"The TC Turn!"

(How to improve your chances of survival in an unavoidable wire strike situation)

Back in the 1984, a young pilot had an horrific accident in a Hiller UH12E while spraying a wheat crop which had a 3 wire high tension power line passing through it and was surrounded by trees.

 

It was the oldest story in the Ag pilots' book - he knew the wire was there - but momentarily forgot about it when he dived down over the tree line to finish off some remaining chemical in the tank.

 

At 60 Kts, just as he switched on the spray, the helicopter impacted with the wire on the right hand skid upright, ripping the wire from one of the power poles some distance away.

The wire flicked back and tore off the complete tail rotor assembly and a third of the rear tail-boom, whipping it all up through the rotor blades, tearing about a meter off the end of each M/Rotor blade.

 

The pilot knew he had a problem when the machine hit the wire and pitched down, became inverted and starting to rotate rapidly around the main rotor mast like a Catherine wheel (Chinese fire work).

 

Witnesses were impressed with how far the white chemical spray was flung out by centrifugal forces as the yellow inverted helicopter whizzed round and round.

 

After traveling quite some distance due to inertia and shedding bits and pieces due the severe oscillations and vibrations, the helicopter came down and hit the ground inverted, breaking the main rotor hub and mast off and completely disintegrating the Perspex bubble.

 It then bounced back into the air and came down tail first, compressing the tail-boom up into the engine bay.

For some reason, probably a combination of good luck and the damp ground, it then stayed stuck in the ground - half the engine buried - looking all the world like a primitive space shuttle waiting to take off as the shocked pilot sat still strapped in his seat hanging grimly onto the controls but now looking up at the sky!

 

The pilot was treated for shock and was fortunate to have no physical injuries.

 

I flew into the crash site about 20 minutes later to lift the wreck out and - while incredulously looking at the scene - figured that there had to be another way to reduce the outcomes from unavoidable wire strikes.

After more than a couple of beers in the pub that night I had it figured out.

 

Since then I have taught the following method ("The TC Turn") and have been rewarded by many pilots contacting me with news of their success and occasionally showing me the wire that they had cut through.

In fact, not long ago, an old mate showed me the $48,000 account he received from an energy authority for replacing a wire he cut.

 

In this case he was passing above some high tension power lines when he hit the earth wire strung above the main power lines.

 

He told me that he immediately thought of the TC Turn and how lucky he was to be set up on the right angle just as he hit and the blades in his R22 cut the wire.

 

Here's the method - use it at your own risk!

Normally when an unavoidable wire strike occurs, the helicopter is arrested violently either by being pitched nose down or inverted when the wire hits the skid gear or becomes an unguided missile when the wire slides over the cabin roof and takes out the control tubes.

This is because there is usually nothing to cut the wire.

So.... when you are in an unavoidable wire strike situation, "Do the TC Turn!"

 

Immediately initiate a roll of the machine to any side with the cyclic. 

 

You now have made the normally horizontal Main Rotor Disc into a big, buzz saw blade as it is now no longer horizontal with the ground and has big mobs of energy to cut through most wires before they entangle themselves around the main rotor mast or controls.

I have seen Robinson R22 blades with only a small leading edge dent after cutting through a thick power wire.

You have turned a virtually unsurvivable accident into a 95% chance of walking away without a scratch.

 

Instructors - I always spent an hour of ab-initio training with student pilots working around a power line.

The student is shown all the traps - sun, dirty bubble, guy wires, secondary wires, earth wires, sagging wires (heat of the day), rising ground, fences, wires strung from high ground to high ground etc, culminating in flying safely under a normal domestic power line wire.

You are the professional expert - please spend time with your students around wires - you may well save their life by preventing future accidents.

 

Last, but not least - scrap any Robinson R22 Main Rotor blade which cuts through a power wire. It has saved your life once - don't risk a blade failure later!!!

 

Safe flying - TC  T

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Extra: Make sure you also read this survival tip - click here