I90 controller described a loss of separation event when one developmental was relieving another; on...

Narrative:

A developmental was relieving another developmental with no cpc (certified professional controller) plugged into the position. The briefing developmental turned air carrier X to a heading that conflicted with air carrier Y who was established; descending on the localizer runway 12R. Recommendation; the 2 developmentals were the only controllers plugged into the position at the time the briefing developmental issued the heading that created a conflict. The cpc instructing the briefing developmental would not have been able to correct the situation even if the cpc was aware of the problem as the cpc was no longer able to override the developmental. My recommendation would be to always have a cpc plugged into a position while a developmental is working to avoid this from reoccurring.

Original NASA ASRS Text

Title: I90 Controller described a loss of separation event when one developmental was relieving another; one issued a conflicting heading; but no CPC was plugged in to hear and/or correct the error.

Narrative: A developmental was relieving another developmental with no CPC (Certified Professional Controller) plugged into the position. The briefing developmental turned Air Carrier X to a heading that conflicted with Air Carrier Y who was established; descending on the Localizer Runway 12R. Recommendation; the 2 developmentals were the only controllers plugged into the position at the time the briefing developmental issued the heading that created a conflict. The CPC instructing the briefing developmental would not have been able to correct the situation even if the CPC was aware of the problem as the CPC was no longer able to override the developmental. My recommendation would be to always have a CPC plugged into a position while a developmental is working to avoid this from reoccurring.

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	869548
Time
Date	201001
Local Time Of Day	1201-1800
Place
Locale Reference	I90.TRACON
State Reference	TX
Aircraft 1
Make Model Name	Commercial Fixed Wing
Flight Phase	Cruise
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy

I90 controller described a loss of separation event when one developmental was relieving another; one issued a conflicting heading; but no cpc was plugged in to hear and/or correct the error.