Narrative:

I had filed IFR for a flight to van nuys, ca (vny). WX was cavu over the entire route. The flight plan route filed did not include a STAR, but I did not include 'no STAR' in the remarks. About 30 mi north of ehf we were given a revised route, direct lhs and the lynxx 7 arrival, and maintain 9000 ft. I studied the published lynxx 7, and noted that it called for departing lhs on the 150 degree radial. As lhs is only 27 NM from van nuys, I knew that a steep descent would be necessary. The STAR shows stepdown altitudes from lhs, 7800 ft for the first 5 mi from lhs, then 7000 ft. I have much experience flying IFR, but I had not had occasion to use a STAR for several yrs, there are few in the area I normally fly IFR now. I mistakenly thought that the altitudes shown on the STAR route were mandatory. Upon crossing lhs VORTAC I turned to 150 degrees and called center to advise I was departing 9000 ft for the published 7800 ft. I lowered the gear as a speed brake and started the descent. The controller did not respond to the first transmission, so I called again. He replied, 'aircraft ending in X, say again.' I repeated my transmission again. The controller responded, 'negative.' don't leave the assigned altitude until the controller tells you to. Those altitudes are for planning purposes only. I need you back up to 9000 ft within 20 seconds or I'll have to spin you around.' I returned to 9000 ft and nothing further was said. I was handed off to socal approach and completed the ILS approach to vny without incident. Upon returning home I consulted aim and noted the section that says that on a STAR the last assigned altitude should be maintained, and that the published altitudes are only for planning.

Related reports:

Google
 

Original NASA ASRS Text

Title: BE35 PLT LEAVES ASSIGNED ALT WITHOUT ATC CLRNC BELIEVING THAT IT WAS NECESSARY TO COMPLY WITH PUBLISHED STAR ALT.

Narrative: I HAD FILED IFR FOR A FLT TO VAN NUYS, CA (VNY). WX WAS CAVU OVER THE ENTIRE RTE. THE FLT PLAN RTE FILED DID NOT INCLUDE A STAR, BUT I DID NOT INCLUDE 'NO STAR' IN THE REMARKS. ABOUT 30 MI N OF EHF WE WERE GIVEN A REVISED RTE, DIRECT LHS AND THE LYNXX 7 ARR, AND MAINTAIN 9000 FT. I STUDIED THE PUBLISHED LYNXX 7, AND NOTED THAT IT CALLED FOR DEPARTING LHS ON THE 150 DEG RADIAL. AS LHS IS ONLY 27 NM FROM VAN NUYS, I KNEW THAT A STEEP DSCNT WOULD BE NECESSARY. THE STAR SHOWS STEPDOWN ALTS FROM LHS, 7800 FT FOR THE FIRST 5 MI FROM LHS, THEN 7000 FT. I HAVE MUCH EXPERIENCE FLYING IFR, BUT I HAD NOT HAD OCCASION TO USE A STAR FOR SEVERAL YRS, THERE ARE FEW IN THE AREA I NORMALLY FLY IFR NOW. I MISTAKENLY THOUGHT THAT THE ALTS SHOWN ON THE STAR RTE WERE MANDATORY. UPON XING LHS VORTAC I TURNED TO 150 DEGS AND CALLED CTR TO ADVISE I WAS DEPARTING 9000 FT FOR THE PUBLISHED 7800 FT. I LOWERED THE GEAR AS A SPD BRAKE AND STARTED THE DSCNT. THE CTLR DID NOT RESPOND TO THE FIRST XMISSION, SO I CALLED AGAIN. HE REPLIED, 'ACFT ENDING IN X, SAY AGAIN.' I REPEATED MY XMISSION AGAIN. THE CTLR RESPONDED, 'NEGATIVE.' DON'T LEAVE THE ASSIGNED ALT UNTIL THE CTLR TELLS YOU TO. THOSE ALTS ARE FOR PLANNING PURPOSES ONLY. I NEED YOU BACK UP TO 9000 FT WITHIN 20 SECONDS OR I'LL HAVE TO SPIN YOU AROUND.' I RETURNED TO 9000 FT AND NOTHING FURTHER WAS SAID. I WAS HANDED OFF TO SOCAL APCH AND COMPLETED THE ILS APCH TO VNY WITHOUT INCIDENT. UPON RETURNING HOME I CONSULTED AIM AND NOTED THE SECTION THAT SAYS THAT ON A STAR THE LAST ASSIGNED ALT SHOULD BE MAINTAINED, AND THAT THE PUBLISHED ALTS ARE ONLY FOR PLANNING.

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.