“Be at TAL at seven. There’ll be a couple of Ag blokes along as well.”

“Uh, okay sir.”

“Good, see you then.” He picked up his pen. There was no more to be said.

Back in my office, I turned to all the matters that needed last-minute attention before I went on leave.

The ‘Daulo’ that Downs referred to was a road camp I’d built at a pass at 2,492 metres, part of the Highlands Highway we were constructing. At this point, the just-built, narrow, winding jeep track crossed a major divide between Goroka and Mount Hagen..

The ‘peculiar bit of grassland’ was a flat area high in the rainforest behind Daulo. Downs thought it might be suitable for a crop of pyrethrum, a daisy-like plant from which an insecticide is extracted.

In other parts of the world, pyrethrum was proving to be an easy and useful village cash crop. Trials in PNG at lower altitudes had been unsuccessful, but the pyrethrum daisies I’d planted at Daulo had produced a good flowering, PNG’s first.

The Agriculture Department was now interested in trying it as a cash crop in other upland areas.

With four passengers, we took off from Goroka as planned in an old twin-engined, fabric-covered biplane, a de Havilland DH84 Dragon.

The flight took only 20 minutes but, as we approached, we found the cloud-base at 2,700 metres too low to fly safely through the slight gap in the ridge which would have allowed us to over-fly the grassed area.

Tony Vadim, a highly-experienced pilot, realised he could give us quick sideways glimpses through the gap by flying back and forth just below the cloud-base. After several passes, Downs shouted over the din of the engines, “We can’t see enough, Tony. Take us home.”

Tony eased back on the throttles and began descending. Almost immediately, both engines fell silent and our decline steepened alarmingly.

No one said anything. Maybe, like me, they hoped this was Tony’s way of losing altitude.  Then, reality struck – we were not under power. The propellers were just rotating in the wind. The terrain below suddenly looked very rugged indeed. My first thought was ‘Damn! I’ll miss the plain South tomorrow.’

Tony’s not-quite-calm voice rose over the rushing noise of the air stream. “It’s okay. The carbys have iced up. The engines will start as soon as the ice melts.”

That didn’t relax me nor, I suspect, the others. Apart from several sharply exhaled expletives, we said nothing, just waited anxiously.

Tony began a careful turn towards a small airstrip below. The ridges and trees and some villages in the valley were getting closer. Someone said, “Come on, come on.”

Then one engine started with a splutter, then a roar. The aircraft slewed. Then the other spluttered to life, and we were back flying under control.

“That was awkward,” said Tony, reverting to his habitually laconic style. “All okay?”

We could only smile weakly, but a babel of chatter burst from us with the release of tension. We wiped the sweat from our faces, formed despite the cold air.

Once safely back in Goroka, Tony explained that the air immediately under a layer of cloud is very humid because it is loaded with super-cooled moisture on the verge of turning to cloud.

When this air rushed into the engine’s unsophisticated carburettors, it formed a film of ice which built up until the engines choked for lack of air. In our case – coincidently – the engines had both stopped at the same time.

“Just as well they started quickly,” he added

“Quickly?” One of the Ag blokes said.

“Yeah. It was only about 30 seconds until they started.”

We all agreed it felt like many minutes. “The longest half-minute of my life,” said the Ag-man.

The next day I flew to Port Moresby, then on to Sydney in the comfort of a pressurised, four-engine Qantas Douglas DC-4 Skymaster.

I appreciated the difference between this aircraft and the 25-years-older Dragon. It made the flight so much sweeter.