Flight crew was issued a very low altitude to destination. En route the flight was briefly cleared t...

Attributes
ACN	408430
Time
Date	199807
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : mco
State Reference	FL
Altitude	msl bound lower : 17000 msl bound upper : 23000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zma
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude cruise other descent other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : cfi pilot : atp
Experience	flight time last 90 days : 255 flight time total : 15500 flight time type : 600
ASRS Report	408430
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance none taken : unable
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

We were on a scheduled flight from fll to mco. With thunderstorms along our route of flight, we were assigned a northerly heading by ATC, and an altitude of 17000 ft. Due to traffic, etc, we were advised that 17000 ft would probably be our final altitude, which was significantly lower than normal. Mins later, ZMA then cleared us to FL230. I acknowledged the clearance (with full call sign and readback). The captain also heard the same clearance and promptly started programming the FMC and verified I had dialed the altitude into the altitude alert window. A few mins later the same controller then cleared us back to 17000 ft. I tried to negotiate to stay at FL230 because it would put us above most of the cumulus buildups, but the controller was insistent that we descend back to 17000 ft. When the captain questioned why the clearance was changed, another voice appeared and said we had taken the wrong clearance. Both the captain and myself are absolutely sure the first controller used our call sign for the altitude change. After further discussion, we hypothesized that the controller mistakenly issued the clearance to us, that is why he reissued a new clearance to 17000 ft. Never were our actions questioned by ATC, and it was the wording used by the supervisor (other voice) that put some doubt in our minds. If the clearance was intended for another aircraft, then I believe the controller could have worded his response better.

Original NASA ASRS Text

Title: FLC WAS ISSUED A VERY LOW ALT TO DEST. ENRTE THE FLT WAS BRIEFLY CLRED TO FL230 THEN INSTRUCTED TO DSND BACK TO 17000 FT. WHEN THE CAPT QUESTIONED THE CHANGE, ANOTHER VOICE ADVISED THAT THE CREW HAD TAKEN THE WRONG CLRNC.

Narrative: WE WERE ON A SCHEDULED FLT FROM FLL TO MCO. WITH TSTMS ALONG OUR RTE OF FLT, WE WERE ASSIGNED A NORTHERLY HEADING BY ATC, AND AN ALT OF 17000 FT. DUE TO TFC, ETC, WE WERE ADVISED THAT 17000 FT WOULD PROBABLY BE OUR FINAL ALT, WHICH WAS SIGNIFICANTLY LOWER THAN NORMAL. MINS LATER, ZMA THEN CLRED US TO FL230. I ACKNOWLEDGED THE CLRNC (WITH FULL CALL SIGN AND READBACK). THE CAPT ALSO HEARD THE SAME CLRNC AND PROMPTLY STARTED PROGRAMMING THE FMC AND VERIFIED I HAD DIALED THE ALT INTO THE ALT ALERT WINDOW. A FEW MINS LATER THE SAME CTLR THEN CLRED US BACK TO 17000 FT. I TRIED TO NEGOTIATE TO STAY AT FL230 BECAUSE IT WOULD PUT US ABOVE MOST OF THE CUMULUS BUILDUPS, BUT THE CTLR WAS INSISTENT THAT WE DSND BACK TO 17000 FT. WHEN THE CAPT QUESTIONED WHY THE CLRNC WAS CHANGED, ANOTHER VOICE APPEARED AND SAID WE HAD TAKEN THE WRONG CLRNC. BOTH THE CAPT AND MYSELF ARE ABSOLUTELY SURE THE FIRST CTLR USED OUR CALL SIGN FOR THE ALT CHANGE. AFTER FURTHER DISCUSSION, WE HYPOTHESIZED THAT THE CTLR MISTAKENLY ISSUED THE CLRNC TO US, THAT IS WHY HE REISSUED A NEW CLRNC TO 17000 FT. NEVER WERE OUR ACTIONS QUESTIONED BY ATC, AND IT WAS THE WORDING USED BY THE SUPVR (OTHER VOICE) THAT PUT SOME DOUBT IN OUR MINDS. IF THE CLRNC WAS INTENDED FOR ANOTHER ACFT, THEN I BELIEVE THE CTLR COULD HAVE WORDED HIS RESPONSE BETTER.

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 was issued a very low altitude to destination. En route the flight was briefly cleared to FL230 then instructed to descend back to 17000 ft. When the captain questioned the change, another voice advised that the crew had taken the wrong clearance.