Working with Aircraft

A significant part of my duties was to supervise the aerial application of chemicals as land preparation or to release forest crops from weed growth.
This immediately brings up connotations of Vietnam and 'Agent Orange' but we did not connect our work with that, or arguments about 245T.

Having said that, John Pury-Cust (now there's a name) had asked me to do a Forestry Assignment with him on the Mekong Delta in 1965, but the escalation of the war caused the work to be permanently suspended.


The first two years I was at Herbert Forest, John MacDonald pitoted a Fletcher fixed wing aircraft. Of course, the pilot has to be shown where to go, and the Fletcher was a single set machine, so I had to sit in the hopper - glad he didn't tip me out that way!


The first year we flew from the hill on Colin McLean's property and used a water tank that was from the Herbert Rural supply. Colin charged us for the water as he was a County Councillor and I remember thinking how stingy he was. That spraying was 245T on to Compartment 40 and was very tight flying conditions.


The next year we flew from a ridge on Donald Sinclair's farm, (Bert Bennett bought it later), it was a long ridge and the aircraft had to fly over the gully of the Waianakarua River and climb rather steeply. Inside the belly of the Fletcher, it seemed a long takeoff and the vibration was considerable. But I liked the aircraft and thought John to be a very competent pilot. like most he did crash sometime later - a wire strung across a gully.


For the perceived 'precision' spraying of Diamond Hill, a helicopter was required. The only helicopters available at the time were the Bells of MASH fame. They were not able to lift big loads and most operators carried the minimum amount of fuel so they could carry a larger payload.


For several years these aircraft were used and I might say, the pilots were often cowboys - as were their loader drivers [actually they operated pumps rather than loaders]. These were the years of venison recovery, now etched into New Zealand folk-lore. Sometimes the cracks on the bubbles on the helicopter were sown together with catgut!
Spraying could not be done in any wind that was more than a few knots, so I would keep weather readings and we would spray at first light of last light of the day. This meant I would be phoned at 3:00am for a wind update, then I would be on the job one hour later.


The pilot would land on exactly the same spot for loading. The mark left by the skids was the target. We would be waiting for the machine to land - the loader driver would have a 20 litre container of fuel, and tip that in the fuel tank (very close to the rotors) and I would fill the spray tanks with the mixture. Actually dangerous work.

There were a number of experiences worthy of note:

Most of the operators used second-hand petrol tankers to carry water. Although we did not always need water to be carried in, the tanker also carried equipment such as pumps and hoses.

We were spraying on Frasers Block with a Bell Helicopter fitted with a turbo - apparently you have to wind the motor down (to allow it to cool) for half an hour before shuting it down. Well the loader driver was going in to fuel up, and I was going in with the hose to fill the spray tank. The pilot had just misjudged by an inch or two and there huge bang! The loader driver ran off and I dropped to the ground an lay flat! The engine was shut down immediately! The tip of the rotor had struck the rack on the tanker! It blew the ends of both rotor blades completely off!


A truck brought new blades down from Nelson and it had to hauled up the muddy track with Mick and his D6. It turns out [well to me anyway] there is not much holding those rotors on! One bolt about 1 cm in diameter and another about half that! Once they were fitted, the 'trimming' process started there are wee, thin strips of metal on the rotor blade no more than 4"x 2" and a few mm thick. They have to bend to catch the air perfectly. Bend, try, cool down motor, stop motor/rotors and repeat. This took all day. Mick had a trial ride, straight up and when he asked the pilot what was wrong - and the reply was a miss in the motor; Mick held on to his arm until back on hard ground!

There were this pair sporting large flowing mustaches. They made themselves out to be "cool dudes'. Often the helicopters would pick me up from home - never landing but hovering for me to climb aboard. You do that gently so as not to destabilise the machine. Anyway I'm not sure if they were testing me, but the helicopter would lost power and we would lose altitude down, down and then whrrrr up we go again. I sat there 'calmly' while this was going on - not once, several times. To this day I don't know if they were having me on or not.

Then there was the helicopter that I thought was poorly maintained. I thought the thing seemed unstable and light in the rear end! What did I know? Well I radioed through to Berwick Forest, where it was going next and told them. They demanded the machine be looked at. The machine was grounded because the tail part (rotor) was irregular. Oh, after it was going again, one of the exhaust pipe covers fell off. They get red hot (you see it in the dark when you are working with it) and it started a fire in the forest!


I will do another blog of experiences, but first mention that government department called for tenders to have aerial spraying carried out. Contracts were drawn up and the successful contractor would have all the spraying of Southland Conservancy. So it would be a useful contract.
But some were brilliant and others were cowboys (as I have said) and this made the job interesting. We supplied all the chemical, because that was bought by the Government Stores Board.



Most ofen we used 245T and then Tordon, which was more powerful on gorse. Broom was another target weed and for us minor, in other areas majorly himalayan honeysuckle.
We did trials for grass control as a release and we were successful with the different chemical cocktails.
Asulox was used to control bracken fern 0f the waxy cuticle being a challenge, so added 20% desiel and an emulsifier. A safer chemical to use (someone said a guy had represented its safety by drinking a teaspoonful of it - yeah right). We had tried dessicants which helped the burn, but Asulox prevented regrowth.

Some of this stuff has been taken over by the Roundups of this world and its forms, but the big thing in my opinion is Velpar - the granule application is excellent after planting and the wettable powder can be aerially applied. I'm out of that now though and pleased to be so as you will see when I continue with these flying experiences.