Instructing In The Sierra Nevada
by Bill Schroeder

Article reprinted from the August Issue of "Mentor Magazine"- The official publication of The National Association of Flight Instructors (NAFI)

While departing South Lake Tahoe at a high gross weight, the Cessna 177RG climbed about 50 feet and did not accelerate. The aircraft was observed descending before colliding with the trees, about ½ mile off the departure end of the runway. All four persons on board were killed. Weight and balance computations placed the aircraft over maximum allowable gross weight. The density altitude was computed at 8,493 msl. There was no evidence of mechanical failure. A review of the pilot's flight experience revealed he had operated at one high density altitude airport in the past, where he accomplished one takeoff and landing with a flight instructor.

The probable cause of the accident was the pilot's decision to take off from a high density altitude airport at an over allowable gross weight condition. Factors in the accident were the high density altitude, down drafts, and the pilot's lack of familiarity operating from high density altitude airports.

Accidents such as this are not rare in the high density altitudes of the Sierra Nevada Mountains. Pilots with little or no experience in high altitude operations regularly fly into the mountainous areas and find themselves unable to cope. Pilots with substantial mountain flying experience sometimes push the envelope and find themselves in critical situations that are difficult, if not impossible, to safely resolve. Based upon my 35 years of flight experience as a pilot, flight instructor and Civil Air Patrol Instructor/Check Pilot who lives and flys in the Sierra Nevada, I am always aware that if the proper training is not provided, pilots lives may be in jeopardy.

So, how do we teach new students to fly in this environment where aircraft altimeters sometimes read well over 5000 feet when the aircraft is parked on the ramp? The following are some of the critical areas that must be explored when instructing new students and giving instruction to licensed pilots who are not familiar with flying in the Sierra Nevada.

Weather

Weather can change very rapidly in the Sierra Nevada. Not only is weather created by frontal systems passing over the mountains, but weather is created by the mountains. Students have to be made aware of the fact that weather can change rapidly and that they must be able to watch for signs that indicate changing weather. For instance, during the summer, a build-up of cumulus clouds along a ridgeline can give advance warning of thunderstorms. In the winter, an increase in wind speed, a drop in temperature and a change in wind direction usually indicate a change in weather that will lead to rain or snow.

Standard weather reports are not as readily available due to the limited number of reporting stations in the Sierra Nevada. With the advent of AWOS and ASOS more weather information is available now than was in the past. But, still students must be taught that those stations are limited in what they can report. For example, an automated station may report that the sky is clear below 12,000 feet. However, the mountains surrounding the reporting station may be obscured, or there may be impassible weather on each side of the automated station. So, students have to be taught to obtain weather information from other sources such as a local radio station, California Department of Transportation, Nevada Department of Transportation or by calling a local law enforcement agency. By calling the airport direct the student can obtain first hand information about the weather and also learn if the runway is clear of snow and ice. Please refer to my web page for information on obtaining weather in the Sierra Nevada.

Turbulence

Turbulence is almost always a factor in mountain flying and must be considered when teaching students to fly. Most initial training flights should be scheduled in the early morning when the air is calm. Once students are capable of flying in calm air, then it is important to schedule flights later in the day so that they may experience turbulence and learn that they can control an aircraft in turbulent air. As students progress, they must be exposed to light, moderate and severe turbulence so that they will be able to judge their flying skills against the turbulence. However, it is up to the instructor to gauge whether the turbulence is of such a nature that it could be dangerous for the student pilot. For the comfort of the student, every attempt is made to have summer cross country flights begin in the early morning and complete by late morning. During the winter months, when there is no frontal activity, turbulence is greatly reduced, so that those flights can be scheduled later in the day.

Students must also be taught to expect turbulence, and down drafts in certain locations such as ridge lines, canyons and the lee side of the mountains. Students must be taught to approach ridges at a 45 degree angle so that if they encounter a down draft that overpowers their aircraft's capability to climb or maintain altitude, they can immediately turn towards lower terrain without having to make a 180 degree turn. The Sierra Wave can produce updrafts and down drafts extending many miles from the Sierra's summit. There have been times when it was extremely difficult, if not impossible, for an aircraft to climb out of the wave. And there have been times when it was almost impossible to descend due to the wave. Flight instructors must be extremely knowledgeable of the conditions that cause this "Sierra Wave" and be able to instruct students on its causes and characteristics. Glider altitude records have been set on the lee side of the Sierras utilizing the wave.

Ice, Snow and Frost

Students must also learn that moisture and low temperatures usually mean that ice will form and that, of course, can be extremely dangerous if it forms on an aircraft in flight. Many times during the winter an aircraft will be removed from the hanger and immediately frost will begin to coat the surfaces. We have to teach the students that all frost and ice must be removed from the aircraft before flight. If frost forms on the aircraft surfaces just after it is removed from a hanger, and it continues to form after being scraped off, then it is time to put the aircraft back in the hanger and schedule the flight for another time. It is extremely important to be sure that the student understands that any ice, frost of snow left on the aircraft will greatly reduce the ability of that aircraft to fly.

Students must also be taught to dry off all control surfaces prior to flight. The temperature on the ground may be just above freezing, but 1000 feet in the air, the temperature could be below freezing and any moisture will freeze causing the control surfaces to become inoperable.

In addition, instrument students must be made aware that flying over the Sierra requires higher minimum enroute altitudes. In the winter months, icing will be a problem if flight into clouds is anticipated. So, the flight instructor must have complete knowledge of the situation prior to instrument flight and let the student know that the flight might have to be rescheduled.

During the summer, the flight instructor must make the student aware of the high density altitude problems associated with the high MEAs, being that many training aircraft cannot maintain those required altitudes. Oxygen and the proper use of oxygen must be included in instrument training if flights are conducted over those routes.

High Density Altitudes/Weight and Balance

High density altitudes exist in the winter and in summer, but are much more pronounced in the summer when temperatures can reach as high as 90 degrees in some areas. At South Lake Tahoe Airport, 6264 feet msl, a temperature of 80 degrees and a barometric pressure of 29.85 can produce a density altitude of 9389 feet msl. A temperature of 80 degrees at Mammoth Lakes, field elevation 7128 feet msl, and the same barometric pressure can produce a density altitude of 10,431 feet msl. From the very first day of training, the student must be introduced to density altitude and the problems associated with it. And, they must be able to calculate density altitude and do so before every flight. It is a habit that must be developed from the very beginning of flight instruction.

The use of the KOCH Chart (refer to my web page for an example of that chart) becomes routine in assisting the student to determine aircraft performance in high density altitude environments. Aircraft performance must be determined prior to each flight.Students must learn that high density altitude effects takeoff and landing distances. But most importantly, they must learn that high density altitude effects climb rate. Many pilots not familiar with mountain flying do not give much thought to climb rate. They look at the performance charts and determine that there is sufficient runway length for lift off. But, they forget to determine their climb rate following lift off. At South Lake Tahoe and Mammoth Lakes, climb rates less than 500 feet per minute should be expected in most training aircraft when high temperatures exist. When it is determined that the aircraft will not climb at 300 feet per minute, the student must be taught to wait for cooler temperatures before attempting to take off and as flight instructors, we must adhere to this rule by example.

In addition to determining density altitude, students are required to perform a weight and balance calculation on each flight. A weight and balance form is made up that is specific to the training aircraft and copies are made so that the student can practice as well as work a problem before each flight. (Refer to my web page for an example of an aircraft specific weight and balance sheet) Again, this is for the purpose of developing a habit pattern. It is extremely critical, that in high density altitude environments, the aircraft be as light as possible for takeoff and within its center of gravity envelope. Students are given instruction in weight and balance at the beginning of their flight training and made aware of the importance of keeping the plane with CG limits. They are made aware early on in their training that most accidents occur when the aircraft is over gross weight or has been improperly loaded.

Another area that must be covered by the flight instructor is that of oxygen requirements. The rule is that any a pilot must use oxygen if the flight is over 12,500 feet msl for more than 30 minutes. I'll use 12,500 msl as an example to show that in a high density altitude environment, the requirement for oxygen may become evident at a lower indicated altitude. At an indicated altitude of 10,500 msl, barometric pressure of 29.85 and an outside air temperature of 50 degrees, the density altitude is approximately 12,400 feet.

High density altitude can effect the aircraft's service ceiling as well. In high density altitude situations, an aircraft with a service ceiling of 13,000 feet may be quite near that when it is flying at a much lower indicated altitude. Many times during instruction in slow flight, the aircraft is simply not capable of maintaining altitude at a full power setting. And, sometimes it is not possible to cross the Sierra summit due to high density altitudes. Students must be taught not to guess, but to calculate.

Night Flying

Flying in Sierra Nevada at night requires specialized training. Prior to commencing night flight training, the student must complete the instrument training requirement for the Private Pilot License. The regulations require a minimum of 3 hours of instrument training, but I often give more as night flying, especially on moonless nights, requires the student to refer to the instruments. After performing the ten required takeoffs and landings, I take the student on the night cross- country. Pre flight planning is so important and the elevation of every peak along the route is noted. Altitude is a pilot's best friend while flying at night. As most pilots who train in the Sierra also live in the Sierra, oxygen is usually not a problem. I do not plan student night flights above 12,000 msl.

When departing an airfield at night, I always insist on doing an overhead ascent until sufficient altitude is obtained to clear the closest terrain. When approaching an airfield, I insist on an overhead descent. So, the student is taught to fly to the beacon, turn on the runway lights, if there is pilot controlled lighting and then descend over the field and enter the pattern. This way, the student is assured of terrain clearance during the landing phase of the flight. Many of the airfields do not have a VASI system, so it is really important to develop the students skills at cross checking instruments, especially the altimeter and the position of the aircraft in relation to the runway. No solo night cross country flights are authorized during the training.

Emergency Operations Training

Students must be constantly made aware of suitable emergency landing locations along their route of flight. Flight instructors must routinely challenge the student by simulating emergency situations and evaluating the student's performance. Prior to a cross country flight, the instructor must review the sectional chart with the student and evaluate areas where an emergency landing might be made. The instructor's personal knowledge of the area is also important and must be included in the training. With extremely steep canyon walls along most of the Sierra Nevada range, an emergency landing on the top of a mountain is most preferred so that searchers have a better chance of seeing the aircraft. If that is not possible, then landing in a meadow or along a lake should be made. In addition, the student must file a flight plan with a Flight Service Station on any flight out of the airport area. An important note here is that many times, the aircraft radio can not be utilized to contact the FSS, therefore the student must either telephone the FSS or give them an assumed time off when they file their flight plan.

Speaking about cross country flight training, this is no place for the straight line GPS flight. In fact, students must be taught that when planning a flight in the Sierra they should expect that it will not be a straight line between to points. For instance, flying a straight line between Truckee Airport and South Lake Tahoe Airport will require that the flight be conducted over the deepest and coldest waters of Lake Tahoe. Many an aircraft that has flown over the center of the lake, lost power and crashed into the lake has never been recovered. And in those accidents, most occupants do not survive due to the cold water temperatures. I teach students to never cross the center of the lake. I teach them to take off from Truckee, fly over the lowest pass at Northstar and then over to Kings Beach. From there they should fly over the lake just to the south of Incline Village and over to the east shore. Then the flight should proceed along the east shore until reaching a Round Hill and then, proceed direct to South Lake Tahoe Airport.

The same goes for flying from Nervino Airport, north of Truckee to the Sacramento area. The student should be taught to fly south over State Highway 89 to Truckee and then over Donner Summit keeping Interstate 80 in site. The four lane highway makes a suitable landing site in case of an emergency.

Regarding emergency communications, it must be noted that at lower altitudes, below 9000 feet msl, it is difficult to reach ATC in the Sierra Nevada. Students must be taught to communicate on frequencies other than 121.5 in case of an emergency. The use of CTAF frequencies at nearby airports and the use of CTAF to communicate with other aircraft in the area may be the only way to let someone know about an emergency. If the student has a cellular telephone, I encourage them to carry it with them.

Students must be taught basic survival skills and be prepared for an emergency should it occur. Following a crash in the Sierra, it may be some time before search and rescue locate the downed aircraft and pilots should be prepared to spend some time on the ground. By taking a survival kit on each flight, the flight instructor sets the right example. Students are encouraged to obtain their own kit and take it with them on each flight. (See my web page for suggested survival kit contents)

Finally, most instructors that teach in the Sierra Nevada, make their training available to pilots who do not. By giving safety seminars to groups from out of the area, many pilots will have an opportunity to learn about flying in the Sierra Nevada. And from those seminars should come a number of pilots who wish to obtain training in mountain flying. I offer safety seminars and specific courses to assist pilots who want to fly into, over and around the Sierra Nevada Mountains. These courses require about 8 hours of training and incorporate ground instruction as well as flight instruction to several mountain airports.

Remember the crash mentioned at the beginning of the article. The pilot had only one take-off and landing at a mountain airport under the direction of a flight instructor. Those of us who teach in the Sierra Nevada know that one take-off and one landing does not give the pilot the training required to fly safely in Sierra. Students who learn to fly in the Sierra Nevada know that is true. I feel that if a student learns to fly in the Sierra Nevada, they will have the tools necessary to fly just about anywhere. This is because they have been taught to calculate, think and fly an aircraft in some of the most demanding terrain in the world.

And, just as the advertisement states, I do require that everyone I train watch "Mountain Flying" from Sporty's Air Facts series before the completion of their flight training.

Bill Schroeder instructs in the Reno/Lake Tahoe area. He holds a Master of Science Degree, ATP-ME, MEL, SEL, CFI and CFII. In addition, he serves as an FAA Aviation Safety Counselor and an Instructor/Check Pilot for the Nevada Wing of the Civil Air Patrol. He can be reached by e-mail at checkpilot@thegrid.net. You can go to his web site at www.flightsafetycounselor.com

© Copyright 2000 Bill Schroeder