Leadville: “On Top of it All”
The Joy and Challenge of Flying in to (and Out of) America’s Highest Airport
The Town. Leadville (Elev. 10,200’) is America’s highest incorporated city. It’s a mining town: historically it saw stupendous hauls of silver, zinc, gold, and, yes, lead, and they still mine molybdenum today at the nearby Climax Mine. The city hosts the National Mining Hall of Fame and honors its mining history every year with its “Boom Days” celebration, complete with feats of mining legerdemain and even a competitive pack burro race.
But mining’s a volatile industry, and in the 1980s when the last mine closed (the Climax mine re-opened in 2012), miner-turned-runner Ken Chlouber (in the tux) reinvented Leadville as a high-altitude trail running and mountain biking Mecca. The town now hosts Chlouber’s successful annual Leadville Race Series, which culminates in a 100-mile mountain bike race and a grueling 100-mile trail run, each dubbed the “Race Across the Sky.” Ken, inducted into the Mountain Biking Hall of Fame in 2018, fires a shotgun to start and end every race. Finishing all the races in a summer earns you a mining axe and the honorific “Leadman” (right, buddy Shane Merz with his coveted axe).
It’s this race series (off-topic exploits here) that’s kept us flying in and out of the Leadville airport in the summers.
The Airport. At 9,934 feet above sea level, Leadville-Lake County Airport (KLXV) is North America’s highest airport. The airfield sits at the north end of the Arkansas River Valley, at the headwaters of the Arkansas River, surrounded by the 14,000’+ Mosquito Range to the east and the 14,000’+ Sawatch Range to the west and north.
Parked at the Leadville airport, you get a magnificent view of the two highest peaks in Colorado: Mt. Elbert (a.k.a. the “Gentle Giant” for its relative hikability among Colorado 14-ers) and Mt. Massive, so named for its enormity, with 5 summits above 14,000’. Because there’s only 10 feet of height between them, rumor has it fans of Mt. Massive can sometimes be found piling rocks atop its summit to create the highest point in Colorado….
For some, the Leadville airport’s elevation is a business draw: Bell Helicopters, Sikorsky and others routinely use the field for high-altitude testing. The Colorado Army National Guard High-Altitude Aviation Training Site frequently uses KLXV to train multiple branches of the military to safely conduct high-altitude flight operations. For others (like us) it’s a challenge and a learning opportunity.
Flight from Houston. One amusement of flying from Houston (KAXH) to Leadville is that, unlike most other cross-country flights, you never descend. In a Beech Bonanza, at least, you depart Houston, climb to 10,500’ and, 900 miles later, you’re on final approach to Runway 34 at Leadville. The ground rises to meet you. Here’s a sample flight profile:
Before you get to the Rockies, though, the route from Houston to Leadville takes you right over the Royal Gorge, one of the deepest canyons in Colorado and home of America’s highest suspension bridge. It’s not marked on a sectional map, but it’s just west of Cañon City and Fremont County Airport (1V6). The gorge is quite a sight: some call it the “Grand Canyon of the Arkansas River.” But don’t dawdle. In the summer, you’ll want to be on the ground before the mid-afternoon mountain winds kick up in the Arkansas River Valley.
Approaching Leadville from the south is a picturesque flight following the Arkansas River upstream, with 14-ers to the west and east. If you’re flying on a windy afternoon, the leeward side of the valley (usually the east) often offers a smoother ride.
About 30 miles south of Leadville, the route takes you over Central Colorado Regional Airport (KAEJ), elev. 7950’, in Buena Vista, CO. The first summer we visited the town of Leadville, we weren’t so sure about flying into its fabled airport, so we landed in Buena Vista (2000’ lower) and drove the short rest of the way. The flight and take-off performance at KAEJ’s lower and longer (8300’) runway gave us confidence to go all the way into KLXV the next trip. But be warned: if you decide to stop in Buena Vista, don’t make the mistake I did: it’s uniformly pronounced “BEW-na Vista.”
As an aside, approaching Leadville from the north (as my wife and I’ve done flying from Sun Valley, Idaho (KSUN)), is a whole ‘nother story. The mountains are spectacular, but if you don’t want to buzz the cars on Route 24, bring some oxygen or a turbocharger, because Tennessee Pass at 10,424’ is as low as it gets until you’re over the field. Once you’re through Tennessee Pass and land, though, head over to Tennessee Pass Cafe, arguably the best restaurant in Leadville. Get the flash-fried brussels sprouts and the buffalo burger.
Here’s Runway 34 at Leadville, looking north at the end of the valley. Unlike Telluride's KTEX, the terrain immediately surrounding the field is unimposing. It’s the altitude that makes KLXV special.
The Altitude. So what’s the big deal about a high-elevation airport? For the same reasons altitude affects physiology, farming and even baking, it impacts aviation. Basically, higher (and hotter) reduces plane performance. As every student pilot’s taught, lower air pressure at altitude dampens engine combustion (less air to mix with fuel), reduces the efficiency of propellers, and reduces the lifting force generated by wings. None of that is unsafe — you just have to plan for it. When you combine high altitude with the additional effect of high temperatures at altitude in the summer (a concept called “density altitude” — think “effective altitude”), the impact can be dramatic.
Taking Off. How dramatic? In Leadville, about 3x. At sea level (Houston) on a (rare) 50-degree day, a fully-loaded A-36 Bonanza with a Continental IO-550 engine should (at 29” MP and 2700 RPM) develop almost its full (100%) 300hp, lift off in about 1300' of runway, and clear a 50’ obstacle in 2150’. In Leadville, that same Bonanza, also at 50 degrees (a typical summer temperature at 8 a.m.), makes about 63% power and needs ~3 times that distance: it’ll use 3600’ to lift off and a disconcerting 6600’ to clear a 50-foot obstacle. And those are the book numbers, which are usually impossible to achieve. I know from experience it takes more than 1300’ to get a fully-loaded Bonanza off the ground at sea level. I haven’t been foolhardy enough to try to launch a fully loaded Bonanza from Leadville to see if the 3600’/6600’ numbers are realistic. After all, the Leadville runway’s only 6400’ long.
Here’s the National Weather Service’s overly dramatic diagram of the effects of high density altitude. And they’re worried about a lowly 5,000 feet! The good news for the NWS is that no 747s take off from Leadville.
But the massive C-130 Hercules does. Watch it use every foot of the Leadville runway taking off on KLXV’s Instagram here (This link takes you to the C-130’s low pass over Leadville. Swipe left for the take-off run video.) That’s precision flying.
I’d never cut it that close. On a summer morning, a lightly loaded Bonanza (2 people, a pair of mountain bikes, light luggage and enough gas to easily get to Dalhart to refuel) will lift off about halfway down the Leadville runway, just shy of 3000’. That leaves a lot of margin for error. And leaving Leadville, you don’t need much climb performance. As co-pilot Jeff Cotner and I joked just before our first take-off from Leadville: all you have to do is get the plane 50’ in the air and you can safely fly to Houston. It’s the opposite of the profile above: the ground falls away below you.
So, what are the pilot take-aways on Leadville take-offs?
In the summer, don’t wait until the afternoon to take off. On a typical 72-degree summer day, the airport’s density altitude is 13,000 feet! As John Denver exclaimed, that’s “Rocky Mountain High!” Instead, leave in the morning, when it’s cooler (we’ve scraped frost off the wings on August mornings) and the air’s denser. Leadville summer mornings are usually calm and you’ll have your choice of runways: choose Runway 16, pointed south down the valley.
Abide the 50/70 Rule. On your take-off roll, if you’re not at 70% of your rotation airspeed by the time you’re halfway down your expected runway takeoff distance, abort and rethink your plan.
Don’t overload! As much as you want to support the awesome folks at the Leadville FBO, they’ll understand if you don’t buy enough gas to top off your tanks before take-off. Buy a KLXV t-shirt instead!
Lean! Us flat-landers almost unconsciously firewall the throttle and mixture for take-off. Do that in Leadville (in a non-turbocharged plane) and your engine will quickly flood and sputter, if not quit (and this is true on take-off, go-around, or landing). Know how to lean your engine’s fuel mixture properly. We cross-check these two methods in Leadville: (1) full throttle with the hottest cylinder reading 50-100°F rich of peak on the EGT gauge and (2) max cruise performance for 10,000’ (from charts), then prop full forward (fuel flow will increase slightly), then add a pinch more fuel for cooling (~1gph). In our A-36 IO-550 Bonanza, full throttle take-off power in Leadville on a summer morning is ~19” MP leaned to ~16 gph fuel flow. Always double-check your analysis/calculations with a full-power (for this altitude) run-up. Doesn’t sound like much power, I know, but it gets us in the air and headed home….
Land early, too. Try to keep landings to the morning, too. Mountain winds aren’t unique to Leadville, but afternoon mountain winds can be wicked and often don’t mix well with substantially reduced climb performance and proximity to the ground. An old adage: a mountain flying pilot’s lunch always includes a cold beer, so he or she won’t be tempted to go fly the mountains in the afternoon!
Start carefully. Finally, with the thin air, treat every start as a flooded start. One Leadville old flyin’ hand joked to us that he purposefully floods his engine every start so he’ll know just what to do.
Other Surprises. Of course, most of what’s set out above applies only to normally aspirated (non-turbocharged) piston engines. But Leadville has surprises for others too. For example, many pressurization systems voice an audible alarm if the cabin pressure nears 10,000’. That’ll probably happen as you set pressurization to land at KLXV, so expect it (and warn you passengers it’s coming!). And think twice about enriching your mixture for landing, regardless of what your flatlander checklist says, even in a turbo-charged plane, because you might find yourself stranded on the runway with a flooded engine after your otherwise successful landing. No matter what you’re driving, the Leadville airport is no place to be complacent…
Flying into and out of Leadville can be dangerous – it’s not a forgiving environment. But Ken Chlouber’s Leadville Race Series motto — "You're better than you think you are, you can do more than you think you can" — applies to KLXV as well. Any decent pilot can fly in and out of America’s highest airport — it just takes advance planning, preparation, and judgment. Once you’ve done it, you’ll thank yourself. Not only is the flying epic and the town full of adventure, but you’ll have earned a certificate — proudly presented by the FBO — attesting to your “elevated” prowess….
Give Leadville a go!
NOTE: ABS Magazine, the monthly publication of the American Bonanza Society, published a version of this article in its October 2020 issue. To read or download the ABS Magazine version, click this button:
