Flight Path Characteristics

Section author: Luke Frisken <l.frisken@gmail.com>

Table of Contents

• Flight Path Characteristics
  • Standard Rate Turn
    • Turn Radius
    • Bank Angle
  • Holding Patterns
    • Pattern Entry
  • Adhering to Airways or Routes
  • Bibliography

Standard Rate Turn

According to the FAA Aeronautical Information Manual [FAA15], a standard rate turn is defined as:

A turn of three degrees per second

From this information, and the airspeed of the aircraft, a number of parameters can be derived for an aircraft undergoing a turn as descussed by Luiz Monteiro [Mon]. As a side node, the following parameters ignore slip, and are therefore at least marginally inaccurate.

Turn Radius

\(v = Velocity\)

\(\omega = AngularVelocity\)

\(r = TurnRadius\)

\(r = \frac{v}{\omega}\)

For a standard rate turn, the Angular Velocity is:

\(\omega = \frac{d\phi}{dt} = \frac{3^{\circ} \times \frac{\pi}{180^{\circ}}}{1}\)

\(\omega = \frac{\pi}{60}\)

Therefore the turn radius for a standard rate turn would be:

\(r = \frac{v * 60}{\pi}\)

Bank Angle

\(\alpha = tan^{-1}(\frac{v^2}{g \times r})\) [Mon]

Holding Patterns

Holding patterns are planned flight paths involving a series of turns which are designed to keep an aircraft at a certain location.

Some Example Situations from AIM:

Holding Patterns [FAA15]

Holding Pattern Terms [FAA15]

Below 14,000 feet, both the inbound and outbound legs are supposed to take 1 minute. Above 14,000 feet this increases to 1.5 minutes. [FAA15]

Turns during a holding pattern are typically at a standard rate and have a maximum bank angle of 30 degrees. [FAA15]

Pattern Entry

The choice of entry procedure into a holding pattern is determined by the relative aproach direction to the direction of the hold.

Entry Procedures [Wik]

Entry Procedures [FAA15]

Adhering to Airways or Routes

The FAA is expecting pilots to take actions necessary to remain within route boundary. This could take the form of leading turns. [FAA15]

Adhering to Airways or Routes [FAA15]

Bibliography

[FAA15]

(1, 2, 3, 4, 5, 6, 7, 8) FAA. Aeronautical Information Manual. 2015. URL: http://www.faa.gov/air{\_}traffic/publications/media/AIM.pdf.

[Mon]

(1, 2) Luiz Monteiro. Bank Angle and the Physics of Standard Rate Turns. URL: http://www.luizmonteiro.com/Article{\_}Bank{\_}Angle{\_}for{\_}Std{\_}Rate{\_}01.aspx.

[Wik]

Wikipedia. Holding (Aeronautics). URL: https://en.wikipedia.org/wiki/Holding{\_}(aeronautics).