tire-related?
One probability/possibility, based upon the eye-witness account of flames from #1, is likely to be:
.
a. A tread-worn port main-gear tyre shredding at the point of rotation (Vrot) and being ingested into the port engine. During rotate, the engines are momentarily much closer to the ground and ingestion of point-of-rotate tyre debris becomes more likely.... partly due to the changed airflows over the slats/wings/TE flaps at rotation. Aircraft was at or near (or slightly in excess of?) max AUW for take-off (172 souls going on holiday with excess luggage). Who knows what the Spanish Regulator stipulates for average pax weights nowadays? The obesity epidemic is as prevalent in Spain as elsewhere in Western civilization. It was inevitable that there should eventually be an average pax-weight related jet crash equivalent to that Beech 1900's at Charlotte-Douglas. Think about the momentary "pivot-about-main-gear" effective weight increase pressure on the tyres at Vrot. V1 cuts have always been the main area of concern for engine failure and that is why these drills are emphasized in simulator training. If an operator is trying to save money on tyres and is using re-retreaded casings and also changing them very late in their wear-cycle, then they are increasingly liable to this type of "point-of-rotate" failure event for a heavily laden jet. A high-speed abort following a port tyre failure(s) would lead to directional control problems - notwithstanding what may have happened by way of debris ingestion.
.
On January 27, 2003 the FAA issued Notice N8400.40 requiring a number of operators of 10 to 19 passenger seat aircraft to validate the Weight and Balance Control Program to sample passenger weights, carry-on baggage weights, and checked baggage weights for part of their flights.
The survey showed that the average passenger weight was higher than the estimates by 20.63 pounds, carry-on bags were higher by 5.72 pounds and domestic checked bags by 3.81 pounds. Consequently, on May 12, the FAA reported it is adding 10 pounds to its estimate for passengers and five pounds to luggage (Notice 8300.112). This notice was cancelled by the publication of AC 120-27D August 11, 2004.