Air carrier large transport altitude deviation excursion from clearance altitude in response to TCAS...

Attributes
ACN	179155
Time
Date	199105
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ign
State Reference	NY
Altitude	msl bound lower : 10000 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute airway : zny
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 3500 flight time type : 150
ASRS Report	179155
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Miss Distance	horizontal : 500 vertical : 500
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

The aircraft was at 10000' and 250 KTS approaching the valre intersection. The TCAS showed a TA at the 1-2 O'clock position along with the 'traffic, traffic' aural warning. No visibility contact was made. We then received a 'monitor vertical speed' warning, still with no visibility contact. A few seconds later the TCAS commanded a climb of 2500 FPM. A climb was initiated and while approaching 11000' we made visibility contact with an light transport. We leveled the aircraft at 11000'. After we were clear of the conflict we descended to 8000' at center's request. The system worked very well with 1 exception: while monitoring the TCAS display on the vsi and the radar screen we were dividing our attention between the INS and looking outside to make visibility contact, other than that the system performed as advertised.

Original NASA ASRS Text

Title: ACR LGT ALT DEVIATION EXCURSION FROM CLRNC ALT IN RESPONSE TO TCASII RA.

Narrative: THE ACFT WAS AT 10000' AND 250 KTS APCHING THE VALRE INTXN. THE TCAS SHOWED A TA AT THE 1-2 O'CLOCK POS ALONG WITH THE 'TFC, TFC' AURAL WARNING. NO VIS CONTACT WAS MADE. WE THEN RECEIVED A 'MONITOR VERT SPD' WARNING, STILL WITH NO VIS CONTACT. A FEW SECS LATER THE TCAS COMMANDED A CLB OF 2500 FPM. A CLB WAS INITIATED AND WHILE APCHING 11000' WE MADE VIS CONTACT WITH AN LTT. WE LEVELED THE ACFT AT 11000'. AFTER WE WERE CLR OF THE CONFLICT WE DSNDED TO 8000' AT CENTER'S REQUEST. THE SYS WORKED VERY WELL WITH 1 EXCEPTION: WHILE MONITORING THE TCAS DISPLAY ON THE VSI AND THE RADAR SCREEN WE WERE DIVIDING OUR ATTN BTWN THE INS AND LOOKING OUTSIDE TO MAKE VIS CONTACT, OTHER THAN THAT THE SYS PERFORMED AS ADVERTISED.

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.

Air carrier large transport altitude deviation excursion from clearance altitude in response to TCASII RA.