Visiting Pilot Briefing

Posted by on April 11, 2020


Welcome to Mifflin County Airport (KRVL), located in the Big Valley (also known as the Kishacoquillas or Kish Valley) of central Pennsylvania.  This is a great place for glider flying: especially during the Spring and Fall, the many ridges here combine with northwest winds to produce world-class ridge soaring.  It’s also an excellent place for thermal soaring – indeed, first-rate thermal days easily outnumber great ridge days.

The airfield has been the site of many soaring competitions, and is a destination for pilots seeking everything from a ridge introduction to a 1000-km diplome.  The purpose of this document is to give the pilot new to this area some useful information about the airfield and the Mifflin task area.


Mifflin County Airport (KRVL) is located in central Pennsylvania near the small town of Reedsville, about 3 miles west of Lewistown, and 12 miles southeast of State College.  The airfield is at 819’ MSL and has a single paved runway 5000’ long, oriented 06-24.

A grass strip lies parallel to and just northwest of the paved runway for its full length.  This is often used by towplanes, and is acceptable for glider landings.

A paved taxiway lies parallel to and southeast of the runway for its full length; the taxiway connects with a ramp and fueling area; additional taxiways lead to several hangars and grass areas useful for parking gliders and trailers.

KRVL is rarely a busy airfield, and has a long history of successful glider operations.  You can expect that most local power pilots will have seen gliders before and may even know something of their habits.  They will expect you to be reasonably considerate of their needs as well – treatment they’ve grown used to from glider pilots.  Please pay particular attention to not blocking taxiways and especially the area around the fuel pumps.

The CTAF here is 122.7MHz. Towplanes will be on this frequency; radio-equipped gliders should be, too, when in or near the traffic pattern.  There is an AWOS (automated weather observation system) on the field; you can listen to its broadcast of current conditions on 123.85.  Also note the University Park AWOS broadcast on 127.65.

The three main airfield buildings are typically known as the Terminal Building (has toilets and a small pilot lounge), the Big Hangar, and (near the airport beacon) the Maintenance Hangar.

Glider pilots are sure to be interested in the Clubhouse, a post-and-beam building northeast of the Terminal Building that is home to the Mifflin Soaring Association.  Visiting pilots can join (short-term memberships are available) and make use of facilities that include bathrooms (with showers), a full kitchen, wireless internet access, a video projector, and a map of the task area.

Staging for launch

The common launch direction is southwest.  The staging scheme is for gliders to wait on the ramp until a towplane is available, then to push (one glider at a time) to the area where the cross-taxiway meets the runway; the towpilot maneuvers in front of the glider, and the towrope is attached. Other gliders remain southeast of the hold-short line until the towplane is either in the pattern for landing or taxiing out.

Glider pilots should have completed most pre-launch checks before the glider is pushed out – expect some strange looks if you plan on waiting to start your checklist until an idling towplane is in front of you, burning expensive avgas.

Launching southwest from the taxiway-runway intersection means about 3800’ of the 5000’ runway is available.  As this is plenty even with a modest tailwind, there’s no need to stage gliders at the runway end.

Should winds dictate a launch to the northeast, it will be necessary to stage at the southwest end of the runway.  Though it’s a long way from normal parking areas, there is also plenty of room here.

In all cases you must plan not to be closer to the runway than 200’ (the distance of the hold-short lines) until a towplane is inbound. When staging a glider, have a radio tuned to 122.7 so you can stay aware of traffic arriving and departing.


The most common tow pattern involves a left turn after a southwest takeoff, heading toward Jacks Mountain (the prominent ridge southeast of the airfield).  On a day with northwest winds, there’s little point in towing higher than a few hundred feet above the top of this ridge, which means a release about 1200’ above the airfield.  On a day with thermal activity, tows above 2000’ AGL are rarely called for.

If the wind is east through south, it might make sense to tow past the crest of Jacks Mountain, with the goal of using ridge lift on its east side.  It could also be worthwhile to look for thermals in the area of Seven Mountains (the high ground northwest of the airfield).

On a few days a year, the crosswind at Mifflin is enough to cause problems.  On a strong ridge day, there could possibly be a 20+ knot pure crosswind at ground level. This alone would be treacherous, but it can be accompanied by rotor, sometimes down to the ground. Experienced Mifflin towpilots (the only kind likely to be flying on such a day) have seen this enough to know it can be trouble. They may decide it’s no longer safe to tow.  If they do, you can be sure it’s a better plan to stay on the ground.

As noted above, use 122.7 Mhz during launch and when close to the airfield below about 4000’ MSL. Switch to 123.3 (for glider-to-glider comms) when clear of KRVL.


Left-hand patterns are used at Mifflin. You should have your radio tuned to 122.7 during landing, and make appropriate pattern calls.

Most landings take place on the main runway.  The goal is usually to roll to a stop at the cross-taxiway, as this makes it easy to then push the glider off the runway. It’s then important to move the glider southeast of the hold-short line; glider pilots on the ground should help with this, without being asked.

If you are landing to the northeast (or southwest, with a good headwind), this can be just a bit tricky: Glider pilots are typically used to short runways and have the (normally commendable) habit of touching down “on the numbers”.  With a long runway, this means it will take you a long time to roll to the cross-taxiway, and you may not make it all the way there – you’ll come to a stop in the middle of the runway and need some time to get clear.  Your plan should be to touch down at a reasonable speed about 800 – 1000’ short of your intended stopping point, which will make stopping at the intersection easy.

Note that there are lights along the runway and all taxiways.  You must be careful of these – they can make it tricky to roll safely from the pavement into the grass. When in doubt, stop on the runway and promptly push the glider clear of it.

If you don’t wish to land on the main runway (perhaps the pilot ahead of you didn’t manage to roll clear), the parallel grass strip northwest of the pavement is a good choice.  Avoid the grass areas southeast of the paved runway – they include too much sloping and uneven ground.

For gliders with wingspans of 15 m and under (whose pilots use reasonable care) either end of the taxiway is landable.  The lights here are 60’ apart, and a bit taller than those on the main runway – so take care to be on the centerline.

It’s worth noting that the airfield is surrounded by all sorts of excellent landable agricultural fields.  Bear in mind the old adage: “It’s better to land off the airfield than to crash on it.”


Not all flights end at the home airfield; here, this is often less of a problem than at many soaring sites:  Much of our task area has good landability, and the Big Valley is almost absurdly good (it’s probably not much of an exaggeration to say that at times of the year when crops are low the entire US cross-country glider fleet could land in this valley simultaneously, safely and with room to spare).

The fact that gliders fly – and outland – here a lot imposes some special requirements: Your first duty after landing, securing your glider and calling in, is to find the landowner and do your best to make him your friend.  You should apologize for the trouble and take great care to minimize damage to any crop (by preventing spectators from trampling it, for example).  A friendly, humble demeanor works best.

Much of the land in this area is owned by Mennonites or the Amish. They dress more simply than the “English”.  Some folks tend to look down on them as unsophisticated. This is a mistake – they are in fact hardworking and very sharp (two qualities required for success as a farmer).  They tend to be friendly, but will not tolerate a condescending or inconsiderate attitude especially well. They are devout, and will not appreciate profanity.  Try to come across as a reasonable person politely asking a favor, rather than as an arrogant stranger playing with his expensive toy.

Note that you may fly in this area only a couple of weeks a year, but many others pilots do too, and some live here.  If you treat a landowner badly, you can expect serious repercussions, as this can threaten the future of soaring in this area.  If you do have a problem (and not all problems are the pilot’s fault) be sure to make it known – there are local folks who may be able to calm troubled waters.


The Mifflin task area includes a reasonable number of airfields.  As it also includes a huge number of excellent farm fields, airfields are not as important as at some soaring sites.  But some local airfields have quirks worth knowing about.  See Mifflin Area Airfield Notes for details.


Airspace restrictions aren’t much of a factor when flying out of Mifflin County Airport.  The only Restricted Areas anywhere near here are R5802A near Harrisburg, and R5801 and R5803 near Chambersburg.  As these lie on the extreme southeast edge of the task area, they are unlikely to be important during tasks flown out of Mifflin

The University Park airport (KUNV) north of the town of State College is now a towered field surrounded by Class D airspace to 3500’ MSL (about 2300’ AGL).  Gliders wishing to pass through this airspace (e.g. when flying along Nittany Mountain) will need to contact the tower on 128.475 MHz.


The preferred place for “ablutions” is the Clubhouse building, which has first-class restrooms with showers. There is a toilet in the Terminal building; another is located in the maintenance hangar, and this one includes a shower.  Please be considerate of others who may wish to use these facilities.  As there are no professional cleaning services, please do your best to keep things tidy (which should occasionally include cleaning up mess you didn’t create).

Outlets for battery charging can be found in the Clubhouse (preferred) and the maintenance hangar.

You can’t drive for long in the Big Valley without encountering horse-drawn Amish buggies.  Please be quite careful around these.  They don’t move very fast – it may surprise you how quickly you come up on them.  It is acceptable to cross a double-yellow line to pass one, but use great care – it takes a bit of experience to judge this when other traffic is approaching (which you may not be able to see well) and especially when you have a trailer in tow.

As most people know, the Amish do not like to be photographed.  Please respect this.


Task Area Briefing

The Mifflin task area is huge – thanks to the Appalachian ridges, on a good day it extends roughly from Blairstown NJ to Tazewell VA (and beyond).  A comprehensive briefing could be the subject of a fair-sized book.

This discussion doesn’t range that far.  The purpose is to give beginners and pilots new to the area some idea of the possibilities for interesting flights reasonably close to home.

You might wish to have access to a mapping program such as GoogleEarth when reading these discussions: terrain depiction can be quite helpful to a pilot new to the area.

Jacks Mountain

This ridge forms the southeast border of the valley in which Mifflin County Airport is located.  It is the “local” ridge and deserves your attention.

In prevailing west and northwest winds, area glider pilots speak of running the “front” (i.e. northwest) side of a ridge.  On its front, Jacks Mountain is well shaped and high (the crest is roughly 1000′ above the valley floor), though it does have something of a “shoulder” along much of its length. It can be ridge soared from a point about 12 miles northeast of the airfield to near the town of Mill Creek, about 25 miles southwest. It works well along its entire length; the only gap is the one that lies about 2 miles east of the airfield near the town of Reedsville, and this is narrow enough that it rarely causes difficulty.

As noted above, the landability of the Big Valley is really good, another factor that makes Jacks Mountain one of the best “school” ridges anywhere.  The ends of the valley (especially the southwest end) tend to be a bit less flat and the fields there may require a bit more care of the outlanding pilot.  Yet the number of huge, wide, flat, smooth fields is impressive.  And since the Amish spurn electricity, the valley has fewer wires than would otherwise be the case (though you certainly still need to check for these).

When the wind is between about 100 and 170 degrees, the southeast or “back” side of Jacks Mountain is the place for local ridge soaring.  Its shape on this side is close to perfect, which means reliable ridge lift can be found even when the wind is modest (8-10 knots) or the direction is well off perpendicular.  And headed northeast, the back side of Jacks Mountain is soarable all the way to the Three Barns turnpoint – about 29 miles from of the airfield.  The only drawbacks to a “back side mission” on Jacks Mountain is that easterly winds are often associated with bad weather (e.g. low cloud, rain, poor thermals) and the valley you’ll be running along is not as friendly for off-field landings as the Kish Valley – though it’s not bad.

Stone Mountain

This is the ridge that forms the northwest boundary of the Big Valley.  It’s lower than Jacks Mountain, but still plenty high enough.  Its southeast side has a significant “shoulder” so it’s not as good as Jacks on a “back-side” day, but it still usually works well (and overlooks the excellent fields of the Big Valley).

On the more normal “front-side” day, you’ll be running the northwest side of Stone Mountain, looking at the Stone Valley.  This is undeniably scenic, but not nearly as friendly as the Big Valley – much more hilly and wooded.  Indeed, in the first 10 miles of the run from the Mill Creek area northeast along Stone Mountain, the landing options aren’t much.  For this reason, it sees a lot less glider action than Jacks.

At its northeast end things are better, and there’s even a grass airfield just west of the village of Mcalevys Fort.  But this strip (significantly uphill to the southwest) is not close to the ridge and isn’t easy to see – it might be worth scouting by automobile, if you’re planning to fly in this area.

Note that when flying the northwest side of Stone Mountain you “run out of ridge” about 4 miles west of Mifflin County Airport – the Seven Mountains get in your way.  At the point where you must give up ridge flying and either thermal up or head downwind into the Big Valley, you’ll be something like 1400’ above the airfield and thus should have little trouble getting home.

Seven Mountains

This is the name for the high ground northwest of the airport. It’s a mostly wooded area of jumbled ridges, much more often flown in thermals than in ridge lift (on many days these broad high areas tend to generate the best thermals).

For longer ridge flights, the usual scheme is to head northwest from Mifflin County Airport to Tussey Mountain (the ridge that forms the northwestern edge of Seven Mountains).  To do this involves crossing the Seven Mountains area, and this can be easy or quite challenging depending on the day. It should be clear that flying at low altitudes in this sort of area (where the distance you’d need to glide to reach a landable field can be considerable, and the route less than obvious) is not for beginners.

On a thermal day, it can be worth studying the Seven Mountains area with a view toward how to return from Tussey late on a ridge day, when thermals are dying.  Heading downwind, this is easier than it might seem, but once again some detailed knowledge of the area would be needed to make this at all comfortable at low altitudes.

Tussey Mountain

This ridge starts just east of the town of State College near the village of Boalsburg and runs about 75 miles southwest, past Spruce Creek, the Blair County airport and the town of Everett.  It has some gaps and wiggles on the way, and there’s a sort of “spoiler” sub-ridge along much of it, but is generally a good route, with mostly very good landability in front of it.

It’s important to note the way its orientation changes at Spruce Creek: the change in angle is approximately 30 degrees, from about 030-210 to 060-240.  Depending on the wind strength and direction, this can mean a significant change in the character of the ridge lift.

Nittany Mountain

This is the high ridge that starts northeast of the town of State College and runs about 30 miles northeast to The Bowl (the glider pilot’s name for the area southeast of the town of Lock Haven, where Nittany and Bald Eagle ridges come together).

To use Nittany Mountain on a ridge day, you’ll likely have to do the “Tussey-Nittany transition”.  You’ll need some thermal help to climb above Tussey before heading generally upwind to Nittany.

Once you’re on it you’ll find Nittany to be quite good, though it has a few small gaps toward its northeast end.  Except for the extreme southwest end, the fields in the valley are very good.  There’s a mile-long “wiggle” at one point that looks as if it could be trouble, but rarely is. Note that at its northeast end, you’ll not be flying the highest part of this ridge, but rather a lower, upwind section.

The Bald Eagle Ridge

This is probably the most famous glider ridge in the country, perhaps the world.  It’s the home of Ridge Soaring Gliderport and Eagle Field. Many record, Hilton Cup, 1000-km and Diamond flights have originated here.

The full Bald Eagle ridge runs from Williamsport southwest to Altoona, some 95 miles.  There’s a substantial change of angle along this route: at Altoona, the orientation is about 035-215 whereas at Williamsport, it’s nearly east-west.  The small change in angle at Lock Haven often makes this the most northeasterly point that can reliably be reached in ridge lift (which typically is due to west-northwest winds).

Despite its storied history, the Bald Eagle Ridge is not as friendly as many others.  It has some low areas, some troublesome gaps, and some stretches that are not very landable.

Prominent among the problems is the famous Milesburg Gap, about 7 miles northeast of Ridge Soaring Gliderport.  Lots of gliders have landed in this area over the years.  It doesn’t look formidable, but you’ll do well to be careful here, especially when headed southwest on a day with plenty of west in the wind.

The areas with landability problems include the dammed-up lake near Howard, the areas near the towns of Port Matilda and Tyrone, and the city of Altoona.

Dunning Mountain

This is the ridge that lies southwest of the Altoona Gap.  It’s not very high but is notably well-shaped and often provides an illustration of the value of this: it’s usually one of the best-working ridges anywhere. It runs about 18 miles, ending at the north end of the Bedford Gap.

Evitts Mountain

This ridge starts just downwind (southeast) of the Bedford Gap and runs about 30 miles southwest, to within about 7 miles of the city of Cumberland MD.  Some stretches are not all that high and rather close to some upwind terrain, but the shape is good and the ridge nearly always works well. 

The landability is not always great, but mostly a bit better than it seems: from ridgetop height, fields are within reach but not always in view (due to a low & close upwind ridge).

This ridge starts at The Wall, so named because the usual way to get here is to fly down Tussey and do a short upwind transition over a high, unbroken section of ridge.  Some care may be needed, but even a short thermal climb will make this work.

Raystown Ridge

This is probably the most spectacular – and intimidating – ridge in the Mifflin task area.  It’s not all that high but has a fine shape.  The essential feature here is Raystown Lake (the largest in Pennsylvania) that fills the valley upwind of the ridge. There are fields near either end, but in a 20-mile run the only landing place is the water!

This ridge is nearly always run from the southwest to the northeast.  It’s often the fast way home from Blair County airport or the Bedford area.  But you have no business here until you have a reasonable amount of ridge experience and are confident the wind is reliable. (The rule of thumb is that if Tussey is working well, this ridge also will be.)

The usual scheme is to thermal up near the Blair Country airport, then drop downwind to the Raystown ridge.  You need to get down on the ridge to be sure it’s working well before you leave the safety of the large cornfield at the southwest end of the lake – the last dry place to land.  From there it’s usually a fast run to the dam at the northeast end.  There’s a 2-mile-long wiggle in the ridge for which you should have some height in reserve, but it’s rarely much of an obstacle.

From the northeast end of this ridge, the best way home to Mifflin is either along Jacks Mountain or Stone Mountain.  The former is higher and thus may have stronger ridge winds, but will require a better thermal climb.  The latter is well shaped and has a slightly better orientation for a westerly wind, but (as noted above) its landability isn’t nearly as good.

Shade Mountain

This is the ridge that starts east of Lewistown and heads northeast about 25 miles toward – but not quite as far as – Selinsgrove.  It’s nice and high, though at its northeast end its slope becomes uncomfortably shallow at the top.  In general, it’s flown a lot less often than other ridges, and usually on days when reasonable help from thermals can be expected.

The valley upwind of this ridge is not bad, but can be lumpy in many areas and doesn’t come up to the standards of the Big Valley for landability.  There’s a small airfield called Snook near the village of McClure that occasionally does a good business in gliders that fell off Shade Mountain.

Blacklog Mountain

This is the ridge that starts south of Lewistown and heads southwest some 40 miles, past Orbisonia to a high point (known as Gobblers Knob) just west of Burnt Cabins.  From there, it’s usually easy to connect to other ridges near McConnellsburg.

This ridge is reasonably good along most of its length, though it has a few areas that need some attention (and often a bit of thermal help).  Landability is variable.  This is an interesting route, but not one especially well suited to beginners.

Jacks Mountain Extension

This is the ridge that starts south of the Juniata River, between the towns of Mill Creek and Mount Union, and runs about 12 miles to the town of Saltillo.  It’s much the same shape and height as the more familiar parts of Jacks Mountain, with an orientation that’s somewhat more favorable to a westerly wind.

The catch here is that the landability isn’t much – the valley to the northwest is narrow and mostly wooded.  You won’t run this ridge unless winds are reliable, and you’ll want to maintain enough height to glide to either end (the south end is friendlier) or to fields that lie southeast (downwind).

Woodward Ridge

This is the glider pilot’s name for the low and occasionally broken ridge that runs from the northeast limit of the Seven Mountains about 20 miles northeast to a point east of the town of Woodward.  It is much lower than most ridges in the area, has several small gaps, and doesn’t look as if it should be worth much.  But on a day when the wind is reasonably strong and not too westerly, it can work surprisingly well.

Landability is generally okay, but declines as you approach the town of Woodward (the fields are smaller there, and much more rolling).

Routes to consider

Northwest wind conditions

The ridge run up and down Jacks Mountain is almost mandatory for pilots new to this area.  It’s a great ridge, very scenic and with fewer landing worries than almost anywhere.  Don’t neglect the stretch that’s northeast of Mifflin County Airport, but take care that you don’t run too far along this, to where it is shielded by an upwind ridge.

The next step is to widen your horizons a bit on Tussey Mountain.  You must do the 10-mile upwind transition from the airport (probably in thermals across the Seven Mountains) but then you can look forward to interesting (and, depending on the wind, easy) runs down to Blair County airport and beyond.

Nittany Mountain is next – run it up to The Bowl.  If the day is good and you have the time, head upwind to the Bald Eagle Ridge, then southwest as far as Altoona.  From here, you can easily drop back to Tussey and then head northeast; when you return to your starting point, you’ve completed the “Alpine Tour”. If from Altoona you continue along Dunning Mountain to Bedford before dropping back to Tussey, you have the “Extended Alpine Tour”.

On a really good day, you can make Cumberland your southern turnpoint.  The most variety is had when you head down via the “front” ridges, then back via Evitts Mountain (or the reverse).  This is the “Grand Alpine Tour.”

West winds

When there’s a lot of west in the wind (often the case), the local ridges may become tricky.  You may need some thermal help to get to Spruce Creek (on the Tussey ridge) or to Mill Creek (on Jacks Mountain).  Heading southwest from either of those points, the ridge orientation is more favorable to westerly winds, and some good ridge action can be had.  Common destinations include Bedford, Cumberland and McConnellsburg.

North winds

When there’s a lot of north in the wind, the section of the Bald Eagle Ridge from Lock Haven to Williamsport works well (but note that Williamsport airport has a control tower).  You should also think about heading east.  Across the Susquehanna River are a whole bunch of ridges that run nearly east-west (the ideal wind direction is about 340 degrees) and see much less glider action than they deserve.

The river valley is an obstacle, though usually a manageable one.  The favored routes to the east follow the ridges (even in thermal conditions).  If you drop downwind to the beautifully shaped Tuscarora Mountain, you have easy access to a ridge route across the river: Buffalo Mountain to Mahantango Mountain (rather low, but one of the best ridges anywhere).

Because you’re downwind, you’ll need some thermal help to get home again.  In case you can’t find it, it’s reassuring that much of this area has good landability.

“Back-side” ridge conditions

Fair-weather southeast winds are rarer, but open up interesting possibilities. The best and easiest has been mentioned: run northeast along Jacks Mountain to the Three Barns turnpoint, then southwest to Mount Union (or past it).

If you’re lucky enough to have reliable southeast winds and decent thermals (a rare combination) there are lots of other possibilities.  The back sides of Stone Mountain, the Bald Eagle Ridge, some parts of Tussey Mountain, Nittany Mountain and a number of others are ridgeable.  Because this weather is unusual, few such flights have been done, so these routes are not well known.

Thermal conditions

Much that’s written about this area (including this document) puts an emphasis on ridge soaring.  Given what has been shown to be possible, this isn’t surprising.  But it’s fair to note that thermal days seriously outnumber ridge days, and many of these offer excellent soaring in their own right.

The Mifflin task area is friendly in good (and even so-so) thermal conditions.  Even when the wind isn’t strong enough (or from the proper direction) to produce ridge lift, the ridges still tend to focus and organize the lift, as well as providing high ground that gets better solar heating than the valleys.  With lots of valleys within reach (most of which have at least good and often excellent fields) landouts should not be a problem for pilots who use even moderate care.

One area that’s not visited on ridge days butis promising in thermal conditions is the Allegheny Plateau – the area parallel to and northwest of the Bald Eagle Ridge.  This offers vast amounts of well-heated high ground that not infrequently yields the best thermals around.  The catch is that much of this area is “boonies” – you’ll need to pay more attention to landability than elsewhere.