View Single Post
  #4  
Old October 9th 06, 03:37 PM posted to rec.aviation.soaring
Chris Reed[_1_]
external usenet poster
 
Posts: 46
Default Open Cirrus Pilots Notes

This is based on 3 years owning my own Open Cirrus, including as much XC
as I could manage.

Flight notes:

1. On launch, watch out for the seat back hammock, which can move you
back in your seat. Adjust rudder pedals to allow for this, and then move
them forward in flight.

2. Tape up the tailchute cone with wing tape for the first few flights -
accidental deployment would be a bad idea.

3. Practice the tailchute regularly - it only requires an extra 5kt
airspeed for deployment and make crosswind landings easy.

4. Airbrakes are less powerful than modern glass - I'd say around K6Cr
equivalent - so approach speed control is important. Do NOT add an extra
10 kts for safety, as you could float the length of the field. Nil wind
landing speed is around 47kt (52 with tailchute), plus 1/2 wind speed.
5kt more is safe on a runway but not in a field, but you should be
practising for fields - this is definitely an XC glider.

5. Stall characteristics are benign, with plenty of aerodynamic warning.
HOWEVER, wet wings can raise the stall speed by 10 kts or so. If you
hear the rumble (at height), check out the stall speed (mushing stall
will tell you if it's risen).

6. This is a 1967 polar, so flying fast increases the sink rate by a
large factor. I'd say that the normal working speed range in the UK is
45-60kt (maybe 45-70 in strong conditions). Don't rush, and you'll get
there - I work on 12 km per 1,000 ft @ 50kt, and regularly achieve that.

7. Spin is benign, with plenty of warning on entry. However, on recovery
the rudder forces change and what feels like full opposite rudder may
not be. Push harder. The Cirrus (or mine anyway) requires ALL the
opposite rudder to stop the spin, at which point it comes out
immediately. This is worth practising.

8. Undercarriage lever works differently from most other gliders - worth
practising on the ground if possible but not really a problem.

9. Trim works differently, so worth practising on the ground first as
you can't see it. If the knob unscrews in flight (e.g. you move against
it) then the springs produce unexpected stick forces - don't panic, just
reach for the trim and readjust.

10. Trim knob is next to tailchute knob, and both need to be worked by
feel not sight. Practice to make sure you have the right one. Practice
unscrewing the trim tension before moving it - the tailchute knob
shouldn't unscrew, which is an additional way of ensuring you have the
right control.

Rigging notes:

1. Wings are heavy (the German LBA failed to break them at 15G), so make
some trestles to take the weight.

2. Line up the spars inside the fuselage with the weight on trestles -
once everything is lined up, the "grunging" bar will slide them into
place. If it won't, you're not lined up. There's no point 2 or 3 people
puffing and swearing while you do this, thus the trestles.

3. Make your friends watch you fit the tailplane - no-one believes it's
that easy!

4. Always tape up the wing/fuselage join, as otherwise turbulent airflow
hits the tailplane and makes flying unpleasant.

Overall, a nice glider, easy to fly - have fun!