Sunday, March 16, 2008

On the ridge at Taupo and a tricky landing


Finally back in the air. Today (Sunday 16 March 2008) I managed to find time out of some work in New Zealand to visit the Taupo Gliding Club. The forecast, which I'd been watching eagerly from Australia, was indicating westerlies and better than 24 degrees C. Westerlies at Taupo mean the ridge at Mount Tauhara, the 4,000 foot hill south of the club field, works, so I was looking forward to a good day.


However, by the time I arrived in NZ, the forecast was for south-easterlies gusty, and strengthening. I took my chances and arrived around midday to find it breezy, but not too bad. Gusting 10-15 knots or so.


It was nice to see all the familiar faces and aircraft. It was a real blue day with nary a cloud (expect for some high lennies suggesting wave far out to the east), but Gordon, coming in from some air experience flights said there was some lift around.


I didn't have long to wait before my flight, though we needed to do some mechanical work on the PW6. One of Gordon's passengers had pulled the wrong red knob - the front canopy emergency release, rather than the red normal canopy release (thankfully on the ground when he was getting out, rather than in the air, which would have been expensive and messy), so we took a few minutes to refit the canopy.


It felt good to climb in and do my NZ checks (which I still remembered). Tom was my instructor and he said we would go to the south-east face of the ridge.


Getting off was a bit tricky - it was quite turbulent near the ground, but I got things under control and it smoothed out a bit above 1,000 feet, though it was still a bit of a roller-coaster ride, with big bits of lift and bumps.


I bunged us off at 3,700 feet when we'd reached the SE face of the ridge. This height puts you just under the top of the ridge. We released in strong sink, but I got in close, really feeling the wind pushing me onto the ridge, and then we were in quite strong lift. A good 6 knots up and it was like an elevator ride - woosh, up we went and almost immediately I could see the people standing around the trig point on the mountain and on the track leading to it (there's a walking track up the mountain and being a Sunday, there were probably a dozen hikers on the mountain). We were above them so quickly in steady strong lift, that lasted well out beyond the western end of the ridge.


In three turns we were at 4,500 feet, so we turned upwind and did a couple of stalls (preceded by the HASELL checks). The stalls were no problems at all, losing only a couple of hundred feet in all, then we pointed back to the ridge to get back the height.


There's something special about being on a ridge - you're close to the topography, which is always exhilarating, there's the strong constant lift that's exciting, and you can see and wave to people on the ridge below (or often on the same level) and imagine how you look to them.


After gaining our height back, we pointed out again for some practice in sideslipping and maximum rate descents. I'd not done sideslipping before so deliberately. I was conscious of the theory and the technique, and had done a little almost intuitive sideslipping on approaches with a crosswind component, but I'd been eager to learn them properly. We did several, rudder over, then ailerons to the reverse direction. The airspeed indicator is entirely unreliable in a sideslip, as the air is travelling across the sensor, so you have to be alert.


We also did a maximum rate descent, combining full airbrakes with a sideslip. Man, you can shed some height quickly that way - useful to get out of unwanted lift.


Back to the ridge for another couple of passes to regain height. I took a couple of photos - the lake was looking beautiful and I managed to get a shot over my shoulder of the end of the ridge.


Then back out to try a couple of wingovers (Tom did these) - nice! Nose down to get about 75 knots, then up and drop a wing at the top. One each direction - brilliant!


After this, things got interesting. We heard on the radio Lima Sierra, the privately-owned vintage Ka-6, getting a tow, requesting to be dropped off at 4,000 on the same part of the ridge as we were. There was a radio call from the towplane soon afterwards, that he was downwind to land, so we started to look out for the Ka-6, which we were expecting to see around our height and close by.


However, no sight (and it's a brightly-coloured aircraft - there's a photo of it in an earlier blog entry) and Tom called up the Ka-6 and Centennial Traffic to find out his position. Centennial Traffic reported that no other aircraft was up, and that the Ka-6 had aborted takeoff at 200 feet and was almost back in the hangar! Apparently, it was starting to get very gusty and windy at the field and the light Ka-6 had got seriously out of shape very soon after takeoff. The pilot had bunged off at 200 feet, done a fast turn and put it back on the ground.


Very soon after this Centennial Traffic called up to say they were suspending operations due to strong crosswinds that had quickly built up. Time to go back!


I headed us back to the field, around the eastern side of the mountain. In front could be seen thermals over ploughed fields, lifting plumes of dust, which were beiing strongly blown sideways at about 100 feet. There was strong lift out there, but also strong winds.


I positioned us downwind for 06, but we had lots of height and patches of strong lift meant we needed a different plan. I pushed out further downwind from the field to lose height, but there was even stronger lift out here.


Tom, looking at the windsock standing straight out on the field, and considering the cramped 06 approach, decided on a mid-field approach to 22 to get down quickly and safely, as it was clear the wind was only getting stronger and our approach, wherever it was, would be in rotor from Mount Tahuara (as we were directly downwind of it and needed to move upwind to the field).


Tom took control and we headed perpendicular to the field, passing through some strong turbulence off Tauhara. I took a short video (link below), and even holding with both hands it was impossible to hold it steady. Check out the video to see how bumpy it was. I could feel Tom working the brakes and rudder pedals like mad.


We got close and low, before Tom turned us onto runway 22, about halfway down it's length. With what looked like gusting 25-30 knot crosswinds, he had lots of speed in hand and we were approaching at a good 75 knots. Tom kept us in a long float and we touched down and stopped just short of the clubhouse. An exhilarating landing and I learned a lot in that few minutes.


A 39-minute flight (brings me to 9 hours 40 minutes total from 49 flights) and an exciting day.


The wind built to the extent that lots of strength was required to put away the gliders, and the towplane even tried to fly onto the fueling tractor! It actually rolled forward into the wind - very strange, but the folk looking after the pre-packing away fueling were able to hold it until it was chocked.

video