HK36R Flyers????
Myers Pete
has flown the HK36R for a period of time. If you have, please contact me
at:
Pete Myers
hel...@isl.stanford.edu
Pete,
I bought a Super Dimona motor glider a little
over a year ago and am very happy with it. I've
put almost 200 engine hours and over 300
airframe hours on it in that time. While I'll be
happy to talk with you by phone, I am posting
this since others may be thinking about that
plane too. (They too are free to call me at 415-
857-1377 after 8 am and before 9 pm California
time any day). There are about five other Super
Dimona owners listed in the the Self-Launching
Sailplane Pilot's Association (SLSPA)
membership list. I've found them (and everyone
else in SLSPA that I called when making my
decision a year ago) happy to help with
information. I encourage you to join SLSPA by
sending $20 ($25 foreign) to
SLSPA Inc.
c/o Brian Utley
Membership Chairman
1930 SW 8th Street
Boca Raton, FL 33486 USA
Among other things, that gets you the
membership list which lists names, phone
numbers and type aircraft owned or flown.
I chose the Super Dimona (now called the
Katana Extreme in the USA to trade on the
Katana's popularity and acceptance) for a
number of reasons:
CLIMB PERFORMANCE: It had the best climb
performance of any of the motor gliders (over
800 fpm standard day sea level). That's not
important flying out of Palo Alto, CA, where I
base it, but I take it to the Sierras a lot and have
to deal with 10,000 foot density altitudes and
occasional strong downdrafts on takeoff in the
summer.
AVAILABILITY OF PARTS: Unlike many
motor gliders, the Super Dimona is currently in
production -- and with a company that seems
likely to be around for a while. (The Taifun
looked attractive, but was an orphan plane, some
of which had gone experimental for lack of
certified parts.) In fact, HOAC (the Austrian
company that designed both the Super Dimona
and the Katana and sold the Katana design to
Diamond Canada to produce) has now merged
with Diamond Canada, so with the Katana's
acceptance, long term parts availability looks
even better now than a year ago when I bought.
(There are 10 Katanas at San Carlos, and 2 or 3
here at Palo Alto already! And they're in use
almost constantly so their lower hourly running
costs make them profitable.) The Super
Dimona's similarity to the Katana also came in
handy when I needed a canopy cover (the
pattern was the same as for the Katana, which
pattern was already in hand at the shop) and
when I need parts.
ENGINE RELIABILITY: The Rotax 912A
engine has a reputation as being highly reliable
and this has been borne out by my experience
thus far -- in fact my mechanic marvels at the
lack of any oil drips. The engine has water
cooled cylinder heads and the plane has a cowl
flap so, unlike the Limbach/Grob combo, you
don't have to worry much about thermal shock
when you shut down after a climb. At least on
the Grobs, the Limbachs also had a problem with
the oil temp getting high during climb --
something I've never experienced with the Super
Dimona, even flying out of Nevada desert
airports in the summer. In contrast, the Grob
109B I transitioned in got hot during climb even
when the outside air temperature was 60 degrees
F.
ABILITY TO CRUISE UNDER POWER: It
had good cruise speed and range when flown
under power. I live 150 nm (direct) from
Truckee and Minden (both near Lake Tahoe,
with excellent soaring) and at some point want
to soar the Rockies and maybe Alaska. Including
climb time,the Super Dimona typically gets me
to the Tahoe area in an hour and forty-five
minutes (100-105 kt TAS once I'm at altitude),
and burns only about 1/4 of its fuel load. It
carries over 5 hours of fuel -- 21 US gallons,
with a cruise burn rate of 3.5-4 hours in my
experience -- so up to four hour hops under
power leave a comfortable reserve. This is
comparable to the Taifun and Grob 109B, but
much better than some of the other motor gliders
(e.g., the Vivat).
PRICE: At $91k list (when I bought it), it wasn't
much more than most used motor gliders -- and
you're getting a new plane with superior
performance. The 109B's were going for about
$70k, the Taifuns for $75-100k, etc. The only
much cheaper motor glider ($40k) was the Grob
109A and its climb performance in the mountains
was too low for me.
MAINTENANCE COSTS: When it is needed,
overhauling the Rotax engine is going to cost
only in the $5k range through Diamond Canada.
(I don't know how much Limbach charges, but
am comparing to American aviation engines
whose overhauls cost at least $10k.) Also, the
Rotax uses automotive engine oil and spark
plugs, at a significant cost savings. It also runs
best on unleaded auto fuel (but is certified for
100LL as well), which can save $0.50 a gallon.
But, to be honest, I'd rather pay the extra $2.00
per hour of engine time (at 4 gal/hr) and not
have to haul fuel cans around. I could burn the
100LL and not mess with fuel cans, but am
babying the plane with unleaded.
OK, I love the plane. But even the best of planes
has its weak points. What are they here?
SOARING PERFORMANCE: Compared to
modern pure sailplanes its 28:1 glide ratio is
anemic. But it's in the same ballpark as all the
other tractor engine motor gliders (except the
Stemme, but who has a quarter of a million
dollars?). And the retractable engine, self-
launching sailplanes are not designed to crusie
any distance -- too little fuel and too much drag
with the engine up. So the soaring performance
is not really a weak point when compared to the
motor glider competition in the same price class.
ELECTRICALLY CONTROLLED PROP:
While the electrically controlled constant speed
prop is a plus when under power, it becomes a
minus when soaring since it takes about one
minute to feather or unfeather. It's the
unfeathering that's more annoying, since you
have to start 500-1000' above the altitude you
want to turn on the engine. That's not much of
an issue when I'm at 15,000 MSL in the Sierras,
but it is when first turning off the engine
(typically 1500-2000 AGL) or when I do local
soaring here near Palo (cloud bases are typically
only 2500-4000 AGL). In both those cases, I
soar unfeathered, with some drop in
performance.
INABILITY TO WINDMILL START: The
Grob could be windmill started at 80 kts if the
battery or starter failed. The Rotax has a gear
reduction drive and is either very hard or
impossible to windmill start. Another Super
Dimona owner told me he did get his to windmill
start by going near Vne, but it wasn't a maneuver
I'd like to try. The Pilot Operating Handbook
does not mention windmill starting.
DIFFICULTY IN TAKEOFF AND LANDING:
When I moved to the Super Dimona, I could
usually grease the Grob onto the runway. Hence
I expected the transition to the Super Dimona to
be a piece of cake, but instead, the first time I
got in the plane, it felt like I'd forgotten how to
fly! Takeoffs and landings looked like those of a
novice pilot. Some of this difficulty can be laid
to my inexperience (only 250 hours at the time,
so who was I to judge how easy the transition
between two similarly looking planes should be?)
and some to the higher performance of the plane
(that 800+ fpm climb increased takeoff torque
compared to the Grob). But conversations with
a number of more experienced pilots who have
flown the Super Dimona confirm that it is a
challenging plane to learn to takeoff and land.
While I regard that as a negative, two CFIGs in
Colorado who instruct in the plane, told me they
like it because it pushes the pilot's ability. As one
of them put it, "If you can fly a Super Dimona
well, you can fly most small planes." Some of the
problem can probably be traced to a lack of
differential braking. (There are no toe brakes.
Instead the brakes come on when the spoilers are
fully extended. The tail wheel is linked to the
rudder and steers the plane while taxiing.)
Consequently, when you are taxiing, you have
one hand on the throttle and one hand on the
spoilers/brakes. That doesn't leave a hand free
for the usual tail dragger stick control to ensure
the tail wheel stays on the ground while taxiing.
As a result, they made the plane more tail heavy
than the Grob. That keeps the tail wheel on the
ground due to gravity, freeing one hand, but
accentuates all the nasty tail dragger instabilities.
At least that's my take on it. Another factor (not
documented in the Pilot Operating Handbook) is
that the plane has poor rudder authority almost
until takeoff speed is reached. Hence, if you do
the usual tail dragger thing and raise the tail at
20 knots, it's easy to lose directional control.
Wheel landings are also not possible as a result
(also not documented, though the handbook
never mentions them as being possible either).
STALL WARNING: While earlier models did
not have it, my plane was blessed with a stall
warning device. While a nice safety feature when
flying under power -- and for letting me know
when I'm getting close to takeoff speed and have
rudder authority -- it's a royal nuisance when
soaring. I've tried to think of it as poorly played
music rather than a "Don't do that!" blast, but it's
hard. It would be best if they would put a switch
on the device, so you could turn it on in power
mode and off in soaring mode.
HEAVY RUDDER CONTROL: After a day of
flying, my leg muscles almost feel like I've been
bicycling instead of flying. OK, that's a slight
exaggeration, but the rudder control forces are
high. All control forces are high compared to a
light weight, single seat pure sailplane, but the
rudder pedals are the main offenders. I'm not
sure, but this could be due to the springs on the
tailwheel needing to be stretched to move the
rudder.
COWL FLAP CONTROL: My cowl flap control
often sticks, sometimes to the point that I
wonder if I'll be able to open the cowl flap after
soaring. From discussions with the dealer, I
gather this problem is not unique to my plane
and the factory should be working on a fix.
Hoping this helps.
Martin Hellman
Lars Rieckmann
>
> Thanks for taking a peak a my note. I would like to contact some one that
> has flown the HK36R for a period of time. If you have, please contact me
> at:
>
> myer...@aol.com
>
> Pete Myers
Hello Pete !
We have a Super Dimona in our club located close to Hamburg in Germany
since four years. We are very happy with the plane but the introduction
in our club was not very succesful:
Our club members had to change from our former motorglider a SF 25 to
this high-performance motorglider, so we did check-flights with a flight
teacher who had as well just a few hours on the plane. In a difficult
landing situation just before touching the ground the flight teacher
changed by mistake the stick with the stick for the Schempp-Hirth brakes
and the aircraft crashed some meters before the runway into a field.
Luckily noone was injured but the aircraft was totally damaged. But since
that time we had no problems neither with the airframe nor with the
engine. We have 1300 hours now. The HK36 is easy to fly (accept landing,
you have to be very concentrated) and has good performance (around 100
knots TAS).
There is a new version of the Super Dimona the HK36 TTS and TTC out now
(compare new aerokurier) which is able to aerotow gliders and matches
some of the little problems the old Super Dimona has:
-poor maneuverability on ground due to a fixed tail wheel (On small
fields you sometimes have to get off the plane and turn the plane by your
own hands because there is no enough space to turn by the pedals)
The new Super Dimona has a nose wheel as an option (The HK36 TTC)
-A lack off power. In my opinion the HK36 is too heavy and has too little
power. The TTS has the Rotax 914 (a turbocharged version of the 912) with
115 HP.
-A slow constant speed propeller. You always have to wait a while until
your requested RPM is on. From Sailing-position to normal flight position
is more than 1 minute. This is because the old HK36 has an electrical
engine to adjust the pitch of the prop, which is much too slow. The TTS
has a hydraulical pitch adjustment.
The TTS and TTC have also winglets. Cruising speed of the TTS is around
130 knots TAS (according to HOAC) the TTC is a bit slower. Fuel
consumption is a bit higher than in the old HK36. Also the price is above
the old HK 36 (about 6 %)
All together I think it is a very interesting aircraft. It´s first
appearance will be on ILA ´96 in Berlin I hope. Does anyone on the net
know if it will be there ?
Lars
Lars Rieckmann
>>In a difficult landing situation just before touching the ground the
>>flight teacher changed by mistake the stick with the stick for the
>>Schempp-Hirth brakes and the aircraft crashed some meters before the
>>runway into a field. Luckily noone was injured but the aircraft was
>>totally damaged.
The problem on the HK36 is that on the pilot“s seat the stick for the
Schempp-Hirth brakes is on the left side and on the right seat it is on
the right side. Another problem is that once you pull off the brakes you
have to hold the stick in your hand. If you don“t do this strong enough
the stick does periodically move back and forth very quickly. The
possibility to change by mistake the stick and the stick for the brakes
is very high if you are used to fly on the left seat. We "solved" this
problem by training the flight teachers doing a lot of landings from the
right seat with an experienced pilot on the left seat. But there is
always a risk. I know that other clubs in Germany have the same problem.
My question is: Does anyone know if there is a conversion kit for the
HK36 to get a stick on the left side for the right seat?
Good flying season for all of you (In Germany we had a very nice start
with very good weather)
Lars
Lars Rieckmann
Milchberg 4a
21220 Seevetal
Germany Tel.: +49-04105/83200
Daimler-Benz Aerospace Airbus HFB-Fluggemeinschaft Wenzendorf
hel...@isl.stanford.edu
>There is a new version of the Super Dimona the HK36 TTS and TTC out now
>(compare new aerokurier) which is able to aerotow gliders and matches
>some of the little problems the old Super Dimona has:
>
>-poor maneuverability on ground due to a fixed tail wheel (On small
>fields you sometimes have to get off the plane and turn the plane by your
>own hands because there is no enough space to turn by the pedals)
I have a Super Dimona (HK36R) and the tail wheel is steerable
from the rudder pedals. Even so, the lack of differential braking
makes tight turns hard and near pivoting impossible. Perhaps
you meant that it is not fully castering, which is the case with
my plane.
>-A lack off power. In my opinion the HK36 is too heavy and has too little
>power. The TTS has the Rotax 914 (a turbocharged version of the 912) with
>115 HP.
While the 80 hp Rotax 912 is not a lot of power, the plane has
amazing climb performance -- 800+ fpm (over 4 m/sec) at sea
level on a standard day, which is quite adequate and higher
than any other motor glider I've seen. I specifically bought
a Super Dimona for its climb performance, so was surprised
to see this assessment. Multiplying the almost 1700 pound
max gross weight times 830 ft/min yields 43 horsepower
of real lift -- more than half the engine's rated output!!
Of course, more power would be nice, especially if one
were to use the plane for towing, etc.
----
One other point occurred to me that is unrelated to
Lars' posting: There is an older version of the
Super Dimona that uses the Limbach 90 hp engine.
I heard from a German fellow that I met that
his club had one of these and had reliability
problems, but they seemed engine related. Hence
one must be careful in designating which Super
Dimona is being discussed. I was really interested
in hearing about the TTC and TTS versions Lars
mentioned. They sound very interesting. But how
do they put a steerable nose wheel on the plane?
Did they make it into a tricycle gear plane? And if
so, how does the heavier, larger nose wheel
(compared to tail wheel) affect performance?
Martin Hellman
HK36Rgroundcrew
Are any of you HK36 owners still active on this group? Do you still own/fly your motorglider?
Michael Bamberg
I would try and contact Robin Reid, (Look him up on the FAA Examiner site).
Mike