Mountain Checkout / Mountain Flying
Due to the unique set of challenges encountered, it's a good idea to do a mountain checkout before flying as PIC in the mountains, deserts, and other remote areas. WVFC requires a Mountain Checkout before members are allowed to take club aircraft into the mountains.
The outline below serves as a framework for a mountain checkout. The ground portion usually take approximately 2-4 hours, depending on your background and experience, and your success at completing the prescribed reading ahead of time. The flight portion typically takes all day, and includes approximately 5 hours of flight time. We usually get lunch at someplace interesting along the way.
It is best to do the ground portion in a separate session days in advance of the flight portion. You should schedule 2.5-4 hours for the ground session (depending on your experience), and a full day (0800-1900) for the flight portion. The day of the flight usually starts with a thorough flight briefing and a complete review — and possible rework — of the flight plan in light of the current conditions and forecast. Don't forget to bring the various recommended items (below) with you on the day of your mountain checkout flight.
Reading and References (read before ground session)
POH for your aircraft - Especially the chapters on performance (5) and Emergency Procedures (3)
Note: Some additional references (such as relevant videos) are included in-line, below. But these are more supplemental rather than fundamental, and are therefore not enumerated here.
Discussion Topics (for ground and flight sessions)
Aircraft Performance Issues
The trifecta of performance hits (due to thinner air as density altitude increases):
Thinner air ⇒ less power from engine (unless turbocharged or turbine)
Thinner air, less power ⇒ less thrust from prop
Thinner air, less power, less thrust ⇒ less lift from the wings
Climb rate reduced
Same indicated airspeed but higher ground speed for both takeoff and landing
Higher ground speed but with lower performance ⇒ greatly increased takeoff and landing distances
Density altitude (rough rule of thumb is to add 120 feet per 1 °C over standard)
Density altitude horsepower rule of thumb: A normally aspirated aircraft engine will lose approximately 3.33 percent of its horsepower for every 1,000-foot increase in density altitude. So at a density altitude of 7,000 feet, 25 percent of engine power has vanished.
Minimum required Rate of Climb (ROC) performance is a function of pilot skill level, relevant experience, and conditions. But a good guideline is to require at least 400 FPM expected performance at the airport elevation. If the performance charts predict performance less than this number, in the expected conditions, then you should plan for another day, time, or location.
Use POH and actual/predicted conditions to calculate expected performance
From the above data, you should note that the C182 has approximately 150' better ROC performance at any given altitude than the C172. This performance improvement translates to about 3,000'-4,000' feet of additional usable altitude (to meet the same minimum required ROC performance).
Also note that the C172SP has better climb gradient performance than the Cirrus SR20. The SR20 is not a good match for the mountains.
Make sure to use recommended leaning - often lean above 3,000-5,000 feet (for the C182T use the fuel flow placard per the POH)
Abort takeoff if unable to reach 70% of Vr by midpoint of runway
W&B / DA / fuel / performance
Spiral up if/as needed to gain altitude (plan for extra flight time)
Leverage orthographic lift
Larger turning radius due to higher ground speed
Adjust mixture for maximum power during run-up/pre-takeoff power check
Consider runway slope
Given in at least 4 different forms: degrees, percentage, gradient, ratio (be careful not to use the wrong units)
Even 1% is very noticeable, 4% is huge! (See O54 - Lonnie Pool Field at Weaverville, CA)
Consider both slope and winds for both takeoff and landing
Consider takeoff/departure before landing, especially at one-way in / one-way out airports
Flaps - alternate flap settings should be considered for both takeoff and landing:
Takeoff flaps offer more lift, but they also present more drag
In a high density altitude environment this additional drag saps the already limited excess power available
Takeoff flaps can result in a shorter takeoff roll but at the expense of a lower climb gradient
Consider runway length available vs expected climb performance
Consider a no flap takeoff if sufficient runway length is available
If you do use takeoff flaps retract them as soon as safe and practical to minimize drag and maximize performance
Make sure to use speeds appropriate for the chosen flap configuration
The use of full flaps can help reduce approach and landing speed and increase drag, thereby reducing landing runway requirements
But the use of full flaps reduces the excess power available (due to the significant drag) to overcome downdrafts or LLWS
Consider using full (or nearly full) flaps when landing on a short runway, as long as downdrafts and LLWS are not expected
Consider using only partial flaps to reduce drag and leave more excess power available to overcome downdrafts or LLWS, if sufficient runway is available
Consider an aiming point 1/3 the way down the runway if landing in the presence of downdrafts or LLWS, if sufficient runway is available
Make sure to use speeds appropriate for the chosen flap configuration (and appropriate corrections for gusting winds and LLWS)
Turbulence OK if < 20-30 kts, moderate if > 20-30 kts
Mountain wave if > 20-30 kts (can be indicated by a series of standing lenticular clouds) (rare photo of a mountain wave visible due to smoke)
Rotors / extreme turbulence
Up/down drafts (visualize and exploit updrafts, avoid downdrafts)
Venturi effect through passes and narrows
Gusts & LLWS (Low Level Wind Shear) (TRK - Truckee, runway 20 in particular)
(See winds, above)
Can obscure mountains and obstacles
Can change rapidly
Thunderstorms are common in the afternoons
Maintain a minimum of 20 miles from thunderstorms (greater distance is better)
Poor visibility - smoke/fog can settle into a valley/canyon
Box/narrow canyons (L05 - Kern Valley)
Cables and towers
non-standard airports, patterns, and approaches
Emergency / Rescue Issues
Airports and fuel stops can be sparse, plan accordingly
Few good emergency landing options
Tell others of your plans
Flight plan / flight following
You may be injured or on your own for a long time
If remote, stay with or near aircraft if able
Survival Kit / Emergency Gear
Communication/signalling is often your best bet for rescue, have multiple options available
Aviation handheld radio (121.5/guard for overflying aircraft even in canyons)
Cell phone (TXT, messaging, email, voice mail - use them all)
Tablet with cell service (same options as cell phone)
Strobe lights (aka "Electric flares")
Signal flares - pyrotechnic and/or smoke, may be difficult to find / purchase / maintain, See AC 91-58A for more details
Fire starter and kindling - to create smoke for signaling. See "emergency supplies", below
Bring emergency supplies
First aid kit
Food and water
Fire starter and kindling - How to build a campfire by NPR
Communications / signaling devices (see list above)
Extra power for electronic devices (cell phone, tablet)
Warm clothing and good shoes
Knife / rifle (Canada, Alaska)
Repair kit (duct tape, pliers, safety wire, etc.)
Poor Communication Issues
COM radios may not work
NAV radios (including GPS!) may not work
Cell phones may not work
Close your flight plan / terminate flight following while still in COM range
Climb if/as needed for COM/NAV
Bring paper (or pre-downloaded) charts just in case
Altitude and Physiology
Bring water and drink as appropriate to stay sufficiently hydrated
Visual illusions due to:
sloping or unusual terrain (PVF - Placerville)
narrow or ill-defined runways
higher ground speeds
Beware of fatigue - mountain flying is very demanding
Pre-flight briefing for each airport of intended use
For each airport of intended use (including possible alternates) read all available information, including chart supplement entry, ForeFlight comments and remarks, airport-specific web pages (often related to the local municipality), etc. You goal is to learn of any hazards, limitations, conventions, recommendations, reporting points, contact information, etc. relevant to each specific airport. In particular, be alert for:
Defer to another day if winds are > 20-30 kts.
Remember to bring your mountain go bag (emergency kit)
Remember to bring emergency clothing, food, water, etc.
Give thunderstorms a wide berth - usually at least 20 miles.
Fly at least 2,000' above nearby peaks when flying over mountains.
Cross ridgelines at a 45° angle to improve escape options when flying near the peaks.
Lean the engine to maximize power at altitude (non-turbocharged engines).
Compute density altitude - DA adds 120' for every 1 °C over standard.
Consult the performance section of your POH to verify performance under expected conditions. Determine climb performance and runway requirements for takeoff and landing.
Allow an additional margin of safety to account for sub-optimal performance of aircraft, pilot, winds, down-drafts, etc. (+20-50%?).
Abort takeoff if unable to reach 70% of Vr by midway point of runway.
Adjust airport pattern to avoid/compensate for terrain, box canyons, downdrafts, etc.
Learn/use canyon turn to maneuver/escape in tight canyons.
Always have a plan just in case you don't achieve the expected performance. (Eg, "On takeoff we're going to veer to the left around that hill if we don't achieve enough climb rate to climb over it.")
Learn/master short field landings and takeoffs.
Consider flap settings for takeoff and landings as appropriate for the situation
Make a reconnaissance pass of airport and runway before landing.
Departure often takes more runway than landing - check the numbers before landing.
Visualize the winds and airflow - when able, exploit updrafts and avoid downdrafts.