Air carrier at cruise has TCASII RA to climb. Does so.

Attributes
ACN	241038
Time
Date	199305
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : dqo
State Reference	PA
Altitude	msl bound lower : 15000 msl bound upper : 16100
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc tower : ord
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	arrival other
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 15000 flight time type : 3000
ASRS Report	241038
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 0 vertical : 1500
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Level at 15000 ft, an aircraft appeared on the TCASII scope at 18 NM (20 NM scope selected). Position was 12 O'clock and altitude indicated -4. Both pilots tried to spot the aircraft but visual contact was never attained. Captain attempted to call center but frequency was congested and when he did get through, there was no response. At approximately 8 NM, TCASII commanded 'climb, climb, climb.' autoplt was immediately disengaged and climb initiated at 2200 FPM in response to ivi cues. ZDC was notified of climb. At approximately 16000 ft the TCASII command changed to 'monitor vertical speed.' aircraft was leveled at 16100 ft. 'Clear of conflict' was quickly announced and aircraft was returned to 15000 ft. Intruder aircraft was never sighted. Controller was busy and said aircraft was VFR and he had planned to call him out. In a later phone conversation with a ZDC supervisor, the supervisor stated, 'the TCASII shouldn't have done that. The aircraft was VFR.' this appears to be a situation where control of IFR and VFR aircraft was acceptable, but greater controller understanding of TCASII parameters could have avoided the requirement for the crew to leave their assigned altitude in response to a TCASII RA.

Original NASA ASRS Text

Title: ACR AT CRUISE HAS TCASII RA TO CLB. DOES SO.

Narrative: LEVEL AT 15000 FT, AN ACFT APPEARED ON THE TCASII SCOPE AT 18 NM (20 NM SCOPE SELECTED). POS WAS 12 O'CLOCK AND ALT INDICATED -4. BOTH PLTS TRIED TO SPOT THE ACFT BUT VISUAL CONTACT WAS NEVER ATTAINED. CAPT ATTEMPTED TO CALL CTR BUT FREQ WAS CONGESTED AND WHEN HE DID GET THROUGH, THERE WAS NO RESPONSE. AT APPROX 8 NM, TCASII COMMANDED 'CLB, CLB, CLB.' AUTOPLT WAS IMMEDIATELY DISENGAGED AND CLB INITIATED AT 2200 FPM IN RESPONSE TO IVI CUES. ZDC WAS NOTIFIED OF CLB. AT APPROX 16000 FT THE TCASII COMMAND CHANGED TO 'MONITOR VERT SPD.' ACFT WAS LEVELED AT 16100 FT. 'CLR OF CONFLICT' WAS QUICKLY ANNOUNCED AND ACFT WAS RETURNED TO 15000 FT. INTRUDER ACFT WAS NEVER SIGHTED. CTLR WAS BUSY AND SAID ACFT WAS VFR AND HE HAD PLANNED TO CALL HIM OUT. IN A LATER PHONE CONVERSATION WITH A ZDC SUPVR, THE SUPVR STATED, 'THE TCASII SHOULDN'T HAVE DONE THAT. THE ACFT WAS VFR.' THIS APPEARS TO BE A SIT WHERE CTL OF IFR AND VFR ACFT WAS ACCEPTABLE, BUT GREATER CTLR UNDERSTANDING OF TCASII PARAMETERS COULD HAVE AVOIDED THE REQUIREMENT FOR THE CREW TO LEAVE THEIR ASSIGNED ALT IN RESPONSE TO A TCASII RA.

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.