Narrative:

Flight was dispatched out of eham with #3 INS inoperative. Flight was normal to leveloff at FL300 and we were direct to rodsi on a course about parallel to UP1. After leveloff with alert for rodsi and checking the next point on our navigation (givem), scottish gave us direct eraka. After the first officer entered eraka, he noticed the flags for the navigation on his HSI vof flag were normal. The flags in navigation indicate the information from the INS is flawed, not acceptable. Reviewing minimum equipment for the airspace we were in, the first officer requested FL280 to get us below mnps/rvsm airspace. The so and I were working on a phone patch to flight control and maintenance control to discuss our options for continuing or returning. Flight control said we could continue on a route over sum, kef, 63n30w, 61n40w, ozn, 59n50w, prawn, ydp, etc, to dlh flight plan route. The concerns of the crew were twofold. First, with 1 INS, we are very limited for navigation. The rest of the flight was routine until switching to ZMP. With the first issue in mind, rykavick control offered us direct 63n30w when we were in radar contact, but we turned it down due to concern over possible other problems, ie, loss of radar or lost communication. We looked at leg lengths too long for navigation with VOR and/or ADF and if the last INS failed, we would be dead reckoning. The second concern comes from lack of reasonable handling by ZMP and approach control. Flight control had coordinated a shortcut to save 800 pounds of fuel because the new route used much of our contingency fuel. When we got to the last ZMP sector after changing to the eau 6 arrival over twinz, we were slowed and vectored to use more than our 800 pounds saved fuel to follow all other aircraft inbound (4) and ended on a 12 mi final with no traffic ahead. So much for coordination or cooperation.

Google
 

Original NASA ASRS Text

Title: EXTENDED OVERWATER DC10 PIC RPTS INS EQUIP PROBS NECESSITATING REROUTING CAUSING FUEL USAGE CONCERNS. COMPANY COORD EXPEDITED HANDLING WITH ZMP DUE TO FUEL CONCERNS APPARENTLY FAILS TO MATERIALIZE.

Narrative: FLT WAS DISPATCHED OUT OF EHAM WITH #3 INS INOP. FLT WAS NORMAL TO LEVELOFF AT FL300 AND WE WERE DIRECT TO RODSI ON A COURSE ABOUT PARALLEL TO UP1. AFTER LEVELOFF WITH ALERT FOR RODSI AND CHKING THE NEXT POINT ON OUR NAV (GIVEM), SCOTTISH GAVE US DIRECT ERAKA. AFTER THE FO ENTERED ERAKA, HE NOTICED THE FLAGS FOR THE NAV ON HIS HSI VOF FLAG WERE NORMAL. THE FLAGS IN NAV INDICATE THE INFO FROM THE INS IS FLAWED, NOT ACCEPTABLE. REVIEWING MINIMUM EQUIP FOR THE AIRSPACE WE WERE IN, THE FO REQUESTED FL280 TO GET US BELOW MNPS/RVSM AIRSPACE. THE SO AND I WERE WORKING ON A PHONE PATCH TO FLT CTL AND MAINT CTL TO DISCUSS OUR OPTIONS FOR CONTINUING OR RETURNING. FLT CTL SAID WE COULD CONTINUE ON A RTE OVER SUM, KEF, 63N30W, 61N40W, OZN, 59N50W, PRAWN, YDP, ETC, TO DLH FLT PLAN RTE. THE CONCERNS OF THE CREW WERE TWOFOLD. FIRST, WITH 1 INS, WE ARE VERY LIMITED FOR NAV. THE REST OF THE FLT WAS ROUTINE UNTIL SWITCHING TO ZMP. WITH THE FIRST ISSUE IN MIND, RYKAVICK CTL OFFERED US DIRECT 63N30W WHEN WE WERE IN RADAR CONTACT, BUT WE TURNED IT DOWN DUE TO CONCERN OVER POSSIBLE OTHER PROBS, IE, LOSS OF RADAR OR LOST COM. WE LOOKED AT LEG LENGTHS TOO LONG FOR NAV WITH VOR AND/OR ADF AND IF THE LAST INS FAILED, WE WOULD BE DEAD RECKONING. THE SECOND CONCERN COMES FROM LACK OF REASONABLE HANDLING BY ZMP AND APCH CTL. FLT CTL HAD COORDINATED A SHORTCUT TO SAVE 800 LBS OF FUEL BECAUSE THE NEW RTE USED MUCH OF OUR CONTINGENCY FUEL. WHEN WE GOT TO THE LAST ZMP SECTOR AFTER CHANGING TO THE EAU 6 ARR OVER TWINZ, WE WERE SLOWED AND VECTORED TO USE MORE THAN OUR 800 LBS SAVED FUEL TO FOLLOW ALL OTHER ACFT INBOUND (4) AND ENDED ON A 12 MI FINAL WITH NO TFC AHEAD. SO MUCH FOR COORD OR COOPERATION.

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.