Narrative:

While training a developmental on local control, 2 IFR aircraft called for departure. Small aircraft X was cleared to depart off runway 29 at XX36Z and assigned an initial heading of 250 degrees. When small aircraft X was 2 NM from the departure end of runway 29 (as determined by BRITE conrac in the tower cabin attendant), small aircraft Y was issued a 250 degree heading and cleared to depart at XX41Z. (Considering that runway 29 is more than 1 NM in length, I considered this an application of paragraph 3-104 of 7110.65F.) apparently, small aircraft Y overtook small aircraft X after he was switched over to bos approach frequency. When I realized that sep was probably going to decrease to less than 3 NM (7110.65F, paragraph 5-72 a.1), I advised bos approach (through my flight data personnel) that he had permission to turn small aircraft Y as he felt necessary.

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Original NASA ASRS Text

Title: DEPARTING IFR ACFT OVERTOOK A PRECEDING IFR ACFT WHICH RESULTED IN LESS THAN STANDARD SEPARATION (RADAR).

Narrative: WHILE TRNING A DEVELOPMENTAL ON LCL CTL, 2 IFR ACFT CALLED FOR DEP. SMA X WAS CLRED TO DEPART OFF RWY 29 AT XX36Z AND ASSIGNED AN INITIAL HDG OF 250 DEGS. WHEN SMA X WAS 2 NM FROM THE DEP END OF RWY 29 (AS DETERMINED BY BRITE CONRAC IN THE TWR CAB), SMA Y WAS ISSUED A 250 DEG HDG AND CLRED TO DEPART AT XX41Z. (CONSIDERING THAT RWY 29 IS MORE THAN 1 NM IN LENGTH, I CONSIDERED THIS AN APPLICATION OF PARAGRAPH 3-104 OF 7110.65F.) APPARENTLY, SMA Y OVERTOOK SMA X AFTER HE WAS SWITCHED OVER TO BOS APCH FREQ. WHEN I REALIZED THAT SEP WAS PROBABLY GOING TO DECREASE TO LESS THAN 3 NM (7110.65F, PARAGRAPH 5-72 A.1), I ADVISED BOS APCH (THROUGH MY FLT DATA PERSONNEL) THAT HE HAD PERMISSION TO TURN SMA Y AS HE FELT NECESSARY.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.