Enroute controller described an alleged loss of separation event when radar contact was lost between...

Narrative:

Aircraft X & aircraft Y where 2 of 3 CH47's en route IFR at 050. They were radar separated and both under radar control and in trail; estimating around 8-10 miles in trail. When they got southeast of abc VOR we lost radar on aircraft Y because of limited radar coverage in the area. We advised the aircraft that radar contact was lost; advised aircraft X that he could expect the same thing and decided to climb to 070 for better radar coverage. We later picked up aircraft Y back on radar. I came in the next day; and before the end of the day my supervisor advised me that quality assurance considered what had happened as an operational error because the 2 aircraft were not 'non-radar' separated and I needed 10 minutes or 20 miles between the two the instant aircraft Y dropped off radar coverage. If this is considered an operational error; then my recommendations would be to put every single aircraft we work on that sector below 7;000 ft on a non-radar route and non-radar separated regardless if we have them on radar or not.

Original NASA ASRS Text

Title: Enroute Controller described an alleged loss of separation event when RADAR contact was lost between two IFR helicopters that were appropriately separated prior to the RADAR loss; the facility determination indicating that non-RADAR separation was needed immediately.

Narrative: Aircraft X & Aircraft Y where 2 of 3 CH47's en route IFR at 050. They were RADAR separated and both under RADAR control and in trail; estimating around 8-10 miles in trail. When they got Southeast of ABC VOR we lost RADAR on Aircraft Y because of limited RADAR coverage in the area. We advised the aircraft that RADAR contact was lost; advised Aircraft X that he could expect the same thing and decided to climb to 070 for better RADAR coverage. We later picked up Aircraft Y back on RADAR. I came in the next day; and before the end of the day my supervisor advised me that Quality Assurance considered what had happened as an Operational Error because the 2 aircraft were not 'non-RADAR' separated and I needed 10 minutes or 20 miles between the two the instant Aircraft Y dropped off RADAR coverage. If this is considered an operational error; then my recommendations would be to put every single aircraft we work on that sector below 7;000 FT on a non-RADAR route and non-RADAR separated regardless if we have them on RADAR or not.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	976874
Time
Date	201110
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Aircraft 1
Make Model Name	Chinook (CH-47)
Flight Phase	Cruise
Flight Plan	IFR
Person 1
Function	Enroute
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy

Enroute controller described an alleged loss of separation event when radar contact was lost between two IFR helicopters that were appropriately separated prior to the radar loss; the facility determination indicating that non-radar separation was needed immediately.