B727 had less than standard wake turbulence separation from B747.

Attributes
ACN	280907
Time
Date	199408
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : err
State Reference	NJ
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : n90 tower : ewr
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B747 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
ASRS Report	280907
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Miss Distance	horizontal : 24000 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Inter Facility Coordination Failure Operational Error

Narrative:

Air carrier X is 4 mi intrail to air carrier Y and the intrail should be 5 mi behind a heavy jet. Each day I work at ewrt I see almost every aircraft behind a heavy less than required 7110.65 separation. I have written to you before about this problem and have made my supervisor and atm aware of this problem and yet no one can help this problem. I guess I could report an operational error, but that would not go over well with my fellow co-workers. The rule is simple, 5 mi behind a heavy, why can't N90 provide it! Callback conversation with reporter revealed the following information: reporter stated lack of heavy jet separation on final approach is an ongoing problem on final approach because of N90 interpretation of controller handbook. N90 interps separation to exist if the following aircraft is 1000 ft above the heavy even though both have been cleared for approach. Reporter stated N90 is now going through an evaluation and separation has improved but separation breaks down during rush periods.

Original NASA ASRS Text

Title: B727 HAD LESS THAN STANDARD WAKE TURB SEPARATION FROM B747.

Narrative: ACR X IS 4 MI INTRAIL TO ACR Y AND THE INTRAIL SHOULD BE 5 MI BEHIND A HVY JET. EACH DAY I WORK AT EWRT I SEE ALMOST EVERY ACFT BEHIND A HVY LESS THAN REQUIRED 7110.65 SEPARATION. I HAVE WRITTEN TO YOU BEFORE ABOUT THIS PROB AND HAVE MADE MY SUPVR AND ATM AWARE OF THIS PROB AND YET NO ONE CAN HELP THIS PROB. I GUESS I COULD RPT AN OPERROR, BUT THAT WOULD NOT GO OVER WELL WITH MY FELLOW CO-WORKERS. THE RULE IS SIMPLE, 5 MI BEHIND A HVY, WHY CAN'T N90 PROVIDE IT! CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED LACK OF HVY JET SEPARATION ON FINAL APCH IS AN ONGOING PROB ON FINAL APCH BECAUSE OF N90 INTERP OF CTLR HANDBOOK. N90 INTERPS SEPARATION TO EXIST IF THE FOLLOWING ACFT IS 1000 FT ABOVE THE HVY EVEN THOUGH BOTH HAVE BEEN CLRED FOR APCH. RPTR STATED N90 IS NOW GOING THROUGH AN EVALUATION AND SEPARATION HAS IMPROVED BUT SEPARATION BREAKS DOWN DURING RUSH PERIODS.

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.