Narrative:

Upon arrival at mem; ATIS included the notation that 'recat wake turbulence separation standards in effect.' unsure of what that meant; crew queried ATC and received an explanation. ATC planned to sequence our flight for arrival 3.5 NM behind a heavy md-11. ATC complied with our request for additional spacing but informed us that had they been busy; our request would not have been accommodated and we would have been placed on the approach 3.5 miles behind the heavy aircraft. Cause; the FAA has apparently decided that current spacing is too conservative and that more aircraft can be handled with reduced spacing. Suggestions; while 3.5 NM behind a heavy aircraft might seem like a good idea from a desk in washington; in the real world; that appears to compromise safety. It also appears problematic that ATC would reject a pilot request for additional spacing based on these arbitrary standards.

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Original NASA ASRS Text

Title: MEM air carrier arrival expressed concern regarding the RECAT Wake Turbulence Separation being utilized.

Narrative: Upon arrival at MEM; ATIS included the notation that 'RECAT Wake Turbulence Separation Standards In Effect.' Unsure of what that meant; crew queried ATC and received an explanation. ATC planned to sequence our flight for arrival 3.5 NM behind a Heavy MD-11. ATC complied with our request for additional spacing but informed us that had they been busy; our request would not have been accommodated and we would have been placed on the approach 3.5 miles behind the heavy aircraft. Cause; The FAA has apparently decided that current spacing is too conservative and that more aircraft can be handled with reduced spacing. Suggestions; while 3.5 NM behind a Heavy aircraft might seem like a good idea from a desk in Washington; in the real world; that appears to compromise safety. It also appears problematic that ATC would reject a pilot request for additional spacing based on these arbitrary standards.

Data retrieved from NASA's ASRS site as of July 2013 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.