A descending HS25B overshot its assigned altitude on a STAR arrival. Crew was under the impression t...

Attributes
ACN	426419
Time
Date	199901
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ftz
State Reference	MO
Altitude	msl bound lower : 12000 msl bound upper : 15000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : corporate
Navigation In Use	Other
Flight Phase	descent other
Route In Use	arrival other arrival star : star enroute airway : zkc
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : cfi
Experience	flight time last 90 days : 90 flight time total : 7760 flight time type : 63
ASRS Report	426419
Person 2
Affiliation	Other
Function	flight crew : captain oversight : pic
Experience	controller non radar : 2 flight time last 90 days : 90 flight time total : 14000 flight time type : 59
ASRS Report	426418
Events
Anomaly	altitude deviation : overshoot non adherence : published procedure other anomaly other
Independent Detector	other controllera
Resolutory Action	other
Consequence	Other
Supplementary
Air Traffic Incident	Pilot Deviation Operational Deviation

Narrative:

At approximately XA45 ZKC, on frequency 134.50, issued a clearance to cross the kayla arc at 11000 ft. At that time, we were cleared to stl via the trake 8 arrival bum transition. After a short vector around the trake intersection we were established on the ftz 265 degree radial inbound as depicted on the STAR. This is my best recollection of what happened leading to our altitude deviation. Aircraft: cross what at 11000 ft? ZKC: the kayla arc. Aircraft: cross the kayla arc at and maintain 11000 ft. ZKC: cross the kayla 11 DME arc at and maintain 15000 ft. Aircraft: I've got it now, cross the kayla 11 DME arc at and maintain 15000 ft. With the crossing being the 11 DME arc, my reading back 11000 ft twice and the first altitude notation on the STAR being 11000 ft, I set the FMS and the altitude preselect for the descent to 11000 ft. At the beginning of the descent, I advised ZKC we were descending from xxxxxx to 11000 ft. I do not recall his response, if he did, but I know I was not corrected. Once in the descent, I switched to unicom to advise them of our arrival. When I returned to the ZKC frequency, I heard the PF say, 'we read 11000 ft back twice.' we were at 12000 ft. I realized the altitude was 15000 ft and advised the PF of my error. With ZKC permission and coordination, we continued to 11000 ft without incident. The issuance of the clearance to cross the 'kayla arc' appears to be nonstandard terminology or seldom used at best. Even after briefing the STAR, it didn't sound right the first time the controller issued it to us. Had the clearance been, cross kayla at 15000 ft, or cross the foristell 11 DME arc at 15000 ft, the clearance would have been clear and concise. To mix the intersection, arc and VOR terminology just created confusion. I believe this is supported by the fact that 2 experienced pilots completely missed the actual clearance. Supplemental information from acn 426418: did the controller mean one thing and say another?

Original NASA ASRS Text

Title: A DSNDING HS25B OVERSHOT ITS ASSIGNED ALT ON A STAR ARR. CREW WAS UNDER THE IMPRESSION THAT 11000 FT WAS ASSIGNED.

Narrative: AT APPROX XA45 ZKC, ON FREQ 134.50, ISSUED A CLRNC TO CROSS THE KAYLA ARC AT 11000 FT. AT THAT TIME, WE WERE CLRED TO STL VIA THE TRAKE 8 ARR BUM TRANSITION. AFTER A SHORT VECTOR AROUND THE TRAKE INTXN WE WERE ESTABLISHED ON THE FTZ 265 DEG RADIAL INBOUND AS DEPICTED ON THE STAR. THIS IS MY BEST RECOLLECTION OF WHAT HAPPENED LEADING TO OUR ALTDEV. ACFT: CROSS WHAT AT 11000 FT? ZKC: THE KAYLA ARC. ACFT: CROSS THE KAYLA ARC AT AND MAINTAIN 11000 FT. ZKC: CROSS THE KAYLA 11 DME ARC AT AND MAINTAIN 15000 FT. ACFT: I'VE GOT IT NOW, CROSS THE KAYLA 11 DME ARC AT AND MAINTAIN 15000 FT. WITH THE XING BEING THE 11 DME ARC, MY READING BACK 11000 FT TWICE AND THE FIRST ALT NOTATION ON THE STAR BEING 11000 FT, I SET THE FMS AND THE ALT PRESELECT FOR THE DSCNT TO 11000 FT. AT THE BEGINNING OF THE DSCNT, I ADVISED ZKC WE WERE DSNDING FROM XXXXXX TO 11000 FT. I DO NOT RECALL HIS RESPONSE, IF HE DID, BUT I KNOW I WAS NOT CORRECTED. ONCE IN THE DSCNT, I SWITCHED TO UNICOM TO ADVISE THEM OF OUR ARR. WHEN I RETURNED TO THE ZKC FREQ, I HEARD THE PF SAY, 'WE READ 11000 FT BACK TWICE.' WE WERE AT 12000 FT. I REALIZED THE ALT WAS 15000 FT AND ADVISED THE PF OF MY ERROR. WITH ZKC PERMISSION AND COORD, WE CONTINUED TO 11000 FT WITHOUT INCIDENT. THE ISSUANCE OF THE CLRNC TO CROSS THE 'KAYLA ARC' APPEARS TO BE NONSTANDARD TERMINOLOGY OR SELDOM USED AT BEST. EVEN AFTER BRIEFING THE STAR, IT DIDN'T SOUND RIGHT THE FIRST TIME THE CTLR ISSUED IT TO US. HAD THE CLRNC BEEN, CROSS KAYLA AT 15000 FT, OR CROSS THE FORISTELL 11 DME ARC AT 15000 FT, THE CLRNC WOULD HAVE BEEN CLR AND CONCISE. TO MIX THE INTXN, ARC AND VOR TERMINOLOGY JUST CREATED CONFUSION. I BELIEVE THIS IS SUPPORTED BY THE FACT THAT 2 EXPERIENCED PLTS COMPLETELY MISSED THE ACTUAL CLRNC. SUPPLEMENTAL INFO FROM ACN 426418: DID THE CTLR MEAN ONE THING AND SAY ANOTHER?

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 descending HS25B overshot its assigned altitude on a STAR arrival. Crew was under the impression that 11000 ft was assigned.