes at about 42 knots. With full flaps (Pat isn’t getting a full 50 degrees) it comes down closer to 35 knots. Using power to hold altitude, I ran it down under 30 knots and made turns left and right and it showed no tendency to do anything stupid.

I did some deep stalls (full stall and left the stick nailed full back) and played with the ailerons and rudder. Both are still working and with the stick full back I could execute gentle turns left and right. If I got aggressive with the ailerons you could feel them nibbling and getting ready to stall.

Since we were going to try some slow approaches, I set it up at 40 knots with power and drove it around trying steeper and steeper banks and didn’t feel it wanted to do anything but fly. I did the same thing at 35 knots with the same result.

As the airplane goes under 45-50 knots the controls all get softer, as you’d expect, but that’s largely an illusion as they are still working but need bigger deflections to make things happen the way you want them to.

One thing that did make slow flight difficult and was to haunt us a little when playing with slow approaches was that we ran out of trim at around 60 knots. This meant we were holding increasingly heavier stick forces the slower we went. The forces never became burdensome, but they were making it difficult to stabilize at super slow speeds.

Pat has his trim linkage at the very end of the trim arm on the elevator but has another hole further in. He’s going to move the arm in, which will increase the trim tab travel and see if that gives him a slower minimum trim speed. It will make his trim more sensitive but it isn’t very sensitive to begin with so it probably won’t be a problem. We’ll let him tell us whether it helps or is more trouble than it’s worth.

*What else could you possibly want or need?*

Skylight Comments
Because you sit so far back in the wing, in a normal Bearhawk, visibility is of the pick-up-the-wing-before-you-turn variety. In Pat’s you had to do the same thing, but as soon as a bank over 15-20 degrees was established, you could see over the down wing. It was great and something well worth doing.

Pat flattened out the top of the fuselage, getting rid of the Bearhawk Hump, which very much squares off the fuselage lines. This is noticeable all the way back to the tail but not particularly objectionable. We (AviPro) raised the stringer line just in front of the fin an inch to make the fuselage more rounded in that area and we’re going to look at a way to put skylights in the fuselage without flattening it out.

To answer those who are saying, "Sky lights are entirely too hot," I have to reply that I'd agree with you, but not in this case. The tint of the skylight is such that you aren't even aware it's tinted from the inside, but not once did I even notice the sun and believe me, we had plenty. It was a perfect balance of visibility and comfort.

Landings/approaches
My first landings were all made at 50 knots at which speed the airplane is totally normal in all respects. Also, since it bleeds off to well under 40 during the flair, runway control isn’t even worth talking about because you’re moving so slowly. I still don’t know why people ask us about a nose wheel for the airplane. There are very few taildraggers that are easier to fly.

I started out with three notches of flaps but quickly decided I liked it better at full flaps because it got the nose down further and the speed bleed during flair was a little quicker. In many airplanes this would make the flair timing-critical (you have to rotate just right to keep from dropping it) but that wasn’t the case here. Even at full flap (something short of 50 degrees, Pat is going to measure and let us know what he has), power-off rotation from a stabilized glide was no sweat.

When I got it down to 45 knots, the first time or two I found myself using a little power in the flair to help get the tail down because I didn’t think it would rotate, but later I found the power wasn’t needed. It had sufficient elevator power left to get the tail down and this was at a far forward CG location. With people in the back or a load, it will probably flair into three-point at 45 just like it does at 50.

When we got down to 40 knots on short approach things got a little more difficult because of the amount of backpressure we were holding. This wouldn’t be a factor because the backpressure isn’t that high but it is aggravated by the way the elevator effectiveness changes with power.

When you get down to 40 knots, the elevator effectiveness naturally diminishes but it’s not anything you notice. However, both Pat and I did the same thing once a piece. We were shooting for the numbers and got just a little low and were late putting the power in. The second we hit the power (just a hint of it but too big of a hint), the tail surfaces instantly became totally effective and the amount of backpressure we were holding became too much and the nose shot into the air.

This is a pilot technique problem not an airplane handling problem. If you hold the nose stable (this is in Student Pilot 101, I believe), when applying power in this situation, you don’t get balloons. Next time around we didn’t do that.

The balloons taught us something, however. When Pat did his, I kept my eyes in the cockpit (I hate watching crashes in which I'm actively involved) and studied the airspeed as he recovered. We were a little under 40 knots when the nose jumped and we started up hill. We were decelerating through 35 knots on the top and he kept pulling as we came down while he added power. We went down through 32 knots and arrived on the runway tailwheel first in what he thought was a hard landing but which I thought was only a little harder than usual. By the way, the airplane barely bounced, a sterling testimony to the Bob shock system.

What was of some importance during this little whoop-dee-do was that the tailwind was screwing with us, trying to shove the airplane around and at no time, even though we were hanging there at 32-35 knots, was control an issue.

Personally, I’d bet money that if we had another hour to practice, in more normal wind and temperature conditions, we’d become perfectly comfortable making 35-knot approaches.

Because of the goofy wind conditions I was never able to determine a speed at which it slid over the backside of the drag curve and began falling for the ground, thereby transferring most glide slope control to the throttle. In fact, it felt as if there was no such point and it kept flying all the way down. This will take more investigation.

In summarizing the landings, I’d say that 50-55 knots should be considered the normal approach speed and three notches used. We didn’t do any landings with two notches but I’d ignore it for landing and use that position only for takeoff.

Incidentally, even though it was 100-103 degrees (runway temps probably MUCH higher) and we had a tailwind, we still turned off on the first taxiway after the threshold much of the time and that’s 400 feet. With no wind, even at those temps it would have been a no-brainer. With 5 knots on the nose we could have backed into that space :-)

I’m really looking forward to flying the airplane in more user-friendly conditions. We’ve established that it has no serious boogie-men hiding at the bottom end of the airspeed indicator so now it’s time to figure out how best to use those capabilities.

AviPro's Bearhawk: Pure and Simple

J. Douglas Hinton from Southern Aviator online edition

Have you noticed that the sales literature of many aircraft manufacturers present aircraft features in terms of speed, range and payload in their best light, but cannot be met collectively in all parameters? In other words, the range may be calculated at economy cruise power, the speed for max. continuous settings and the payload may be out of sync with maximum seating capacity and baggage, i.e., you can't enjoy all the best numbers at the same time.

The folks at AviPro Aircraft will tell you up front you can fill all four seats of the Bearhawk, top off the fuel tanks, add 200 pounds of baggage and go 650-800 sm depending on power settings. No apologies or "Yes, buts..."

And what is a Bearhawk? Pure and simple it's a rugged, kit-built, tail-dragging, single-engine bush plane, with a high wing and a number of engine and propeller choices available. Originally designed by engineer Bob Barrows in 1995, it's somewhat larger than a Cessna 172, has huge cargo double doors and is convertible to floats. To date, sales of Bearhawk plans

exceed 700. More than 200 are under construction, with many close to flight and 13 completed aircraft are operating in 13 states.

If you're an experienced builder, you can just buy the plans and have at it. Or you can buy the Quick-Build kit from AviPro and hasten the time to get airborne. In either case the plans have to be purchased separately from Bob Barrows for $250.

In order to get a better feel for how this works, I met with Jim Clevenger at the Kissimmee, Fla., airport. He contracts with AviPro Aircraft LLC (honcho'd by well-known aviation writer and publisher Budd Davisson) as the sole quick-build center for the Bearhawk in the U.S.

GAN: Jim, by reputation, it seems like you've flown just about every warbird and homebuilt there is. Are you ex-military?

Clevenger (chuckles): No, I've just been knocking around a long time. Flown, built, tested and taught in a lot of stuff. And my wife, Julie, who's in the business with me, flies as well. She's got a sackful of licenses and ratings, even flies the TBM Avenger, though I have to help her out with the rudder on occasion.

GAN: Where are the Bearhawk kits manufactured?

Clevenger: In Atlixco, Mexico, about two hours south of Mexico City. The facility was built in 1996 and leased by AviPro, which is headquartered in Phoenix, in 2000. We employ about 22 people there. Distribution and shipping is done through Austin, Texas.

GAN: We have to ask. Do you get much static from customers about NAFTA and sending jobs out of the country?

Clevenger: Not a bit. There was some concern in the beginning about the quality of workmanship, but I have to tell you, these kids are great. The welds are about the best I've ever seen. We do all the training and Bob Barrow and I visit the factory regularly to ensure quality control and make improvements to the process.

Furthermore, all the materials and tooling they use are shipped in from the States.

GAN: Why not tell us about the construction of the airplane?

Clevenger: We construct a tubular steel fuselage frame both for longevity and crash survivability. It's also easier to repair than composite. The fabric-covered wings are metal for the same reason. The only things you'll find in the kits are those peculiar to the Bearhawk. By that I mean we don't supply the interior, avionics, engines, propellers, wheels and brakes, nuts and bolts, control cables, instruments and so on, as they are readily available from well-known vendors. We do, however, pass along OEM prices on engines and props.

GAN: We're a little confused. It seems like you offer about five kits with different ingredients and prices.

Clevenger: No need to be. The Quick-Build Kit is priced at $27,700 and meets all FAA requirements for the 51% rule. It includes a completed fuselage with no further welding required, ready for cover, stringers and systems installation. The landing gear and tail are finished, ready for cover and installation. The control system and surfaces are ready to install. The wing is finished with only the top skin, riveted at the front spar, dimpled and drilled, ready for final riveting. Struts are done and fuel tanks are ready to be put in, less caps. The motor mount is ready for attachment and the seat frames are finished. Finally, the utility door and float attachments are standard. And while the firewall is finished, the nose bowl and cowling are not drilled or final trimmed. Two options that we also supply upon request are steps for both sides and 18 gallon auxiliary fuel tanks.

The other kits you refer to allow the builder to buy just what he's comfortable with. Some people are good welders, others not. Some folks are good at doing wings, but not landing gear installations. So we make it easy for them them to purchase subassemblies they're not comfortable attacking by themselves so they can concentrate on other areas where their capabilities are better served.

GAN: What are we talking about in build time?

Clevenger: With the Quick-Build kit, a good average might be 1,100 to 1,300 hours. Obviously, first-timers are going to run longer and experienced builders are going to come in under that. If a person wants to scratch-build the airplane from plans alone, build time could run 2,500-3,000 hours or more. In either case, that doesn't include time spent on plush interiors, exotic avionics or wild paint schemes.

GAN: How many kits have you sold?

Clevenger: As we speak, 34. We're now running about one a month.

GAN: And Kissimmee is the only Quick-Build completion center in the U.S.?

Clevenger: Yes and no. People can have their kit shipped here and we'll help them over the rough spots for a price, depending upon how much assistance they need. Or for a fee and expenses, we'll go to their location and do the same. One thing I might mention here is a CD produced by Russ Erb and available for sale. It has a tremendous amount of information about building the Bearhawk. There are also a couple of Bearhawk websites where builders can exchange information and get assistance, plus a newsletter by Bob Barrows when you buy his plans.

GAN: Which engines do you recommend?

Clevenger: Generally the Lycoming 250 hp O-540-A4D5 at $33,556 or the Lycoming 180 hp O-360 A1A at $22,995. Those are OEM prices and include the starter, alternator, magnetos, carburetor and engine-driven fuel pump. If the builder buys from us, we require a 35% deposit and the balance a week before shipment, transportation and insurance paid for by the buyer.

GAN: How about props?

Clevenger: It depends on the engine. A Hartzell prop is only available on the Lycoming O-540 series. Otherwise, heavier counterweights or a McCauley prop is required. Bob Barrows says as long as you're not pulling more than 250 hp and 2,700 rpm, the 84 inch diameter prop gives better performance than the 80 inch unless ground clearance is a concern.

GAN: How about deposits and delivery times?

Clevenger: A deposit on any kit is $1,000 except for the rib/spar component kit, which is $500. A deposit establishes a delivery position, which right now is about five to six months because of the backlog. If a buyer cancels, 50% of the deposit is refundable.

GAN: So what's a builder looking at investment-wise when all is said and done?

Clevenger: Without putting a value on his or her build time, we estimate $45,375 on the low end with a used prop and mid-time engine, to $54,850 for an overhauled engine and prop, to $81,450 for a bird with new engine and prop — plus avionics.

These numbers will vary up and down depending on the engine and propeller choices.

FLYING THE BEARHAWK

As we strolled toward N509RF, due for delivery to a Texas customer a week later, Florida's 90° temperature and 100% humidity prompted a rather abbreviated walkaround inspection so we could blow some prop blast through the windows at the earliest opportunity.

Clevenger first opened the huge utility doors and pointed out that the rear two seats could be reversed for extra cargo space, at the same time moving the center of gravity forward. He also mentioned the CG has 12 inches of travel, i.e., it's almost impossible to get the aircraft out of the envelope. Next he pointed out the overhead wing tanks, each holding 50 gallons. If optional auxiliary fuel is ordered, these tanks, each holding nine gallons, are mounted in the outboard wing panels.

Fuel quantity is measured from the cockpit by sight gauges attached to the fuselage walls above either entry door. Not exotic, but practical, inexpensive and accurate. The cockpit windows open fully to latch under the wings, making the Bearhawk an excellent camera platform. The former Cessna 170 windshield is now formed and trimmed through AviPro.

After engine start, we taxied to Kissimmee's runway 15 without any need to fishtail as visibility over the nose is excellent. Turning Lycoming's 250 horses loose, the tail came up immediately and we were off in a few hundred feet despite the density altitude, floating upwards at 70 mph IAS and 1,300 fpm. Climb was then flattened to 80 mph with 1,000 fpm up to 3,500 ft.

Setting up 75% power (24 in. and 2,400 rpm), we clocked 130 kts with a fuel burn of 14.5 gph. Though the roll rate is agile, this is definitely a rudder airplane.

Coordinated turns definitely take some practice, but Clevenger assured me it would only take an hour or so to get the "feel" of the Bearhawk.

Next he demonstrated a few stalls, clean and with the massive flaps lowered. With feet off the rudder pedals in each case, the aircraft dropped a wing, easily picked up with aileron. But when the stalls were executed with the ball centered, the nose merely mushed downward until back pressure was released.

We next flew a couple of inherent stability maneuvers and found the bird to be very stable in every axis. No autopilot required. A sagging wing can easily be picked up with a touch of rudder.

Returning for landing, the approach angle was dramatic when the huge flaps were fully lowered. Carrying a little extra for the thermals, we flared at about 50 mph for a perfect three-pointer (Clevenger's, not mine!). When I asked him about tailwheel conversions, he responded seven to 10 hours should do it for someone who's never flown a taildragger before.

Overall, I was impressed with the Bearhawk. It is a well-designed, honest, no-nonsense (or unpleasant surprises) utilitarian that offers excellent field performance as well as acceptable speed, range and useful load for the price.