B737-300 first officer reports descending below FL240 at misen on the kepec 3 arrival to las due to ...

Attributes
ACN	1122550
Time
Date	201310
Local Time Of Day	1801-2400
Place
Locale Reference	ZLA.ARTCC
State Reference	CA
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	STAR KEPEC3
Flight Plan	IFR
Person 1
Function	First Officer
Experience	Flight Crew Last 90 Days 227
Events
Anomaly	ATC Issue All Types Deviation - Altitude Crossing Restriction Not Met Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy

Narrative:

On the kepec 3 into las cruising at FL250. La center issued pd descent to FL240 and then issued next frequency. Next controller stated; 'after misen; cross clarr at 250 knots and one three thousand feet.' at no time were we given a crossing clearance for misen. The chart shows to expext misen at FL240. Captain and I discussed the clearance and agreed we could disregard the misen expect crossing and I set 13;000 in the alt preselector. We descended below FL240 prior to misen. ATC asked us what we were doing and told us to maintain FL210. Pm and ATC attempted to clarify issue. ATC seemed to be under the assumption that we were in violation of the misen FL240 crossing. Proceeded normally from this point on. ATC sould have issued the misen crossing. We should have clarified clearance with ATC.

Original NASA ASRS Text

Title: B737-300 First Officer reports descending below FL240 at MISEN on the KEPEC 3 arrival to LAS due to lack of a specific instruction from ATC to comply with the RNAV procedure. Only the speed and altitude at CLARR is issued.

Narrative: On the KEPEC 3 into LAS cruising at FL250. LA Center issued PD descent to FL240 and then issued next frequency. Next Controller stated; 'After MISEN; cross CLARR at 250 knots and one three thousand feet.' At no time were we given a crossing clearance for MISEN. The chart shows to expext MISEN at FL240. Captain and I discussed the clearance and agreed we could disregard the MISEN expect crossing and I set 13;000 in the alt preselector. We descended below FL240 prior to MISEN. ATC asked us what we were doing and told us to maintain FL210. PM and ATC attempted to clarify issue. ATC seemed to be under the assumption that we were in violation of the MISEN FL240 crossing. Proceeded normally from this point on. ATC sould have issued the MISEN crossing. We should have clarified clearance with ATC.

Data retrieved from NASA's ASRS site as of July 2013 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.

B737-300 first officer reports descending below FL240 at misen on the kepec 3 arrival to las due to lack of a specific instruction from ATC to comply with the RNAV procedure. Only the speed and altitude at clarr is issued.