| Date of Interpretation |
Applicable 7110.65 section |
| 6/6/2016 |
5-5-9 |
Background Information
This is in response to a request for an interpretation of Federal Aviation Administration (FAAO) 7110.65, paragraph 5-5-9b, Separation from Obstructions.
Question
1. If an aircraft is on radar vectors and has passed the depicted obstacle for that particular MVA, what can ATC descend to?
2. If an aircraft is on a radar vector and has passed the depicted obstacle for that particular MVA, can ATC use the altitude of the next lower MVA for which the aircraft is vectored towards?
3. In 5-5-9b states vertical separation may be discontinued after passing a depicted obstruction. If the obstruction is depicted in the MVA sector, when an aircraft passes that obstruction what vertical separation must then be applied to?
Reply
1. Question one first requires that the aircraft be observed to be overflying or passing abeam the depicted obstacle and the obstacle is buffered from adjacent airspace by a depicted 3/5 NM MVA buffer area. This buffer requirement depicts the obstacle as controlling and accounts for surrounding terrain of like altitude. The obstacle itself must be a prominent man-made obstruction. When these conditions are met, the aircraft may be descended to the adjacent lower MVA altitude.
2. Yes, provided the conditions in the answer to question 1 are met.
3. Question 3 requires that the depicted obstacle be contained within a 3/5 NM MVA buffer area. Simply depicting an obstruction, un-buffered within an MVA sector, passing it and then descending, is a misapplication of paragraph 5-5-9b. When a portion of an obstacle buffer is inclusive of the MVA sector boundary, and the obstacle is depicted, the aircraft may be descended to the adjacent lower MVA altitude.
