Narrative:

The handover point from uncontrolled (non-radar) environment from accra radio to lagos approach control is over tye VOR. I was the relief pilot in the jumpseat. The captain; PNF; reported tye to accra. We were maintaining FL210. The response from accra was something like; 'you are past traffic...FL180...contact lagos on (I can't remember the frequency).' the first officer; PF; dialed in FL180 in the altitude command window and pointed in accordance with our company procedures. The captain pointed to the command window and verbally acknowledged while simultaneously responding to the radio call; 'roger; descend to FL180 and contact lagos on (whatever frequency it was).' I did not specifically hear the word 'descend' by accra; but I was also involved with other relief pilot duties to include attempting to contact company operations at lagos on another radio and making a PA to the passenger about the WX at lagos. The lagos controller queried us as to the clearance that we received from accra but the query was fairly short. Once on the ground at lagos; the lagos tower queried us extensively about our actions. Lagos tower informed us of a particular procedure that we allegedly failed to comply with. Namely; that we were 'supposed to intercept the 270 degree radial off of lag and fly it inbound after passing tye VOR.' the procedure is supposedly accompanied by altitude constraints. The way lagos tower made it sound; this procedure is published. This is the 7TH or 8TH time that I've flown into lagos since dec/07 and I am unaware of such a procedure. I have looked extensively through our commercial chart pubs and have found no published arrival procedures. Supplemental information from acn 779874: descending into lagos; nigeria; just before handoff to lagos control from accra; myself; as captain in left seat; first officer flying in right seat about 15 mins after taking over after our second break. Relief captain and relief first officer on jumpseats; also monitoring. While descending from FL310 to FL210; all 4 of us heard accra clear us to descend to FL180. Since we usually cross tye at FL210; I slowly and clearly read back clearance to descend passing through FL270 for FL180. Accra said nothing to make us doubt my readback. A few moments later; I asked about our handoff to lagos control and he said to stand by; he was working on it. Accra said nothing further but on the safe side; we did cross tye at FL210 while in the descent. Upon contacting lagos control with passing FL207 for FL180; control queried and I confirmed FL180 clearance. He responded with a radar vector of 020 degrees; and we complied. After a few moments he said there was traffic on climb out passing FL180. We never saw him visually or on TCAS on 40 mi scale and he was never a factor. Later; lagos tower said we should not have been cleared to FL180 and should have flown the procedure of tye 050 degree radial to the lag 270 degree radial inbound and maintain FL210. We scoured our manuals and our company guidance handouts and still have found no such procedure. I also don't know if accra denied giving us the clearance to FL180. I have flown this route a dozen times and have been given the 050/270 clearance before; but an equal number of times I have been given direct lag! Interestingly enough; while leaving lagos the next day we were contacting accra on another radio to let them know we were approaching tye with clearance from lagos to FL200. Accra cleared us to climb unrestr to FL310. We told lagos of the accra clearance and he simply handed us off to accra! I know we were all tired from the 11 hour flight; but all of us heard the FL180 clearance and my uncontested readback. We still don't know if this was an altitude deviation or not because it seems that lagos and accra might not have the best of communication with each other. We still haven't found the 'procedure' but will continue to look. I return in 3 days and plan to call lagos well in advance and find out exactly what he wants us to do. Our normal procedure is to call them '10 early;' but rather than having jumpseat do so; I will; earlier. Supplemental information from acn 780141: lagos control queried us as to our altitude assignment and mentioned that there was traffic at FL180; although we never saw traffic visually or electronically and lagos never said where the traffic was located. We were then given further descent clearance and directly vectored to the ILS localizer to runway 18R and landed. Language was probably the most important human factor involved. Coordination between adjacent controling states was also a factor.

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Original NASA ASRS Text

Title: B767 FLT CREW REPORTS CONFUSION OVER PROPER PROCEDURES ENTERING DKNN FIR AND LANDING DNMM; FROM DGAC FIR.

Narrative: THE HANDOVER POINT FROM UNCTLED (NON-RADAR) ENVIRONMENT FROM ACCRA RADIO TO LAGOS APCH CTL IS OVER TYE VOR. I WAS THE RELIEF PLT IN THE JUMPSEAT. THE CAPT; PNF; RPTED TYE TO ACCRA. WE WERE MAINTAINING FL210. THE RESPONSE FROM ACCRA WAS SOMETHING LIKE; 'YOU ARE PAST TFC...FL180...CONTACT LAGOS ON (I CAN'T REMEMBER THE FREQ).' THE FO; PF; DIALED IN FL180 IN THE ALT COMMAND WINDOW AND POINTED IN ACCORDANCE WITH OUR COMPANY PROCS. THE CAPT POINTED TO THE COMMAND WINDOW AND VERBALLY ACKNOWLEDGED WHILE SIMULTANEOUSLY RESPONDING TO THE RADIO CALL; 'ROGER; DSND TO FL180 AND CONTACT LAGOS ON (WHATEVER FREQ IT WAS).' I DID NOT SPECIFICALLY HEAR THE WORD 'DSND' BY ACCRA; BUT I WAS ALSO INVOLVED WITH OTHER RELIEF PLT DUTIES TO INCLUDE ATTEMPTING TO CONTACT COMPANY OPS AT LAGOS ON ANOTHER RADIO AND MAKING A PA TO THE PAX ABOUT THE WX AT LAGOS. THE LAGOS CTLR QUERIED US AS TO THE CLRNC THAT WE RECEIVED FROM ACCRA BUT THE QUERY WAS FAIRLY SHORT. ONCE ON THE GND AT LAGOS; THE LAGOS TWR QUERIED US EXTENSIVELY ABOUT OUR ACTIONS. LAGOS TWR INFORMED US OF A PARTICULAR PROC THAT WE ALLEGEDLY FAILED TO COMPLY WITH. NAMELY; THAT WE WERE 'SUPPOSED TO INTERCEPT THE 270 DEG RADIAL OFF OF LAG AND FLY IT INBOUND AFTER PASSING TYE VOR.' THE PROC IS SUPPOSEDLY ACCOMPANIED BY ALT CONSTRAINTS. THE WAY LAGOS TWR MADE IT SOUND; THIS PROC IS PUBLISHED. THIS IS THE 7TH OR 8TH TIME THAT I'VE FLOWN INTO LAGOS SINCE DEC/07 AND I AM UNAWARE OF SUCH A PROC. I HAVE LOOKED EXTENSIVELY THROUGH OUR COMMERCIAL CHART PUBS AND HAVE FOUND NO PUBLISHED ARR PROCS. SUPPLEMENTAL INFO FROM ACN 779874: DSNDING INTO LAGOS; NIGERIA; JUST BEFORE HDOF TO LAGOS CTL FROM ACCRA; MYSELF; AS CAPT IN L SEAT; FO FLYING IN R SEAT ABOUT 15 MINS AFTER TAKING OVER AFTER OUR SECOND BREAK. RELIEF CAPT AND RELIEF FO ON JUMPSEATS; ALSO MONITORING. WHILE DSNDING FROM FL310 TO FL210; ALL 4 OF US HEARD ACCRA CLR US TO DSND TO FL180. SINCE WE USUALLY CROSS TYE AT FL210; I SLOWLY AND CLEARLY READ BACK CLRNC TO DSND PASSING THROUGH FL270 FOR FL180. ACCRA SAID NOTHING TO MAKE US DOUBT MY READBACK. A FEW MOMENTS LATER; I ASKED ABOUT OUR HDOF TO LAGOS CTL AND HE SAID TO STAND BY; HE WAS WORKING ON IT. ACCRA SAID NOTHING FURTHER BUT ON THE SAFE SIDE; WE DID CROSS TYE AT FL210 WHILE IN THE DSCNT. UPON CONTACTING LAGOS CTL WITH PASSING FL207 FOR FL180; CTL QUERIED AND I CONFIRMED FL180 CLRNC. HE RESPONDED WITH A RADAR VECTOR OF 020 DEGS; AND WE COMPLIED. AFTER A FEW MOMENTS HE SAID THERE WAS TFC ON CLBOUT PASSING FL180. WE NEVER SAW HIM VISUALLY OR ON TCAS ON 40 MI SCALE AND HE WAS NEVER A FACTOR. LATER; LAGOS TWR SAID WE SHOULD NOT HAVE BEEN CLRED TO FL180 AND SHOULD HAVE FLOWN THE PROC OF TYE 050 DEG RADIAL TO THE LAG 270 DEG RADIAL INBOUND AND MAINTAIN FL210. WE SCOURED OUR MANUALS AND OUR COMPANY GUIDANCE HANDOUTS AND STILL HAVE FOUND NO SUCH PROC. I ALSO DON'T KNOW IF ACCRA DENIED GIVING US THE CLRNC TO FL180. I HAVE FLOWN THIS RTE A DOZEN TIMES AND HAVE BEEN GIVEN THE 050/270 CLRNC BEFORE; BUT AN EQUAL NUMBER OF TIMES I HAVE BEEN GIVEN DIRECT LAG! INTERESTINGLY ENOUGH; WHILE LEAVING LAGOS THE NEXT DAY WE WERE CONTACTING ACCRA ON ANOTHER RADIO TO LET THEM KNOW WE WERE APCHING TYE WITH CLRNC FROM LAGOS TO FL200. ACCRA CLRED US TO CLB UNRESTR TO FL310. WE TOLD LAGOS OF THE ACCRA CLRNC AND HE SIMPLY HANDED US OFF TO ACCRA! I KNOW WE WERE ALL TIRED FROM THE 11 HR FLT; BUT ALL OF US HEARD THE FL180 CLRNC AND MY UNCONTESTED READBACK. WE STILL DON'T KNOW IF THIS WAS AN ALTDEV OR NOT BECAUSE IT SEEMS THAT LAGOS AND ACCRA MIGHT NOT HAVE THE BEST OF COM WITH EACH OTHER. WE STILL HAVEN'T FOUND THE 'PROC' BUT WILL CONTINUE TO LOOK. I RETURN IN 3 DAYS AND PLAN TO CALL LAGOS WELL IN ADVANCE AND FIND OUT EXACTLY WHAT HE WANTS US TO DO. OUR NORMAL PROC IS TO CALL THEM '10 EARLY;' BUT RATHER THAN HAVING JUMPSEAT DO SO; I WILL; EARLIER. SUPPLEMENTAL INFO FROM ACN 780141: LAGOS CTL QUERIED US AS TO OUR ALT ASSIGNMENT AND MENTIONED THAT THERE WAS TFC AT FL180; ALTHOUGH WE NEVER SAW TFC VISUALLY OR ELECTRONICALLY AND LAGOS NEVER SAID WHERE THE TFC WAS LOCATED. WE WERE THEN GIVEN FURTHER DSCNT CLRNC AND DIRECTLY VECTORED TO THE ILS LOC TO RWY 18R AND LANDED. LANGUAGE WAS PROBABLY THE MOST IMPORTANT HUMAN FACTOR INVOLVED. COORD BTWN ADJACENT CTLING STATES WAS ALSO A FACTOR.

Data retrieved from NASA's ASRS site as of May 2009 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.