Narrative:

On 4/xx/90, I reported to work at N90. At XX49 local I assumed control of the hpn or position known as 'nyack.' hpn was departing runway 16 at the time. At XX50 local an light transport X departed hpn runway 16 and did not comply with the prescribed departure procedure. As a result I took action to maintain sep of light transport X (altitude 3000') from lga arrival traffic above him at 4000' on a southwest heading to land at lga. This action required a right turn to a northwest heading (340 degrees) to bring light transport X to a point west of hpn where a higher altitude could be obtained. Unknown to me (reasons to be listed below) at XX52 local hpn tower departed light transport Y off runway 16. The ARTS tag on light transport Y did ont acquire, nor was I in radio communication with the aircraft. At XX53, after observing a target that appeared to have departed hpn runway 16 and was making the prescried IFR climb, I took further action to separate light transport X from, at this time, unk traffic. These 2 aircraft were 1/2 mi and 300' apart at their closest. Why was I unaware of light transport Y? 1) no departure strip was posted. 2) no 'rolling' departure call was issued by hpn tower. 3) light transport Y was issued the wrong departure frequency. 4) no automatic ARTS tag for a period of 2 mins!

Related reports:

Google
 

Original NASA ASRS Text

Title: PLT OF ACFT X DEVIATED FROM ASSIGNED SID. ACFT Y FLYING THE SAME SID OVERTOOK ACFT X, WHICH RESULTED IN LESS THAN STANDARD SEPARATION.

Narrative: ON 4/XX/90, I RPTED TO WORK AT N90. AT XX49 LCL I ASSUMED CTL OF THE HPN OR POS KNOWN AS 'NYACK.' HPN WAS DEPARTING RWY 16 AT THE TIME. AT XX50 LCL AN LTT X DEPARTED HPN RWY 16 AND DID NOT COMPLY WITH THE PRESCRIBED DEP PROC. AS A RESULT I TOOK ACTION TO MAINTAIN SEP OF LTT X (ALT 3000') FROM LGA ARR TFC ABOVE HIM AT 4000' ON A SW HDG TO LAND AT LGA. THIS ACTION REQUIRED A RIGHT TURN TO A NW HDG (340 DEGS) TO BRING LTT X TO A POINT W OF HPN WHERE A HIGHER ALT COULD BE OBTAINED. UNKNOWN TO ME (REASONS TO BE LISTED BELOW) AT XX52 LCL HPN TWR DEPARTED LTT Y OFF RWY 16. THE ARTS TAG ON LTT Y DID ONT ACQUIRE, NOR WAS I IN RADIO COM WITH THE ACFT. AT XX53, AFTER OBSERVING A TARGET THAT APPEARED TO HAVE DEPARTED HPN RWY 16 AND WAS MAKING THE PRESCRIED IFR CLB, I TOOK FURTHER ACTION TO SEPARATE LTT X FROM, AT THIS TIME, UNK TFC. THESE 2 ACFT WERE 1/2 MI AND 300' APART AT THEIR CLOSEST. WHY WAS I UNAWARE OF LTT Y? 1) NO DEP STRIP WAS POSTED. 2) NO 'ROLLING' DEP CALL WAS ISSUED BY HPN TWR. 3) LTT Y WAS ISSUED THE WRONG DEP FREQ. 4) NO AUTO ARTS TAG FOR A PERIOD OF 2 MINS!

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.