Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 5
Confusion; Training / Qualification
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Procedure
A small twin was enroute to MYLS descending from FL210 to FL190. When the small twin was leaving FL198 or FL199; a medium transport was cleared to from FL210 to FL200. At this time the medium transport was overtaking the small twin about 7 miles behind. I had just received a briefing and I was D61. During this event; there was OJTI going on at R61 and the clearance was issued by the Developmental. The R44 Controller mentioned to the R61 team 'watch out for the little guy' in reference to the small twin when he heard the clearance for the medium transport. That was discussed briefly and the R61 Controller conducting the training mentioned that the small twin had left FL200 and he considered it so the altitude was available for the medium transport. Like I mentioned above; I was the D-Side during this time and although I saw and heard the clearance after I heard the Controller conducting the OJT say that he was looking at it and the small twin was out of FL200; I moved on with other D-Side duties.This event highlights the confusion surrounding vertical separation procedures described in 7110.65 paragraph 5-5-5. The rule is vague and it even states that standard separation might not be maintained at all times while using this rule. Further more the CBI [Computer Based Instruction] that we complete about radar separation gives a bad example on the application of this rule. The example is about a F18 requesting a climb after a prop reports leaving the altitude. According to the CBI; that altitude is available and ok to assign as long as you consider aircraft performance. In my opinion; that is an example of when not to use the rule; but the CBI teaches that it is ok to do so. The event between the small twin and the medium transport can be thought of as similar to the F18 and prop example. The point is that the 5-5-5 Paragraph B rule is vague and a more clear description of its application is needed in order to avoid misapplying it. Also the CBI should be consistent with the interpretation of the rule.
ZMA Controller describes situation related to vacated altitude separation and his concern that the application of this rule needs a more clear description.