Hello wpm1000,
First of all, I am not a commercial pilot and as such have no in depth technical knowledge of the Airbus or any other commercial jet.
However, being a frequent traveller who is interested in aircraft I have spoken to pilots in the past and asking the same question about the length of take off roll on an A320 compared with say a B757 or B767 I can tell you this.
I understand that runway length, loading ( fuel, pax etc ) weather and other factors are taken in to account and the engine power is adjusted accordingly. I believe the computer on board the "Bus" calculates the engine power required. The aircraft appears to accelerate a bit slower and thus the take off roll is longer as full power ( 100% N1 I think ) is not always used.
A B757 always seems very eager to get into the air whereas an Airbus uses more runway.
As for the "shiver" I would say that is more like an oscillation and I too have noticed it but, I have no idea what that might be and if any pilot is looking at the SLF forum postings maybe they can answer.
Regards G-GBPED ( Now waits to be corrected by an Airbus expert )
