Rules of the Air Article 21
The aircraft that has the right-of-way shall maintain its heading and speed.An aircraft that is obliged by the following rules to keep out of the way of another shall avoid passing over, under or in front of the other, unless it passes well clear and takes into account the effect of aircraft wake turbulence.1. Approaching head-on: When two aircraft are approaching head-on or approximately so and there is danger of collision, each shall alter its heading to the right.2. Converging: When two aircraft are converging at approximately the same level, the aircraft that has the other on its right shall give way, except as follows:(1) Power-driven heavier-than-air aircraft shall give way to airships, gliders and balloons;(2) Airships shall give way to gliders and balloons;(3) Gliders shall give way to balloons;(4) Power-driven aircraft shall give way to aircraft which are seen to be towing other aircraft or objects.3. Overtaking: An overtaking aircraft is an aircraft that approaches another from the rear on a line forming an angle of less than 70 degrees with the plane of symmetry of the latter, i.e. is in such a position with reference to the other aircraft that at night it should be unable to see either of the aircraft’s left (port) or right (starboard) navigation lights. An aircraft that is being overtaken has the right-of-way and the overtaking aircraft, whether climbing, descending or in horizontal flight, shall keep out of way of the other aircraft by altering its heading to the right, and no subsequent change in the relative position of the two aircraft shall absolve the overtaking aircraft from this obligation until it is entirely past and clear.4. Landing:(1) An aircraft in flight, or operating on the ground or water, shall give way to aircraft landing or in the final stages of an approach to land.(2) When two or more heavier-than-air aircraft are approaching an aerodrome for the purpose of landing, aircraft at the higher level shall give way to aircraft at the lower level, but the latter shall not take advantage of this rule to cut in in front of another which is in the final stages of an approach to land, or to overtake that aircraft.(3) Power-driven heavier-than-air aircraft shall give way to gliders.(4) An aircraft that is aware that another is compelled to land shall give way to that aircraft.5. Taking off: An aircraft taxiing on the manoeuvring area of an aerodrome shall give way to aircraft taking off or about to take off.6. Taxiing: In case of danger of collision between two aircraft taxiing on the movement area of an aerodrome the following shall apply;(1) When two aircraft are approaching head on, or approximately so, each shall stop or where practicable alter its course to the right so as to keep well clear;(2) When two aircraft are on a converging course, the one which has the other on its right shall give way;(3) An aircraft which is being overtaken by another aircraft shall have the right-of-way and the over-taking aircraft shall keep well clear of the other aircraft.7. An aircraft taxiing on the manoeuvring area shall stop and hold at all runway-holding positions unless otherwise authorized by the aerodrome control tower.8. An aircraft taxiing on the manoeuvring area shall stop and hold at all lighted stop bars and may proceed further when the lights are switched off.
中文原文 飛航規則第21條
有飛航優先權之航空器，應保持航向及空速。
各航空器依下列規定應採取避讓措施時，除取得足夠之安全隔離並考量機尾亂流之影響外，應避免在其他航空器上、下或前方通過：
一、對頭接近：當兩航空器對頭或近乎對頭接近而有碰撞危險時，應各向右方變更航向。
二、交叉接近：當航空器之右方有另一航空器以近似高度交叉接近時，應即避讓之，並共同遵守下列規定：
（一）用動力推動重於空氣之航空器，應避讓飛艇、滑翔機及氣球。
（二）飛艇應避讓滑翔機及氣球。
（三）滑翔機應避讓氣球。
（四）用動力推動之航空器，應避讓拖有其他航空器或物體之航空器。
三、超越：當超越之航空器從後方接近另一航空器，且與被超越之航空器在對稱面構成之角度小於七十度時，亦即由該位置在夜間無法看到被超越航空器之左右航行燈。
被超越之航空器有飛航優先權。
超越航空器無論升降或平飛，均應向右方避讓，在未完成超越至足夠隔離前，無論該兩航空器相關位置如何改變，超越之航空器仍應負避讓之責。
四、降落：
（一）航空器在飛航中或地面或水面作業時，均應避讓其他正在降落或在進場最後階段之航空器。
（二）兩架或兩架以上重於空氣之航空器，同時接近同一機場準備降落時，其高度較高者應避讓高度較低者，但高度較低之航空器亦不得據此而擅自切入或超越在進場降落最後階段之航空器。
（三）動力推動重於空氣之航空器仍應避讓滑翔機。
（四）航空器警覺另一架航空器緊急迫降時，應避讓之。
五、起飛：機場操作區內滑行之航空器應避讓正在起飛或即將起飛之航空器。
六、滑行：當兩架航空器於機場活動區滑行而有互撞之危險時，應遵守下列規定：
（一）當兩航空器對頭或近乎對頭接近時，兩方均應停止前進或視情況許可應向右方偏讓以保持足夠之間隔。
（二）當兩航空器交叉接近時，其右方有另一航空器者應避讓之。
（三）當航空器欲超越另一航空器時，被超越之航空器有優先權，超越者應避讓，以保持足夠之間隔。
七、航空器於操作區滑行時，除獲得塔台許可，應在跑道等待位置停止並等待。
八、航空器於操作區滑行時，應在所有停止線燈亮時停止並等待，於停止線燈熄滅後繼續滑行。
各航空器依下列規定應採取避讓措施時，除取得足夠之安全隔離並考量機尾亂流之影響外，應避免在其他航空器上、下或前方通過：
一、對頭接近：當兩航空器對頭或近乎對頭接近而有碰撞危險時，應各向右方變更航向。
二、交叉接近：當航空器之右方有另一航空器以近似高度交叉接近時，應即避讓之，並共同遵守下列規定：
（一）用動力推動重於空氣之航空器，應避讓飛艇、滑翔機及氣球。
（二）飛艇應避讓滑翔機及氣球。
（三）滑翔機應避讓氣球。
（四）用動力推動之航空器，應避讓拖有其他航空器或物體之航空器。
三、超越：當超越之航空器從後方接近另一航空器，且與被超越之航空器在對稱面構成之角度小於七十度時，亦即由該位置在夜間無法看到被超越航空器之左右航行燈。
被超越之航空器有飛航優先權。
超越航空器無論升降或平飛，均應向右方避讓，在未完成超越至足夠隔離前，無論該兩航空器相關位置如何改變，超越之航空器仍應負避讓之責。
四、降落：
（一）航空器在飛航中或地面或水面作業時，均應避讓其他正在降落或在進場最後階段之航空器。
（二）兩架或兩架以上重於空氣之航空器，同時接近同一機場準備降落時，其高度較高者應避讓高度較低者，但高度較低之航空器亦不得據此而擅自切入或超越在進場降落最後階段之航空器。
（三）動力推動重於空氣之航空器仍應避讓滑翔機。
（四）航空器警覺另一架航空器緊急迫降時，應避讓之。
五、起飛：機場操作區內滑行之航空器應避讓正在起飛或即將起飛之航空器。
六、滑行：當兩架航空器於機場活動區滑行而有互撞之危險時，應遵守下列規定：
（一）當兩航空器對頭或近乎對頭接近時，兩方均應停止前進或視情況許可應向右方偏讓以保持足夠之間隔。
（二）當兩航空器交叉接近時，其右方有另一航空器者應避讓之。
（三）當航空器欲超越另一航空器時，被超越之航空器有優先權，超越者應避讓，以保持足夠之間隔。
七、航空器於操作區滑行時，除獲得塔台許可，應在跑道等待位置停止並等待。
八、航空器於操作區滑行時，應在所有停止線燈亮時停止並等待，於停止線燈熄滅後繼續滑行。