A B737 flight crew receive a TCASII RA and descend to avoid a learjet.

Attributes
ACN	612628
Time
Date	200403
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : zdc.artcc
State Reference	VA
Altitude	msl single value : 26000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdc.artcc
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : enroute altitude change cruise : level
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zdc.artcc
Operator	other
Make Model Name	Gates Learjet Corp Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	cruise : level cruise : enroute altitude change
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 160 flight time total : 18000 flight time type : 160
ASRS Report	612628
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	conflict : airborne critical non adherence : required legal separation
Independent Detector	aircraft equipment : tcas other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew faa : investigated
Miss Distance	horizontal : 18000 vertical : 400
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	ATC Human Performance

Narrative:

Traffic coming directly at us from 1 O'clock position and descending, learjet (800 ft above us) caused a TA. High rate of closure caused almost immediate RA of 'descend.' we descended by 500 ft to FL255. The plane climbed. Minimum vertical separation was 400 ft at approximately 3 mi, but a little more than that (not sure how much) when traffic passed directly overhead. Upon arrival at atl, I telephoned ZDC. The supervisor said it was 'controller error.' thank god for TCASII, and also that pilots responded to their RA. Recognizing his ZDC controller had told him to 'expedite descent,' aircraft Y refused, instead informing controller they were climbing to comply with TCASII RA. Had they listened to ATC, rather than their RA, a fatal accident might very well have occurred, and would have claimed the lives of 130+ people. I immediately recalled the fatal midair in europe, and how it was caused by one of the crews listening to ATC, rather than their TCASII. I strongly feel that this topic should continue to be emphasized in our training system, to include the military aviation community. When the closing velocity of 2 aircraft is 1000 mph or more, there simply is no way ATC can react to the above scenario in sufficient time. Only TCASII, working at the speed of light, can handle the job. All pilots should be aware and trained to respond to a TCASII RA, and to disregard ATC in this type of situation.

Original NASA ASRS Text

Title: A B737 FLT CREW RECEIVE A TCASII RA AND DSND TO AVOID A LEARJET.

Narrative: TFC COMING DIRECTLY AT US FROM 1 O'CLOCK POS AND DSNDING, LEARJET (800 FT ABOVE US) CAUSED A TA. HIGH RATE OF CLOSURE CAUSED ALMOST IMMEDIATE RA OF 'DSND.' WE DSNDED BY 500 FT TO FL255. THE PLANE CLBED. MINIMUM VERT SEPARATION WAS 400 FT AT APPROX 3 MI, BUT A LITTLE MORE THAN THAT (NOT SURE HOW MUCH) WHEN TFC PASSED DIRECTLY OVERHEAD. UPON ARR AT ATL, I TELEPHONED ZDC. THE SUPVR SAID IT WAS 'CTLR ERROR.' THANK GOD FOR TCASII, AND ALSO THAT PLTS RESPONDED TO THEIR RA. RECOGNIZING HIS ZDC CTLR HAD TOLD HIM TO 'EXPEDITE DSCNT,' ACFT Y REFUSED, INSTEAD INFORMING CTLR THEY WERE CLBING TO COMPLY WITH TCASII RA. HAD THEY LISTENED TO ATC, RATHER THAN THEIR RA, A FATAL ACCIDENT MIGHT VERY WELL HAVE OCCURRED, AND WOULD HAVE CLAIMED THE LIVES OF 130+ PEOPLE. I IMMEDIATELY RECALLED THE FATAL MIDAIR IN EUROPE, AND HOW IT WAS CAUSED BY ONE OF THE CREWS LISTENING TO ATC, RATHER THAN THEIR TCASII. I STRONGLY FEEL THAT THIS TOPIC SHOULD CONTINUE TO BE EMPHASIZED IN OUR TRAINING SYS, TO INCLUDE THE MIL AVIATION COMMUNITY. WHEN THE CLOSING VELOCITY OF 2 ACFT IS 1000 MPH OR MORE, THERE SIMPLY IS NO WAY ATC CAN REACT TO THE ABOVE SCENARIO IN SUFFICIENT TIME. ONLY TCASII, WORKING AT THE SPD OF LIGHT, CAN HANDLE THE JOB. ALL PLTS SHOULD BE AWARE AND TRAINED TO RESPOND TO A TCASII RA, AND TO DISREGARD ATC IN THIS TYPE OF SIT.

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.