Saturday, October 11, 2008

Spin, Spin, Spin

N561UA 0.9 hrs - Today I got my spin endorsement which is a requirement for the CFI rating. I had already presented my ground brief on spins so after a safety briefing we launched in the C-152 Aerobat. We wanted to start at 5500' for spin practice over the Carnation valley, so we got a clearance to climb through class Bravo airspace shortly after takeoff from Boeing field. First, my instructor had me do a few 60 degree turns just to get the feel of 2G's of load, since that is close to the G forces encountered on the pull-out from a spin recovery. Next I practiced putting the airplane into a stall and mainting directional control with rudder/aileron. Suprisingly, the Aerobat will fly with full back elevator.

Next my instructor had me try and spin the airplane by doing "stupid" things that one of my future students may do at some point and its amazing how docile the Cessna's are, and with crazy control inputs they still remain stable.

After that is was showtime, and we reviewed what is required for a spin to occur (stall and yawing) and the recovery procedure (power idle, aileron neutral, full rudder opposite direction of spin/elevator briskly forward to break the stall, neutralize rudder when spinning stops, recover from the dive).

I started with a spin to the left, by reducing power to 1800 RPM, slowing to stall speed, and then full back elevator, full left rudder and full left aileron (basically doing a roll to force the wing over). The incipient stage lasted about 1 1/2 turns then the full spin developed and we corkscrewed for another 3 turns before recovering. I was supprised how my hands and feet just went through the recovery procedure without me having to think about it. I actually applied too much forward elevator to break the stall and pulled some -G's on the subsequent dive. The accelerometer showed +2.5G and -1.0 on the recovery.

I did a few more spins to the left and to the right with my instructor demontrating a few in between. We headed back to KBFI where I proceded to make a squeeker landing in the 152 (this was my first time ever in a C-152).

1 comment:

David S said...

Wow, that sounds like a thrilling ride. I'm looking forward to doing my own spin training in the FSI Zlim later this fall. It's hard to believe you managed to avoid the 152 all these years.