Phl controller witnessed an asde-X conflict alert that was unheeded by the local controller. The rep...

Narrative:

I was relieving clearance delivery; the supervisor was also being relieved. The asde-X went off for 27R and 35 converging. The controller on local east took no action. Both 27R (an E190) and 35 (a CRJ2) aircraft landed and a [runaway] 35 departure was at the end of the runway. I don't know if this was legal; it was certainly the tightest 27R and 35 I have ever seen in many years at phl; and this operation is our standard. I believe this to be very dangerous; even if the operation were legal. I think it is highly likely that the pilots may choose to go around on their own; and if both aircraft's pilots made that decision simultaneously it could be disastrous given that both would be a tie in the air with noses up and unable to see one another. I believe this has been reported as an issue in the past. There was to have been a work group to study this operation. I do not think it was ever formed. So far as I know; management at phl has taken no action. I suggest this work group be formed. It has also generally been practice to send one aircraft [around]if the asde goes off with the converging when in this operation. I don't know if that is suggested practice; but if so; perhaps the facility should be reminded of it.

Original NASA ASRS Text

Title: PHL Controller witnessed an ASDE-X conflict alert that was unheeded by the Local Controller. The reporter notes this type of no-action event is on-going and very dangerous.

Narrative: I was relieving Clearance Delivery; the Supervisor was also being relieved. The ASDE-X went off for 27R and 35 converging. The Controller on Local East took no action. Both 27R (an E190) and 35 (a CRJ2) aircraft landed and a [Runaway] 35 departure was at the end of the runway. I don't know if this was legal; it was certainly the tightest 27R and 35 I have ever seen in many years at PHL; and this operation is our standard. I believe this to be very dangerous; even if the operation were legal. I think it is highly likely that the pilots may choose to go around on their own; and if both aircraft's pilots made that decision simultaneously it could be disastrous given that both would be a tie in the air with noses up and unable to see one another. I believe this has been reported as an issue in the past. There was to have been a work group to study this operation. I do not think it was ever formed. So far as I know; management at PHL has taken no action. I suggest this work group be formed. It has also generally been practice to send one aircraft [around]if the ASDE goes off with the converging when in this operation. I don't know if that is suggested practice; but if so; perhaps the facility should be reminded of it.

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.

Attributes
ACN	1079052
Time
Date	201304
Local Time Of Day	1801-2400
Place
Locale Reference	PHL.Airport
State Reference	PA
Aircraft 1
Make Model Name	Regional Jet 200 ER/LR (CRJ200)
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Route In Use	Visual Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Dash 8 Series Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Route In Use	None
Flight Plan	IFR
Person 1
Function	Flight Data / Clearance Delivery
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types

Phl controller witnessed an asde-X conflict alert that was unheeded by the local controller. The reporter notes this type of no-action event is on-going and very dangerous.