A mechanic pulled and collared the wrong tcasii circuit breaker which led to a return to land, when ...

Attributes
ACN	337278
Time
Date	199605
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : gso
State Reference	NC
Altitude	msl bound lower : 10000 msl bound upper : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 135
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 225 flight time total : 1700 flight time type : 850
ASRS Report	337278
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe non adherence : far non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

The event being reported was an air return to gso, 10 mins after departure. We (the captain and I) brought the aircraft into gso from jax. On the trip inbound we noticed the TCASII portion of the TCASII vsi unit was not functioning properly. We wrote up the TCASII and a mechanic deferred it in gso. We reviewed the deferral and verified that the TCASII circuit breaker had been pulled and tie wrapped by the mechanic as per the MEL. We departed gso on an IFR flight to orf. The WX conditions were VFR at gso but we expected to enter into instrument conditions on the descent into orf because of the current and forecast conditions at the orf airport. After departure, we noticed the captain's vsi and TCASII unit was blank (inoperative). As directed by the captain, I looked up the vsi in our MEL. The MEL specified that 1 vsi may be inoperative for VFR flts only. We discussed the matter and decided that the TCASII must have been deferred improperly by the mechanic and since we were not in IFR conditions but expected to go into IFR WX, we needed to return to gso and have the vsi fixed. After landing in gso we contacted company operations and maintenance. A mechanic in gso told us that there were 2 circuit breakers for the TCASII and the wrong one had been pulled. He remedied the problem. We tested the vsi and found all deferrals in order and flew the trip to orf.

Original NASA ASRS Text

Title: A MECH PULLED AND COLLARED THE WRONG TCASIi CIRCUIT BREAKER WHICH LED TO A RETURN TO LAND, WHEN THE FLC DISCOVERED THAT THEY WERE IN NON COMPLIANCE WITH THE ACFT'S MEL.

Narrative: THE EVENT BEING RPTED WAS AN AIR RETURN TO GSO, 10 MINS AFTER DEP. WE (THE CAPT AND I) BROUGHT THE ACFT INTO GSO FROM JAX. ON THE TRIP INBOUND WE NOTICED THE TCASII PORTION OF THE TCASII VSI UNIT WAS NOT FUNCTIONING PROPERLY. WE WROTE UP THE TCASII AND A MECH DEFERRED IT IN GSO. WE REVIEWED THE DEFERRAL AND VERIFIED THAT THE TCASII CIRCUIT BREAKER HAD BEEN PULLED AND TIE WRAPPED BY THE MECH AS PER THE MEL. WE DEPARTED GSO ON AN IFR FLT TO ORF. THE WX CONDITIONS WERE VFR AT GSO BUT WE EXPECTED TO ENTER INTO INST CONDITIONS ON THE DSCNT INTO ORF BECAUSE OF THE CURRENT AND FORECAST CONDITIONS AT THE ORF ARPT. AFTER DEP, WE NOTICED THE CAPT'S VSI AND TCASII UNIT WAS BLANK (INOP). AS DIRECTED BY THE CAPT, I LOOKED UP THE VSI IN OUR MEL. THE MEL SPECIFIED THAT 1 VSI MAY BE INOP FOR VFR FLTS ONLY. WE DISCUSSED THE MATTER AND DECIDED THAT THE TCASII MUST HAVE BEEN DEFERRED IMPROPERLY BY THE MECH AND SINCE WE WERE NOT IN IFR CONDITIONS BUT EXPECTED TO GO INTO IFR WX, WE NEEDED TO RETURN TO GSO AND HAVE THE VSI FIXED. AFTER LNDG IN GSO WE CONTACTED COMPANY OPS AND MAINT. A MECH IN GSO TOLD US THAT THERE WERE 2 CIRCUIT BREAKERS FOR THE TCASII AND THE WRONG ONE HAD BEEN PULLED. HE REMEDIED THE PROB. WE TESTED THE VSI AND FOUND ALL DEFERRALS IN ORDER AND FLEW THE TRIP TO ORF.

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.

A mechanic pulled and collared the wrong tcasii circuit breaker which led to a return to land, when the flight crew discovered that they were in non compliance with the aircraft's MEL.