Air carrier expressed concern regarding ATC's attempts to expedite las departure traffic by utilizin...

Narrative:

I want to alert safety officials of a situation/procedure I believe is unsafe. Increasingly ATC tower personnel are attempting to expedite traffic flow by clearing aircraft for takeoff with preceding traffic in sight. My concern is that more and more they are doing this while another aircraft is still on takeoff roll. On this particular day they cleared a jet for takeoff (who was holding short at an intersection taxiway) just; as the preceding aircraft was rolling by and maybe doing 20 - 30 KTS. Very unsafe and improper procedures; please address.

Original NASA ASRS Text

Title: Air carrier expressed concern regarding ATC's attempts to expedite LAS departure traffic by utilizing visual separation between departing aircraft prior to achieving standard separation.

Narrative: I want to alert safety officials of a situation/procedure I believe is unsafe. Increasingly ATC Tower personnel are attempting to expedite traffic flow by clearing aircraft for takeoff with preceding traffic in sight. My concern is that more and more they are doing this while another aircraft is still on takeoff roll. On this particular day they cleared a jet for takeoff (who was holding short at an intersection taxiway) just; as the preceding aircraft was rolling by and maybe doing 20 - 30 KTS. Very unsafe and improper procedures; please address.

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	839434
Time
Date	200905
Local Time Of Day	1201-1800
Place
Locale Reference	LAS.Airport
State Reference	NV
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Flight Plan	IFR
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types

Air carrier expressed concern regarding ATC's attempts to expedite las departure traffic by utilizing visual separation between departing aircraft prior to achieving standard separation.