Heading deviation, less than standard separation, airborne conflict, delayed frequency change.

Attributes
ACN	96200
Time
Date	198810
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : dfw
State Reference	TX
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : dfw
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent : approach
Route In Use	approach : visual enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Large Transport
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 50 flight time total : 9000 flight time type : 50
ASRS Report	96200
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation other anomaly other other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance
Consequence	Other
Miss Distance	horizontal : 2000 vertical : 1500
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While on downwind we received a clearance including a turn, descent and instructions to look for traffic. We were also given a frequency change but were not cleared for a visual approach. Due to the complexity of the clearance there was a bit of a delay before the frequency change was accomplished. The vector put us on the runway 35R extended centerline by the time the new controller was contacted. The new controller vectored us out of our traffic sequence and resequenced us to runway 36L. Apparently this was due to a traffic conflict, possibly arising out of the delayed frequency change. The problem was the bulk of information given in the clearance at a point so close to the final approach area. Also the clearance did not include clearance for the visual approach. This necessitated following a vector (base leg) that in less than a minute must be changed. This is a set up for a conflict situation if even the slightest communication hitch arises. The problem could be resolved by giving frequency changes while on either downwind or final or after clearance for the visual approach. Don't, however, give the frequency change while on a tight base leg heading assignment.

Original NASA ASRS Text

Title: HEADING DEVIATION, LESS THAN STANDARD SEPARATION, AIRBORNE CONFLICT, DELAYED FREQ CHANGE.

Narrative: WHILE ON DOWNWIND WE RECEIVED A CLRNC INCLUDING A TURN, DSCNT AND INSTRUCTIONS TO LOOK FOR TFC. WE WERE ALSO GIVEN A FREQ CHANGE BUT WERE NOT CLRED FOR A VISUAL APCH. DUE TO THE COMPLEXITY OF THE CLRNC THERE WAS A BIT OF A DELAY BEFORE THE FREQ CHANGE WAS ACCOMPLISHED. THE VECTOR PUT US ON THE RWY 35R EXTENDED CENTERLINE BY THE TIME THE NEW CTLR WAS CONTACTED. THE NEW CTLR VECTORED US OUT OF OUR TFC SEQUENCE AND RESEQUENCED US TO RWY 36L. APPARENTLY THIS WAS DUE TO A TFC CONFLICT, POSSIBLY ARISING OUT OF THE DELAYED FREQ CHANGE. THE PROB WAS THE BULK OF INFO GIVEN IN THE CLRNC AT A POINT SO CLOSE TO THE FINAL APCH AREA. ALSO THE CLRNC DID NOT INCLUDE CLRNC FOR THE VISUAL APCH. THIS NECESSITATED FOLLOWING A VECTOR (BASE LEG) THAT IN LESS THAN A MINUTE MUST BE CHANGED. THIS IS A SET UP FOR A CONFLICT SITUATION IF EVEN THE SLIGHTEST COM HITCH ARISES. THE PROB COULD BE RESOLVED BY GIVING FREQ CHANGES WHILE ON EITHER DOWNWIND OR FINAL OR AFTER CLRNC FOR THE VISUAL APCH. DON'T, HOWEVER, GIVE THE FREQ CHANGE WHILE ON A TIGHT BASE LEG HDG ASSIGNMENT.

Data retrieved from NASA's ASRS site as of August 2007 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.