There are, JT. Both ICAO and JAR limit the maximum clearway to 50% of TORA. Many AFMs have a further limitation on the amount of clearway that can be used to prevent the take-off calculation becoming TORA limited.
I reckon the extra clearway would reduce the minimum speed to go, VGO, this would increase MTOM and reduce V1. The explanation is graphical, I'll try to post the pictures later.
Last edited by Alex Whittingham; 28th May 2003 at 17:36.