# Other aircraft doesn't apply right of way rules [duplicate]

I was flying VFR a couple of days ago and was warned by ATC that another aircraft was coming from my left to my right.

At some point I saw it and we were clearly converging and getting pretty close. According to the right of way rules I had priority, but the other aircraft didn't change its heading (maybe the other pilot didn't see me - he/she didn't seem to be in contact with ATC).

According to the rules I was supposed to keep flying the same heading and altitude but I decided to turn left to avoid her and it worked fine - however I can see how it could have been dangerous had the other aircraft changed its heading at the same time.

So I'm now wondering:

What is the "right thing" to do when another aircraft doesn't follow the right of way rules?

See and avoid is the backbone of VFR flight. The right thing to do when there is a potential collision is to take positive action, which is exactly what you did. There's no one-size-fits-all solution as to whether to turn one way or the other, climb or descend - it all depends on the position and course of the aircraft in question.

Often which way to turn in these situations is the lesser of two evils, if you turn left you clear sooner but if the other airplane turns right there's a potential conflict, if you turn right then you are in potential conflict longer. You have to choose one and hope the other person takes the right action.

One way to avoid conflict is a change of altitude, if you are slightly higher than the other airplane then climbing quickly takes you out of conflict, if you are lower then a descent does the same thing. If you are the same altitude then I favor descending as most people's default reaction is to climb - if the other pilot sees you they're more likely to pull up, giving you better separation. Even if you are under ATC direction changing altitude is the right action as it's necessary for the safety of the flight. You change altitude, avoid the collision, then go back to your assigned altitude before radioing ATC and explaining the deviation. I doubt they'd have a problem with that and even if they did regulations are on your side.

• How are the "right of way" rules worded for aviation? On the water there is no right of way. Instead, there is only obligation to give way. If one boat fails to yield in due time, the course holding boat is obliged to yield. Is it the same in the air?
– bogl
Jul 8, 2017 at 9:18
• They are clear, are laid out in regulation and use words such as "shall" and "must". They are not optional. Jul 8, 2017 at 13:37

You did the right thing. The opening paragraph of section 3.2 (Avoidance of collisions) in ICAO Annex 2 (Rules of the Air) states:

Nothing in these rules shall relieve the pilot-in-command of an aircraft from the responsibility of taking such action, including collision avoidance manoeuvres based on resolution advisories provided by ACAS equipment, as will best avert collision.