Flight crew question about ATCT local controller phraseology.

Attributes
ACN	98681
Time
Date	198811
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : dfw
State Reference	TX
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	ground : holding
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : instrument pilot : flight engineer pilot : commercial pilot : cfi
Experience	flight time last 90 days : 150 flight time total : 5000 flight time type : 1750
ASRS Report	98681
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : radar
Events
Anomaly	non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

Tower issued the following clearance (frequency 126.55) 'cleared into position and hold, maintain visual separation with departing traffic.' this is a double clearance which is prohibited by the ATC handbook. This clearance is a safety hazard due to the fact that if only part of the clearance is heard, the aircraft in question could mistakenly commence takeoff roll. Due to the fact that the amount of hold time is unknown, the pilot may, in fact, not be able to maintain visual separation once he is cleared for takeoff. Dfw tower should cease issuing this clearance.

Original NASA ASRS Text

Title: FLT CREW QUESTION ABOUT ATCT LCL CTLR PHRASEOLOGY.

Narrative: TWR ISSUED THE FOLLOWING CLRNC (FREQ 126.55) 'CLRED INTO POSITION AND HOLD, MAINTAIN VISUAL SEPARATION WITH DEPARTING TFC.' THIS IS A DOUBLE CLRNC WHICH IS PROHIBITED BY THE ATC HANDBOOK. THIS CLRNC IS A SAFETY HAZARD DUE TO THE FACT THAT IF ONLY PART OF THE CLRNC IS HEARD, THE ACFT IN QUESTION COULD MISTAKENLY COMMENCE TKOF ROLL. DUE TO THE FACT THAT THE AMOUNT OF HOLD TIME IS UNKNOWN, THE PLT MAY, IN FACT, NOT BE ABLE TO MAINTAIN VISUAL SEPARATION ONCE HE IS CLRED FOR TKOF. DFW TWR SHOULD CEASE ISSUING THIS CLRNC.

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.