Local controller departed a B757 behind a slow climbing heavy DC8 without the required separation.

Attributes
ACN	339848
Time
Date	199606
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : slc
State Reference	UT
Altitude	msl bound lower : 7000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	tracon : slc tower : rdu
Operator	common carrier : air carrier
Make Model Name	DC-8 10 20
Operating Under FAR Part	Part 121
Flight Phase	climbout : initial
Route In Use	departure other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : initial
Route In Use	departure other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Experience	controller military : 4 controller radar : 12 flight time total : 5000
ASRS Report	339848
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 22800 vertical : 300
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Air carrier #1 heavy DC8 on departure slow climb and close to MVA. I instructed him to increase rate of turn for MVA. Replied roger. Next departure was B757, 3.8 mi behind heavy. 5 mi is required, non waiverable and visible separation cannot be applied. Aircraft on downwind at 9000 ft. Departure climbing to 8000 ft. DC8 was about 5 flying mi from runway end still only out of about 6800 ft. B757 was 3.8 mi behind already climbing out of 6500 ft. Unable to climb either aircraft due to downwind traffic, could not turn because of close proximity to terrain and final was descending abeam airport.

Original NASA ASRS Text

Title: LCL CTLR DEPARTED A B757 BEHIND A SLOW CLBING HVY DC8 WITHOUT THE REQUIRED SEPARATION.

Narrative: ACR #1 HVY DC8 ON DEP SLOW CLB AND CLOSE TO MVA. I INSTRUCTED HIM TO INCREASE RATE OF TURN FOR MVA. REPLIED ROGER. NEXT DEP WAS B757, 3.8 MI BEHIND HVY. 5 MI IS REQUIRED, NON WAIVERABLE AND VISIBLE SEPARATION CANNOT BE APPLIED. ACFT ON DOWNWIND AT 9000 FT. DEP CLBING TO 8000 FT. DC8 WAS ABOUT 5 FLYING MI FROM RWY END STILL ONLY OUT OF ABOUT 6800 FT. B757 WAS 3.8 MI BEHIND ALREADY CLBING OUT OF 6500 FT. UNABLE TO CLB EITHER ACFT DUE TO DOWNWIND TFC, COULD NOT TURN BECAUSE OF CLOSE PROX TO TERRAIN AND FINAL WAS DSNDING ABEAM ARPT.

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.