Sunday, April 24, 2011

Touch and go

Flight lesson #3 today at Odessa Schlemeyer Field.  Drove the Tacoma over so I could listen to Alt Nation on XM, my new favorite radio station after the trip to Big Bend Fri-Sat.  After normal preflight, we took off on runway 34 into a gentle north wind.  Pulling up too hard upon takeoff we experienced the stall horn, but safely lower the nose to a safer angle of attack.  Flew out north of Odessa and practiced ground reference maneuvers: "S" turns; flying in a constant-radius circle; and a large rectangle.  I still have some trouble maintaining altitude while manuevering.  Turning tends to make the aircraft sink; need to keep back pressure on elevator to avoid this.  When ending a turn, then, there is a tendency to continue back pressure which results in gaining altitude.  I do it nearly every time.  Back south toward the airport, Josh (instructor) had me do a left turn to approach runway 34.  I was looking at the wrong runway so we went around.  On pass #2 I came in too high and fast.  Approaching to land is a bit complicated; there is so much happening at once.  The objective is to reduce speed and reduce altitude at the same time; normally these actions are opposed (falling tends to increase airspeed).  So landing involves the following steps (my current understanding):

  1. maintain altitude (4000' ASL) and reduce power (2000 rpm)
  2. At a safe speed, lower flaps to TO (middle) position
  3. After passing end of runway, reduce power again (1750 rpm)
  4. At a safe speed (white arc), lower flaps to down position
  5. Turn 180 degrees into final approach
  6. Maintain speed above 60 knots, ideally ~70 knots
  7. Reduce power to idle if necessary
  8. Aim for runway; maintain speed and continue to lose alitude
  9. As the aircraft sinks into the runway, pull back on elevator to control the sink rate
Step 9 is the most difficult.  Everything is happening, and you're just a few feet off the ground, but still flying at 70 knots (~80 mph).  Control movements need to be pretty extreme (I think).  The next steps, by the way, involved touching down, then keeping the nose up (but not too much), and slowing down until you're not flying anymore.  Then keep steering with the rudder pedals and coast to near the end of the runway, where brakes are applied.  Throttle at idle if not already.

On my first attempt I came in too high, and instructor decided to do a go-around.  Back to full power, gentle back pressure on elevator until well above stall speed; climb out, go around.  Our second attempt was a touch-and-go, where we made contact but continued and took off again; the third time was a charm and I landed it ok. Really a little hard but not bad.

Cockpit of the Diamond 20.  Student sits on left (captain's seat).  

  • stick (center of seats) - controls pitch (nose up/down) and roll (wing up/down)
  • rudder pedals (in foot well) - controls yaw (nose left and right)
  • In center divider (silver): 
    • far right = fuel mixture control
    • center = throttle
Other things I look at are the altimeter; the climb rate indicator; the airspeed indicator; and the tachometer.


1 comment:

Plants Amaze Me said...

Wow, what a lot going on at once, sounds a bit scary. Does the instructor have control while you have control? Well he must right. Nice shot of the cockpit.