DESERT OPERATIONS

Red Sea

Arabian Sea

Persian Gulf

Med. Sea

CaspianSea

IndianOcean

REFERENCES

FM 1-202, Environmental Flight

FM 1-230, Meteorology for Army Aviators, September 1982

FM 90-3, Desert Operations, August 1993

OUTLINE

• Desert Weather• Desert Flying

• Density Altitude• Sand • Hazards to Flight

DESERT WEATHERTemperature

• Max recorded: 136o F, (58o C). 160o inside a WW2 tank.• Minimum temperature in Siberian and Gobi deserts dive to -50o F (-45oC).• Day/night fluctuations reach as much as 72o F in the Sinai

Wind• Iran is known for its “wind of 120 days”. The wind blows almost constantly at velocities of up to 70 mph.• Sandstorms may develop to thousands of feet high and last for several days. They may form and stop suddenly.• Visibility may go from 30 miles to 30 ft. in minutes.

Precipitation• Lack of water is the most important single characteristic of the desert.• Annual rain fall may vary from 0 to 10 inches.• Severe thunderstorms may cause flash flooding.

ACCLIMATIZATION

• Significant acclimatization can be attained in 4-5 days

• Full acclimatization takes 7-14 days , with 2-3 hours per day of exercise in the heat.

• Acclimatization does not reduce, and may increase water intake

DESERT FLYING

DENSITY ALTITUDE

• Pressure altitude corrected for non-standard temperature.

• Altitude at which your aircraft will perform at.• As DA increases-------air density decreases

As we increase in altitude-----the pressure around us decreases» At sea level/standard day (15oC.)

29.92 in = 14.7 psi.» At 18,000ft = 7.0psi.

As temperature increases-----the density (thickness) of the air decreases.

(air molecules move further apart.)

DENSITY ALTITUDE

Sea Level

FL 180

DENSITY ALTITUDE

= Air Molecules

Effects of DA on aircraft performance?

Reduced horsepower (Torque) available.» As DA incr. - air molecules spread out - less air

going into the engine = less horsepower (Torque) being produced.

Reduced wing efficiency» Less air molecules acting on the wings to

produce lift.

RESULTS Increased takeoff roll Reduced climb performance (ft./min.) Increased landing distance (higher TAS,

higher GS) Decrease in the “excess power available” Aircraft response----more sluggish Deceleration effects (ability to slow down,

and not fall through)

What to do about it

Plan ahead-----ppc, understand how DA will affect aircraft performance.

ANTICIPATE!!!

Sand and the aircraft

• Engines/blades [blade erosion,wear on engine components(particle separator, filters,inlet and turbine blades)]» higher than normal oil temperatures

• Avionics» electricity will attract the dust» overheat of the black boxes» lead acid batteries more susceptible to overheating in

the desert

HAZARDS TO FLIGHTSandstorms

• Altitudes up to 10,000 feet• Near zero visibility• High winds

AIRCRAFT OPERATIONS

Engine TGT

High TGT during engine start

Avionics

High humidity can subject electronics equipment to malfunction due to corrosion

QUESTIONS??