Narrative:

At phx there [are] two departure sectors; north departures navajo and south departures santan. All northbound departures go out to 9 miles on west flow and turn to a 360 heading and all fly the same departure on east flow until departure sectors separate them. The tower launches most of our traffic visually without regard to aircraft type or aircraft characteristics. So a northbound can be visual with another northbound departure even though the courses do not diverge until the departure sector separates the two. In many cases there are over takes and situations where the trail aircraft out climbs the lead aircraft making it impossible to maintain visual separation with the lead aircraft. This is a rather big issue at phx that never gets resolved. In this case an A321 was launched on a Silow2 departure and an A319 was launched on the SJN6 departure with less than one and a half miles between them. The A319 had a 20 KT overtake and was well out climbing the A321. At the 9 DME the A319 was 1;500 ft above and half mile in trail. Due to this I know there is no was they can still have visual separation with the A321. I stopped the A321 climb and turned the A319 to provide adequate and safe separation. We should not allow visual separation on same direction sids. No visual on two north or south bound departures. Visual should only be applied between a north and a south bound departure. Our tower launches departures visually even when there is no need; there can be only 2 aircraft on the field and they will be launched visually.

Related reports:

Google
 

Original NASA ASRS Text

Title: P50 Controller expressed concern regarding the visual separation techniques used by PHX Tower and the resulting wake turbulence concerns.

Narrative: At PHX there [are] two departure sectors; North Departures Navajo and South Departures Santan. All northbound departures go out to 9 miles on west flow and turn to a 360 heading and all fly the same departure on east flow until Departure Sectors separate them. The Tower launches most of our traffic visually without regard to aircraft type or aircraft characteristics. So a northbound can be visual with another northbound departure even though the courses do not diverge until the Departure Sector separates the two. In many cases there are over takes and situations where the trail aircraft out climbs the lead aircraft making it impossible to maintain visual separation with the lead aircraft. This is a rather big issue at PHX that never gets resolved. In this case an A321 was launched on a Silow2 departure and an A319 was launched on the SJN6 departure with less than one and a half miles between them. The A319 had a 20 KT overtake and was well out climbing the A321. At the 9 DME the A319 was 1;500 FT above and half mile in trail. Due to this I know there is no was they can still have visual separation with the A321. I stopped the A321 climb and turned the A319 to provide adequate and safe separation. We should not allow visual separation on same direction SIDs. No visual on two north or south bound departures. Visual should only be applied between a north and a south bound departure. Our Tower launches departures visually even when there is no need; there can be only 2 aircraft on the field and they will be launched visually.

Data retrieved from NASA's ASRS site as of July 2013 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.