HOMEWORK PHAK CHAPTER 10 JEPPESEN Chapter 8 section A GLEIM CHAPTER 5 5.1-5.6 ASA CHAPTER 8 8-21 TO 8-35 The next test will be 100% ASA

Private Pilot Ground School Class #7

Content of Lesson Meterlogical conditions and their effect on performance. Density altitude effect on takeoff and climb. Use of Various performance charts. Safe and efficient operation of aircraft

Meterological Conditions Weather greatly effects aircraft performance. Wind, Atmospheric Pressure, Temperature, Humidity all affect how an aircraft performs.

Terms Density altitude; measurement of the density of the air expressed in terms of altitude. Density altitude is pressure altitude corrected for a non standard temperature. High density altitude; a condition in which the air is less dense

High Density Altitude 4 things contribute to a high density altitude: 1. High field elevation Density altitude is increased by an increase in field elevation i.e. Seattle to Denver 18,000 feet atmospheric pressure is roughly halved

High Density Altitude 2. Low pressure system Density altitude is increased by a decrease in pressure Low pressure weather system = lower pressure

High Density Altitude 3. High temperature Density altitude is increased by an increase in temperature Spreads out molecules makes air less dense

High Density Altitude 4. High humidity Density altitude is increased by an increase in humidity A given volume of dry air is more dense than the same volume of moist air

High Density Altitude The atmosphere is 78% nitrogen 21% oxygen 1% inert gases Water vapor varies from almost none to 5% by volume Water vapor then displaces oxygen molecules

High vs. Low Density Altitude Hot, humid, high elevation and low pressure = High density altitude Cold, dry, low elevation and high pressure = Low density altitude

High Density Altitude Airplane effected several ways: 1. Wing is less effective 2. Propeller is less effective 3. Engine puts out less horsepower

Performance is effected High Density Altitude: 1. Rate of climb is lower 2. Time to climb is longer 3. Takeoff roll is longer 4. Acceleration is slower 5. Higher true airspeed means faster approach 6. Longer landing roll

So how can the pilot minimize the effects of High density altitude? 1. Leave in the morning when its cooler 2. Off load some baggage and or passengers 3. Make two trips 4. Take a higher performing aircraft

Continued 5. Lean the engine for more horsepower unless POH says not to 6. Do your calculations ahead of time and make the go, no go decision early. Do not let the people you travel with or Boss make you compromise safety

Density Altitude The primary reason for computing density altitude is to determine aircraft performance Remember Density altitude is Pressure altitude corrected for nonstandard temperature

Density Altitude It can be found 2 ways 1. Use the chart 2. Use the computer

Standard Atmosphere 29.92, 1013.2 millibars, 14.69 psi standard sea level 59 F or 15 C standard temp. at sea level

Computing Density Altitude 1st step: convert elevation or altitude to pressure altitude. can be done by setting 29.92 into altimeter or by subtracting 29.92 from the current pressure then multiplying by 1000 then either adding or subtracting from the current pressure value

Computing Density Altitude E.G. Field elevation 1185 pressure 30.55 29.92 - 30.55 - .63 x 1000 = -630’ 1185 + -630 = 555’ Pressure Altitude

Computing Density Altitude So the airplane thinks its flying at 555 feet because of the extra pressure 555 is closer to sea level than 1185

Computing Density Altitude E.G. Field elevation 1185 pressure 29.62 29.92 -29.62 .30 x 1000 = 300 1185 + 300 = 1485

Computing Density Altitude So the airplane thinks its flying at 1485 feet because of the decrease in atmospheric pressure 2nd step: Take the pressure altitude and the temperature at your elevation or altitude and follow the lines on the density altitude chart until they intersect.

DENSITY ALTITUDE CHART

Summary of Effects of Density Altitude (P153) Low-Density Altitude - made with Low temperature, Dry air and High Pressure High-Density Altitude - made with high temperature, humid air, low pressure.

Performance Charts Conversion charts Wind component chart Take-off distance chart Climb chart Time, Fuel and distance to Climb chart Cruise Power Settings Cruise Speeds Range/Endurance Charts Landing Distance Chart

Crosswind chart

B-19 CROSSWIND

DENSITY ALTITUDE CHART

Takeoff distance chart

Cruise Performance Chart

Landing Distance Chart

Landing Distance

Vy & Vx Vy=best rate of climb (most altitude over any unit of time) Vx=best angle of clime (most altitude over a given distance) B-19 Vy=72 knots Vx=65 knots

Maximum Range & Endurance Maximum Range=gives longest distance for a given amount of fuel. Maximum Endurance=gives you most time for a given amount of fuel.

PERFORMANCE #2

B-19 CHARTS Airspeed Calibration Altimeter Correction Crosswind Takeoff Distance Climb charts Cruise Landing distance charts BRING A CALCULATOR, B-19 MANUAL AND SECTIONAL CHART NEXT CLASS PLEASE

AIRSPEED CALIBRATION

ALTIMETER CORRECTION

CROSSWIND CHART B-19

Sample X-Wind problems Runway 18, Wind 210@25kts What is the headwind & crosswind components? Runway 22, wind 260@32 knots What is the headwind and crosswind components?

Sample X-Wind problems Runway 18, Wind 210@25kts What is the headwind & crosswind components? Runway 22, wind 260@32 knots What is the headwind and crosswind components? H.W. = 21.65 knots C.W. = 12.5 knots H.W. = 5.56 knots C.W. = 31.51 knots

Takeoff Distance B19

Takeoff Distance B19 Given Wind 0 knots, Temp. 7 degrees C, Pressure Altitude 2000 ft What is the Takeoff distance?

Takeoff Distance B19 1 degree = 1062 11 degrees = 1178 7 degrees = ? (you need to interpolate)

Takeoff Distance B19 1 degree = 1062 11 degrees = 1178 7 degrees = ? (you need to interpolate) 11-1=10 1178-1062=116 11-7= 4 116x.4=46.4 4/10 or .4 1178-46.4=1131.6

Takeoff Distance B19 1 degree = 1062 11 degrees = 1178 7 degrees = ? (you need to interpolate) 11-1=10 1178-1062=116 7-1= 6 116x.6=69.6 6/10 or .6 1062+69.6=1131.6

Takeoff Distance B19 What if the Pressure Altitude was 1000 feet instead of 2000 feet We have already solved for 2000 feet the next step would be to solve for sea level for 7 degrees C. 15-5=10 1030-930=100 15-7= 8 100x.8=80 8/10 or .8 1030-80=950

Takeoff Distance B19 (7 Degrees) Takeoff distance at 2000 feet Pressure altitude = 1131.6 Takeoff distance at sea level = 950 Last step is to interpolate for 1000 feet Pressure altitude 2000-0=2000 1131.6-950=181.6 2000-1000= 1000 181.6x.5=90.8 1000/2000 or .5 1131.6-90.8=1040.8

CLIMB CHARTS B19

CRUISE CHART B19

LANDING DISTANCE CHART B19