Two departing aircraft less than standard separation.

Attributes
ACN	86494
Time
Date	198804
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : las
State Reference	NV
Altitude	msl bound lower : 7000 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : las
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	departure sid : sid
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	departure other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 8200 flight time type : 180
ASRS Report	86494
Person 2
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Company aircraft departed about 1 min ahead of us on runway 25 at las airport. We were cleared for takeoff to fly the oasis 5 departure. After contacting departure, we were cleared unrestricted to 15000' and asked if we had company aircraft in sight at our 12 O'clock position. We replied, 'affirmative.' departure told us to maintain visual contact. We completed the left turn at 3 DME, and upon rolling level saw our traffic in a turn toward us. This surprised us, as we were expecting the aircraft to turn north as per a mead 7 departure. Departure never advised us company aircraft was cleared for a left turn. We leveled at 7000' and company passed over us 500' higher (according to departure control). The first officer was flying and I feel he had difficulty perceiving the aircraft' relationships, as the night was too dark to see an outside horizon when he rolled level. He may have stopped our ascent earlier. The night was too dark to maintain visual sep, which we never asked to do, and departure should have advised us of company aircraft's clearance to make a left turn.

Original NASA ASRS Text

Title: TWO DEPARTING ACFT LESS THAN STANDARD SEPARATION.

Narrative: COMPANY ACFT DEPARTED ABOUT 1 MIN AHEAD OF US ON RWY 25 AT LAS ARPT. WE WERE CLRED FOR TKOF TO FLY THE OASIS 5 DEP. AFTER CONTACTING DEP, WE WERE CLRED UNRESTRICTED TO 15000' AND ASKED IF WE HAD COMPANY ACFT IN SIGHT AT OUR 12 O'CLOCK POS. WE REPLIED, 'AFFIRMATIVE.' DEP TOLD US TO MAINTAIN VISUAL CONTACT. WE COMPLETED THE LEFT TURN AT 3 DME, AND UPON ROLLING LEVEL SAW OUR TFC IN A TURN TOWARD US. THIS SURPRISED US, AS WE WERE EXPECTING THE ACFT TO TURN N AS PER A MEAD 7 DEP. DEP NEVER ADVISED US COMPANY ACFT WAS CLRED FOR A LEFT TURN. WE LEVELED AT 7000' AND COMPANY PASSED OVER US 500' HIGHER (ACCORDING TO DEP CTL). THE F/O WAS FLYING AND I FEEL HE HAD DIFFICULTY PERCEIVING THE ACFT' RELATIONSHIPS, AS THE NIGHT WAS TOO DARK TO SEE AN OUTSIDE HORIZON WHEN HE ROLLED LEVEL. HE MAY HAVE STOPPED OUR ASCENT EARLIER. THE NIGHT WAS TOO DARK TO MAINTAIN VISUAL SEP, WHICH WE NEVER ASKED TO DO, AND DEP SHOULD HAVE ADVISED US OF COMPANY ACFT'S CLRNC TO MAKE A LEFT TURN.

Data retrieved from NASA's ASRS site as of August 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.