Sedona Pilot Briefing

Transcription

1 Sedona Pilot Briefing Sedona has incredible beauty and a scenic airport with some good airmanship challenges September 16, Jim Hergert & Valin Thorn The Sedona airport is one of the most scenic airports in the world. It has also been judged by some aviation publications as one of the top ten most challenging airports for aviators. With a little local wisdom, though, pilots can safely fly to Sedona and enjoy the beauty and its airmanship challenges. Many aircraft and pilots of all types fly safely to Sedona every year representing the whole gamut of aviation including training flights, high performance single and multi-engine aircraft, experimental home-built aircraft, air tour operators, business jets as large as Gulfstream G650 s, and various military aircraft. This Sedona Pilot Briefing is a compilation by the authors of the piloting insights and suggestions provided by many veteran Sedona pilots for newcomers to Sedona. The authors provide these insights in a spirit of assistance for fellow aviators to help them manage their aviation risks and safely fly into and out of the amazing Sedona airport. As with everything in aviation, each aviator must consider these insights and the influence on their aeronautical decision making in the context of their own experience, skills, the performance characteristics of their airplane, and the environmental conditions at any given time. The Sedona Airport Sedona is in the heart of Arizona and is known for its unique geology, natural beauty, world class hiking & biking, native American ruins, resorts, and metaphysical vortexes. There are around 10,000 year-round residents and about 3 million tourists visiting every year. The Sedona airport is located on a mesa resulting from millions of years of geological processes including plate tectonics and erosion that revealed a hill with a natural flat surface suitable for an airport. The airport rests on this mesa above the city of Sedona. The surrounding mountains and cliffs to the north and east are the exposed layers of the Colorado Plateau which ends just before Sedona, showing its colorful red, orange, and tan layers of rock created during the Paleozoic era over 250 million years ago. Here are aerial views of the Sedona area looking to the north. Sedona Area High Aerial View Looking North, Sedona Airport on Mesa In Middle Page 1 of 11

2 View of Sedona Airport Looking North The Sedona Airport runway 3-21 is at an elevation of about 4,830 ft MSL, is 5,132 ft long, 100 ft wide, sits on the mesa that ranges from 400 to 800 ft above surrounding terrain/city, and is also surrounded at a greater distance to the north and east by terrain higher than the mesa. Think of it as a very large and stationary aircraft carrier mostly surrounded by mountains and cliffs. Sedona Airport Operations The Basics The Sedona Airport is a non-towered airport where pilots coordinate air traffic operations amongst themselves on the Common Traffic Advisory Frequency (CTAF) of Automated Weather Observation Service (AWOS) is available on Runway Asphalt surface in excellent condition, resurfaced in ,000 ft aim point markers/blocks are now included in the runway s markings. Standard left-hand traffic to both runways 3 & 21 Traffic Pattern Altitude TPA o Low performance aircraft: 6000 ft (~1200 ft above airport) o High performance and turbine aircraft: 7000 ft (~2,200 ft above airport) Noise abatement: o The Sedona area is a noise sensitive region and no touch and go or stop and go landings are permitted. o Soon after takeoff, please reduce your propeller rpm by at least 100 rpm as studies and testing have shown significant reductions in noise for the first 100 rpm reduction in propeller speed. RNAV GPS Instrument Approach for Runway 3. This non-precision approach has very high Minimum Descent Altitudes (MDAs) because of the surrounding terrain s impact on acceptable missed approach pathways. Page 2 of 11

3 Take notice of the non-standard above airport traffic pattern altitudes and note they are not above ground level altitudes because they are relative to the airport on the mesa that ranges from 400 to 800 ft above its surrounding terrain. For example: On a one-mile final approach to runway 3, one will be flying over terrain that is 800 ft below the height of the airport. On a one-mile final approach to runway 21, one will be flying over terrain that is 460 ft below the height of the airport. So, the normal visual cues for altitude and speed will be different than seen at typical flat land airports and one must stay aware of this difference. Sedona aviators received significant help with the potentially misleading visual cues this unusual geography can present to pilots when the Sedona Airport in 2018 installed modern Precision Approach Path Indicators (PAPI) on both runways. Runway 3 s PAPI are set to a 3 degrees approach slope where runway 21 s are set to 3.5 degrees, because of the rising and high terrain to the northeast of the airport. Runway 21 s PAPI should not be used outside 2 miles because of insufficient terrain clearance. High Density Altitude At Sedona s high elevation there are four climate seasons though most of the year it is much warmer than the ISA standard atmospheric temperature of 42 deg F for its 4830 ft altitude/elevation. It is not unusual to have 7000 ft to 8500 ft density altitudes in the summer months. At these high density altitudes, true airspeeds can be up to 15% higher than the indicated airspeed. A 15% higher true airspeed results in about 32% more trajectory energy, 32% larger turn radius for the same bank angle, and about 32% longer landing rollouts compared to flight at near sea level density altitudes. Aviators should not rely only on the sight speed picture they are used to seeing at sea level airports to manage their airspeed and turns! As in all airport terminal operations, regardless of density altitude, check your airspeed indicator frequently in the traffic pattern, especially on the base turn to final and the final approach. Also, remember the airport mesa rests 400 to 800 ft above the surrounding terrain. So, don't just focus on the surrounding area when flying the pattern to judge your height above the runway fly the numbers, indicated airspeed, altitudes, and the PAPI lights when on final. Note that the PAPIs are guiding to an aimpoint about 1,000 ft from the runway thresholds which may set the touchdown point too far down the runway for some high performance aircraft. Page 3 of 11

4 Runway 3 The Easiest Landing Runway The approach to runway 3 is over lower elevation terrain and runway 3 is sloped uphill 1.9% which noticeably reduces runway rollout. The Sedona airport runway has a 92 ft difference in elevation from the southwest end to the northeast end -- runway 3 s threshold being the low side and runway 21 s threshold the high side. The key points -- runway 3 is significantly uphill and runway 21 is significantly downhill. In calm winds, flight operations normally use runway 3 for landings and runway 21 for departures. Pilots coordinate on the CTAF frequency to prevent collisions and it has worked effectively for many years without a collision. Given the challenges yet to be discussed in approach and landings to runway 21, local pilots will land on runway 3 even with some tail wind as much as 5 to 10 kts depending on the type of aircraft. Sedona Runway 3 Approach View Short Final The slope of the edges of the mesa are more gradual for runway 3 than runway 21 but, pilots can still expect a downdraft on short final with a headwind and with a tailwind they can expect an updraft. If one does not need the majority of the runway length to land their airplane, moving the touchdown point beyond the normal touchdown zone may help avoid this downdraft or updraft disturbance near the runway threshold. Regardless of the touchdown aimpoint strategy needed for one s aircraft type and wind condition, all aviators should be prepared for some quick and correct adjustments in power and flight attitude close to the ground. Do not hesitate to abort the landing and go around for another pass, especially if one is unlucky enough to catch a bad gust of wind at just the wrong time. Page 4 of 11

5 Runway 21 The Most Challenging Landing Runway Approach and landings to Sedona s runway 21 are the key reasons the Sedona Airport ranks as one of the most challenging airports in the USA. The traffic pattern to runway 21 takes aircraft close to the nearby mountains and cliffs. The close proximity of the rocks often motivates aviators to fly a tighter pattern than usual, especially high performance aircraft. This often results in arriving on the final approach course high and fast. Sedona Runway 21 Approach, Looking East The close proximity of the rocks and the high density altitude provides a higher sense of speed than at a typical airport. If pilots react to this higher visual speed awareness by slowing their airplane, they may get dangerously close to stalling their airplane, especially in a turn. Fly the proper indicated airspeeds throughout the approach and landing check the airspeed indicator or AOA indicator frequently! The typical winds that result in landing operations on runway 21 are usually from the south, providing a crosswind component and a necessary wind correction/crab angle on downwind and final. The proximity of the rocks makes pilots reluctant to apply the proper wind correction heading angle on downwind, with the likely southerly crosswind, which requires pointing the airplane s nose more directly at the nearby rocks to the right. This results in the downwind leg of the pattern drifting closer to the runway reducing the distance available for making the required turns to the final approach course without overshooting the runway centerline. This is compounded by the higher true airspeeds, resulting larger turn radii, and the southerly crosswind adding ground speed to one s base leg. So, it is not unusual for aviators to significantly overshoot the runway 21 final approach course. If one overshoots the final approach course, do not over bank the airplane or cheat the turn with rudder! These are the perfect ingredients for the classic base turn to final stall and spin fatal accident. If one overshoots the final, just continue the turn around to join the final approach course banks less than 25 degrees and the ball in the middle. One can always take it around for another approach if there s not time to get stabilized on final. Go arounds also have the benefit of a firsthand look at all the windsocks. Page 5 of 11

6 Given the preference for landings on runway 3, even with some tail wind, landings on runway 21 are likely because there may be a 10 kt wind or more, as previously noted usually from the south, so also a crosswind and often gusting. Notice in the image how much steeper the slopes of the mesa are near the approach end of runway 21 than runway 3. Sedona Runway 21 Approach View The southerly winds will also generate turbulence as they flow by the rock formations and they ll be felt on downwind, base and final. This can be disconcerting especially for newcomers facing Sedona s runway 21 challenges for the first time. With winds there will likely be strong downdrafts, proportional to the speed of the wind, near the approach end of runway 21 as the air flows up and over the mesa and then back down the north side. As suggested for runway 3, if the required landing distance for one s airplane permits it, move the touchdown aim point down the runway to help avoid this approach end downdraft and turbulence. If it s not already clear, an approach to Sedona runway 21 will also benefit by a steep approach, greater than 3 degrees, to the runway. This will help clear the downdraft area without sacrificing too much runway shifting the touchdown point. A slow, shallow approach, on the backside of the power curve is not recommended because of the lower altitudes, increased exposure to the downdraft, and the reduced maneuver response capability in that energy state. If one s airplane requires much of the runway s length and a touchdown point shift is not wise, be ready for quick aggressive adjustments in power and flight attitude as one flies through the downdraft off the approach end. For these situations, some additional airspeed on approach may be wise to provide more maneuver capacity in a sudden downdraft disturbance. Too much additional airspeed, though, will likely complicate things thereafter with the flare to touchdown. The extra speed/energy taken into ground effect will extend the distance to touchdown especially with runway 21 sloped significantly downward and the runway descending below the airplane at about the same descent angle as a normal flare to landing descent. The resulting delayed Page 6 of 11

7 touching down and increasing length of runway behind the airplane makes it very tempting for pilots to force their airplane to touchdown at higher speeds than normal, with its own resulting hazards. Patience is important. In such situations it is helpful to be reminded for a typical landing, the aerodynamic drag of the airplane takes out more than half the energy of a typical landing. So just because the wheels have not yet touched down does not mean that speed/energy is not being dissipated especially in a prolonged landing flare attitude. Once past the turbulence in the pattern and beyond the final approach downdraft zone, it is typical for there to be smoother winds on top of the mesa which usually comes as quite a relief. Don t relax at this point -- the challenges are not yet over Touchdown & Roll Out With any extra energy taken into ground effect and the sloping runway 21, it is not unusual to see airplanes touch down halfway down the 5100 ft runway. By this point most pilots, especially of high performance airplanes that need more runway for landing, are concerned and likely realize they should have taken it around for another approach. With the late touchdown and rollout now underway, they are all set up for the next challenge an optical illusion that makes it look like only 1000 ft of runway are remaining. In response to such a surprising sight, many aviators have locked up their brakes and blown out tires coming to a stop. The optical illusion is the result of a crest in the runway about 1,000 ft from the end of runway 21 that hides the last 1000 ft of runway when seen from some distance. To avoid touching down way down the runway and make a more informed decision to go around for another approach or not, it is good to have a clear landmark for a better idea of the runway remaining. There are signs at 1000 ft intervals along the left side of the runway showing runway remaining though they are often missed. The airport s restaurant, The Mesa Grill, is an easy to see landmark almost abeam the midpoint of the runway so about 2500 ft from either threshold. It is easily recognizable because of its large tilted roof. The restaurant provides a good reference for pilots to estimate where they will or have already touched down on the runway. If one is rolling down the runway and sees the restaurant off their wing, they know they ve got about 2,500 ft of runway remaining no matter what optical illusion they re seeing in front of them. Another important point is, as always, to not stop flying until one s airplane is stopped on the ramp especially for airplanes with low wing loading that are more sensitive to winds. Compared to typical flat land airports, Sedona can have all three windsocks, which are distributed along the length of the runway, pointing in different directions. One can be rolling out on the runway and see significant wind shifts and lose control if not applying the proper configuration to the flight controls for the changing winds. As is typical worldwide, flights in the morning with cooler more stable air make everything easier and more enjoyable. For arrivals in hot summer afternoons, be prepared for turbulent air and tighten your seat belts! One of the authors has hit his head very hard on the door frame of his Lancair IVP and lost his headset when he was sure his seat belt was tight enough. Page 7 of 11

8 Instrument Approaches The only instrument approach to Sedona is a non-precision GPS approach to runway 3. Runway 21 is surrounded by too much imposing terrain to enable an instrument approach. With the surrounding mountains and cliffs, the enroute minimum altitudes are high with lots of altitude to lose after the Initial Approach Fixes (IAF) and when turned on the final approach course. The MDA is fairly high because of terrain constraints on the missed approach procedure. Note that the MDA for Category A airplanes is only 460 feet below the 6600 ft crossing altitude of the final approach fix so it comes up quickly after the FAF. For Category C & D aircraft, it is essentially at the FAF altitude. Executing the GPS Rwy 3 approach and circling to land on runway 21, in IFR weather, carries even more risk than a typical circling approach. Attempting a circling approach to runway 21 at night, even for an experienced Sedona pilot, would entail considerable risks not recommended! Instrument Approach Plate for Sedona Runway 3 in September 2018 Make Sure You Have the Latest One Page 8 of 11

9 Alternate Airports Should arrival conditions present unacceptable aeronautical risks, there are several nearby airports which may provide better landing options. Flagstaff KFLG, only 18 nm North, 8800 ft runway, rental cars, emergency equipment, and airline service. Multiple precision instrument approaches. Tower controlled. lt is about a 45 min drive to Sedona. Cottonwood P52, only 14 nm West SW, runway only 4200 ft but flat approaches so easier to touchdown near the threshold and utilize more runway, cheap gas, rental cars come from in town. One nonprecision instrument approach. Non-towered. It s about a 25 min drive to Sedona. Prescott KPRC, Love Field, only 33 nm SW. They have three runways, one 7600 ft on relatively flat ground. Multiple precision instrument approaches. Towered controlled. lt is more than a one hour drive. Airline service. Embry Riddle flight school with extensive training traffic. Takeoffs/Departures Don t forget about the high density altitude impact on takeoff and climb performance! Just as runway 3 is the preferred runway for landings, runway 21 with its downhill slope and with generally descending terrain on climb out is the preferred runway for takeoffs. Depending on aircraft type, takeoffs from runway 21 will be performed even with some tailwind. As mentioned before, it is routine at Sedona for pilots to coordinate dual runway operations takeoffs on runway 21 and landings on runway 3 -- in relatively calm wind conditions. Should the winds be strong enough to require departures from runway 3, uphill, pilots should be aware of the rising terrain and cliffs off the departure end of the runway. If insufficient airplane climb performance is available to clear the cliffs for a desired straight out departure, additional altitude may best be achieved by turning left and continuing the climb on downwind southwest bound. Flying up the Oak Creek Canyon to the north with marginal climb performance is not advised since it is rising terrain flying north toward Flagstaff. Descending terrain is to the south. Enroute Sightseeing Opportunities Arriving from the WNW, one can navigate around or thru Las Vegas airspace and fly over Hoover Dam, its new bridge, then continue next to some parts of the Grand Canyon (check the special Grand Canyon Airspace chart for restrictions, VFR corridors, altitudes) then Flagstaff Mountains. Arriving from the NE, one can fly over Monument Valley around Kayenta airport OV7, which is most beautiful in the morning shadow hours and then the Painted Desert. Continuing west for a low flight over Lake Powell is also amazingly beautiful. Page 9 of 11

10 Also from the EAST, a bit south of the above track, is the Meteor Crater, just west of Winslow, Arizona -- KINW. lt is great to fly over the crater circling to the right so passengers can see and take pictures. This is the largest crater in North America and the very best preserved in the World. A ground trip from Sedona is possible, about a 2 hr drive vs. a 15 minute flight. lt is about 35 nm east of Sedona. Additional Information For more information, check out the Sedona Airport website at: It can also be very useful for pilots to explore new and different airports using the Google Earth application and it s free. Be sure to enable terrain to see it in 3D perspective. Final Notes Sedona is one of the most beautiful places on Earth and has a wonderful airport for easy and fast access from distant locales. The airport also presents some unique aviation challenges that require competent and sometimes demanding airmanship knowledge and skills. Preparing for and overcoming the challenges aviation often presents is also one of the most satisfying aspects of flying. Remember, the normal visual cues will be misleading because of the unusual topography and high density altitude effects on speeds. Be aware and ready for the airflow up and over the mesa and the runway s steep slope. Fly the numbers, indicated airspeeds and altitudes. If the approach isn t looking good, a go around will likely be your best option. The authors hope sharing these pilot tips from local, veteran Sedona pilots will help fellow aviators better prepare and conduct safe flights to Sedona for years to come. Page 10 of 11

11 Comments, Suggestions, or Questions Contact the authors: Jim Hergert, Valin Thorn, Author Hergert s Lancair IVP Based in Sedona Author Thorn s Lancair Legacy StarHawk Set for Departure on Sedona Runway 21 Page 11 of 11