Patrol Flying Report
By Greg King
The Bearhawk Patrol is a 2 place tandem sport-utility aircraft that is heavily
influenced by the 4 place Bearhawk. It has the same wing span -33'- but slightly longer wings to make up for the narrower
fuselage. The flaps are longer with the inboard ends now extending all the way to the fuselage to increase effectiveness.
The tail is smaller because of a slightly smaller CG range and a more effective airfoil shaped horizontal stabilizer.
The fuselage is significantly narrower then the 4 place version, but still
very wide for a tandem aircraft. There is lots of room both up front and in the back so that even the largest pilots
will have p;enty of room. There is a door on the right side and is similar to the 4 place Bearhawk with a forward swinging
door and upward swinging window. Entry to either seat takes some forethought the first time, but seems easier then a
Super Cub or Citabria because of the added space and larger door. After a few flights, entry and exit seemed easy and
natural. The prototype had a simple and ground adjustable front seat that moves up as it moves forward and seems
to place pilots of varying sizes in a very good flying position.
The stick and rudder pedals move through their large range of movement smoothly
and freely on the ground with the rudders being widly spaced in the wide fuselage. Looking at the control surfaces while
moving the controls reveals that the surfaces themselves have a great deal of deflection available which should be useful
on gusty days at low speeds. There are trim tabs on both elevators that also operate as servo tabs over part of
the elevator travel to lighten control forces. The trim control lever is over the left shoulder and moveable throughout
about a 90 degree arc, similar to a Champ. There are sight tube fuel gauges in each wing root and a total of 55 gallons
available.
Starting the prototype involves hand propping the 170hp auto fuel
burning O-360 which is not nearly as difficult as I had imagined. Taxing is normal with good visibilty overall At 5'
10" I was not able to see directly over the nose which is normal for this type of aircraft, but only need very gentle S-turns
to keep track of the runway ahead. Directional control during taxi is straight foreword with a tall wheel of Bob's design.
Streering is smooth and positve. For tight 180's moderate differential breaking is required to make the tail wheel
swivel which would make unlikely to go into swivel mode without conscious effort. The brakes are powerful, but
not touchy because of the short mechanical advantage on the brake pedals.
Take off happens very quickly with only about 7.6lbs per hp at solo weights.
I am sure that all that power and torque generate significant left turning tendencies, but with the light and powerful rudder,
I didn't really notice. The tail can be raised almost immediately after adding power and the airplane is in the air
and climbing very soon after that. I usually used 2 notches of flaps for takeoff which really makes the airplane
leap into the air. Once in the air, the nose needs to be pointed up sharply to keep the airspeed reasonable and below
VFE if flaps are used. Initial
climb rates solo are about 2000 fpm at 86mph at sea level.
During climb out after coming to grips with the impressive performance, the
next thing that becomes apparent is the light and powerful controls. All controls are very light and harmonized.
I find myself rolling into turns more aggressively and banking more steeply than in aircraft with heavier controls.
The roll rate is quick, but feels evn faster then it truly is because the light ailerons allows the pilot to use large displacements
without having to use a lot of pressure on the stick. Adverse yaw is not noticeable during normal flying because the
light and powerful rudder makes compensating for it feel natural. When using large aileron displacements while purposely
not coordinating with rudder there is some adverse yaw. At first this seems significantly more then a Citabria
or Super Cub, but I believe that the reason for this is because the ailerons are so light that they allow you to apply full
aileron deflection without much force. To apply the same full aileron to a Citabria would require both hands and significant
effort which would mask some adverse yaw. The large windows on each side of the aircraft can be opened in flight at
moderate speeds and provide an open cockpit feel and excellent photo opportunities.
Leveling off at 8000' and leaving the thottle up yields a max cruise of about
140mph (tas) (with no wheel pants!) which feels very fast. Throttling back to 18" still gives about 132mph with 7gph
fuel burn which should provide over seven and a half hours of endurance and 1030 miles of range until dry tanks.
The aircraft is not designed for arobatics, but it does 60 steep turns and
wingovers well and is a joy to fling around. Visibility is good in flight, but being a high wing aircraft the inside
wing ends up blocking the view in the direction of turn until the turn gets steep enough to use the skylight which requires
close to 45 degrees of bank. The airplane has lots of rudder authority and remans composed with full slips which are
very effective at bleeding off energy. At normal loadings, slips are rudder limited. At more rearward loadings,
the rudder and ailerons reach their stops at about the same time. The flaps are very effective and slow the stall down
from 45mph to 35mph (cas) at solo weights. Stall recoveries are straight foreword and the aircraft is docile throughout
stalls. The airplane can be spun with full rudder during a stall, but recovering from incipient spins is quick and normal.
The airplane is statically and dynamically stable in all axes with good damping. These nice characteristics remain with
300lbs in the back seat.
Descent requires some planning as the aircraft is fairly clean and it is hard
to get it to come down steeply without using lots of flaps or bringing the engine back to very low power setting. I
perfer using about 54mph (cas) on final with 30 degrees of flaps. This gives plenty of float for a gradual flare and
enough time to get it where you want it while still not using much runway. For short runways 50mph and 40 degrees of
flaps gives just enough energy to flare with some margin for error but almost no floating. Slower than that would be
possible with some skill for getting into fields around 500' long with room left over.
The airplane exhibited normal characteristics in both wheel and 3 point landings
and seems as easy as any tail wheel airplane on the runway. The elevators have plenty of power to raise the nose beyond
the 3 point attitude and all weights and loadings. The controls might intially feel a light to pilots who have not flown
aircraft with light control pressures in the past, but after getting used to the light control pressures, they feel very natural.
Performance testing was conducted to develop aircraft thrust and drag characteristics
which was used to calculate performance characteristics at varying weights. The top speed, stall speed and climb rate
were verified with empirical testing and correlate well. This is for a 170hp engine with a fixed pitch performance prop.
The prototype weighs less than 1000 lbs. Empty.
Sea
Level
Weight (lbs) 1200
1300 1500 1700 1800 2000
Vmas(MTAS SL") 144.4 144.2 143.7 143.2
143.0 142.4
VmaxCruise
MTAS8k")
140.8 140.5 139.8 138.9 138.4
137.2
Vy (MCAS,SL) 85.7
86.0 86.6 87.2 87.6
88.4
ROC (fpm)
2192 2000 1687 1443 1339
1160
Vx (MCAS)
50.3 52.4 56.2 59.9
61.6 65.0
AOC (degrees) 21.18 18.95
15.44 12.8 11.71 9.86
Vbg (MCAS)
59.6 62.0 66.7 71.0
73.0 77.0
BGA (degrees) 4.65
4.65 4.65 4.65 4.65
4.65
Vmd (MCAS) 45.3
47.1 50.6 53.9 55.5
58.5
ROS (fpm)
373 388 417
444 457 482
Vsl (MCAS)
42.8 44.5 47.8 50.9
52.4 55.2
Vs0 (MCAS)
36.5 38.0 40.8 43.5
44.7 47.2
Va (MCAS)
89.7 93.4 100.3 106.8 109.8
115.8
Greg King has been instrumental during the flight testing of the prototype
Bearhawk Patrol. Greg King is a flight instructor, and holds a bachelors Degree in Aerospace Engineering from Virginia
Tech.
