Aviation Communication | Rules of Thumb

Descent

this is a test

3 Degree Glide Slope Descent Rate

Add a zero to your indicated speed, divide by two. This should keep you stabilized on the approach.
EX: 150 knots on the GS. 150(0) / 2 = 750fpm descent. 120(0) / 2 =600fpm descent, etc.

3 Degree Glide Slope

To maintain a 3 degree glideslope (eg: ILS) multiply the groundspeed you are achieving by 5. The resulting number is the rate of descent to fly.
Ex. Groundspeed = 110 Kts x 5 = 550fpm rate of descent to maintain 3 degree glideslope.

Double the DME for a 1000' ft per minute drop rate at 200 kts IAS. That would tell you how far out you should start the descent.

EX.I'm at FL230, cruising at 200 KIAS. I know I want to be down to what ever the IAF alt is (say 4000') before I get there, maybe 3-5 miles. Based on 1000 ft/min descent rate, if I start the descent when I am FL alt minus the alt of the IAF that gives me 19k to loose. This means if I start with 38 DME and add a fudge factor of about 6-8 then I will hit a point before the IAF at the alt I need. This is not an exact science as under FL180 you have to change to the local alt setting. But, it does work and it usually has you down with plenty of time to spare

The distance to descend at 500 ft per minute. Equals 2 times the ground speed in miles-per-minute times the altitude to lose in thousands of feet.
Ex.If ground speed in the descent is 155kts/180mph(3 miles-per-minute) and you must descend 8000ft, you must begin you descent 48 miles from the point at which you must be at the lower altitude. 2 times your 3 miles per minute ground speed equals 6 times 8 (your altitude to be lost in thousands) equals 48 miles.

Distance To Decend
1. Take your altitude and multiply it by 3. That equals your distance in miles to begin your descent.
2. Now take half your ground speed. This is your rate of descent in hundreds of feet.
Ex.If you are flying at 12000ft at a ground speed of 150kts and you need to descend to 2000ft, the difference is 10000ft. Multiply 10*3=30 miles out you must begin your descent. Half your ground speed is 75, add a zero, and 750 ft per minute is your rate of descent.

Ground Speed

High Speed Aircraft - Ground Speed

For relatively high speed aircraft- say 250 kts or better the quickest way of calculating Ground Speed using the DME (without G/S readout) is to note the distance travelled in 36 seconds. 36 seconds = 1% of one hour
Thus if you travel 3.25 nm your Ground Speed is 325 Kts- voila!!

Ground Speed
1. To find ground speed note the time required to fly a published distance.
2. Pick a number that when multiplied by the flight time yields approximately 60.
3. To get that ground speed, multiply that number by the distance.
Ex.15 minutes is required to fly 30nm (15*4=60)Ground speed equals 120kts. (4*30=120)

Wind Components/Correction

Wind Correction Angle
1. To determine the wind correction angle you must know the crosswind component at that altitude.
2. Divide the crosswind component by your True Airspeed in miles per minute, which will yield the wind correction angle.
Ex. If the crosswind component is 14kts and the True Airspeed is 2 miles per minute (120kts),the wind correction angle is 7 degrees (14/2=7 degrees)

Wind Components
1. The 45 degree multiplier is 0.7 for headwind, tailwind & crosswind components.
2. And, for every 15 degree variation in wind direction from the 45 degree position, the 0.7 multiplier is adjusted by 0.2
Ex.Your heading is 090 and the wind is 165 degrees at 14kts.
The wind is 75 degrees off the nose. (165-90=75)
The headwind multiplier is 0.3, So your Headwind Component is 4kts (14*0.3=4kts)
The crosswind multiplier is 1.0, So yourCrosswind Component is 14 kts (14*1.0=14kts)

Bank Angles

Leading a Heading
1/2 Standard Rate = 1/3 your bank angle
Standard Rate = 1/2 your bank angle

Bank Angle for standard rate turns
1. If indicated airspeed is in MPH, divide airspeed by 10 and add 5 for standard rate turn.
Ex.IAS is 110mph, divide by 10 equals 11, plus 5 equals 16 degrees (110/10=11+5=16 degrees) bank angle for a standard rate turn.
2. If indicated airspeed is in knots, divide airspeed by 10 and add 50% of that value.
Ex.IAS is 100kts divided by 10 equals 10 plus 5 (50% of 10) equals 15 degrees (100/10=10+5 (50% of 10) =15 degrees)bank angle for a standard rate turn.

True Airspeeds

True Airspeed Calculation

Divide your indicated altitude by 1000, multiply this figure by 5, and add this number to your indicated airspeed.
Ex: 30000/1000= 30*5= 150+280= 430 is your TAS.

True Airspeed (TAS)
To find True Airspeed increase your indicated airspeed by 2% per thousand feet of altitude.
Ex.If your indicated airspeed at 8000ft is 120kts, add 16% (2*8=16%) to your indicated airspeed. Your True Airspeed is 139kts

Fuel Flow/Management

Pounds of Fuel vs. Gallons

For every 100 pounds of fuel there is 15 gal.
Ex.So if you need 1000 pounds of fuel that equates into 150 gallons.

Simple and Fast Way To Determine Fuel Burn:

1. Set the index of the rotating bezel (or a marker on the planes clock) of that fancy pilot watch you bought to the minute hand at takeoff.

2. Figure out how many gallons you burn in a unit of time. Example: my old Stinson burns a gallon every five minutes.

3. Now just count off the units. The bezel on my watch is graduated in 5 minute increments. 15 minutes would be 3 units and three gallons.

Simple, just count off from the index one, two three...three gallons!

You'll always know how much fuel you've burned and consequently how much is left. Try it! Fast and easy.

Convert Pounds of Fuel to Gallons
Take the amount of pounds needed, drop the last zero, divide that new number by 2 and add it to the new number. That is the same amount in gallons!!
EX. Say 400 pounds is needed. Drop the last zero = 40. Then divide by 2 which = 20. Add 40 and 20 to get 60 gallons of fuel

Fuel Flow
If your airplane has a fuel flow gauge multiply that number by 3 to get gallons per hour.
Ex.If your fuel flow is 2.3 per engine. Then, you are burning 69 gallons per hour per engine. (2.3*3=69 gals)

Horsepower

Horse-Power At Altitude For Turbo-Prop
To find out what amount of horse-power you are producing at certain altitudes, use this formula. HP=RPM times Torque times .00019
Ex.Assume 1900 on the rpm and 9's on the torque. Hp will equal 325. (1900*900*.00019=325)

Pressure Altitude

Pressure Altitude For Performance Charts
To find pressure altitude for use on performance charts take standard pressure (29.92), subtract the current pressure setting , multiply that number by 1000, and add the elevation and to equal your pressure altitude.
Ex. Current pressure altitude is 28.92 and the elevation is 1200ft msl.
29.92 (Standard pressure)
- 28.92 (current pressure)
= 1.00
* 1000
+ 1200
= 2200 This is your new pressure altitude.

Temperature Conversions

Temperature Conversion Number 2
Another alternative to the above temperature conversion is to 1) Double the number 2) Deduct 10% and 3) Add 32 to get the farenheit figure.
Ex.We have a current temperature of 35 degrees celcius. Double it which equals 70, deduct 10% (7) equaling 63, and add 32, which equals 95 degrees fahrenheit

Temperature Conversion
To convert celcius to fahrenheit, you must multiply the current temperature by 9, divide that number by 5, and add 32.
Ex.We have a current temperature of 35 degrees celcius. Multiplied by 9 it equals 315, divided b y 5 equals 63, and add 32, which equals 95 degrees fahrenheit

Climb Gradient/Climb Rate

Convert Climb Gradient To Climb Rate
To convert the climb gradient to the climb rate in hundreds of feet, divide your current ground speed by 60 and multiply by climb gradient.
Ex.If you are required to gain 200 ft per nautical mile and you have a 150kt ground speed, your rate of climb in hundreds of feet is 500. (150/60=2.5*200=500)

Instrument Flight

Reciprocal Heading

If known heading is 0 -180, add 200 and substract 20. If known heading is 181 - 360, substract 200 and add 20. This is easier and quicker than trying to add or substract 180.
EX: Reciprocal of 120 is 120 + 200 = 320, 320 - 20 =300.
EX: Reciprocal of 210 is 210 - 200 = 10, 10 + 20 = 30.

Northerly Turning Error:

Another easy way to remember this compass tendancy is:
ANDS.
Accelerate - North, Decelerate - South.

VOR orientation

When using a second VOR for cross radials,
"Same side, not yet arrived"

Ex., If the CDI is on same side of vor head as the VOR is from your course, you have not yet arrived at the cross radial fix. Conversely, if the VOR is say, to the left of your course, and the needle is to the right, you have passed the fix

Partial Panel
Remember that if doing partial panel , that you have the other instruments, such as the obs on NAV 1 to help you visualize your postion or heading.

If every 30degress takes 10 seconds, then anytime you have the big numbers on the DG, such as 030, 060, 090, the time in between each will be 10 seconds.

In order to also help you, if you think that you have to turn to a heading that is LOWER usualy turn LEFT.

I know that this does not work if you are on a NW heading and have to go to a north east heading, but use common sense.

Instrument Landing Check

C ompass
L ights
I dentify
F laps
F uel
Use this on my procedure turn outbound in lieu with of the gump check. Check heading, runway lights, landing lights, frequency, approach flaps, check fullest tank.

IFR approach or hold.

Time, turn, throttles, twist, track, talk

Time: start timing as required
Turn: start turning to the desired course
Throttles: set as applicable, precision approach, holding, etc
Twist: re-set the HSI inbound course window if required
Track: fly the airplane and track the inbound course
Talk: tell the controller if you need to.

Calculating VDP
VDP - A point along a straight-in approach at which a 3 degree slope to the runway can not be maintained resulting in a, missed approach, circle to land,or unsafe manuever.
VDP’s are for straight in approaches and are simply used for a reference..it will indicate to you that a 3 degree descent path to the runway will not be obtainable from that position without an evasive manuever
There are three ways to calculate VDP:
1. They are published on the approach plate.
2. By DME - 300ft per nautical mile (from end of the runway)
EX. Say the MDA = 600 and the runway is 1 DME from the fix VOR, LOC, NDB, ETC) Your VDP = 3 DME 600/300 = 2 DME plus the 1 DME = 3 DME
3. Take 10% HAT off your time.
EX. Say the published HAT is 800ft and the time for that approach is 5:20 Your VDP will be at 4:00 along the approach. 10% of 800 = 80 seconds, subtract that from 5:20 and you get 4:00

Drift Correction
300 divided by TAS) X (Crosswind divided by 5) = correction in degrees
Ex.TAS 150, Crosswind=10 300/150=2 Times (10x5) 50 =100...drop the “0” 10 degrees correction

Altitude Deviation Correction
2 X deviation in feet = VSI indication back to altitude

Partial Panel Compass Flying
"OSUN" used for partial panel compass flying.
O vershoot S outh U ndershoot N orth
Remember that the magnetic compass lags from the North and leads to the south. How much you over or under shoot your desired heading depends on the degrees latitude that you are flying. Overshoot the South heading by the required degrees and Undershoot the North heading by the required degrees.
Ex.1 Suppose you are flying in Kansas (approximately 30 degrees latitude) and your heading is 090 degrees and you want to turn to a North heading. Because of the lags to the North you should roll out of your turn when your com pass reads 330 (360- 30=330 degrees)if your turn is to the right and 030 (360+30=030 degrees) if your turn is to the left.
Ex.2 Suppose you are still flying in Kansas and your heading is still 090 and you want to make a turn to a south h eading. Because the compass leads to the South you should roll out of your turn when your compass reads 210 (180+30=210 degrees) if the turn is to the right and 150 (180-30=150 degrees) if your turn is to the left

Cue Words To Remember Reporting Points
Harry Maintains That Little Cats Don't Ever Vaccuum Willows
H. holding entry
M. missed approaches
T. TAS changes by 5% or 10 knots
L. loss of navigation equipment, VOR / DME etc.
C. cumpulsory reporting points
D. deviating for weather
E. ETA changes
V. vacating altitude
W. when unable to climb or descend 500 feet per minute

Items Needed For Instrument Flight
According to FAR 91.205.
GRAB CARD
Generator
Radio
Attitude indicator
Ball
Clock
Altimeter with pressure window
Rate of turn
Direction indicator

Airworthiness

Items Needed for Day/Night VFR Flights

Day VFR

A FAST MOOSE; MAT

A- airspeed indicator
F- fuel guages
A- altimeter
S- seat belt/shoulder harness
T- tachometer
M- magnetic compass
O- oil pressure guage
O- oil temp.guage
S- safety gear (flares,flotation device)
E- ELT

MAT

M- manifold pressure
A- anti-collsion lights
T- transition light

NIGHT VFR:

ASLAP

A- anti-collsion lights
S- spares fuses (3)
L- Landing light when for hire
A- adequate source of electrical power
P- position lighting

Miscellaneous Rules of Thumb

The Nautical Thumb

For the average person, the distance from the tip of your thumb to your knuckle is equal to approximately 10 nautical miles on the Sectional Chart scale. This makes it fast and easy to estimate distances on the sectional chart, especially during diversions to an alternate airport.
To "calibrate" your thumb, just bend your thumb and place it on a standard 10nm class C airspace on your sectional chart. It should fit almost perfectly between the center of the airport to the 10nm ring!

Course Reversal

Add 2 subtract 2 or subtract 2 add 2 for course reversal.
Ex: If you are on a heading of 060 you +2 & -2 = 240
Ex: If you are on a heading of 340 you -2 & +2 = 160
A little common sense and it always works.

Gumps For Low-Wing Aircraft: BCGUMPS

B oost pump on
C arb heat off
G as on fullest tank (no both position in a PIPER)
U ndercarriage - Gear down and locked
M ixture - Rich
P rops - High RPM
S eat Belts Fastened

ATC Speed Reductions

In a turboprop a/c a quick rule of thumb for a speed reduction is take the airspeed subtract 100 from it divided by two and add five. that will give you your torque setting in percent.

EX: 180 kias. 180-100=80 80/2=40 add 5= 45% torque
210 kias. 210-100+110 110/2=55 add 5= 60% torque

1 In 60 Rule

For every 1 degree displacement equals 1 nm in 60 nm.

Ex.If heading is altered 5 degrees to the left:
In 60 nm you will be 5 nm left of track.
In 30 nm you will be 2.5 nm left of track.

Shut Down Checklist

"Remememember to shut everything down"
(R-e-m-m-m ber)
R - adios
E - lectrical
M - ixture
M - aster
M - ags

Diversion-Figuring out time to new destination.

A quick way to figure out how long it will take to get back on course or to a new destination when diverting is:
Ex. Take 2/3 and multiply it by the distance to be travelled.
2
- X 15(miles) = 2 X 15 = 30/3 = 10 minutes.
3
This would work with the slow airplanes like a 150 or cherokee 140.For faster aircraft all you would have to do is work out a different factor.

Quick Shutdown Checklist

S - Switces (all electrics)
L - Lean
I - Ignition(magnetos)
M - Master Switch

Weather Radar
Normal Operating Weather Radar should be able to ground
paint (Dist.) : Square root of your AGL Altitude

Anatomy of a Radio Call:

Who they are, Who you are, Where you are, and What you want

Weight & Balance WAM:

W eight x A rm = M oment

Estimating Cloud Bases:

Temp. minus dew point divided by 4 and multiply by 1000'
Ex. 72-52=20 20/4=5 5x1,000=5,000' bases = 5,000' agl during instability and warmer part of day

Compass errors on an east-west heading

ANDS:
Accelerate North error Deccelerate South

Pre-landing Check GUMPS:

Gas - Fuel to 'BOTH'
Undercarriage - Gear down and locked
Mixture - Full RICH
Props - High RPM
Safety - Seatbelts & Shoulder harnesses

Course Heading
True Virgins Make Dull Company for figuring course Heading

(True course +/- variation = magnetic, +/- deviation= Course heading.)

EX. 240 + 7 degrees equals 247 magnetic + 3 degrees deviation = 250 for a course heading