Altitude deviation altitude excursion by air carrier in flight crew response to TCASII RA.

Attributes
ACN	270624
Time
Date	199404
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : oma
State Reference	NE
Altitude	msl bound lower : 28000 msl bound upper : 28500
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zmp
Operator	common carrier : air carrier
Make Model Name	DC-9 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	DC-9 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 240 flight time total : 17000 flight time type : 5000
ASRS Report	270624
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical conflict : airborne less severe conflict : ground less severe non adherence : required legal separation 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 : 5000 vertical : 500
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

Air carrier flight X proceeding direct to oma VOR at FL280, autoplt on, first officer flying aircraft in clouds with some thunderstorm activity in local area. TCASII on with switch placed in TA/RA. Heard center talk to air carrier flight Y, proceeding from mkc to msp as it was climbing and he was asked about thunderstorms. Air carrier Y cleared to FL270 until he was clear of us. Target came on our TCASII at about 7 O'clock position and showed that it was climbing and about 2000 ft below us. Assumed this was air carrier Y. As target approached our 2 mi range, altitude difference was 1100 ft, then 1000 ft, then 900 ft then 800 ft below us. When this reached 500 ft, our TCASII gave conflict alert and said to climb, which first officer did immediately and added full power. At this time, apparently air carrier Y received a TCASII warning to descend, which it did. We then received 'monitor vertical speed' and then 'clear of conflict' as target passed by us. No visual sighting. We then returned to FL280. Discussion then held on frequency between air carrier X, air carrier Y, and center controller. Air carrier Y said he was level at FL270 when alert occurred. All 3 of us said we would file a report on this event. Air carrier X then continued to oma without further incident.

Original NASA ASRS Text

Title: ALTDEV ALT EXCURSION BY ACR IN FLC RESPONSE TO TCASII RA.

Narrative: ACR FLT X PROCEEDING DIRECT TO OMA VOR AT FL280, AUTOPLT ON, FO FLYING ACFT IN CLOUDS WITH SOME TSTM ACTIVITY IN LCL AREA. TCASII ON WITH SWITCH PLACED IN TA/RA. HEARD CTR TALK TO ACR FLT Y, PROCEEDING FROM MKC TO MSP AS IT WAS CLBING AND HE WAS ASKED ABOUT TSTMS. ACR Y CLRED TO FL270 UNTIL HE WAS CLR OF US. TARGET CAME ON OUR TCASII AT ABOUT 7 O'CLOCK POS AND SHOWED THAT IT WAS CLBING AND ABOUT 2000 FT BELOW US. ASSUMED THIS WAS ACR Y. AS TARGET APCHED OUR 2 MI RANGE, ALT DIFFERENCE WAS 1100 FT, THEN 1000 FT, THEN 900 FT THEN 800 FT BELOW US. WHEN THIS REACHED 500 FT, OUR TCASII GAVE CONFLICT ALERT AND SAID TO CLB, WHICH FO DID IMMEDIATELY AND ADDED FULL PWR. AT THIS TIME, APPARENTLY ACR Y RECEIVED A TCASII WARNING TO DSND, WHICH IT DID. WE THEN RECEIVED 'MONITOR VERT SPD' AND THEN 'CLR OF CONFLICT' AS TARGET PASSED BY US. NO VISUAL SIGHTING. WE THEN RETURNED TO FL280. DISCUSSION THEN HELD ON FREQ BTWN ACR X, ACR Y, AND CTR CTLR. ACR Y SAID HE WAS LEVEL AT FL270 WHEN ALERT OCCURRED. ALL 3 OF US SAID WE WOULD FILE A RPT ON THIS EVENT. ACR X THEN CONTINUED TO OMA WITHOUT FURTHER INCIDENT.

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.