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Old January 19th 04, 03:07 AM
Bill Daniels
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"Jack" wrote in message
...
Fellow r.a.s.'ers:

Tell me about the Lark.

I don't yet know which model, but I hear that our club is about to acquire
one.

Should I be ecstatic, or concerned?



Jack


The following assumes your club is getting an IS28 b2.

I owned an IS28 b2 Lark (two seater) for several years. It was a fine
glider. I found it would soar with the best of the 17 meter glass two
seaters and out-run all of them. The negative flaps really work well at
high speeds. I could circle at 45 knots and 54 degree bank at gross weight
using 5 or 10 degrees of positive flap. Mine was equipped with 50 pounds of
oxygen gear but still had 390 pounds of useful load.

It was intended as an advanced trainer so better than average flying skills
are required. On the other hand, I felt totally prepared for my first
flight in a Nimbus. The Lark makes a fantastic transition trainer for fast
glass. 10 hours in it and you should be able to fly any glider.

Larks come with the same air/oil main gear strut that Blaniks use. The Lark
just uses more gas pressure because it is heavier. If the strut hasn't
been rebuilt in a long time, it's likely that the oil has mostly leaked out
and the strut contains mostly nitrogen from many top-offs. This can make
the strut really bouncy. It still works fine with tail first touchdowns but
a botched wheel landing can produce some spectacular bounces. I found the
directional control on rollout to be fantastic. I could steer it anywhere I
wanted. The brake is a tiny Tost drum that is totally inadequate to stop a
1300 pound glider so plan on not aiming it at anything you want to keep.

You will find some who will criticize the stall spin characteristics but I
found mine to be totally honest. It would spin if abused but a strong
pre-stall buffet (it would shake things off the Velcro) gave ample warning
that you were approaching a stall. In a incipient spin entry the nose would
start to swing as a wing dropped giving an unmistakable signal that a spin
was starting. Releasing the backpressure stopped this instantly.

The ailerons are heavy because they are very large, but you get a control
stick the size of a baseball bat to operate them. Still, you'll need to
develop some shoulder muscles. I was able to demonstrate a 45-45 roll in
4.5 seconds at an airspeed of 50 knots. You need to use full rudder to get
a fast roll rate.

I had several pilots criticize the rudder as inadequate but I could tell
they were only using half the available travel by watching the rear pedals.
The front cockpit pedals travel almost 10 inches so you REALLY have to use
your feet to get full rudder.

You'll have to work to get comfortable in the seats. There will be a need
for an infinite range of cushions. Take very good care of the tail dolly
and the lift tube that goes through the tail boom - you'll need them every
time you want to move the glider on the ground. The tail is VERY heavy so
plan on some help lifting it to fit the dolly.

Get an aggressive maintenance program going and stick with it. The Lark
demands some TLC so plan on it. Don't EVER fly it with a deflated strut -
you will damage the fuselage structure at the gear box. Pay a lot of
attention to the tires and inflation pressures.

Have fun with it.

Bill Daniels