WA Model Aircraft Sports Centre (Inc.)
Would you like to react to this message? Create an account in a few clicks or log in to continue.

The Three Turn Spin

Go down

The Three Turn Spin Empty The Three Turn Spin

Post by Greg Russell-Brown Mon Nov 21, 2016 8:44 am

Another of the MAAA gold wings manoeuvres is the three turn spin.

Essentially the manoeuvre consists of three components:

1: Stalling the aircraft to enter the spin.
2: Executing precisely three turns of spin in a stalled configuration as the aircraft decends in a vertical downline.
3: Recovery and pull-up to resume upright level flight.

As always ensure you begin with sufficient height to recover in case of disorientation - (three mistakes high is a good rule of thumb!)

In the gold wings schedule this manoeuvre is executed into wind only and not in both directions.

To begin we will set the aircraft up on what is referred to as the high line of the aerobatic box (imagine a vertical rectangular box aligned with the runway in use, with the long sides horizontal and the short sides vertical, the aircraft will be flying on the top of this box and the manoeuvre itself is executed in the dead centre of this box right in front of the pilot).

We start by approaching on the high line from downwind in normal upright level flight.

Before the centre of the box is reached reduce power to idle and allow the airspeed to drop, as it does so gradually apply a little up elevator (but not so much as to start climbing) so by the time the aircraft reaches the centre of the box it is very close to stalling.

Once at the centre of the box introduce rudder in the direction of your choice to full deflection gradually over around three seconds then introduce full up elevator over two seconds, this is then immediately followed with full aileron deflection in the same direction as the rudder input, (all these control inputs stay in this configuration during the spin).

(The reason for these delays is to ensure the aircraft stalls and starts its spin immediately so as to avoid having the aircraft banking when entering the manouvre-a correctly entered spin avoids a wing high situation).

Now the aircraft should be spinning correctly and descending on a vertical downline.

As the aircraft approaches the third full rotation (spin) release all control surface inputs to their neutral position except for elevator - apply a little down elevator for around two seconds to maintain the vertical downline then elevator goes to neutral and increase power to around 30%.

The aircraft will stop spinning with a slight delay and this delay varies with different types of aircraft. The release timing for the control surfaces so as to complete three full turns of spin is dependent on many variables, one of the primary variables is the mass of the wing and its inertia induced after rotating in the spin - you will get used to your aircraft and the exact release time with practice.

Now we have been on a vertical downline for a couple of seconds it is time to introduce up elevator to pull up, increase power to cruise setting and resume normal upright level flight.

Manoeuvre complete.
Greg Russell-Brown
Greg Russell-Brown
Admin

Posts : 11
Join date : 2016-11-12
Age : 56
Location : WAMASC

Back to top Go down

Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum