|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||0601 To 1200|
|Locale Reference||navaid : oxi.vor|
|Altitude||msl single value : 11000|
|Controlling Facilities||artcc : zau.artcc|
|Operator||common carrier : air carrier|
|Make Model Name||Embraer Undifferentiated or Other Model|
|Operating Under FAR Part||Part 121|
|Flight Phase||descent : approach|
|Affiliation||government : faa|
|Function||controller : radar|
|Qualification||controller : non radar|
controller : radar
controller : military
|Experience||controller military : 3|
controller non radar : 2
controller radar : 16
controller time certified in position1 : 14
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Anomaly||altitude deviation : excursion from assigned altitude|
|Independent Detector||other controllera|
|Resolutory Action||none taken : detected after the fact|
|Problem Areas||Flight Crew Human Performance|
|Primary Problem||Flight Crew Human Performance|
|Air Traffic Incident||Pilot Deviation|
Air carrier X was given a descent clearance to 17000 ft with the ord altimeter of 29.31. Pilot did not read back the altimeter. Aircraft was eventually descended to 11000 ft. Aircraft mode C showed altitude of 10100 ft. When pilot was questioned of his altitude; he stated level at 11000 ft. Pilot was then asked what altimeter setting he was on; and he said 30.34 (ord ATIS had an updated altimeter of 29.34). Another pilot; air carrier Y; came on the frequency and said I had been giving everyone 30.34. After listening to the tapes; I issued 1 altimeter of 29.31 and 4 altimeters of 29.34 during this time. I never gave an altimeter of 30.34. My sector owns down to 11000 ft. The mdw inbounds are going in at 10000 ft below me. It was only plain luck that there was not an aircraft right below air carrier X at the time. Out of the 5 altimeters that I issued; no aircraft read it back. I believe pilots should have to read everything back in a clearance; including altimeters.
Original NASA ASRS Text
Title: ZAU CTLR DESCRIBED INCIDENT WHEN ACFT WAS USING WRONG ALTIMETER SETTING AND WAS WELL BELOW ASSIGNED ALT.
Narrative: ACR X WAS GIVEN A DSCNT CLRNC TO 17000 FT WITH THE ORD ALTIMETER OF 29.31. PLT DID NOT READ BACK THE ALTIMETER. ACFT WAS EVENTUALLY DSNDED TO 11000 FT. ACFT MODE C SHOWED ALT OF 10100 FT. WHEN PLT WAS QUESTIONED OF HIS ALT; HE STATED LEVEL AT 11000 FT. PLT WAS THEN ASKED WHAT ALTIMETER SETTING HE WAS ON; AND HE SAID 30.34 (ORD ATIS HAD AN UPDATED ALTIMETER OF 29.34). ANOTHER PLT; ACR Y; CAME ON THE FREQ AND SAID I HAD BEEN GIVING EVERYONE 30.34. AFTER LISTENING TO THE TAPES; I ISSUED 1 ALTIMETER OF 29.31 AND 4 ALTIMETERS OF 29.34 DURING THIS TIME. I NEVER GAVE AN ALTIMETER OF 30.34. MY SECTOR OWNS DOWN TO 11000 FT. THE MDW INBOUNDS ARE GOING IN AT 10000 FT BELOW ME. IT WAS ONLY PLAIN LUCK THAT THERE WAS NOT AN ACFT RIGHT BELOW ACR X AT THE TIME. OUT OF THE 5 ALTIMETERS THAT I ISSUED; NO ACFT READ IT BACK. I BELIEVE PLTS SHOULD HAVE TO READ EVERYTHING BACK IN A CLRNC; INCLUDING ALTIMETERS.
Data retrieved from NASA's ASRS site as of January 2009 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.