Las local controller described an event when a medical emergency B757 may have overtaken a B737 duri...

Attributes
ACN	873170
Time
Date	201002
Local Time Of Day	0001-0600
Place
Locale Reference	LAS.Airport
State Reference	NV
Aircraft 1
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Landing
Route In Use	Visual Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Landing
Route In Use	Visual Approach
Flight Plan	IFR
Person 1
Function	Local
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Deviation - Procedural Clearance

Narrative:

A B737 was on a visual approach to runway 25L at about 4 mile final. A B757; a medical emergency; was turned by the final controller side-by-side with the B737 for a visual approach to 25R. According to the data tag; the B757 had the B737 in sight and maintaining visual separation. I noted the B757 might pass the B737 on final so I asked the B737 if he had the B757 in sight; he stated he did and was instructed to maintain visual separation. During the approach; it was hard to tell which aircraft was in front. It had appeared that the B757 touched down slightly in front of B737 breaking wake turbulence separation. Recommendation; the final controller should not have paired a 757 with a 737 on final. Had I been able to tell who was really in front; I may have had time to send the B737 around for the wake turbulence.

Original NASA ASRS Text

Title: LAS local controller described an event when a medical emergency B757 may have overtaken a B737 during a visual approach to parallel runways that required wake turbulence spacing.

Narrative: A B737 was on a visual approach to Runway 25L at about 4 mile final. A B757; a medical emergency; was turned by the final controller side-by-side with the B737 for a visual approach to 25R. According to the data tag; The B757 had the B737 in sight and maintaining visual separation. I noted the B757 might pass the B737 on final so I asked the B737 if he had the B757 in sight; he stated he did and was instructed to maintain visual separation. During the approach; it was hard to tell which aircraft was in front. It had appeared that the B757 touched down slightly in front of B737 breaking wake turbulence separation. Recommendation; the final controller should not have paired a 757 with a 737 on final. Had I been able to tell who was really in front; I may have had time to send the B737 around for the wake turbulence.

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.

Las local controller described an event when a medical emergency B757 may have overtaken a B737 during a visual approach to parallel runways that required wake turbulence spacing.