11.  Most involve corrosion on various internal metal parts, a common problem in older planes.

12.  Nonetheless, the FAA is not now planning to require capacitors for the data recorders on older planes.

13.  Now, with cut-rate airlines buying up the older planes, the companies with the least experience suddenly are dealing with the equipment most in need of maintenance.

14.  Older planes are more expensive to fly because they burn more fuel, require more maintenance and, in some cases, require more pilots.

15.  That number accounts for older planes that are retired from service.

16.  The model has become popular with airlines for trans-Atlantic flights, replacing older planes, partly because it has a lower operating cost than older models.

17.  They can keep the older planes flying at a much lower cost than buying new ones.

18.  This is more true of modern jets than older planes, he said.

19.  Those older planes are the ones companies such as Dee Howard rely on for their maintenance work.

20.  TWA also has begun acquiring new, more efficient aircraft, replacing its older planes that required more maintenance checks.