Correcting for Errors

Question 1

What is the 1:60 rule

Answer 1

at 60nm, for every 1॰ off track, the aircraft will be 1nm off track

at 60nm if 10॰ off track, aircraft 10nm off track

We know that if we shortened the distance, the same number of nm off track would increase the angle i.e after 30nm, if we were 10nm off track, we would actually be 15॰ off track.
Same principle if we extended the distance travelled, 10nm off track would be a smaller angle. If we travlled 90nm and were 10nm off track, we would be 5॰ off track

Question 2

What is the formula to determine track error

Answer 2

Track error ॰ = ( Distance off track (nm) / Distance gone (nm) ) x 60

Track ॰ = ( nm off / nm gone) x 60

Question 3

If an aircraft were flying 10॰ off track and pilot corrected by 10॰, what would the aircraft heading be in relation to the required track

Answer 3

PARALLEL

By correcting by 10॰ the aircraft is simply parallel to the required track but the nose is not aiming at the target destination. If the pilot doubled the correction, this would fly the aircraft back towards track

Question 4

If an aircraft is 10॰ off track and has travelled further than the half way point, 2x track error correction (i.e. 20॰) will get the aircraft to the destination; TRUE or FALSE

Answer 4

FALSE

Aircraft will fly past the destination as more track correction is required given the distance to travel is less than the distrance gone.

Question 5

What is the formula to calculate the closing angle॰

Answer 5

Closing angle ॰ = ( Distance off track (nm) / Distance to go (nm) ) x 60

Closing angle ॰ = ( nm off / nm to go) x 60

Question 6

What is the formula to calculate the heading correction when an aircraft has flown past the halfway point

Answer 6

Track error॰ + Closing angle॰ = Heading correction

[Track error ॰ = ( Distance off track (nm) / Distance gone (nm) ) x 60 ]
+
[Closing angle ॰ = ( Distance off track (nm) / Distance to go (nm) ) x 60]
= heading correction

Question 7

Rule of thumb track correction

On your aviation chart, having drawn the 1/4, 1/2, and 3/4 points on your track true line, what is the rule of thumb to calculate track error correction in order to get you overhead at destination

Answer 7

1. 1/4 = Track error॰ x 1.5
2. 1/2 = Track error॰ x 2
3. 3/4 = Track error॰ x 3

Question 8

What is the formula to determine a given aircrafts standard closing angle

Answer 8

Standard closing angle॰ = (60 / TAS ) x 60

Cessna at 90kts is ( 60 / 90 ) x 60 = 40॰
PA28 at 100kts is ( 60 / 100 ) x 60 = 36॰

Question 9

On an aviation chart, use your track line and fan lines to determine;

A Cessna track error is approximate 4nm off track, showing approximately half way between the track line and the fan line. Using the standard closing angle method, what is the correction formula to use

Answer 9

Standard closing angle॰ + Track error॰ for nm off track as minutes

40॰ Standard closing + 5॰ off track = 45॰ track correction
4nm off track = 4 minutes
SO;
45॰ track correction and fly for 4 minutes to get back to track
REMEMBER: Standard closing angle is determined by (60/TAS) x 60.
In this instance we know we are in a Cessna so TAS = 90 kts

Question 10

Using rule of thumb, if you were 1m late than your ETA at your half way point, how many minutes will you be late at your destination

Answer 10

2m

Use easy maths. If 1m late at half way point, traveling the same distance again would add another minute late i.e. 2m late by time at destination