High Altitude Endorsement: pressurized aircraft and mountain flying.

FAR 61.31(g) requires a one-time endorsement to act as PIC of a pressurized aircraft operating above 25,000 ft MSL. Required for pilots stepping into turbine or pressurized piston aircraft.

Beyond the reg, mountain and density-altitude competence is something every Southern California pilot benefits from.

One of the few Southern California schools running a structured high-altitude and mountain program. Based at Redlands (KREI) because KREI sits at the doorstep to Big Bear City Airport (KL35) at 6,752 ft MSL and the San Bernardino range.

To act as PIC of a pressurized aircraft with service ceiling above 25,000 ft MSL, you must receive ground and flight training from an authorized instructor and receive a one-time endorsement.

Ground training (minimum):

• High-altitude aerodynamics and meteorology
• Respiration physiology and hypoxia
• Duration of consciousness without supplemental oxygen
• Effects of prolonged supplemental oxygen use
• Gas expansion and gas bubble formation
• Prevention measures for high-altitude sickness

Flight training (minimum): normal cruise above 25,000 ft MSL and emergency procedures for rapid decompression and emergency descent.

Logged in your logbook by the instructor. Good for the life of your certificate.

The pressurized-aircraft reg gets the headline. The day-to-day risk for GA pilots in the western U.S. isn't the flight levels. It's density altitude.

Density altitude is pressure altitude corrected for non-standard temperature. On a 95-degree summer afternoon at Big Bear (field elevation 6,752 ft MSL), density altitude routinely climbs above 9,500 ft. The airplane performs as if it were a mile and a half higher than the runway sign says.

Consequences: takeoff rolls lengthen dramatically. Climb rates drop, sometimes by half. Service ceilings shrink. A normally aspirated airplane that does fine at 1,000 ft on a cool morning is a different airplane at KL35 on an August afternoon.

Mountain weather stacks on top: mountain wave, lee-side rotor, valley winds, upslope and downslope flow, sudden visibility loss in canyons. The pilot who's never flown west of the I-5 hasn't had to think about any of this.

Real flights into Big Bear City (KL35), Apple Valley (KAPV), and surface-route navigation across the San Bernardino range:

• Density altitude calculation at planning. Performance charts, takeoff distance correction, climb gradient, accelerate-stop and accelerate-go.
• Mountain weather briefing. Mountain TAFs, area forecasts, lenticular signatures, valley wind patterns.
• Ridge crossing. 45-degree angle approach, escape valleys, never cross directly into a headwind.
• Canyon flying. One-way entry, when not to enter, recognizing terrain that closes around you.
• High-elevation airport ops. Lean for takeoff, short-field technique on KL35's actual runways, go-around discipline.
• Emergency descent. Required by 61.31(g). Good airmanship regardless.

Most students complete the endorsement and mountain orientation in 3 to 5 flights, 6 to 10 hours total, including a stay-on-field day at KL35 for multiple high-density-altitude pattern circuits.

• Pilots stepping into turbine or pressurized aircraft needing 61.31(g): King Air, Citation, TBM, Meridian, M600.
• Southern California pilots wanting practical skills to safely fly into Big Bear, Mammoth, Lake Tahoe, and the high desert.
• Career pilots wanting a credible high-altitude block before regional airline interviews.
• Cross-country pilots planning summer Rocky Mountain trips.

Big Bear City Airport sits at 6,752 ft MSL in the San Bernardino mountains, 30 minutes by air from Redlands. On any warm afternoon, density altitudes at KL35 climb past 9,000 ft. Real terrain. Real mountain weather. Real downdrafts on the lee side of ridges.

The 5,850-foot runway is long enough to absorb learning errors, so you can practice high-density-altitude departures with margin instead of on a 2,000-foot mountain strip. Once you understand energy management at KL35, the principles transfer to Mammoth (KMMH, 7,135 ft), Truckee (KTRK, 5,902 ft), and Telluride (KTEX, 9,078 ft).

High-altitude and mountain training is a specialty. Most Southern California schools never take their aircraft above 5,000 ft. We base mountain training at Redlands because the proximity to KL35 means we fly the scenario for real, not in simulation. The endorsement in your logbook reflects actual high-altitude operations and actual mountain flight.

Stepping into a pressurized airplane? We run a compact program that signs you off in a focused training block. SoCal pilot wanting practical skills? We run a longer program with multiple mountain airports and multiple weather scenarios.