Flight crew of air carrier large transport aircraft deviated from assigned altitude in response to a...

Attributes
ACN	212212
Time
Date	199206
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : sby
State Reference	MD
Altitude	msl bound lower : 27000 msl bound upper : 27800
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	artcc : zdc tower : orf
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute airway : zdc
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 225 flight time total : 5000 flight time type : 725
ASRS Report	212212
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : flight engineer pilot : atp pilot : commercial
Experience	flight time last 90 days : 210 flight time total : 17000
ASRS Report	212208
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 0 vertical : 1000
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While at cruise (FL270), we noted a target on TCASII coming head-on indicating a climb and passing FL259. At approximately 4.5 mi on the TCASII, the target indicated FL261 and still climbing. At the same moment TCASII gave us an RA to climb at approximately 2000 FPM. I clicked off the autoplt and began a climb at the indicated rate. We deviated to approximately FL278, then returned to FL270 after the RA was over. The entire event took less than 30 seconds. We advised center of what had just occurred and center then informed us that the target had been leveling at FL260 and had passed directly beneath us. Center reported no conflicting traffic at FL280.

Original NASA ASRS Text

Title: FLC OF ACR LGT ACFT DEVIATED FROM ASSIGNED ALT IN RESPONSE TO A TCASII 'RA.'

Narrative: WHILE AT CRUISE (FL270), WE NOTED A TARGET ON TCASII COMING HEAD-ON INDICATING A CLB AND PASSING FL259. AT APPROX 4.5 MI ON THE TCASII, THE TARGET INDICATED FL261 AND STILL CLBING. AT THE SAME MOMENT TCASII GAVE US AN RA TO CLB AT APPROX 2000 FPM. I CLICKED OFF THE AUTOPLT AND BEGAN A CLB AT THE INDICATED RATE. WE DEVIATED TO APPROX FL278, THEN RETURNED TO FL270 AFTER THE RA WAS OVER. THE ENTIRE EVENT TOOK LESS THAN 30 SECONDS. WE ADVISED CTR OF WHAT HAD JUST OCCURRED AND CTR THEN INFORMED US THAT THE TARGET HAD BEEN LEVELING AT FL260 AND HAD PASSED DIRECTLY BENEATH US. CTR RPTED NO CONFLICTING TFC AT FL280.

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.

Flight crew of air carrier large transport aircraft deviated from assigned altitude in response to a TCASII 'RA.'