Narrative:

Long delays at lga due to WX. We spent a lot of time holding near the approach end of runway 13. Just prior to taking the runway, the no autoland light came on due to slight differences in heading. I mentioned that, as per the 10-7 pages, that wasn't unusual for our location on the airport. We were given a revised clearance to 3000 ft and assigned the whitestone climb. At the beginning of the takeoff roll, we got a heading annunciator on the FMA and I elected to continue the departure. Shortly after liftoff, the flight director disappeared. I told the first officer to try to fly the departure using his heading but added to the confusion by not telling him which compass to use. Our departure headings were close, but not precise, and may not have followed the noise abatement routing. We complied with all other altitude and speed requirements. Shortly after the turn to 040 degrees, I advised ATC of our heading problems and he provided vectors as needed. I tried to xchk the standby compass but, even though the light was ok, I was unable to see the numbers due to ambient light conditions in the cockpit. (It always works in the dark simulator but is pretty worthless on a bright afternoon.) after about 5 mins, the compasses were back in sync and the flight proceeded uneventfully. This was the last leg of the day and we were both getting tired after the long delays. If I had been fresh, I probably would have fixed the problem before takeoff instead of deciding that the headings were good enough for a VMC day. Supplemental information from acn 618576: the captain had already briefed the departure notes concerning magnetic deviations for runway 13 departures. After liftoff, the roll mode began flashing heading hold and the flight director heading mode could not be selected. We were both concerned because the noise abatement procedure required an immediate right turn to a 180 degree heading followed quickly by a left turn to a 040 degree heading. Additionally, our initial altitude was changed from 5000 ft to 3000 ft. I turned off my flight director and flew raw data. The captain said use your side for heading information. I started the right turn to 180 degrees and asked which one, meaning HSI or RMI. There was at least a 15 degree difference in the headings. Headings were ballpark at best. We received several vectors during the departure to clear thunderstorms.

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Original NASA ASRS Text

Title: HDG TRACK DEV WHEN A DEP MD80 FLT CREW EXPERIENCES COMPASS AND HSI PROBS WITH BOTH COMPASSES AND OTHER ASSOCIATED EQUIP BECAUSE OF MAGNETIC INTERFERENCE NEAR RWY 13 AT LGA.

Narrative: LONG DELAYS AT LGA DUE TO WX. WE SPENT A LOT OF TIME HOLDING NEAR THE APCH END OF RWY 13. JUST PRIOR TO TAKING THE RWY, THE NO AUTOLAND LIGHT CAME ON DUE TO SLIGHT DIFFERENCES IN HDG. I MENTIONED THAT, AS PER THE 10-7 PAGES, THAT WASN'T UNUSUAL FOR OUR LOCATION ON THE ARPT. WE WERE GIVEN A REVISED CLRNC TO 3000 FT AND ASSIGNED THE WHITESTONE CLB. AT THE BEGINNING OF THE TKOF ROLL, WE GOT A HDG ANNUNCIATOR ON THE FMA AND I ELECTED TO CONTINUE THE DEP. SHORTLY AFTER LIFTOFF, THE FLT DIRECTOR DISAPPEARED. I TOLD THE FO TO TRY TO FLY THE DEP USING HIS HDG BUT ADDED TO THE CONFUSION BY NOT TELLING HIM WHICH COMPASS TO USE. OUR DEP HDGS WERE CLOSE, BUT NOT PRECISE, AND MAY NOT HAVE FOLLOWED THE NOISE ABATEMENT ROUTING. WE COMPLIED WITH ALL OTHER ALT AND SPD REQUIREMENTS. SHORTLY AFTER THE TURN TO 040 DEGS, I ADVISED ATC OF OUR HDG PROBS AND HE PROVIDED VECTORS AS NEEDED. I TRIED TO XCHK THE STANDBY COMPASS BUT, EVEN THOUGH THE LIGHT WAS OK, I WAS UNABLE TO SEE THE NUMBERS DUE TO AMBIENT LIGHT CONDITIONS IN THE COCKPIT. (IT ALWAYS WORKS IN THE DARK SIMULATOR BUT IS PRETTY WORTHLESS ON A BRIGHT AFTERNOON.) AFTER ABOUT 5 MINS, THE COMPASSES WERE BACK IN SYNC AND THE FLT PROCEEDED UNEVENTFULLY. THIS WAS THE LAST LEG OF THE DAY AND WE WERE BOTH GETTING TIRED AFTER THE LONG DELAYS. IF I HAD BEEN FRESH, I PROBABLY WOULD HAVE FIXED THE PROB BEFORE TKOF INSTEAD OF DECIDING THAT THE HDGS WERE GOOD ENOUGH FOR A VMC DAY. SUPPLEMENTAL INFO FROM ACN 618576: THE CAPT HAD ALREADY BRIEFED THE DEP NOTES CONCERNING MAGNETIC DEVS FOR RWY 13 DEPS. AFTER LIFTOFF, THE ROLL MODE BEGAN FLASHING HDG HOLD AND THE FLT DIRECTOR HDG MODE COULD NOT BE SELECTED. WE WERE BOTH CONCERNED BECAUSE THE NOISE ABATEMENT PROC REQUIRED AN IMMEDIATE R TURN TO A 180 DEG HDG FOLLOWED QUICKLY BY A L TURN TO A 040 DEG HDG. ADDITIONALLY, OUR INITIAL ALT WAS CHANGED FROM 5000 FT TO 3000 FT. I TURNED OFF MY FLT DIRECTOR AND FLEW RAW DATA. THE CAPT SAID USE YOUR SIDE FOR HDG INFO. I STARTED THE R TURN TO 180 DEGS AND ASKED WHICH ONE, MEANING HSI OR RMI. THERE WAS AT LEAST A 15 DEG DIFFERENCE IN THE HDGS. HDGS WERE BALLPARK AT BEST. WE RECEIVED SEVERAL VECTORS DURING THE DEP TO CLR TSTMS.

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.