Airports general

Factors in site selection

PROXIMITY TO OTHER AIRPORT
Avold interference with traffic patterns of other airports. Radii of airport patterns are as follows local, i mile to 2 miles : trunk ,3 miles, continental and larger, 4 miles instrument operations requires greater separation study traffic patterns and approach procedures in the crec.

FUTURE EXPANSION
Sufficient land available to buy on cotion to allow for economical development of master plon see pp 15-20 to 15-22

APPROACH CONDITIONS
Safety and dependability of operations are seriously affected by terrain or structures in aerial approoches. Thus, for airports requiring instrument weather operations, approach conditions become the most important single factor. See pp. 15-06 and 15-07

OBSTRUCTIONS
Practicability of removal of high buildings, stacks, power lines etc. Should de determined. Legal zoning steps should be taken to protect approach zones against future erections of obstructions. See approach standards, pp. 15-06 and15-07

VISIBILITY
Avoid known areas of frequent fogs and smoke, often found clong badles of water near industrial areas. Avoid lee side from prevailing winds.

VINDS
sites with prevailing winds from one or two directions may require runways in only one or two directions , thus reducing cost and taxiing time. See p. 15-14.

GROUND TRANSPORTATIONS
Site should be served by adequate and rapid ground transportation for passenger, freight, employees, and visitors. Generally an express highway is required for the large airport. Speed, allowable traffic volume, cost, and distonce from city are factors.

TOPOGRAPHY AND DRAINAGE
Belenced costs of grading and drainage shold be attained. Flat land may requirebexcessive arainage. Hilly land requires excessive granding. Investigate floods at valey sites destructive winds at elevated or exposed sites. Lock for sites slightly above level of flat country or on long easy slopes in hilly country. Avoild sites with high ground water level for which the necessery subdrainage will be costly.

SOILS
See p.9-19 for classification. E1 to E5 soils desirable. E5 to E12 usually require substantial base and subbase courses and may require expensive surface drainage systems. E13 is not suitable for subgrade.

KONSTRUCTIONS MATERIAL
Short heuls to deposits of E1 to E5 soils or stone quarries is important. Availability of bituminous plants, concrete plants, etc may be important.

ECONOMICS
Cost of land, constructions, utilities, and operations against the revenve that the airport will bring, should be studied.

RUNWAY LENGTHS
Increase besic length due to elevations above sea level and effective runway gradient. See pp. 15-55

FACILITIES
Study cots of providing sewer, water, gas, electricity, gasoline, telephone, telegraph etc,