The White and Inyo mountain ranges are famous in the literature of soaring, and rightfully so. Where else in the world is it frequently possible to fly well over 100 km in an average glider, at Vne and just below 18,000 feet MSL, without stopping or turning?
Paradoxically, it’s sometimes difficult for visiting pilots to climb to the top of the Whites from their release altitudes. Over the years many pilots have asked about the techniques involved. The following is a brief summary of these techniques.
Unlike flying at most other soaring sites, it’s impractical to release near the ridgetops; the White Mountains are nearly 10,000 vertical feet above the airport at Bishop. Releasing at 2,000 feet above the airport means that there are still 8,000 feet to gain before finally cresting the White Mountains, a task that’s almost unique in US soaring. A further complication is that the Owens Valley between the Sierra and the White/Inyo Mountain chain is not only deep, but quite narrow. This means that early in the day, when a long cross-country flight is likely to begin, what light winds are present are likely to blow parallel to the valley axis rather than up the slopes of the mountains. In turn, both ridge lift and the upslope breezes that would otherwise trigger thermals are absent just when they’d really be helpful.
The solution is to look for situations in which anabatic flow is likely to be present. Anabatic flow occurs when the thin layer of air adjacent to the terrain is heated by conduction and flows upslope while still being heated by the surface over which it’s passing. This layer of rising air is generally too thin to be exploited by sailplanes, so long as it remains attached to the surface.
The lower slopes of the White Mountains feature numerous small peaks that are shallow enough on all sides to prevent the formation of shadows from 11:00 AM to noon, the time of day when a flight typically begins, and so many of these little peaks will have anabatic flow on all sides. When the air slowly flowing up the side of one of these little peaks reaches the peak, it can’t descend down the opposite side, because it meets the air from the other side, which is also rising anabatically. The only real possibility is for these airstreams to merge into a tiny thermal.
The technique for exploiting this anabatic flow in a sailplane is to make passes exactly as if ridge soaring, seeking out the little peaks likely to sprout these tiny thermals. These thermals will generally be too small to safely circle in and so the best technique is to try to “connect the dots” to the extent possible, combined perhaps with a little judicious dolphin flying, taking due account of the modest terrain separation you’ll probably have.
In this way you’ll slowly gain altitude which in turn will allow the temperature advantage of higher terrain to work for you. As you climb the thermals will become larger, stronger, and better organized. Sometime before it will become safe to circle in these thermals, you’ll find it advantageous to fly very short ridge passes, in effect to fly “Figure 8s,” so as to make best use of each thermal without prematurely committing yourself to completing a low turn into rising terrain. Ultimately it will become possible to safely circle in thermals, as usual, at which point there’s no longer any need to use any special techniques.
You might find that early in the day you’ll have to repeat this cycle once or twice on your way to the top of the Whites. reaching the top of a thermal at, say 10,000 or 11,000 feet, simply angle in toward the most promising nearby terrain within easy reach and begin making ridge passes again.
In summary, you’ll begin your climb using standard ridge soaring passes, dolphining where appropriate and safe, transition to Figure 8’s, then finally spiraling in thermals. Repeat as necessary.
Using this technique you’ll find that the initial climb to the top of the Whites takes only twenty minutes or so. This is quick enough that if your planned flight takes you out toward Tonopah, it’s easy to arrive there before good thermals have had time to form; that valley is notorious for late starting. Consider placing your first turnpoint toward the south end of the Inyo range: abeam Lone Pine, perhaps, or over Cerro Gordo. This will allow you to cover a fair distance while waiting for the Tonopah area to heat up for your arrival there.n
A reminder: as you climb, your density altitude, and therefore your turn radius, will dramatically increase! Always allow yourself plenty of margin and bear in mind that in the clear air above 10,000 feet MSL it’s extremely difficult to eyeball distances.