Narrative:

For the last approximately 2 yrs I have flown for an on-demand freight airline. From the moment we are legal, we are 'on call' 14 hours on duty, and 10 hours off is more often the rule than the intended exception. On sep/thu/96 I arose at XH00 am legal and ready to fly. Fully expecting to fly sometime during that day, I didn't (couldn't) sleep until XA30 am on sep/fri/96. At XC45 am dispatch called for a 45 min launch (SOP). However, due to a maintenance delay, we didn't depart yip until XD45 am for sdf. Hauled freight from sdf to cae (approach to minimums), continuing to sav. Oh yeah, the entire trip flying with a deferred (typical) autoplt. The problem occurred during my leg hand flying from sav to mia. Things got busy on the descent to mia. No sleep, no food, and hand flying at FL310 for 1 hour 20 mins had taken its toll. I was cleared to 8000 ft. When we passed through 7700 ft, the altitude alerter sounded. I reacted at 7500 ft and climbed to the assigned altitude. During this period of a couple of seconds, mia approach announced 'you just blew through your altitude.' we were handed off and landed without further incident. 5 1/2 hours later, because of the often occurring 'freight delay' we departed mia for orf. We part 91'ed home for yip arriving at XW20 pm local. That's approximately 20 hours from call-out till block-in. In conclusion, I believe the major contributing factor was lack of sleep, compounded by unusable autoplt. The current part 135 duty and rest period regulations need changing, including the infamous 'freight delay,' which can turn what should be a normal work day into 20 hours or more. On more than one occasion, I have awakened from a little copilot nap, to see the captain still enjoying his. Well, I'm still tired now, I hope I've made my point.

Related reports:

Google
 

Original NASA ASRS Text

Title: LTT ATX CARGOLINER DSNDED THROUGH ASSIGNED ALT DUE TO CREW FATIGUE.

Narrative: FOR THE LAST APPROX 2 YRS I HAVE FLOWN FOR AN ON-DEMAND FREIGHT AIRLINE. FROM THE MOMENT WE ARE LEGAL, WE ARE 'ON CALL' 14 HRS ON DUTY, AND 10 HRS OFF IS MORE OFTEN THE RULE THAN THE INTENDED EXCEPTION. ON SEP/THU/96 I AROSE AT XH00 AM LEGAL AND READY TO FLY. FULLY EXPECTING TO FLY SOMETIME DURING THAT DAY, I DIDN'T (COULDN'T) SLEEP UNTIL XA30 AM ON SEP/FRI/96. AT XC45 AM DISPATCH CALLED FOR A 45 MIN LAUNCH (SOP). HOWEVER, DUE TO A MAINT DELAY, WE DIDN'T DEPART YIP UNTIL XD45 AM FOR SDF. HAULED FREIGHT FROM SDF TO CAE (APCH TO MINIMUMS), CONTINUING TO SAV. OH YEAH, THE ENTIRE TRIP FLYING WITH A DEFERRED (TYPICAL) AUTOPLT. THE PROB OCCURRED DURING MY LEG HAND FLYING FROM SAV TO MIA. THINGS GOT BUSY ON THE DSCNT TO MIA. NO SLEEP, NO FOOD, AND HAND FLYING AT FL310 FOR 1 HR 20 MINS HAD TAKEN ITS TOLL. I WAS CLRED TO 8000 FT. WHEN WE PASSED THROUGH 7700 FT, THE ALT ALERTER SOUNDED. I REACTED AT 7500 FT AND CLBED TO THE ASSIGNED ALT. DURING THIS PERIOD OF A COUPLE OF SECONDS, MIA APCH ANNOUNCED 'YOU JUST BLEW THROUGH YOUR ALT.' WE WERE HANDED OFF AND LANDED WITHOUT FURTHER INCIDENT. 5 1/2 HRS LATER, BECAUSE OF THE OFTEN OCCURRING 'FREIGHT DELAY' WE DEPARTED MIA FOR ORF. WE PART 91'ED HOME FOR YIP ARRIVING AT XW20 PM LCL. THAT'S APPROX 20 HRS FROM CALL-OUT TILL BLOCK-IN. IN CONCLUSION, I BELIEVE THE MAJOR CONTRIBUTING FACTOR WAS LACK OF SLEEP, COMPOUNDED BY UNUSABLE AUTOPLT. THE CURRENT PART 135 DUTY AND REST PERIOD REGS NEED CHANGING, INCLUDING THE INFAMOUS 'FREIGHT DELAY,' WHICH CAN TURN WHAT SHOULD BE A NORMAL WORK DAY INTO 20 HRS OR MORE. ON MORE THAN ONE OCCASION, I HAVE AWAKENED FROM A LITTLE COPLT NAP, TO SEE THE CAPT STILL ENJOYING HIS. WELL, I'M STILL TIRED NOW, I HOPE I'VE MADE MY POINT.

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.