While first officer coords with company, captain acknowledges climb clearance meant for company with...

Attributes
ACN	508410
Time
Date	200104
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : jvl.ndb
State Reference	WI
Altitude	msl bound lower : 28000 msl bound upper : 29500
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : xna.tower
Operator	common carrier : air carrier
Make Model Name	MD-82
Flight Phase	cruise : holding
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 180 flight time total : 10000 flight time type : 1900
ASRS Report	508410
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Resolutory Action	controller : issued new clearance controller : issued advisory flight crew : returned to assigned altitude flight crew : returned to original clearance
Supplementary
Problem Areas	Environmental Factor Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We had entered holding over jvl VORTAC at FL280, destination (mke). WX was below landing minimums. Captain was PF. I was off center frequency to advise passenger of delay and to confer with our dispatcher about alternates and current alternate WX. I heard PIC acknowledge clearance to FL310 and start climb. I returned to frequency and PIC advised me of our clearance to FL310. Climbing through FL295, center queried us as to our altitude. I advised climbing through FL295 to our cleared altitude of FL310. Center said that clearance was for a company flight. He told us to maintain FL280 and for company to climb to FL310. Center frequency was very congested due to our deviations. WX cells were building all around us. We immediately returned to FL280. We believe no loss of separation occurred. We decided to divert to our alternate airport and landed without incident. Factors contributing include the inability of using both pilots concerning an altitude clearance when one pilot leaves frequency, the frequency congestion possibly blocking a critical clearance readback, and the ongoing problem of similar sounding call signs.

Original NASA ASRS Text

Title: WHILE FO COORDS WITH COMPANY, CAPT ACKNOWLEDGES CLB CLRNC MEANT FOR COMPANY WITH SIMILAR CALL SIGN. ZAU CTLR CHALLENGES CLB, RETURNING THE FLT TO ORIGINAL ASSIGNED ALT.

Narrative: WE HAD ENTERED HOLDING OVER JVL VORTAC AT FL280, DEST (MKE). WX WAS BELOW LNDG MINIMUMS. CAPT WAS PF. I WAS OFF CTR FREQ TO ADVISE PAX OF DELAY AND TO CONFER WITH OUR DISPATCHER ABOUT ALTERNATES AND CURRENT ALTERNATE WX. I HEARD PIC ACKNOWLEDGE CLRNC TO FL310 AND START CLB. I RETURNED TO FREQ AND PIC ADVISED ME OF OUR CLRNC TO FL310. CLBING THROUGH FL295, CTR QUERIED US AS TO OUR ALT. I ADVISED CLBING THROUGH FL295 TO OUR CLRED ALT OF FL310. CTR SAID THAT CLRNC WAS FOR A COMPANY FLT. HE TOLD US TO MAINTAIN FL280 AND FOR COMPANY TO CLB TO FL310. CTR FREQ WAS VERY CONGESTED DUE TO OUR DEVS. WX CELLS WERE BUILDING ALL AROUND US. WE IMMEDIATELY RETURNED TO FL280. WE BELIEVE NO LOSS OF SEPARATION OCCURRED. WE DECIDED TO DIVERT TO OUR ALTERNATE ARPT AND LANDED WITHOUT INCIDENT. FACTORS CONTRIBUTING INCLUDE THE INABILITY OF USING BOTH PLTS CONCERNING AN ALT CLRNC WHEN ONE PLT LEAVES FREQ, THE FREQ CONGESTION POSSIBLY BLOCKING A CRITICAL CLRNC READBACK, AND THE ONGOING PROB OF SIMILAR SOUNDING CALL SIGNS.

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.

While first officer coords with company, captain acknowledges climb clearance meant for company with similar call sign. ZAU controller challenges climb, returning the flight to original assigned altitude.