Flight Crew Air Transport Pilot (ATP)
Communication Breakdown; Confusion; Other / Unknown
Deviation - Altitude Crossing Restriction Not Met
General None Reported / Taken
Chart Or Publication; Human Factors; Procedure
We were over LUVYN at 10;000 FT and were cleared to descend via the ILS 25L procedure. The pilot flying programmed the VNAV and we started our descent. We were approaching TAROC at 9;800 FT. The plate showed TAROC at 9;000 FT; I told the pilot flying we need to be at 9;000 FT at TAROC and he said we could be at or above 9;000 FT. We were crossing DYMMO 800 FT above the charted 8;000 FT and I again mentioned that we should cross DYMMO at 8;000 FT again the pilot flying said it was at or above 8;000 FT. We were crossing FUELER 800 FT above the charted 7;000 FT and then we crossed GATTE at the charted 5;000 FT. The rest of the approach was flown as indicated on the chart.We are trained and highly encouraged by our company to use the VNAV function. Some of the older aircraft FMS have very slow processors and sometimes have trouble meeting crossing restrictions. Many crewmembers have made this known to the company training department and the company continually strongly encourages the use of VNAV. I believe we should have manually flown the procedure to ensure we crossed the points at the charted altitudes.
When on the ILS 25L approach at LAX; the Captain elected to cross the intermediate segment fixes approximately 800 FT above the charted crossing altitudes. The First Officer advocated the need to cross at those altitudes; but the Captain disagreed; believing them to be minimum altitudes.