Rules of the Air Article 50
Unless otherwise prescribed by the CAA, the aircraft shall comply the following procedures when a radio communication failure precludes compliance with Article 49.1. The aircraft station shall attempt to establish contact on another frequency appropriate to the route;2. If the attempt specified in (1) above fails, the aircraft station shall attempt to establish communication with other aircraft or other aeronautical station on frequencies appropriate to the route, and select radar SSR MODE A CODE 7600.3. If the attempts specified in (1) and (2) above fail, the aircraft station shall transmit blind its message twice on both primary and secondary frequencies, preceded by the phrase "TRANSMITTING BLIND".4. When an aircraft station is unable to establish communication due to receiver failure, the message transmitted shall be preceded by the phrase "TRANSMITTING BLIND DUE TO RECEIVER FAILURE". During this procedure, the aircraft shall also advise the time of its next intended transmission.5. The aircraft, when forming part of the aerodrome traffic at a controlled aerodrome, shall keep a watch for such instructions as may be issued by visual signals.6. If in visual meteorological conditions, the aircraft shall:(1) continue to fly in visual meteorological conditions; land at the nearest suitable aerodrome, and report its arrival by the most expeditious means to the appropriate ATC unit.(2) if considered advisable, complete an IFR flight in accordance with (1).7. If in instrument meteorological conditions or when weather conditions are such that it does not appear feasible to complete the flight in accordance with Subsection 6. (2), the aircraft shall:(1) unless otherwise prescribed on the basis of regional air navigation agreement, in airspace where radar is not used in the provision of air traffic control, maintain the last assigned speed and level, or minimum flight altitude if higher, for a period of 20 minutes following the aircraft’s failure to report its position over a compulsory reporting point and thereafter adjust level and speed in accordance with the filed flight plan;(2) in airspace where radar is used in the provision of air traffic control, maintain the last assigned speed and level, or minimum flight altitude if higher, for a period of 7 minutes following：(a) the time the last assigned level or minimum flight altitude is reached; or(b) the time the transponder is set to Code 7600;or(c) the aircraft’s failure to report its position over a compulsory reporting point; which is later, and thereafter adjust level and speed in accordance with the field flight plan.(3) when being radar vectored or having been directed by ATC to proceed offset using RNAV without a specified limit, rejoin the current flight plan route no later than the next significant point, taking into consideration the applicable minimum flight altitude.(4) Proceed according to the current flight plan route to the appropriate designated navigation aid or fix serving the destination aerodrome and, when required to ensure compliance with (5) below, hold over this aid or fix until commencement of descent;(5) commence descent from the navigation aid or fix specified in (4) at, or as close as possible to, the expected approach time last received and acknowledged; or, if no expected approach time has been received and acknowledged, at, or as close as possible to, the estimated time of arrival resulting from the current flight plan;(6) complete a normal instrument approach procedure as specified for the designated navigation aid or fix; and(7) land, if possible, within 30 minutes after the estimated time of arrival or the last acknowledged expected approach time, whichever is later.
中文原文 飛航規則第50條
除民航局另有規定外，航空器因無線電通信失效無法遵守前條規定者，應採取下列措施：
一、試通其他適當頻率連絡之。
二、經採取前款措施無效時，試通其他航空器或航空電臺轉遞之，並將雷達代碼置於七六○○。
三、經採取前二款措施均無效時，分別以主頻率及次頻率盲目發送，發話前並冠以「盲目發送」，所發電文需每句重覆一遍。
四、通信失效如由於接收機故障，發話前應冠以「接收機故障盲目發送」，並告知下一次發話時間。
五、在管制機場操作區內活動及機場附近飛航之航空器，應注意可能由目視信號所發出之指示。
六、如為目視天氣情況，航空器應：
（一）繼續在目視天氣情況下飛航，降落於最近之適當機場，並以最迅速之方法向適當之航管單位提出到達報告。
（二）如經駕駛員合理考量，無法依前目完成飛航時，則依第七款完成儀器飛航。
七、如為儀器天氣情況或有前款第二目之情形時，航空器應：
（一）在未提供雷達服務之管制空域，除區域航行協議另有規定外，當航空器通過強制報告點且無法做位置報告時，保持最後指定之空速，並保持最後指定高度或最低之飛航高度取其較高者，經二十分鐘後，再依據填報之飛航計畫調整高度及空速。
（二）在提供雷達服務之管制空域，保持最後指定之空速，並保持最後指定之高度或最低之飛航高度取其較高者，取下列時間最遲者，經七分鐘後，再依據填報之飛航計畫調整高度及空速：1.到達最後指定高度或最低飛航高度之時間。
2.雷達代碼置於七六○○之時間。
3.航空器通過強制報告點無法做位置報告之時間。
（三）如經雷達引導或經航管許可區域航行偏航飛行且未頒發特定限制時，最遲應於下一顯著航點前重新加入飛航計畫所填之航路，並應考量適合之最低飛航高度。
（四）依現行飛航計畫繼續飛航至目的地機場適當之助航設施或定位點上空等待，直到符合第五目之規定時開始下降高度。
（五）依第四目規定，儘可能按最後接獲並領知之預計進場時間離開助航設施或定位點開始下降。
如事先未接獲預計進場時間，則儘可能按現行飛航計畫之預計到達時間開始下降。
（六）依特定之助航設施或定位點完成儀器進場程序。
（七）儘可能在現行飛航計畫之預計到達時間或最後領知之預計進場時間後，以較遲者為準，三十分鐘內降落。
一、試通其他適當頻率連絡之。
二、經採取前款措施無效時，試通其他航空器或航空電臺轉遞之，並將雷達代碼置於七六○○。
三、經採取前二款措施均無效時，分別以主頻率及次頻率盲目發送，發話前並冠以「盲目發送」，所發電文需每句重覆一遍。
四、通信失效如由於接收機故障，發話前應冠以「接收機故障盲目發送」，並告知下一次發話時間。
五、在管制機場操作區內活動及機場附近飛航之航空器，應注意可能由目視信號所發出之指示。
六、如為目視天氣情況，航空器應：
（一）繼續在目視天氣情況下飛航，降落於最近之適當機場，並以最迅速之方法向適當之航管單位提出到達報告。
（二）如經駕駛員合理考量，無法依前目完成飛航時，則依第七款完成儀器飛航。
七、如為儀器天氣情況或有前款第二目之情形時，航空器應：
（一）在未提供雷達服務之管制空域，除區域航行協議另有規定外，當航空器通過強制報告點且無法做位置報告時，保持最後指定之空速，並保持最後指定高度或最低之飛航高度取其較高者，經二十分鐘後，再依據填報之飛航計畫調整高度及空速。
（二）在提供雷達服務之管制空域，保持最後指定之空速，並保持最後指定之高度或最低之飛航高度取其較高者，取下列時間最遲者，經七分鐘後，再依據填報之飛航計畫調整高度及空速：1.到達最後指定高度或最低飛航高度之時間。
2.雷達代碼置於七六○○之時間。
3.航空器通過強制報告點無法做位置報告之時間。
（三）如經雷達引導或經航管許可區域航行偏航飛行且未頒發特定限制時，最遲應於下一顯著航點前重新加入飛航計畫所填之航路，並應考量適合之最低飛航高度。
（四）依現行飛航計畫繼續飛航至目的地機場適當之助航設施或定位點上空等待，直到符合第五目之規定時開始下降高度。
（五）依第四目規定，儘可能按最後接獲並領知之預計進場時間離開助航設施或定位點開始下降。
如事先未接獲預計進場時間，則儘可能按現行飛航計畫之預計到達時間開始下降。
（六）依特定之助航設施或定位點完成儀器進場程序。
（七）儘可能在現行飛航計畫之預計到達時間或最後領知之預計進場時間後，以較遲者為準，三十分鐘內降落。