Re: Flight Planning Systems LIDO/Jeppesen
GW-
I've used the Jepp system, its accurate enough, winds usually updated 2x/day with Bracknell, as they seem to have the most accurate Oceanic winds. For the dom US, most carriers using the NWS GRIB winds, which go in every 6 or so hrs, and are very accurate over the CONUS.
As for LIDO, my old company is looking at it, UPS is getting it installed now, Air Canada has it up and running. From what I hear, it blows the Jepp system away, in features and functionality. Jepp really needs some dispatch people helping them out, not just techno/coding guys.
I'm currently using Navtech, which is about the same as Jepp, except the AURORA gui front-end makes it much simpler for these strange charter pairs we seem to be running. Builds a good MTTA route in a matter of seconds, on longhaulish stuff, e.g. US east coast to Germany then to the Mideast.
As far as the burns go, as was said prior, as accurate as the actual burn BIAS and actual flying mileage.
What type of airplane/engine type?
For the A320s we see about +3% overburn for the V2500 and +5% for the CFM56.
Fuel Burn discrepancy issues:
I've seen alot of carriers not properly take into account the actual route mileage (known DP and STAR routings and/or ATC vector miles onto the long final appr).
The location where the fuel burn discrepancy can be quickly confirmed by doing some audits of the route/fltplan vs actual burns. Does the fuel discrepancy occur in climb(DEPT-TOC), cruise, descent (TOD-DEST), or does the entire segment not match up correctly.
Does the plan comply with the flt plan cruise speed enroute. Or do crews speed up to make up time or slow down due ATC. Does crew fly same altitudes in plan, or above/below optimum altitude. I've seen crews step climb into stronger headwinds many times, then complain about inaccurate flt plans & also seen ATC hold down flts for a long time Unable due higher Trfc.
If descent burn is the discrepancy, added vector miles and/or higher burns maybe used. Use of anti-ice may cause slightly higher burns, coupled with additional ATC vector miles. In the US, the east coast is typically descending flts 150-200nm from DEST, and causing overburns for the unknowing.
ZFW and Empty wts may also be a problem. Correct pax/bag wts can be critical on range/wt limited flts. Recall my good days with the B747 JFK-TLV flts, @30W fuel score down 5000lbs due to atypical carryon bag wts.
Cruise Mach policy. I've seen some carriers, tell crews to fly Cost Index Blah Blah and then don't have the accurate burn data for Cost Index Blah Blah, just flt plan them at M.80. Can cause a difference on the longer stage lengths.
Rgrds
MB