Air carrier X misconception about use of TCASII for standard separation.

Attributes
ACN	211446
Time
Date	199206
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : stl
State Reference	MO
Altitude	msl bound lower : 24000 msl bound upper : 24000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zkc
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
ASRS Report	211446
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	other anomaly other
Independent Detector	other controllera
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

This conversation occurred between myself and the pilot of air carrier X. Controller: descend and maintain FL240, reduce speed to 250. Pilot: how much room do you need center? Controller: about what I have now. Pilot: ok -- we have the 2 jets on the box, we'll just follow them in. The conversation was cordial and well- intentioned, I'm sure, but did that mean the crew was going to disregard the speed restriction and keep the in- trail by themselves? A lot of questions rolled through my mind after the exchange. By the way -- I didn't respond.

Original NASA ASRS Text

Title: ACR X MISCONCEPTION ABOUT USE OF TCASII FOR STANDARD SEPARATION.

Narrative: THIS CONVERSATION OCCURRED BTWN MYSELF AND THE PLT OF ACR X. CTLR: DSND AND MAINTAIN FL240, REDUCE SPD TO 250. PLT: HOW MUCH ROOM DO YOU NEED CTR? CTLR: ABOUT WHAT I HAVE NOW. PLT: OK -- WE HAVE THE 2 JETS ON THE BOX, WE'LL JUST FOLLOW THEM IN. THE CONVERSATION WAS CORDIAL AND WELL- INTENTIONED, I'M SURE, BUT DID THAT MEAN THE CREW WAS GOING TO DISREGARD THE SPD RESTRICTION AND KEEP THE IN- TRAIL BY THEMSELVES? A LOT OF QUESTIONS ROLLED THROUGH MY MIND AFTER THE EXCHANGE. BY THE WAY -- I DIDN'T RESPOND.

Data retrieved from NASA's ASRS site as of July 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.