The Roof of the World

A soaring flight from Omarama to Mount Cook and back is one of gliding’s ultimate experiences. Rod Dew decribes what it is like to soar to over 20,000 feet above New Zealand’s  highest mountain and at ground speeds in excess of 200kmh in sub-zero temperatures - all on a day when the wave is not entirely co-operative.

Condensation on the inside of the canopy of Southern Soaring’s high performance Duo Discus, Romeo Zulu, is partly obscuring the awe-inspiring view of New Zealand’s famed mountain soaring playground in the Southern Alps. Efforts to wipe it away prove fruitless.

 The water vapour stuck to the Perspex is frozen solid.

Southern Soaring's Duo Discus soars above the Liebig Range and the Murchison Valley in Mt Cook National Park. Photo: Rod Dew

No wonder. The temperature gauge in the cockpit is off the clock. Its lowest limit is minus 20deg centigrade. In the front seat, Southern Soaring’s chief flying instructor, Chris Rudge, sweeps a hand over the frozen condensation. He estimates the temperature at minus 32deg. A mountain flying veteran, he never fails to be awed by the endless panorama of snow-capped peaks and deep river valleys. Today, peering through a broad gap in the substantial cloud cover hanging around the Mount Cook area, the terrain is spread out like a model relief map.

It is as if we are on top of the world.

The almost overwhelming view is not the only distraction. Romeo Zulu is being tossed about like a cork on the ocean. We are at 20,000ft and still going up, as they say, like a homesick angel. The Murchison River valley is to our right, far below, clasped in the icy embrace of the Malte Brun and Liebig Ranges on either side. The cloud prevents us sighting all but a tiny section of the Murchison Glacier at the head of the valley.    

“Look at that,” Chris says. “That’s pretty awesome. This is better than sitting in the office.” Almost as an afterthought, he adds: “That’s Mount Cook right on the nose.”

There is a tiny piece of rock protruding through the cloud below us. I have to look very carefully to find it. But New Zealand’s tallest mountain (12,316ft/3754m) looks impressive, even from this lofty height, as it thrusts itself through the cloud.

Turning back to Omarama with Mt Cook just visible through the cloud below. Photo: Rod Dew

The ride in the wave is usually as smooth as glass, but today it is unusually turbulent. I have a firm hold of my camera and my water bottle, essential equipment for any cross-country flight.

“Are your seat belts tight?” Chris asks after one particularly severe jolt.

My answer is in the affirmative. I have no intention of cracking my head on the canopy.

What could be causing the rough air? There must be conflicting air masses. The southerly is moving in behind us and there is a northerly ahead. We are sandwiched in between. Every few seconds, the needles on the variometers are swinging wildly from 10knots up to 10 knots down. The actual lift and sink ratio is probably worse than this but it is beyond the capacity of the variometers to record.  

Cruising at 100 knots, 20,400 ft and -32'C. Photo: Rod Dew

And yet we are still climbing. At 20,500ft, with the Murchison Valley stretching away to our right, Chris decides it might be best to head for home. He has been keeping a watchful eye behind us to ensure that building cloud does not slam the door shut. There is no cause for alarm. Although the cloud cover is substantial, there is a wide canyon along the course we plan to take on the return journey. Far below, the Tasman River is winding its way along the valley floor towards Lake Pukaki as we blast along in the furiously pumping Ben Ohau wave.

Our achievements are far exceeding our expectations at the start of this flight. It was almost a spur of the moment decision to go flying.

Chris is sitting at his computer completing the company’s GST return, and clearly not enjoying it. Suddenly, he looks out the window, spies some good wave cloud almost overhead the Omarama airfield, and can’t help himself.

“Rod, feel like a flight in Romeo Zulu?”

“Ah, well. Yes, maybe.”

I am a bit taken by surprise and not at all sure I want to go flying. Conditions look a bit wintry to me, the office seems nice and warm and, most important of all, I haven’t had a chance to have my lunch. Chris doesn’t seem to notice my lack of enthusiasm.

“You give Romeo Zulu its DI (daily inspection) and take it down to the eastern end of the field.”

On occasions at this relatively early stage of the season, we have struggled to find experienced tow pilots for our Piper Dakota towplane but today one of our best, Darren Smith, walks into the office. The aerial top-dressing company he works for is not operating today. The wind is too strong.  This gives Chris, who has been doing a lot of the towing, a chance to actually fly in a glider. It is an opportunity he has no intention of passing up.

I complain again that I still haven’t had lunch. I am given time to rush into the Omarama Village for a quick pie and drink. When I return, Chris is outside the office looking at the sky.

“Mmmmm. It doesn’t look as good as it did,” he says, frowning at the dark band of rain cloud pouring into the Ahuriri River basin over the St Bathans Range. The Lindis Pass is obviously a place to keep away from, even in a car. It is probably snowing there.

“We will go anyway,” he decides. “It might be a short flight.”

It is 1.15pm. The takeoff has to be made without the use of a wing runner. That’s my job, and this time I am in the back cockpit. It is no problem. Darren, just back from a stint towing gliders in Canada, hasn’t lost his touch. He gives the Dakota full power. The wing of Romeo Zulu scrapes along the grass for a few metres before lifting up. Although the takeoff run is quite long, we are soon in the air.

A wide right-hand orbit takes us on course for the Nursery Ridge on the southern side of Mount St Cuthbert, a favourite starting point. There is usually something working there in most conditions, and plenty of options if there isn’t.

We tow past Black Peak, which overlooks the airfield, and onto the start of the Nursery Ridge. There seems to be good lift. We bung off at 3000ft ASL (above sea level). That’s just 1600ft above the airfield. Not much margin for error.

“Have a good one,” says Darren over the radio as he dives back towards the airfield. 

Chris works the ridges and gullies. Slowly, we make height. The ridge lift is not consistent but there are parts which are showing three and four knots. We head further up the ridge in the hope of finding something better. The small basin at the head of the ridge usually works, but today it is not co-operating fully. The lift is weak. We lose several 100ft.

A return to the northern end of the ridge improves our situation.  Slowly but surely we work up the ridges and onto the main slopes of Mount St Cuthbert. We reach 4500ft, but it has been a struggle and the summit (5000ft) is still some distance above. It becomes clear we are not going to get on the tops. Low cloud and rain is already beginning to spill over parts of the St Cuthbert Range. It is starting to look pretty grim to the south. We are being chased off the mountain.

“We are a bit low to try and push into the wave,” says Chris. “We might just have to try, anyway.’’

Romeo Zulu turns out from the mountain towards the Clay Cliffs, one of Omarama’s spectacular and unusual tourist attractions. Romeo Zulu suddenly surges upwards as the Cloud Hills pass to one side. Chris circles. The lift is narrow but strong. In a few minutes we are over 5500ft. Another push forward takes us through some serious sink. Then, just beyond the Clay Cliffs, there is another upward surge. Again, we take time out to circle. The altimeter shows 6500ft. We push forward in the hope of contacting the wave.

There are scraps of wave lift. Things are looking more promising. Chris weaves about. We gain another 1000ft, and suddenly everything goes smooth. We are in the wave rolling over the Diadem Range.  Romeo Zulu climbs steadily as we head north. Quite quickly, the altimeter is showing 9000ft. Time to get the cannulas on and the oxygen ready. The black boxes are set for the oxygen to turn on at 10,000ft.

The lift strengthens somewhat in the lee of Ohau Peak (1914m). We hit 10,000ft and are on oxygen. There is heavy cloud over the Barrier Range and Lake Ohau is also obscured. That wave route to Mount Cook is obviously closed.

Chris decides to jump across to the Ben Ohau wave. The speed is pushed up to 80 knots as we penetrate the sink. At times, 10 knots down is shown on the variometers. We race through it. Lake Ruataniwha passes by on our right. The hydro electric canals linking Lakes Ohau, Ruataniwha, and Pukaki are in sharp relief.

The sink seems to go on forever. In fact, it is just a few minutes. We have lost 1000ft in altitude. Just short of Twizel, there is a comforting beep-beep-beep from the audio vario. Soon, we are climbing steadily. There is still a lot of cloud about but there are signs of some classic wave lines, and there is an open route along the left side of Lake Pukaki. At times, we have to bank away from clouds and our line is not perfectly straight. But we are making excellent progress. No need for circling.

There are 10knots up showing on the variometer, and it is comfortingly steady. We climb through 15,000ft and it is starting to cool down in the cockpit. I am thankful that I had the presence of mind to toss my gloves into one of the pockets before taking off. We are now moving swiftly along at 80knots (airspeed). The ground speed is much faster, probably more than 220kmh.  Mount Dhu passes to our right before we are obliged to move further out over the edge of the lake.  

Visibility to either side is restricted, although the way ahead is surprisingly clear and our route is well defined. We rise above 18,000ft at the head of the lake, and the Tasman River can soon be seen winding along below. Glen Tanner passes underneath. The air is starting to rough up. Romeo Zulu bounces around. Nothing to be alarmed about. Everything in the cockpit is secure.

“This is weird,” comments Chris. “The wave is not normally like this.”

We continue our climb. The varios are starting to wave around but there is far more lift than sink. We pass through 20,000ft as we over-fly the junction of the Hooker and Tasman Rivers. The view is spectacular. The cloud seems to have reduced. Icy valleys, snow-capped peaks, rivers and rocky outcrops increase the feeling of lonely isolation. Here and there a mountain thrusts its rocky peak through the clouds. We are far too high for there to be any concern.

It is becoming very cold. The thermometer is showing minus 20deg centigrade. That’s the minimum temperature it can record. Obviously, it is much colder than that. My nose feels like a piece of wood and my ears have no feeling in them. In the front cockpit, Chris’s ears seem to be turning blue. There is an icy blast coming from the front. Chris has opened the vent in an effort to clear the frost off the canopy. I take comfort from the fact that I am not the only one feeling the chill.

Even so, this can take little away from the incomparable feeling of being on top of the world. They say this is the closest thing to heaven. That’s probably true, in more ways than one.

There is a sharp peak piercing the cloud just ahead. That has got to be Mount Cook. It is a shame that we can’t see the great mountain properly, but it is easy to appreciate why it outranks all the rest in grandeur. To the right, the Murchison Valley stretches into the distance. Mount Chudleigh (9731ft/2966m) can be seen not far off. It is an interesting landmark because this is often used as a turnpoint for glider races, and for record attempts.

Mt Chudleigh at left, the Murchison Glacier centre and the Liebig Range at right. Photo: Rod Dew

The air is now boiling. There is no danger. However, it is short of being comfortable. The cloud is thickening up in front. There seems no point in going further so we bank around and point the nose back towards Omarama. The speed is raised to 90knots and we are still going up, even if it continues to be bumpy. These are the type of conditions in which world speed records are set. Terry Delore (New Zealand’s multiple world record-holder) eat your heart out.

Approaching the Malte Brun Range with the upper Tasman Glacier and Main Divide in cloud. Photo: Rod Dew

After a few minutes, with the altimeter at 20,500ft, Chris reduces speed a little and pulls out the airbrakes. We lose a small amount of altitude and then, to our consternation, resume climbing with the airbrakes still out. Romeo Zulu is turned away slightly from the strongest part of the lift and finally begins to descend at a decent rate. Chris isn’t concerned. I give a faint sigh of relief. I am not as brave as he is.

Heading back down the Tasman Valley from Mt Cook with Lake Pukaki visible in the distance. Photo: Rod Dew

Lake Pukaki is now on our left, a shining azure blue. The cloud is thickening up a little in front of us. We are now down to 16,000ft and speeding along at 110 knots. The dark front rolling in from the south is not yet a problem.

Tracking south towards Glentanner. Photo: Rod Dew

We pull the brakes again to get down below the cloud, veer towards the right, and take a short cut across a small mountain aptly named, The Pyramid. This ensures we avoid controlled airspace. We are now at 7000ft and warming up nicely. The Pukaki and Ohau hydro electric canals drift past to our left with Lake Ohau on the right. Our speed is still high, around 80knots, and we are losing very little height. It is a straight final glide to Omarama, if that is what we want.

Descending back along the Ben Ohau wave over Glentanner with Lake Pukaki below. In the distance is the approaching front that brought snow to Omarama. Photo: Rod Dew

Romeo Zulu heads out over the Ahuriri River plains in the Mackenzie Basin. We are now well below cloud base. I assume we are heading for the airfield. Chris has other ideas.

“You have control. Lets have some fun.”

Now is my chance to show just how little I know. I fly across the basin towards Mount St Cuthbert. My intention is really to just gently let us down to circuit height so I am not at all concerned about the dark clouds covering the back half of the mountain. There is still some ridge lift over the northern slopes but only enough to maintain height.

I bank Romeo Zulu around and head out over the Omarama Village.

Soon, we are over the Buscot Ridge at 5000ft. It is not working today. This needs a good easterly to get it pumping.

Once again, I am thinking about letting down for a landing. And once again Chris has more adventurous intentions. I fly casually back across the Omarama Basin to Mount St Cuthbert. I turn away for another sweep over the Omarama Village.

Ahead, we can see a line of dark clouds. Chris observes that this is probably some sort of convergence. Maybe we can run along it.

I head for the well-defined line of cloud, which seems to stretch from the Cloud Hills to Totara Peak on the Benmore Range. Sure enough, as we move under the dark area of cloud, the variometer begins to sings its happy tune. A right turn puts us in line with the convergence and we head towards snow-clad Totara Peak. At 5960ft (1818m), this is only slightly smaller than the Benmore Peak. It actually looks higher. The convergence is a little ragged and begins to lose power as we approach the eastern end of the Benmore Range.

The decision to turn around well short of the peak is a no-brainer. Hail starts slamming into the canopy. Any worse and it could damage the surface of the glider. We fly out of that in a hurry and head back along the convergence which by now is even more broken.

A challenge from the front seat that I try and dolphin soar to the Cloud Hills without losing any height is accepted. We are at 6000ft. So I speed through the sink and pull up in the lift. The trick is to pull up early by anticipating the lift. It is an interesting exercise. I am no expert at this. We approach the gap in the Cloud Hills at just under 6000ft but can see a dark cloud hanging right over the hills. That should provide the lift I need to win the challenge.

Sure enough. It works a treat. The final pull-up lifts the glider to 6200ft.

Yet again I am assuming we are about to let down for a landing, and once again I am wrong. We drift slowly eastwards over the Buscot Ridge. We are down to 5000ft when we encounter what seems to be a thermal just beyond the ridge.

“See if you can take us back to cloud base,” says Chris.

So round and round we go. The lift strengthens as we edge upwards. My thermalling technique is far from brilliant but I manage to stay in the lift most of the time and soon have the satisfaction of reaching cloudbase at 7000ft.

We are now high enough to cross the Benmore Range. Chris takes over and heads over Mount Benmore (6214ft/1894m). The tops are rolling country, almost level enough in parts to land on. There is no chance of that today. At the northern end of the range, there is a likely looking cloud. We take a small top-up from that before heading back the way we had come. We cruise around the ridges, finding enough to sustain us without any real effort. On another day, this would be worth writing about. But in comparison with what has gone before, it pales into insignificance.

We soar out over the Omarama valley and decide to call it a day. We had enough fun and excitement. I circle around in sink over the Ahuriri River, and go wherever I think the lift isn’t. My instinct for finding sink is up to its usual high standards. We are soon down to 3000ft.

Chris takes over for the landing. There is a strong cross-wind and the Duo can be a handful in these conditions. He sets us up for an angled final approach, which reduces the effect of the cross wind. The touch-down is perfect, a fitting end to a great flight. We have covered more than 250km over some of New Zealand’s most spectacular mountain terrain. The entire flight time is 2hr 55min, not bad considering we spent more than 30min working the convergence near the airfield.

As we put the glider back into its hangar, it is starting to hail. We are back, but not a moment too soon.

That night, winter returns. In the morning, the mountains are gleaming in a fresh covering of snow, almost right down to the flats. It is another reminder that the weather can change rapidly in Omarama, but that is part of what makes it one of the finest gliding sites in the world.

Marc Crozier pre-flights Mike November after overnight snow.

The flight to the Murchison Valley and back might never have happened had we followed our initial instincts about the weather. 

It is easy to assume the worst. If there is a message to be taken from this it is: don’t be backward in having a go. Some of the most memorable flights have been achieved on days which started out in conditions that looked less than encouraging. This was surely one of those great flights. If you want to be King of the World, even for a few short hours, you won’t do it by standing on the ground looking upwards.