Narrative:

I have flown only glass cockpit EFIS aircraft for the last 3 1/2 yrs. When we got the paperwork for the airplane we were going to fly to sfo, it said the EFIS was inoperative--but that the normal VOR navs were working. In the area of big sur, we were given a heading to intercept the oak 151 degree right and to fly the big sur profile. The captain said because the EFIS was inoperative that we should start down early to give us plenty of room to make all the crossing restrictions. He put 10000' in the altitude alerter for the crossing at skunk (44 DME). As I descended I realized we had intercepted the radial beyond anjee (60 DME) and that we were going through 15000' at 65 DME. Prior to anjee I stopped the descent at 14600'. I told the captain we had better tell the controller. The controller then asked us about it. I said to the captain that we had better file NASA reports. He then asked the controller 'do we need to file reports on this?' she said that would not be necessary, that it caused no problem. If the EFIS had been working, I'm sure this would not have happened because of the map display and vertical navigation indications. It's funny how the old fashioned way can feel so awkward when you have not used it in so long. I think it would be comparable to having flown many VOR holds and feeling very comfortable with them, and to then be given an ADF hold which requires more picturing in your mind where you are as you go around the hold.

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Original NASA ASRS Text

Title: ADVANCED COCKPIT ACR WITH INOPERATIVE EFIS DESCENDS BELOW CROSSING RESTRICTION ALT ON THE BIG SUR PROFILE INTO SFO, BECAUSE THEY INTERCEPTED THE PROFILE TRACK EARLIER THAN ANTICIPATED.

Narrative: I HAVE FLOWN ONLY GLASS COCKPIT EFIS ACFT FOR THE LAST 3 1/2 YRS. WHEN WE GOT THE PAPERWORK FOR THE AIRPLANE WE WERE GOING TO FLY TO SFO, IT SAID THE EFIS WAS INOP--BUT THAT THE NORMAL VOR NAVS WERE WORKING. IN THE AREA OF BIG SUR, WE WERE GIVEN A HDG TO INTERCEPT THE OAK 151 DEG R AND TO FLY THE BIG SUR PROFILE. THE CAPT SAID BECAUSE THE EFIS WAS INOP THAT WE SHOULD START DOWN EARLY TO GIVE US PLENTY OF ROOM TO MAKE ALL THE XING RESTRICTIONS. HE PUT 10000' IN THE ALT ALERTER FOR THE XING AT SKUNK (44 DME). AS I DSNDED I REALIZED WE HAD INTERCEPTED THE RADIAL BEYOND ANJEE (60 DME) AND THAT WE WERE GOING THROUGH 15000' AT 65 DME. PRIOR TO ANJEE I STOPPED THE DSCNT AT 14600'. I TOLD THE CAPT WE HAD BETTER TELL THE CTLR. THE CTLR THEN ASKED US ABOUT IT. I SAID TO THE CAPT THAT WE HAD BETTER FILE NASA RPTS. HE THEN ASKED THE CTLR 'DO WE NEED TO FILE RPTS ON THIS?' SHE SAID THAT WOULD NOT BE NECESSARY, THAT IT CAUSED NO PROB. IF THE EFIS HAD BEEN WORKING, I'M SURE THIS WOULD NOT HAVE HAPPENED BECAUSE OF THE MAP DISPLAY AND VERT NAV INDICATIONS. IT'S FUNNY HOW THE OLD FASHIONED WAY CAN FEEL SO AWKWARD WHEN YOU HAVE NOT USED IT IN SO LONG. I THINK IT WOULD BE COMPARABLE TO HAVING FLOWN MANY VOR HOLDS AND FEELING VERY COMFORTABLE WITH THEM, AND TO THEN BE GIVEN AN ADF HOLD WHICH REQUIRES MORE PICTURING IN YOUR MIND WHERE YOU ARE AS YOU GO AROUND THE HOLD.

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.