Narrative:

En route from oak, ca, to burbank, ca, VFR on top 13500'. I started a descent in VFR conditions to a center assigned altitude of 9000'. Completely forgetting my assigned altitude, I called center at 8500' with the airport in sight and cancelled my IFR. The controller acknowledged my IFR cancellation and asked me for my present altitude. I told the controller 'descending out of 8500'' and at that point realized my error. As a pilot for a part 135 cargo company flying light multi-engine reciprocating twins, single pilot, I find the schedule too demanding. The FARS allow 9 hours crew rest in a 24 hour period. 8 hours with reduced rest. Rest does not mean sufficient sleep. My schedule is difficult because the 15-16 hour periods are never the same. Night day - day night - days and weeks become a continuous blur. My biological clock is non existent and the term jet lag, that 121 crews are compensated for has become a part of life with little recovery; one sometimes 2 days out of the week. Crew rest should require the operators to provide a decent layover at outstations, trying to capture a few winks at a passenger terminal during my 9 hours rest just isn't enough. I know our company has had more than one accident where the pilot like myself caught his final moments rest on autoplt during a long leg at night.

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Original NASA ASRS Text

Title: ATX SMT ALT DEVIATION DURING DESCENT.

Narrative: ENRTE FROM OAK, CA, TO BURBANK, CA, VFR ON TOP 13500'. I STARTED A DSNT IN VFR CONDITIONS TO A CTR ASSIGNED ALT OF 9000'. COMPLETELY FORGETTING MY ASSIGNED ALT, I CALLED CTR AT 8500' WITH THE ARPT IN SIGHT AND CANCELLED MY IFR. THE CTLR ACKNOWLEDGED MY IFR CANCELLATION AND ASKED ME FOR MY PRESENT ALT. I TOLD THE CTLR 'DSNDING OUT OF 8500'' AND AT THAT POINT REALIZED MY ERROR. AS A PLT FOR A PART 135 CARGO COMPANY FLYING LIGHT MULTI-ENG RECIPROCATING TWINS, SINGLE PLT, I FIND THE SCHEDULE TOO DEMANDING. THE FARS ALLOW 9 HRS CREW REST IN A 24 HR PERIOD. 8 HRS WITH REDUCED REST. REST DOES NOT MEAN SUFFICIENT SLEEP. MY SCHEDULE IS DIFFICULT BECAUSE THE 15-16 HR PERIODS ARE NEVER THE SAME. NIGHT DAY - DAY NIGHT - DAYS AND WKS BECOME A CONTINUOUS BLUR. MY BIOLOGICAL CLOCK IS NON EXISTENT AND THE TERM JET LAG, THAT 121 CREWS ARE COMPENSATED FOR HAS BECOME A PART OF LIFE WITH LITTLE RECOVERY; ONE SOMETIMES 2 DAYS OUT OF THE WK. CREW REST SHOULD REQUIRE THE OPERATORS TO PROVIDE A DECENT LAYOVER AT OUTSTATIONS, TRYING TO CAPTURE A FEW WINKS AT A PAX TERMINAL DURING MY 9 HRS REST JUST ISN'T ENOUGH. I KNOW OUR COMPANY HAS HAD MORE THAN ONE ACCIDENT WHERE THE PLT LIKE MYSELF CAUGHT HIS FINAL MOMENTS REST ON AUTOPLT DURING A LONG LEG AT NIGHT.

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.