Altitude excursion by air carrier medium large transport. Similar a/north.

Attributes
ACN	104290
Time
Date	198902
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lan
State Reference	MI
Altitude	msl bound lower : 16000 msl bound upper : 17000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute airway : v218
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 9600 flight time type : 5500
ASRS Report	104290
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 175 flight time total : 13000 flight time type : 6000
ASRS Report	103925
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

Over lansing our flight xxyz was cleared to 12000'. The captain (PNF) read back the clearance with the call sign. As we left 16000' the captain requested holding instructions since aircraft not far ahead of us were already holding for dtw (our destination). We were issued the hold to maintain 17000' the captain questioned the altitude assignment and we were again told to maintain 17000' with no elaboration. As we climbed back to 17000', we were issued a turn from our 090 degree heading to a heading of 180 degree, we were eventually vectored back around to our original arwy and proceeded to our hold. During the vectoring, we heard a 10000' clearance issued to a flight xxya (same carrier). Acoustically xxyz sound strangely similar to xxya if not spoken distinctly. We therefore assumed that the clearance was either issued to us by mistake or that we misheard the call sign and the controller misheard the readback.

Original NASA ASRS Text

Title: ALT EXCURSION BY ACR MLG. SIMILAR A/N.

Narrative: OVER LANSING OUR FLT XXYZ WAS CLRED TO 12000'. THE CAPT (PNF) READ BACK THE CLRNC WITH THE CALL SIGN. AS WE LEFT 16000' THE CAPT REQUESTED HOLDING INSTRUCTIONS SINCE ACFT NOT FAR AHEAD OF US WERE ALREADY HOLDING FOR DTW (OUR DEST). WE WERE ISSUED THE HOLD TO MAINTAIN 17000' THE CAPT QUESTIONED THE ALT ASSIGNMENT AND WE WERE AGAIN TOLD TO MAINTAIN 17000' WITH NO ELABORATION. AS WE CLBED BACK TO 17000', WE WERE ISSUED A TURN FROM OUR 090 DEG HDG TO A HDG OF 180 DEG, WE WERE EVENTUALLY VECTORED BACK AROUND TO OUR ORIGINAL ARWY AND PROCEEDED TO OUR HOLD. DURING THE VECTORING, WE HEARD A 10000' CLRNC ISSUED TO A FLT XXYA (SAME CARRIER). ACOUSTICALLY XXYZ SOUND STRANGELY SIMILAR TO XXYA IF NOT SPOKEN DISTINCTLY. WE THEREFORE ASSUMED THAT THE CLRNC WAS EITHER ISSUED TO US BY MISTAKE OR THAT WE MISHEARD THE CALL SIGN AND THE CTLR MISHEARD THE READBACK.

Data retrieved from NASA's ASRS site as of August 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.