I’m grateful to this thread for sending me back to the notes I made the day after suffering a complete T/R drive shaft shear in a 109 some years back. (I caution when reading this that the 109 of course has a very big fin). Part of those notes read:……..
According to both the previous tail rotor failures on 109s the aircraft doesn’t yaw with a failure in forward flight above 120 kts since the tail rotor is completely unloaded and the fin is taking the entire anti-torque load. However in both these cases the entire tail rotor assembly had departed the aircraft. Mine was attached and sometimes windmilling, sometimes not. (I had a chase S76 join me to take a look).
There was a definite and violent yaw to starboard and there was no way it was ever going to fly in the direction it was pointing, or even within 40 degrees of the heading. Although that was uncomfortable it would happily fly at a good range of power settings and between 60 – 100 kts, leaning heavily left “wing” low. The envelope is undoubtedly much wider but I wasn’t brave enough to explore it!
I flew dummy approaches to two out of wind runways in the hope of gaining some help with the heading but the whole thing felt very unnatural and there was no conspicuous advantage to be gained.
I trained the camera man in the left seat (we were returning from a job together) to chop the overhead throttles on my shout. The into wind runway was chosen and I entered a 60 kt constant attitude auto with the engines running (and without intending to flare). The nose stayed 20 degrees to the right of the centreline. At about 20 feet we chopped the engines. It felt very late at the time but was actually a bit early as I was amazed how quickly the nose yawed to port whilst I was pulling in a bit of pitch. I was hard pressed to get onto the ground before the nose swung through the centreline.
In retrospect I would not do an auto next time. I think I would go for a flat approach at 60 kts and accept the increased yaw to starboard (probably as much as 45 degrees). I would then try to gently arrest the descent and then the speed down the centreline at about 5 –10 feet before chopping the throttles, giving more time to worry solely about timing the touchdown to coincide with runway heading. This assumes somebody available in the other seat to look after the throttles.
I found one of the hardest aspects was keeping my feet on the floor instead of constantly trying to pedal a control that wasn’t there.
…………Now don’t ask me for more details, it was a long time ago, but those notes were made the very next day. I’m certain they are very specific to the 109.
I do very clearly remember being astonished at how the brain speeded up with adrenalin and could remember comprehensive details of stuff I’d read or been told about T/R failures from long before. I couldn’t have remembered it all the day before and probably not the day after, but it was all in there somewhere when needed at the critical moment.
JerryG