Houston tower controller and air carrier pilot reported a possible pilot deviation that led to a los...

Attributes
ACN	1419857
Time
Date	201701
Local Time Of Day	1801-2400
Place
Locale Reference	IAH.Tower
State Reference	TX
Aircraft 1
Make Model Name	A319
Operating Under FAR Part	Part 121
Flight Phase	Initial Climb
Route In Use	Vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	EMB ERJ 170/175 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Initial Climb
Flight Plan	IFR
Person 1
Function	Local
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 20
Person 2
Function	Pilot Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Type 6800
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

Narrative:

VFR day. Departing runways 33L/right. Aircraft X turn left heading 110; runway 33L cleared for take off (cft). He went wide so; I waited a bit longer to clear my next departure. Aircraft Y turn left heading 110; runway 33L cft. Aircraft Y turned a bit tighter but not much. I continued working other traffic while keeping an eye on these two aircraft. I was watching both visually (out the window; clear day) and on radar. Aircraft X was told to contact departure.it never appeared to me that radar separation would be lost or that these two aircraft were in an unsafe proximity to each other. However; I wanted the aircraft to be in a nice straight line out the gate. I issued aircraft Y to fly heading 180 to widen him out a bit behind aircraft X. No response from aircraft Y. I tried him again and still; no response. I then called the departure controller working the sector and gave him control on contact with aircraft Y reference aircraft X. I re-attempted to contact aircraft Y both on tower frequency and guard. Still no response. Approach finally called back and said he had aircraft Y on frequency. The departure controller then asked if I had the two aircraft visually out the window; in which I replied yes. Not sure what happened on pilot's side with aircraft Y.

Original NASA ASRS Text

Title: Houston Tower Controller and air carrier pilot reported a possible pilot deviation that led to a loss of separation with previous departure; however the pilot was unaware of any problem.

Narrative: VFR day. Departing runways 33L/R. Aircraft X turn left heading 110; Runway 33L Cleared For Take Off (CFT). He went wide so; I waited a bit longer to clear my next departure. Aircraft Y turn left heading 110; Runway 33L CFT. Aircraft Y turned a bit tighter but not much. I continued working other traffic while keeping an eye on these two aircraft. I was watching both visually (out the window; clear day) and on radar. Aircraft X was told to contact departure.It never appeared to me that radar separation would be lost or that these two aircraft were in an unsafe proximity to each other. However; I wanted the aircraft to be in a nice straight line out the gate. I issued Aircraft Y to fly heading 180 to widen him out a bit behind Aircraft X. No response from Aircraft Y. I tried him again and still; no response. I then called the departure controller working the sector and gave him control on contact with Aircraft Y reference Aircraft X. I re-attempted to contact Aircraft Y both on tower frequency and guard. Still no response. Approach finally called back and said he had Aircraft Y on frequency. The departure controller then asked if I had the two aircraft visually out the window; in which I replied yes. Not sure what happened on pilot's side with Aircraft Y.

Data retrieved from NASA's ASRS site 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.

Houston tower controller and air carrier pilot reported a possible pilot deviation that led to a loss of separation with previous departure; however the pilot was unaware of any problem.