In my experience 'low maintenance' and 'robust' are more important
characteristics in an ab-initio trainer than 'high L/D ratio'.
IMHO trainers are all about compromises, the ASK21 is a very good compromise.
You CAN get a trainer with 44:1 - But you will pay in price, ground handling
and hangar space - to mention only a few. Why does Lasham have a fleet of K13s?
Now if there was a way to get any glass installed as trainer at my club... We
fly vintage Bergfalkes, and a Blanik because they are robust, repairable and
cheap - not because of their L/D (all 30:1) or their control harmony, or
aerobatic capability. Although the L13 is a great aerobatic trainer.
My primary concern with the Puchacz/Perkoz design would be the big canopy frame
obstructing the back seat pilot's vision. Never flown either, but it looks
substantial, and right in the field of vision.
If the list of woes below is accurate the Pooch would make a poor trainer. Fails
the low maintenance test.
Cheers
Bruce
Basil wrote:
Having been responsible for the maintenance of a 4 Puchacz trainer
fleet for some years and noticing that the fuselage is a Puchacz
fuselage I hope they get the following bits sorted out before
production.
1. They bungy sprung main undercarriage is awful. The Polish bungies
last half a season. American ones last two seasons but are quite
expensive and the design means that all the bronze pivot bushes are
heavily loaded all the time and wear rapidly.
2. The spring cable reel that retains the canopy when open brakes
every year and the glider is dangerous until it is fixed (the cable
when not retracted can lasso the rear stick.
3. All the Polish wheels need replacing with Tost or Cleverland. The
main wheel needs a disk brake. The bearing and brake arrangement on
the Polish wheels is very difficult to maintain.
4. The plastic gears in the wing route used to operate the airbrakes
cause a lot of backlash in the airbrake mechanism. They didn't work
well in the Puchacz, Bocian, Jantar etc. Its time to change the
airbrake mechanism.
5. The cables that operate the trim tabs in the elevator are single
strand and not spring tempered. They are routed through the elevator
hinge line and are flexed every time the elevator is moved. The
factory ones fail every year. (replacements from the local model shop
last several years but of course aren't approved).
The Puchacz was almost a good trainer, let down by serviceability
issues and being slightly too easy to spin. The Perkoz could be good
if they would just fix the above.
On Wed, 20 Jun 2007 17:00:29 -0700,
wrote:
SZD Bielsko is in the final phase of testing of "new" 2 seat glider
designed for initial and advanced training. It will be fully aerobatic
with 17.5 m wings and with 20 m wings it becomes pretty good x-c
sailplane with L/D of 41.8. The reason I am saying "new" with
quotation marks is that the glider was designed in the late 80-ties
and bears name SZD 54 Perkoz. But the SZD Bielsko is working right now
to bring the glider into production.
http://www.szd.com.pl/pdf/szd-54_perkoz_doku_en.pdf
Jacek
Washington State
On Wed, 20 Jun 2007 17:00:29 -0700,
wrote:
SZD Bielsko is in the final phase of testing of "new" 2 seat glider
designed for initial and advanced training. It will be fully aerobatic
with 17.5 m wings and with 20 m wings it becomes pretty good x-c
sailplane with L/D of 41.8. The reason I am saying "new" with
quotation marks is that the glider was designed in the late 80-ties
and bears name SZD 54 Perkoz. But the SZD Bielsko is working right now
to bring the glider into production.
http://www.szd.com.pl/pdf/szd-54_perkoz_doku_en.pdf
Jacek
Washington State