B737 Undifferentiated or Other Model
Human-Machine Interface
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Procedure; Human Factors; Aircraft
Since IAH has changed over to the new SIDs and STARs we have been getting STAR clearance changes much more frequently.  Many times these changes come at inopportune times (below 10;000 FT; Taxiout; etc).  As an example this morning while in MSY we received a new clearance which switched our STAR from the HCKRY1 to the GILLL1; then after pushing back and taxing to the runway we were recleared back on the HCKRY1.  Although this may not seem like a big deal it adds chances for mistakes to be made and increases the threat of making a mistake.  While on the STAR we were told to expect 8R but shortly before beginning the transition for 8R we were told to fly the 8R transition but expect 8L.  The 737 FMC will not allow you to do this; it can not fly one transition and load another runway.  So we were below 10;000; intermittent IMC and trying to reprogram the FMC.  Mind you there is no way to fly the STAR without the FMC.  We ended up leaving 8R loaded till we were taken off the arrival and then switching the FMC to 8L.  There is a reason we brief these approaches above 18;000 FT and that is for safety.  We all realize the ATC system is dynamic and changes have to be made on short notice but coinciding with the change over to the new SID's and STAR's these changes have become much more frequent and it is only a matter of time before someone gets violated or something worse.  Most pilots complained about DEN and never flying the STAR they were filed and now we have the same thing here in IAH.  Thank you for your consideration with this matter.
B737 First Officer laments the frequent changes to SIDs and STARs during arrivals and departures from IAH. The FMC will not allow a transition to one runway with an expected landing on a different runway. The change can only be made after leaving the transition.