WINDS
Rule of Thumb--trees
Calm smoke is vertical
1-3 kts smoke drifts with wind
4-6 kts leaves rustle, you feel wind
7-10 kts leaves in motion all the time
11-16 kts Dust & paper move
17-21 kts Small trees move, waves have crests
28-33 kts Trees sway, wires whistle
34-40 kts Branches break, difficulty walking
41-47 kts Signs fall
48-55 kts trees fall, damage
56-71 kts DAMAGE
Wind Correction Angle
Divide crosswind velocity component as flown by your TAS in miles per minute.
Wind component
--A 45-degree wind velocity should be multiplied by .7 to find its effect on your course. Every 15 degrees of change from the 45 is adjusted by .2 .
Example:
Heading of 360; wind 150 at 2ts. Wind is 30 degrees off tail. Tailwind multiplier is .9 (.7 + .2) and crosswind multiplier is .5 (.7 -.2) Tailwind component is 2ts, crosswind component is 12 kts.
Rule of Thumb for Crosswinds
A wind 30 degrees off the nose has only half the wind velocity as a crosswind component. At 50 degrees; off the nose the component is 75% of the wind speed. At 70 degrees; the component is 90%. You can effectively reduce the component by angling across the runway.
Take the wind angle from the runway drop trailing zero add the number 2 move decimal place one place to the left multply by the wind speed
runway 35
wind 320 @ 20
350 - 320 = 30
30 = 3
3 + 2 = 5
5 = .5
.5 X 20 = 10
10 kt crosswind
TURNS
1. Bank Angle for Standard Rate Turn
Airspeed in knots divided by 10 and add half of that value.
Example:
IAS 100kts divided by 10 = 10 + 5 = 15 degree angle of bank
2. Standard rate turn bank angle varies with speed. The airspeed in MILES PER HOUR less the last zero and plus 5 will give about the required angle of bank on the attitude indicator.
Standard Turn Rate
Divide knots of airspeed by 10 and then add back 1/2 of result.
Example: 100 knots divided by 10 = 10 and add 5 - 15degree bank for standard rate.
Pivotal Altitude for Turns on Point
V in knots squared and divided by 14.3
DENSITY ALTITUDE
Density Altitude (DA): temperature deviation (in deg Celsius) from ISA at THE ALTITUDE you're interested in, multiplied by 120 ft + or - depending on whether its ISA + or -. you then add this to the pressure altitude and you have an approximate DA. So for the above problem normal ISA temp at 5000' = +5 deg C (15deg at MSL minus 2 deg/1000 ft)
50 deg F = approx 10 deg C
10 DEG C = ISA +5 @ 5000 FT
5*120=600 FT
5000 FT + 600 FT= 5600 FT DA
Density Altitude
Add 1000 feet of density altitude for every 8.3 degrees Celsius above standard for that pressure altitude.
PERFORMANCE
Rule of Thumb:
Use the POH to figure aircraft performance + 50% any time the...
--Takeoff or landing runway is higher than 3000'
--Temperatures are over 90 degrees
--Takeoff or landing runway is less than 3000' long.
--Best glide speed can be quickly determined by placing the wingtip level with the horizon.
--Minimum sink speed has the leading edge slightly above the trailing edge relative to the horizon.
--The more near the throttle is to full power the more even leaning will be among the cylinders.
--If you don't know best glide speed use best climb. (close)
--Cruise speed for planing purposes should be increased by one knot for every 100 pounds below gross weight.
--You get a two-percent increase in your true airspeed for every thousand feet of higher altitude.
--For every 2% of weight reduction reduce the gross weight POH maneuvering speed by 1%.
. Fuel Consumption
At 5000 feet you only get 75% horsepower. POH numbers are minimums.
Carbureted engines:
Multiply the horsepower available times .08
Fuel Injection engines:
Multiply the horsepower available times .077
TRUE AIRSPEED
Increase indicated airspeed by 2% per thousand feet of altitude. Wind effect on speed can be determined by finding difference between ground speed from DME and your calculated true airspeed.
The TAS = IAS * the square root of (standard sea level air density /current air density). For the usual standard atmosphere, this can be written:
TAS = IAS*[square root (T/288)] * [(1 - h/144000)^-2.75] where T = 273 + OAT (C), and h is the pressure altitude. read ^-2.75 as "raised to the minus 2.75 power".
Survival
Rule of Thumb:
You have a minute in the air for every 1000' of altitude
You can expect to glide one mile for every 1000' of altitude.
A 360 will lose 1000' of altitude
Land into the wind with the rows.
Takeoff Rules of Thumb
--+15 F or 8.5C density altitude changes by 1000 feet.
--Increase takeoff requirement by 10% for each two knots of tailwind.
--Increase POH figures by 7% for takeoff on turf.
--Increase POH figures by 10% for short grass.
--Increase POH figures by 25% for soft surface or tall grass.
Continued on You, the FARs, FAA and NTSB
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