Hypothetical Scenario #2 - Urgent Action required

So - I will bite.

If both pedals go to the floor you have a disconnected rudder - probably
due to a snapped rudder cable OR a failed tensioner.

In either case you have to use secondary aileron effects to obtain yaw
control - with the initial attitude (In a left bank of 30 degrees),
speed and relative degree of adverse yaw determining how successful you
will be.

Scenarios then:
2A Yaw to Left, string to the right - The rudder disconnects and
centres freely, but you were holding the stick to the left (pro-turn) -
adverse yaw on the upward wing caused a yaw to the right. The rudder may
have locked over setting up a high descent rate slip. The yaw will tend
to cause the right wing to drop as it slows.
2.A.1 First lower the nose to avert possible spin entry.
2.A.2 the dropping outer wing should be allowed to continue till level -
then attempt to stabilise with small aileron movements.
2.A.3 if the yaw string returns to centre then the rudder is free and
the use of adverse yaw _ moderate aileron (Secondary and primary effect
of ailerons in unison) technique to head for a safe landing area.

2.B If the string is pointing to the left pedal you have a skid into the
turn.If left unchecked this will result in a spiral dive as the wings
autorotate and the nose drops. Correction would be to:
2.B.1 Momentarily reverse the ailerons to stop the skid (big aileron
deflection without rudder to balance generally results in yaw first then
roll.)
2.B.2 Correct attitude excursion with elevator to maintain safe speed.
2.B.3 Centralise aileron and use small deflections to level the wings.
2.B.4 Continue to use the "early open class" technique of big opposite
aileron to start a yaw, then moderate pro-turn aileron to turn.
2.B.5 if you get it wrong the crossed control aileron reversal can cause
a spin entry...

In both cases, turns have to be wide and gentle and made with enough
speed for safety. If the string stays deflected then you have a locked
over rudder and have little choice about directing the side slip, you
can make it a forward slip and steer to some degree, but landing choices
are limited by the high descent rate. If not facing a suitable landing
area in the limited range available, consider baling out.


Debate?

On 2014/02/08 9:05 PM, OneTango wrote:
This is a voluntary pop quiz.

You're circling in a 30 degree left bank at 3000 AGL.

You hear a sudden change in the relative wind. Both rudder pedals go to the floor. The yaw string is not straight.

Sub-scenarios:

2A The yaw string points to the right pedal (adverse yaw to the left)

2B The yaw string points to the left pedal (adverse yaw to the right)

What do you do next? What just happened?

To derive the full benefit of this exercise, you might respond to this thread with your answer before looking at any of the other replies.

My hypothetical solution is found as a comment below.


--
Bruce Greeff
T59D #1771