UAL747DEN From United States of America, joined Dec 2003, 2385 posts, RR: 12
Reply 2, posted (9 years 7 months 2 weeks 1 day 4 hours ago) and read 6892 times:
I believe that the ER is achieved by doing very little changes, and mostly just within the computer and in certification. The LR represents major changes to an aircraft and actual engineering changes being made so that the aircraft has an entirely different use.... Hope I was able to explained it somewhat understandable, and I could be completely wrong Who Knows!!!