FLATLANDS OF THE MIDWEST AND THE HIGH PLANES AREAS
Between the Appalachians on the east and the Rockies on the west lies approximately one half the area of the United States. Most of this sections east of the Mississippi River consist of rolling country with much of the area west of the Mississippi consisting of wide expanses of flat, level country with an occasional outcropping of rough terrain such as the Boston Mountain of Arkansas, the Ozark Plateau in Arkansas and Southern Missouri and the other similar areas. From Kansas City westward through the eastern third of Colorado the terrain gradually slopes upward on an average of about seven feet per mile from approximately 700 feet to 5,000 feet. In order to maintain the same altitude above the terrain over this route it would be necessary to gradually increase your altitude. This is rather deceptive because the terrain is so flat and the increase is so gradual.
Because much of this area does consist of flat country, many pilots may take flying here to much “for granted”. However, you must remember that is it often the “unloaded gun” that does most of the damage. You may have tendency to be less alert and this should never happen regardless of the type of terrain over which you fly. A pilot who does not remain alert at all times while in an airplane (on the ground or in the air) is nothing but “an accident waiting to happen”.
Experienced pilots tell us that terrain flying is at its best throughout the Midwest. Cultural features on the surface are numerous without being too congested and confusing to the VFR pilot. Terrain is mostly flat and, above all, the True north-south, east-west lines of the earth are plainly visible to the pilot in the form of “section lines” fence lines, and secondary roads in most areas. If the pilot will remember this and compare the TRUE COURSE he wishes to make good with these lines, a simple check is offered to make certain his track over the ground is correct.
A pilot can check the accuracy of his magnetic compass while in flight. When the airplane is aligned parallel to one of the section lines, the compass should read the true direction of the section line minus easterly variation. In this case we are assuming no deviation.
If the pilot will turn the chart so that the north-south lines on the chart are parallel to the north-south section lines, he will have an accurate picture of the direction his desire track should be. He will be looking along, in the direction of, his course line and details below him will then fit the chart more clearly.
However, there is always exception that spoils the rule or else serves to emphasize it. There are a few small areas in the Midwest and West where, for some unknown reason, these section lines do not correspond with the true north. Caution should be exercises so that the accuracy of your compass is known and these section lines disregarded when noted.
In general, visibility in the Midwest is good (expect around the large cities) and a pilot using terrain flying can observe sufficient detail around hilton locate his position accurately. However, the flat appearance of the terrain can lead the pilot into trouble when ceiling and visibility are at minimums. Gradual increases in ground elevations when flying westward can force a pilot, who tries to continue on, to fly at lower and lower altitudes (above the terrain). There are many high radio and television towers that become hazard to flight under these conditions.
The Midwest is also a large area where the warm, moist air from the gulf and the cooler air from the north collide, making it an area where the weather can change in a short distance and violent thunderstorms form quickly. CHECK YOUR WEATHER CAREFULLY AND HAVE AN ALTERNATE AIRPORT IN MIND.
Flight planning is just as important to the VFR pilot in this section of the country as in other sections.
High winds are very common during the month of March and April often causing restricted visibilities from blowing sand and dust.
In many areas the pastures, or grazing lands, are usually the roughest and most rocky portions of the farm land. Holes caused by wild life are often present and often vot visible because of the grass that covers them. So in the event of an emergency landing it is better to land on the tillable soil if its dry. Corn and bean fields should be avoided because of the high ridges formed by the rows.
The Midwest has many small sod fields from which operations can be conducted safely under normal conditions. However, at times unusually high temperatures, aircraft performance problem associated with high density altitudes are present (previously discussed under the Rocky Mountain Region) which most pilots do not take into consideration at these low elevations.
In the Spring of the year (the last part of February to May), the temperature of the earth melt the snow from the bottom up, and what would appear to be a smooth snow surface may be hard crust with very soft sod underneath. This hard crust has caused an unusual number of accidents, especially in nosewheel-type airplanes.
Never take off with frost, snow, or ice on the wings, tail surfaces control surfaces. You may never get the airplane off the runway because of the loss of lift. When a takeoff is made through water or slush, at or near freezing temperatures, in an airplane with retractable landing gear, it is possible for the gear to freeze in the up position. Precautions should be taken to prevent this by lowering and raising the gear several times after the initial retraction and a safe altitude and airspeed have been reached. However, takeoff under such conditions should be considered only as an emergency measure.
Miniature tornadoes are discussed in the Desert Region chapter under the heading of “whirlwinds” or “twister”. The same phenomenon occurs quite frequently in the Midwest during the spring and summer months. They are often called “dust devils” in this area but, whatever the alias they go by, they are still to be avoided and the advise given for the Desert Region “twister” is still apropos.