Air carrier receives TCASII RA to descend. Controller issues a climb due to low MVA. Pilot descends.

Attributes
ACN	224278
Time
Date	199210
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ont
State Reference	CA
Altitude	msl bound lower : 5400 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ont
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Route In Use	approach : visual enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent other
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller military : 3 controller non radar : 7 controller radar : 5 controller supervisory : 1
ASRS Report	224278
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance none taken : unable
Consequence	Other
Miss Distance	horizontal : 3000 vertical : 1000
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Air carrier X on vector (270 degree) for visual approach to ont. Traffic appeared at air carrier X's 2 O'clock and 3 mi, converging sbound at 6500 ft. Traffic descended, slowly to 6200, as I advised air carrier X to climb 500 ft for the traffic. As air carrier X began to reply, I overheard his TCASII alarm. Air carrier X advised he was descending as traffic indicated it was climbing. I told air carrier X to expedite climb to 7000 MSL. Descended to 5400 ft into 6000 ft MVA area. Traffic leveled at 6400 ft and turned eastbound, 1/2 NM north of air carrier X. TCASII has merit, yet I find that unexpected, contradictory maneuvers create a dangerous and unpredictable situation. Often times, aircraft are separated by 500-1000 ft, yet aircraft will take evasive actions contrary to ATC instructions and into more hazardous situations. The result is that the 'control' has been removed from 'ATC.'

Original NASA ASRS Text

Title: ACR RECEIVES TCASII RA TO DSND. CTLR ISSUES A CLB DUE TO LOW MVA. PLT DSNDS.

Narrative: ACR X ON VECTOR (270 DEG) FOR VISUAL APCH TO ONT. TFC APPEARED AT ACR X'S 2 O'CLOCK AND 3 MI, CONVERGING SBOUND AT 6500 FT. TFC DSNDED, SLOWLY TO 6200, AS I ADVISED ACR X TO CLB 500 FT FOR THE TFC. AS ACR X BEGAN TO REPLY, I OVERHEARD HIS TCASII ALARM. ACR X ADVISED HE WAS DSNDING AS TFC INDICATED IT WAS CLBING. I TOLD ACR X TO EXPEDITE CLB TO 7000 MSL. DSNDED TO 5400 FT INTO 6000 FT MVA AREA. TFC LEVELED AT 6400 FT AND TURNED EBOUND, 1/2 NM N OF ACR X. TCASII HAS MERIT, YET I FIND THAT UNEXPECTED, CONTRADICTORY MANEUVERS CREATE A DANGEROUS AND UNPREDICTABLE SITUATION. OFTEN TIMES, ACFT ARE SEPARATED BY 500-1000 FT, YET ACFT WILL TAKE EVASIVE ACTIONS CONTRARY TO ATC INSTRUCTIONS AND INTO MORE HAZARDOUS SITUATIONS. THE RESULT IS THAT THE 'CTL' HAS BEEN REMOVED FROM 'ATC.'

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.