Summary of the 60-to-1 Rule and Other Rules & Formulas

JOINT ADVANCED MULTI-ENGINE T-44A

G. Summary of the 60-to-1 Rule and Other Rules & Formulas:

What is the 60-to-1 Rule and Why Should You Use It? It is a technique for establishing

predictable pitch changes for climbs or descents and lead points for intercepting courses or arcs.

The following are three good reasons to use this rule:

It allows the pilot to compute the pitch changes necessary when establishing an attitude

during the control and performance concept of attitude instrument flying discussed in the BI

stage.

It reduces the pilot's workload and increases efficiency by requiring fewer changes and less

guesswork.

It is an alternative to the TLAR (That Looks About Right) method of flying. After gaining

experience using the 60-to-1 rule, it will improve your TLAR accuracy.

How to Work With the 60-to-1 Rule. The 60-to-1 rule gives us a mathematical equation to help you

figure out all these questions, but it is almost impossible to run these calculations and fly at the same

time. You need to use the formulas before you fly. Find out what your turn radius is at cruise airspeed

up high and at approach airspeed down lower; find out what a 1 pitch change will do to your VVI and

remember those numbers.

The 60-to-1 Rule:

1 = 1 NM at 60 NM(60 NM from the station, there is 1 NM between each radial)

1 = 100 FT at 1 NM(1 climb or descent gradient results in 100 FT/NM)

VSI Versus Pitch Change. We now know how to calculate the altitude gained or lost for each degree

of pitch change over a given distance. Throw in a time factor using True Airspeed (TAS) expressed in

NM per MIN and we can relate this pitch change to a change in VSI.

First, lets convert speed to NM/MIN, since the 60-to-1 rule is based on TAS expressed in

NM/MIN. NM/MIN can be obtained easily from TAS as follows:

NM/MIN = TAS/60

Examples: 120 KTAS = 2 NM/MIN

150 KTAS = 2.5 NM/MIN

Since we don't have a TAS indicator, TAS can be computed from IAS. TAS increases over

IAS at the rate of 2% per 1,000 feet altitude increase. So, the following equation could be

used:

TAS = IAS + (2% per 1,000 FT) X (IAS)

Example: 3,000 FT; 150 KIAS

TAS = 150 + (2% X 3) (150) = 150 + (.06)(150) = 159 KTAS

Another easy but less accurate rule of thumb (best used above 10,000 feet) to determine TAS

is:

"Add 5 kts per 1,000' to IAS"

TAS = IAS + (FL/2)

Example: FL 200; 175 KIAS

TAS = 175 + (200/2) = 275 KTAS

If one degree equals 100 ft/nm, then our VSI can be calculated numerous ways:

VSI for 1 pitch change = NM/MIN X 100 FT

VSI = (Pitch Angle) X (NM/MIN X 100)

VSI = (Gradient) X (NM/MIN) = (FT/NM) X (NM/MIN)

RADIO INSTRUMENTS STAGE

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