An epic mid-winter soaring adventure - Cape to KZN by Glider
By Laurence Hardman (BAT) and John Coutts (S8)
19 July & 10 August 2024
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Photo courtesy of Bronwen Klaas. Sunrise at Worcester
Friday, 19 July 2024
I was next to the pool in Germany when my phone rang. It was John Coutts - "Where's your glider at the moment?". When the conversation starts this way, you know it's bound to be a good one.
John had apparently been watching the Western-cape frontal weather systems quite closely for the past few weeks, comparing the actual conditions to what had been forecast, and had figured out that it should be possible to do a wave flight from Worcester, just east of Cape Town, along the escarpment all the way to the east coast, with a goal of Durban. Admittedly, this seemed like an extremely ambitious goal - even to myself. But after we'd given it some real thought and figured out roughly what was needed to make the goal achievable - and compared that to the actual weather that John had been watching - it suddenly seemed within reach.
My glider was locked away in a hangar in Johannesburg at the time, but as luck would have it, John just happened to be there too. He kindly offered to rent a car and do the 1300km drive to Cape Town the following day. Meanwhile, I was due to fly back from Germany to South Africa a couple of days later.
During the days in between, we had been eagerly watching the weather forecast, and spotted the first promising opportunity, for the following weekend. The timing couldn't have been better!
I landed at home in Port Elizabeth on Wednesday, 24 July - kept half of my bags packed, and by Thursday evening (less than one full week since the original idea had come to light), I had arrived in Worcester.
The Conditions
What John had been observing was that in the winter months, there were frequent, strong frontal systems making landfall on the western coast, from the southern Atlantic Ocean, bringing strong west-north-westerly winds and relatively stable air in over the Western Karoo. The airmass would have a high moisture content, but the Cedarberg Mountain range north of Worcester would effectively dry this airmass out as it passed over and condensed - meaning that further to the east, conditions should be much clearer and more suitable.
The effects of these systems stretched several hundred kilometres inland, over the entire karoo, and as far east as the Drakensburg Mountain range. What excited us most about this, was that with just the right northerly component in the wind, the entire southern escarpment would act as a generator for lee mountain wave, potentially up to altitudes well over 20,000', with wave bars aligning in such a way that it was possible to glide from one to the next without losing much altitude between climbs. Importantly, as long as the wind strength remained strong in the eastern part of the country, it would mean that not only would the Western cape mountains and escarpment generate wave, but so would the eastern edge of the Drakensburg. This all comes together to present a unique opportunity…
Forecasted wave Vertical Velocity across the southern part of the country @ 16,000' - Typical of winter frontal systems.
Friday, 26 July 2024
We spent Friday afternoon rigging gliders, frantically filling oxygen bottles, charging batteries, and packing trailers. The forecast for Saturday looked good. In fact, the day before, the South African Weather Service issued a weather alert for the Western Cape on Saturday - warning of heavy downpours and damaging winds. This meant that the frontal system that we had hoped for, would arrive with a bang.
We were joined by Sven Olivier, who would be accompanying us in his JS-1 (EG) - and had also been eagerly watching the conditions in the days prior. After an evening of getting our bits and pieces together for the flight, and a good few hours of staring at every weather forecast we had available, we concluded that things looked promising, but there were two factors that could put a spanner in our plan. Firstly, the surface wind was expected to be 30-40kt (increasing to 60kt @ 3,000'), and secondly, thick low cloud (with rain) was forecast to cover the entire valley north of Worcester. Both had the potential to bring our flight to a halt before even giving us the chance to launch.
We got to bed at around 1:00am on Saturday, with our alarms set for 5:30am. The wind at the airfield was a relentless 40kt all through the night, so we went to bed without having the faintest idea of what to expect in the morning.
A rather ironic weather warning had been circulating in the days leading up to Friday.
Saturday, 27 July 2024 - Attempt #1
We were awake at 5:30am, and it was immediately apparent that the wind had not dropped at all through the night as hoped. In fact, it only seemed stronger. We agreed that it was going to take a fair bit of luck to find a gap to launch, but decided that we needed to go through the motions and pull our gliders to the launch point nonetheless.
Our tug pilot, Frans Du Toit, arrived just before 7:00am and expressed a similar sentiment. The wind was strong, but not unflyable. This meant that unless something changed, it was all-systems go. At about the same time, John's copilot in the Janus, Jac Snyman, arrived at the field - just in time to help pull the glider onto the runway and strap in.
John and Jac took the first launch with the Janus, while I pulled my glider onto the runway behind them, did my final checks, and quickly strapped in and got ready for my launch. I didn't realise it at the time, but I had completely forgotten to pack any food or water in the glider with me - Not a smart move when one is planning a flight that could potentially last more than 10 hours!
The Janus released from tow overhead Jan du Toit's Kloof at around 5,000', and managed to immediately connect strong, smooth wave. A few minutes later, I was with them, and both gliders climbed up to the maximum allowable altitude of 8,500'. At this altitude, our computers had calculated that we were in a westerly wind exceeding 120km/h (70kt). There was also a seemingly endless blanket of thick clouds covering the mountains below us, with a base of 4,000', which made the initial climb and glide out to the north-east somewhat daunting - with only a few usable gaps in the cloud, should we find ourselves needing to descend. Meanwhile, we could hear Sven on the radio, who was also getting into the air shortly behind us.
Once we had managed to work our way a few kilometres further north (and clear of the Cape Town airspace), we could immediately continue our climb to FL145 (That's 14,500').
At this point, we were directly behind the Matroosberg in the Hex River Valley, which had set up an exceptionally strong wave bar, giving climb rates in excess of 7.5m/s right until the upper limit of FL145
Our next goal was to reach Beaufort-West, and entailed a crosswind glide of approximately 150km with little-to-no lift expected along the way. The Janus crew and I opted for a route slightly further downwind than originally planned - which we would later learn was far from ptimal - while Sven in EG, with no shortage of local experience, took a far better route to the escarpment - ultimately overtaking us (and later passing Beaufort-West almost an hour ahead!)
Fortunately, we did manage to find the occasional patch of weak wave (probably secondary, or tertiary waves) from the smaller mountains surrounding the Verkeerdevlei dam, that allowed us to stretch this glide until we had managed to start reconnecting to the stronger wave system over the escarpment just past Sutherland.
From there, we noticed that the air was significantly less moist than it had been further west (as forecast), meaning that we could rely less on using the clouds as visual markers of the wave, and had to pay closer attention to the landscape below us. We followed the escarpment closely until Beaufort-West, where we stopped to climb as high as possible, since we knew that we would have to glide another 160km before we would find the next area of wave activity. We took the climb up to FL195, and flew at best glide speed, aiming directly at Graaff-Reinet. We arrived there at around 8,000', and immediately found a climb exceeding 3.5m/s. We took it as high as we could, and continued our eastward glide. By the time we had reached Queenstown, we noticed that the wind speed had dropped down to 40kt, and the strength of climbs had also fallen accordingly. It was already 14:30pm, and we had found ourselves under the coastal TMA airspace, meaning that we could not climb above FL145 again.
At this point, we learned that Sven had chosen a route slightly further to the north, heading closer to the Drakensburg foothills, past Hofmeyr - while we had allowed our track to converge on the coastal airspace. After a few minutes of weighing up our options, and debating what the best plan of action was, we decided on East London.
We were approximately 240km away, at FL145, with a direct tailwind of around 40kt, and over 3 hours of daylight remaining. It was easily achievable. We remained high and set course for East London Airport. Around the same time, unfortunately, Sven's flight had also been cut shorter than anticipated - as he struggled with deteriorating conditions after passing Hofmeyr, and after a low save at Dordrecht, ultimately had to land out just short of Elliot. Nevertheless, an exceptional achievement, given the conditions on the day.
Our final glide was relatively uneventful, until we were 50km from our target when we got a call on the radio.
"ZS-GCP, for Safair 143?"
It turned out that flight FA143, a B737 departing from East London to Johannesburg, was piloted by one of our fellow members from the Cape Gliding Club - He had been eagerly watching our progress online, and checked in with a few words of encouragement just before we commenced our descent to join the circuit at FAEL.
Shortly after landing, we were met at the airfield by another CGC member, Chris Way, who along with his wife Pam, had already arranged to accommodate us (and our crews) for the night in their B&B.
By the following day, our gliders were packed in their trailers, and we were ready for the long journey back home. All in all, the retrieve involved a round-trip of just under 2,000km of driving Final glide over the Southern Transkei.
Two Weeks of Waiting
After the first frontal system had passed, we spent the following fortnight catching up on work, analysing our flight, and keeping a close eye on the weather forecasts for the next opportunity to present itself. By Monday, 4 August, we noticed the first indication that a similar system would arrive in Worcester sometime around Friday. Winds were expected to be from the WNW, with an estimated strength of 65kt at altitude.
We could see that, in the area between Worcester and Beaufort-West, the wave was forecast to be spectacular - with the only difference to the previous attempt being that there was significantly less moisture at lower altitudes (although the forecast did suggest that we would have some higher-level lenticular clouds this time around). This meant that getting away from the airfield would be quite a bit easier, with the only limiting factor being the surface wind strength.
This time, it would be myself in the JS-1, along with John and his co-pilot, Bronwen Klaas, in the Janus.We decided it was all systems go, once again. By some miracle, Friday just happened to be a public holiday in South Africa, meaning that it wasn't even necessary to take a day off from work - all that was left was to pack our bags, meet up at the airfield on Thursday evening, do a final check of the weather, and get on our way. We also noticed that the Saturday had the potential to be a suitable day for the task, should Friday not be flyable, albeit with slightly weaker conditions near the Drakensburg, but still a viable alternative day.
One issue that we noticed with the forecasts, however, was that the surface wind strength was often significantly underestimated - and for Friday, it was already expected to be stronger than our previous attempt. This meant that there was a very real chance that we could find ourselves stuck on the ground, due to the winds being simply too strong to safely operate the tug aircraft. Once again, we headed to bed not knowing what to expect in the morning.
Friday, 9 August 2024 - Failure to Launch
On Friday morning, we woke up just before 6:00am to a howling north westerly wind, straight down the runway, with spitting rain coming from further north up the valley. We knew that it would not help to hesitate, so we pulled our gliders out despite the conditions, met our tug pilot, and started preparing to launch.
Unfortunately, just before we were ready to roll, the wind strength seemed to only increase further, and we made a unanimous decision to cancel launching. We still had Saturday as an alternative flying day, and to risk an upset due to the strong wind would not have been wise. We called it a day, packed our gliders into the hangar, set tasks, and were now 100% ready to fly on Saturday.
Saturday, 10 August 2024 - Worcester to Margate
Saturday morning presented us with another stiff north-westerly wind, but clear skies and no sign of rain. The wind seemed slightly less intense than the previous morning, but by no means light - it was once again, a constant 30-35kt - although straight down the runway, with no noticeable gusts. Our tug pilot, Mattias Suter, arrived on schedule at 06:45am, and met us on the launchpoint. We immediately hooked the gliders up - John and Bronwen were first to launch in the Janus, followed by myself in the JS-1 shortly after. I had declared a straight-out goal task of 1058km from Sandhills (just north of Worcester), direct to Margate Airport. We were committed.
Since the wind had a northerly component, this meant that it should be possible to connect to the first area of wave just north of Worcester airfield, in the lee of the Audenberg Mountains. The aerotow was extremely rough (by far the roughest I have ever experienced), as we had to climb through areas of extremely violent rotor turbulence, so a very high release altitude was necessary to ensure we could properly connect the wave behind Jan du Toit's Kloof once again. Once we had reached 8,500', both gliders pointed north and crossed into the Hex River Valley. From there, our next goal was climbing up to FL145, under the Cape Town airspace - which we managed to do with little to no effort in the lee of the Matroosberg overhead De Doorns.
Although we had reached altitude with ease, we noticed that there was a thick layer of low cloud between our current position at De Doorns, and our next forecast climb at Sutherland. The glide itself was over 150km, mostly crosswind, and we were capped from climbing above FL145 due to the airspace. This meant that unless we could guarantee a climb enroute, it was too risky to fly directly to the escarpment - so we weighed up our options once again.
A more upwind track, to the west of the cloud cover, was possible - although there was little in the way of usable wave along that route.
Fortunately, after about 40 minutes of hanging around and trying to find a possible way to reach the escarpment, we spotted that the cloud below us was starting to dissipate, meaning we could now safely continue northbound.
We reached the escarpment just before 11:30am, around one hour behind our planned schedule, to a spectacular climb of 3.5m/s, from FL100 to FL195. Temperatures at altitude were extremely cold, well below -20°C, but fortunately we were well prepared this time around and had sufficient clothing to stay warm. We also enjoyed some well-established lenticular clouds in this area, at least 5,000-10,000' above us, meaning that they likely had a cloud base of around 30,000' (although their orientation, running West-East, implied that the higher altitude wind had more of a northerly component than we had).
The next 140km glide from Sutherland to Beaufort-West was done without a single turn, at FL195 the entire way - simply by following the lenticular markers of the wave. Once again, we had another long glide between Beaufort-West and Aberdeen ahead of us, so slowed down our speed to stretch this and arrive at Aberdeen with as much altitude as possible.
We were now approaching the half-way mark of our flight, and were finding the conditions to be very similar to our forecast - so we set course from Aberdeen to Hofmeyr, crossing the south-eastern part of the Karoo, marked by generally lower mountains, with lots of open space between. Nevertheless, we managed to conserve our altitude and crossed overhead Hofmeyr just below FL190, with very clear air allowing us to visually see Gariep Dam, some 100km to the north of us.
Also visible were the southern foothills of the Drakensburg. After passing Dordrecht and heading to Elliot, still at FL190, we were starting to feel somewhat more confident that our goal on the east coast might be within reach. We rounded the corner on to the southern Drakensburg just past Elliot, but were disappointed with weak climbs averaging little over 1.0m/s. Although this was not what we had hoped for, it was what was forecast, so we had no other option than to exercise some patience and take, what would likely be, our final climb as high as possible and begin the 240km final glide to Margate.
Final Glide
Our flight computers were indicating a relatively light wind of 35kt @ FL195, and a required glide ratio of 40:1 to reach the target. In theory this meant that, all going well, we should be able to make it to our destination quite comfortably, although it was by no means a certainty.
We set course directly to Margate, with just over an hour of daylight remaining. The final glide was smooth and fast, although the terrain below presented very few suitable alternative landing areas, the landscape consisting of rolling hills and sharp valleys as far as the eye could see.
Fortunately, this would not become an issue, as we could soon see the Margate airport and the coastline beyond it.
We passed over Margate at 17:16 local time - meaning that I'd completed my declared task of 1058km at a (relatively low) speed of 119.01km/h.
After taking in the view, a few celebratory manoeuvres and plenty of sunset photographs - we joined overhead to land. I landed first, exactly one minute before official sunset, followed by John and Bronwen in the Janus, approximately 15 minutes later. Conditions on the ground were a very welcoming temperature of around 19°C, and humid (neither of which we minded very much, since we had to spend the next hour regaining feeling in our feet after hours in the radically cold temperatures at altitude!)
From here, all that was left was to park our gliders somewhere safe for the night, book into a nearby hotel, and await the arrival of our crew (which was expected to only be late the following afternoon). We celebrated with a good meal and few beers at a local beach restaurant, packed our things the following day, and headed back home with our gliders in tow. All in all, the retrieve entailed over 3,200km of driving to get our equipment back to Worcester. This must be a record of some sort too! Not to mention, the smiles-permile were sky high. We'd made it to the Transkei coast!
A Word of Thanks to -
• John Coutts - For undeniably being the mastermind and leader behind these extraordinary flights. Without the wealth of experience that John brings to the table, it would simply not have been possible.
• Frans du Toit and Mattias Suter - Our tug pilots, who braved extremely strong conditions to get us into the air.
• SkySight.io / Matthew Scutter - Our primary weather forecasting service, which had modelled the wave to an astonishing level of accuracy.
• Chris and Pam Way - For accommodating us during our stay in East London. • Michel Reolon and the team at Cape Gliding Club - For helping us with all the preparation on the ground, and plenty of early mornings!
• Our crew - Rico Suter, Mark Hardman, Moray and Morris - for covering nearly 10,000km of driving between them!
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