Collision Avoidance Commentary

General Information for Collision Avoidance

For this section you simply need to memorize the order of priority of different types of aircraft and different relative positions of aircraft. It's not difficult, because the order is logical.

Every question in the section has the same references: AIP-RAC 1.10 (note that it says 1.11 in the Transport Canada study guide; they renumbered the sections without updating the document) and CARs 602.19. In this case, the AIP section is exactly the same as the CARs.

Below is an illustrated table showing the order of priority for different types of aircraft.

*An aircraft with an emergency* has the right of way over ...		An aircraft with an emergency -- has an emergency. The pilot may not even be able to fully control the aircraft, so others must give way.
*a balloon*, which has right of way over ...		A balloon has no powered propulsion or steering. The pilot can only ascend and descend, searching for winds that happen to be going the way he wants to go. A balloon moves slowly, and can't do much manoevering to avoid other aircraft, so everyone else gives way to the balloon. Tethered balloons have right of way over everything, in the same way that trees do, like in this joke.
*a glider*, which has right of way over ...		A glider has the same control and steerability as a powered airplane, but is slower, and can only climb if the pilot sacrifices airspeed or finds an area of rising air. A glider cannot execute a go around if another aircraft cuts in front. All power-driven aircraft must yield to the glider.
*an airship*, which has right of way over ...		An airship is like a balloon with a motor on it. It moves and manoevers slowly. All power-driven, heavier-than-air aircraft give way to airships.
*an aircraft towing objects or carrying a slung load*, which has right of way over ...		An airplane towing something may be operating near the edge of its performance envelope. Abrupt manoevering may be outside its capabilities or cause the aircraft to become entangled in its own line. A load slung from a helicopter may shift or swing.
all heavier than air, power-driven aircraft.		All helicopters and airplanes, from ultralights to jumbo jets, are heavier-than-air, power-driven aircraft. They are all in the same right of way category, with no priority based on engine type or speed or size. Common sense should tell you to stay out of the way of an aircraft much faster than yours, and to avoid running over aircraft much slower than yours.

If two aircraft from the same row of the above table are converging at the same altitude, the one that has the other on its right must give way.

two aircraft converging top view of aircraft approaching head on
aircraft passing to the right

If two aircraft are coming head on, both move to their own right, just like cars on a one-lane road in Canada. If one aircraft is passing another, the passing aircraft must give way to the other and pass well to the right. Note that this is different than in a car, but there is a good reason. Look at the picture at the top right corner of this page. Is the green Cessna coming towards you or away from you? It doesn't matter: either way, you alter your course to the right to avoid it.

Just remember, no matter who you think has the right of way, do what you have to avoid other aircraft.

Question-by-Question Explanation of Collision Avoidance

Click the question numbers to return to the PSTAR questions.

1.01

(1) There are no rules giving giving one airplane the right of way over another just because it is heavier, faster, or has a different type of engine. Common sense should tell you to let an airplane that is travelling at triple your speed to go ahead, but air law does not require it.

(2) An aircraft towing objects could be an airplane towing an advertising banner, an airplane towing a glider, or a helicopter lifting out timber. (An aircraft towing objects does NOT have right of way over another power-driven heavier-than-air aircraft if the latter has declared an emergency, but apparently they didn't think of that exception when they made up this question).

(3) While it is true that an airplane has the right of way over another airplane which is converging from the left, what if the other aircraft converging from the left is a glider, a balloon, or a banner tow? Tricky question, eh? Get used to it. Transport Canada likes to play word games on their exams.

(4) There is no precedence between helicopters and airplanes, so a helicopter is just another "power-driven, heavier than air aircraft." CARs 602.19(2)(d) makes it clear that the helicopter is the one that must give way to the glider tow.

1.02 (1) It wouldn't help much. If two aircraft are converging and they both turn left, they'll just end up colliding further to the left.

(2) Two things are wrong with this answer. Firstly, the aircraft on the right is not the aircraft that "has the other on its right" so it doesn't have to cede the right of way. And secondly, while descending is one way to give the right of way, it's not the only way, and in most cases wouldn't be the preferred way.

(3) This answer is straight out of the rules. Use your hands, or two model airplanes to set up different scenarios of converging aircraft and figure out which has the right of way in each case. You don't want to be trying to figure out how the rule applies when there's an airplane coming at you.

(4) The wording of the rule is a little tricky. "The aircraft that has the other on its right shall give way." In most configurations, the aircraft that has the other on its right is the aircraft on the left. You might remember that the aircraft on the RIGHT has the RIGHT of way.

1.03
(1) A glider has the right of way over any aircraft with an engine.
(2) Huh? An airplane IS a power-driven, heavier than air aircraft.
(3) Nope, see answer choice 1
(4) A glider is NOT power-driven, and it has the right of way over power-driven aircraft.

1.04
(1) Gliders don't give way to anyone but balloons and emergencies
(2)&(3) There is no precedence between airplanes and helicopters.
(4) Everyone but balloons give way to gliders.

1.05 Balloons come first, then gliders, then helicopters and airplanes together.

1.06 Balloons have the right of way over everyone.

1.07 The aircraft that has the other on its right must give way, so the aircraft on the right has the right of way. Descending is not necessarily the correct way to give way.

1.08
(1) Slowing down won't help you any if you're still going to collide.
(2) Speeding up certainly won't help you avoid a collision.
(3) Right. Just as it says in 602.19 (5), and the same way you would turn if you met another car coming towards you on a narrow road.
(4) Left is the wrong way. Learn the rule.

1.09
(1) You might not be able to pass them and climb at the same time.
(2) You might already be as low as you can safely, legally or comfortably fly.
(3) Just as it says in 602.19 (5) . Notice that you alter heading to the right when there is an aircraft in front of you, regardless of whether the other aircraft is coming towards you or is going the same way as you.
(4) If you are driving a car, you pass on the left, but in an airplane you pass on the right.

1.10
(1) The rule is given in 602.19 (8).
(2) If you must overtake, do it on the right.
(3) The lower aircraft has priority.
(4) A 360° turn to the right is one way that a pilot of a faster aircraft could give way to a slower, lower aircraft on the approach, but usually the pilot giving way just widens out the circuit or slows down slightly.

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This page written 8 October 2002 by Robyn Stewart. Last revised 3 July 2003.

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Cessna 150 head on