Andermatt and Oberalppass

Andermatt is around 45km from the Heimat takeoff, so you can usually expect to be reaching this point between midday and 2pm.  You will almost certainly be on the south facing side of the valley at this time of day, to maximise benefit from solar heating, and it’s normal to continue along that side.  Crossing over to the north facing side is usually a response to adverse circumstances, but if you arrive here considerably later, when the sun has come round further, this may well be a reasonable option as your primary strategy even in problem-free conditions.

Five valleys meet up around Andermatt like the spokes of a wheel, so the airflow at ground level is often chaotic, but these complications can be avoided if you stay high (i.e. over 3000m).  Areas of convergence lift are not unusual, particularly with south overpressure, but these are generally an unexpected bonus rather than a factor to be taken into account in route planning.  A detailed explanation of the complex aerology of this region appears on the page covering landing here.  When cloudbase is so high that you have been able to track along the spine of the main ridge ever since the Furka, you should have enough altitude to be able to simply continue across the Schöllenen gorge to the peaks beyond, above any valley winds; otherwise, you will need to plan your route carefully and be prepared to adapt to circumstances.  On the positive side, there are four wind turbines at Gütsch, overlooking Andermatt from the north at 2300m, which indicate the wind speed and direction at that point, crucial to planning a safe and effective route through this area.

Valleys around Andermatt and location of Gütsch wind turbines (not to scale!), viewed approaching from the west

Valleys around Andermatt and location of Gütsch wind turbines (not to scale!), viewed approaching from the west

As you approach Andermatt from the Furka, you should try to determine what’s happening with the turbines as soon as you can.  Usually they will all be facing in the same direction and spinning at a similar rate; significant variation between different turbines may arise from thermic activity, positional effects, or a mechanical problem.  Clockwise rotation indicates that you are travelling with the wind, anticlockwise that you are flying against it.  So clockwise is safe (i.e. you are on the windward side of the ridge).  If that doesn’t stick in your mind, remember that the blades must stay upwind of the mast because they would encounter turbulence if they passed behind it!  However, a slow counterclockwise rotation may be caused by good thermic activity on the south-facing slope drawing in air from the north side.  As a rough rule of thumb, the speed of rotation of the turbines in RPM equals the wind speed in km/hr.  Expressing this in another way: each turbine has three blades, so if the mast is being crossed by a blade once per second, that indicates a complete rotation every three seconds, hence 20 RPM and therefore a wind speed of 20 km/hr.

On most good flying days, the wind at Gütsch will be coming from one of three directions:

  • Nil/very light & variable
  • Between south-east and south-west
  • Northerly

If you fail to stay high, different tactics are required for each of these regimes.

NIL/VERY LIGHT & VARIABLE WINDS

Airflows around Andermatt with nil or light wind conditions at Gütsch

Airflows around Andermatt with nil or light wind conditions at Gütsch

The yin of the nil/light wind scenario is the absence of any assistance from dynamic lift until you connect with a thermal, and the yang is the lack of concern about leesides.  As shown in the diagram above, the main area in which to find rising air in this situation is to the north of Andermatt.  I usually aim directly at the turbines, which are often the location of a good thermal, but my rather conservative attitude often inclines me to veer to the right, for the south-easterly facing slopes, as this route allows easy access to landing options if necessary.  However, I often see pilots taking a more committing line to the left, north of Gütsch, and getting stronger climbs there.

The track log below shows a typical route for nil wind conditions with base at around 3500m, average for good summer days.

Good route through Andermatt and Oberalppass in nil wind conditions

Typical route across Andermatt and over Oberalppass in nil wind conditions and average base (click here (and >>> to 85km) for ayvri visualisation, here for XContest details)

SOUTH-EASTERLY TO SOUTH-WESTERLY WINDS

Airflows around Andermatt with southerly wind conditions at Gütsch

Airflows around Andermatt with SE to SW conditions at Gütsch

It’s common to encounter a southerly regime when flying through this area, because these are the conditions which favour a one-way trip from Fiesch towards Chur, rather than staying in the Wallis for a closed triangle with a substantial into-wind leg.  If the breeze at Gütsch is over 20 km/hr, it’s important to stay well upwind.  I always go for the windward side in this situation, as I generally find a pleasant mixture of thermic and dynamic lift here, but it’s not unusual to see pilots diving into the leeside area behind the turbines and rocketing up.  However, failure to find lift here could leave you in deep trouble, as there are cables across the Schöllenen gorge, and a southerly flow – particularly if accelerated by the Venturi effect around the shoulder of Gütsch – could impede your ability to escape back into the main valley for your only decent landing options.  If there is a substantial southwesterly drift speeding you towards the Oberalppass, the lift on the south-easterly terrain on the way there is likely to be torn and scanty, so you will need to keep going to where there are slopes with a southwesterly aspect which force this breeze upwards.  Note that you should still expect a northerly flow at village level even when the wind at Gütsch is from a southerly quadrant.

The track log below shows a route in southwesterly conditions and high base.  I have included the section just before the Rhône Glacier to illustrate how it was unnecessary to pause for a thermal between there and Gütsch, due to the combination of buoyant air and a tailwind.  Note that (in contrast to the nil wind route above) I stay well on the upwind side of the ridge throughout.

Typical route along Urserntal, across Andermatt, and over Oberalppass in south-westerly conditions

Typical route along Urserntal, across Andermatt, and over Oberalppass in south-westerly conditions (click here (and >>> to 73km) for ayvri visualisation, here for XContest details)

NORTHERLY WINDS

Airflows around Andermatt with northerly wind at Gütsch

Airflows around Andermatt with northerly wind at Gütsch

This is far and away the least favourable situation, but also the least commonly encountered, as it’s more tricky to get through the Grimsel and Furka areas with substantial north overpressure, when it’s very important to maintain good height throughout the Urserntal. This is not only to avoid leeside conditions, but also because the easterly valley wind is strengthened, in terms of the speed of this breeze, the distance it extends along the valley, and the height at which it becomes a significant obstacle.  If you have insufficient height to reach the turbines, which are showing such a strong northerly wind that the slope in front of them is obviously out-of-bounds, then you will need to cross the Oberalppass on its southerly side.  In that case, it’s best to aim directly at Rossbodenstock, the mountain due west of Andermatt, unless you are really low, in which case the only way to remain airborne is to cross to Gurschen, the south side of the valley. Watch out for the gondola cables if you are slope soaring here! The dynamic lift may be so strong that you can easily get up from as low as 50m above the village, but this alone will not provide sufficient height for a transition across to Oberalppass, and pilots often get stuck at the crest of the ridge at around 2000m waiting for a decent thermal which never materialises.  In this situation, I have been able to get back into the game by maximising altitude and then gliding east to connect with a thermal tracking up a shoulder below Rossbodenstock, just above a farm at 1764m which often displays either a Swiss or yellow Canton Uri flag.  Obviously, this tends to work better later in the day.

Location of thermal below Rossbodenstock above farm displaying Uri flag

Location of thermal below Rossbodenstock above farm displaying Uri flag, viewed from crest of Gurschen ridge

The track log below shows such a flight in northerly conditions.  I lost a good thermal half way along the valley, and over-optimistically pressed on for the Mutzenberg thermal…..which wasn’t working.  That left me with only one option, as described above: crossing the main valley for some ridge-soaring at Gurschen, from where I could reach a thermal below Rossbodenstock, enabling a long slow climb to get back up high again, which ultimately was quite satisfying, but made for very slow progress in terms of xc distance.

Low route across Andermatt and Oberalppass in northerly conditions

Low route across Andermatt and over Oberalppass in northerly conditions (click here for (and >>> to 95km) for ayvri visualisation, here for XContest details)

If you are stuck at Gurschen but reluctant to try the low option at Rossbodenstock, and the windsocks and flags in Andermatt suggest that the valley wind is either so strong or changeable that you are apprehensive about landing there (e.g. because a southerly blowing out of the Gotthardpass is squabbling with the northerly from the Schöllenen), the safest option would usually be to fly back to Realp, or at least beyond Hospental (where the wind from the Gotthard feeds into the Urserntal). It is only likely to be turbulent at Realp if there is a westerly wind blowing from the Goms through the Furka Pass, or föhn.

If you need a low save approaching Oberalppass, the picture below shows the source of two climbs which I have encountered. The nearer of the two is usually quite smooth, but the farther one may well be turbulent, as it originates just before the pass itself, where wind can feed in to the main (east-west) valley from north or south.  Beware of the cables of the aerial skilifts  going up from Oberalppass to the foot of the cliff of the Schneehühnerstock, located between the two arrows in this image!

Cables and low save options just before Oberalppass