Propellers
Kurt Haukohl
prop was the metal hartzell standard 2 blade propeller. It has
inertia and did the very best maintaining speed and momentum
throughout the flight. Yes you need a solid flange and to watch your
crank conditions. We never had a problem although others did crack
flanges. I was not doing gyroscopics, just the sequences and keeping
the G loads down. The spinners and back plates needed to be composite
not metal.
The 2 blade M&T was the second best. Although it made the airplane
cruse slower, it could tractor out of slow mistakes and does not
damage the crankshaft flange. It has a light hub and you will note
very few in no complaints. All 2 blade propellers vibrate worse than
any 3 blade. They must be dynamically balanced. There is no inertia
to this propeller and it acts like brakes downhill. We never heard of
any cracked crank shafts or flanges with this propeller. Choose this
one if you need gyroscopics.
The 3 blade was very quiet, poor-est performance, slow and does not
have any record of damaging the crankshaft. Any 3 blade probably has
greatest efficiency, but the hubs are heavy.... but NOT great
performers. It probably will not need balancing. You can make up for
loss of cruse speed by adding manifold pressure or RPMs.
We sent the first whirlywinders back 2-3 times for various reasons.
That was 8-10 years ago. I watched others do the same, and many
seriously poor experiences including failures. Our experience was
horrible. Many who open there hearts to us express the same. The
hubs were heavy. The stock hartzell governors were not enough to
control the prop and lots of mismatch issues exist to this day, many
never get full RPM. The sellers of the "cheaper" propellers were very
good at arguing you into stupidity and caused people to spend many
hours mailing propellers back and forth. I have one good friend who
quite flying altogether over issues and incidents with their "cheaper"
propeller. If you hear lots of comments about it being all your fault
or your engine, or your governor, your mechanic, your work, just send
it back. ( It is not your fault.) Occasionally, somebody harks all
about the great virtues of their "cheaper" propeller although we never
hear about their planes winning the US Nationals or witness any
exceptional performance ourselves.
I wish everyone could try them all, on the same airplanes, to compare
notes and bring these debates to fruition. Each has special
characteristics and performs better in certain scenarios. Spend
your hard earned acro dollars on quality equipment.
Mark Mattioli
with what works for you.
Kurt Haukohl
I remember many years that Patty Wagstaff had Hartzell as a sponsor
while she flew an M&T.
At that time the Hartzell was overspeeding for not having
counterweights and was wrecking lots of engines.
.
bruce...@juno.com
Where did you get the composite spinner and backplate for a Hartzell prop?
thanks,
Bruce Green
Eagle N110GM
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Kurt Haukohl
.
Kurt O. Haukohl
PO Box 1413
Manhattan Beach, California
90267-1413
Office: (310) 725-6688
Mobile: (916) 825-3102
Home: (424) 228-4281
.
Eagle N23TS
agree. I have used the MT three blade and the Hartzell stock 2
blade. Almost bought the 2 blade MT but they would not support the
leaking grease problem beyond a year for a $9K prop. Then almost
traded for one even, I'm glad I didn't. Whirlwind 2 blade stopped
production due to risk of lawsuit after two failures back to back.
They refused to sell me one and would not discuss the mater with me.
I have a light crank and the Hartzell two blade which performs well.
I get the 100 hr eddie current inspection and press. No I dont have
the B hub. Yet another aviation rumor that has impacted the already
dwindling sport of aerobatic flying.
Until I get into hard gyro maneuvers,I would not even conside change
from the Hartezell metal 2 blade. I did try to switch and was hell
bent on doing so at one time. I did research for a year and ended
back with what I had. I simply did a overhaul and am glad I did.
What i found in 04...
WHICH PROP IS BETTER
Mike Penketh IAC
#3213
Sean DeRosier IAC#187992
“I dunno,” that’s probably an honest answer. I know we’ve all tried
or flown behind different propellers but its not often we have the
same airframe/engine combination and several composite constant speed
propellers available for evaluations. Several years ago the Hoffman
propeller off my Zlin 50 made an extended visit to the prop shop, a
borrowed a MT propeller gave me a rare chance to compare two aerobatic
composite constant speed propellers on the same aircraft, the Zlin 50
powered by an AEIO-540/260hp.
So…what did I find out?
In this early comparison the take-off, climb and cruise were all
about the same, no marked difference. Slow speed pushes and pulls
revealed a noticeable difference. The Zlin 50 is a remarkable aerobat;
it flies well at slow speeds such as found in the vertical S described
below.
Using the original equipment Hoffman propeller starting at about
160mph in level flight using full power and no more than a 3 G pull
the 1st half of an inside loop was completed. Hanging upside down I
would hesitate a moment looking for a minimum of 85 mph, then with no
more than –3G I could push over the top and the 1st half of an outside
loop was completed; all this with a very solid feel to the aircraft. I
then switched to the MT propeller, using the same technique; all was
the same until I reached the vertical phase of the half outside loop?
Shutter, shutter, shake, shake and the maneuver was all over. Even an
evaluation as simple as this is uncommon. Below we’ve tried to go a
step further and expand the comparison paramaters.
For the ya-buts, what-ifs and nit-pickers…
We have tried to be as consistent as possible in our comparative
evaluations. The same pilot, same aircraft and same procedures have
been used in comparing five different composite aerobatic propellers.
a. The same pilot, Sean DeRosier;
b. the same aircraft, G202 with a Monte Barrett AEIO-360, 180 hp;
c. temperatures varied +- 5 degrees for all evaluations;
d. all power readings were read directly from an electronic VM 1000 ;
e. All speeds are indicated mph with the exception of the GPS mph
ground speed.
The following composite aerobatic propellers were compared:
1. Hartzell Composite wide blade (Claw) 2 blade,
2. Whirl Wind 200 Series 2 blade – wood core, composite skins,
3. Whirl Wind 200C Series Composite wide blade 2 blade,
4. Whirl Wind 400 Series 3 blade – wood core, composite skins, and
5. MT 3 blade – wood core, composite skins.
The following comparisons are offered for information only. They
represent real numbers,
hanger flying, dreaming or salesmanship is not a factor.
We are not in the business of selling propellers, the final decision
in yours.
GSPD R/C VMAX VMAX
VERT PENETRATION
(Notes) (1) (2)
(3) (4)
(5)
HARTZELL CLAW 210 1957 fpm 210 mph 195 mph 1800
feet
2 BLADE
52 lbs. – 78 inch diameter
A/C EW 1037 lbs.
WHIRLWIND 207 1836 fpm 205 mph 195
mph 1500 feet
2 BLADE – 200
Series
45 lbs. – 78 inch diameter
A/C EW 1030 lbs.
WHIRLWIND 210 2000 fpm 210 mph 193 mph
1800 feet
2 BLADE - 200C Series
46 lbs.– 77 inch diameter.
A/C EW 1031 lbs.
WHIRLWIND 204 1682 fpm 202 mph 190 mph
1500 feet
3 BLADE – 400
Series
65 lbs. – 74 inch diameter
A/C EW 1050 lbs.
MT 202 1764 fpm 202 mph
193 mph 1400 feet
3 BLADE
59 lbs. – 76 inch diameter
A/C EW 1044 lbs.
(notes)
(1) GPS ground speed 4 way average, full power – 1500 MSL - 31.5mp /
2680 rpm
(2) 2000-5000’ - full power - speed stabilized at 100mph, 1-G flight
prior to beginning timing.
(3) 3500 MSL - 29 mp / 2680 rpm – level flight
(4) 3500 MSL - 25 mp / 2500 rpm – level flight
(5) Vertical penetration is initiated from level flight at 1500’ MSL,
VMAX (3) using a 3.5G pull and full power (31.5 mp / 2680 rpm.) The
vertical is held till the aircraft begins to slide backwards.
There are numerous distributors for Hartzell and MT propellers, these
can be found in publications such as SPORT AEROBATICS, SPORT AVIATION
or TRADE –A-PLANE. Whirl Wind products are only available from the
manufacturer at:
Whirl Wind Propellers Corp.
1860 Joe Crosson Drive, suite J
El Cajon, CA 92070
619-562-3725
http://www.whirlwindpropellers.com
Brock
Good reply Kurt!
On Sep 19, 6:26 am, Kurt Haukohl <BlackEagle...@musclebiplane.org>
wrote: