Rapo From United States of America, joined Sep 1999, 395 posts, RR: 0 Posted (14 years 5 months 1 week 3 days 23 hours ago) and read 930 times:
The Boeing 747SP has a taller tail than that of other 747's. The A330-200 has a taller tail than an A330-300. What is the effect of having a taller tail on a shorter plane? One would think that to obtain the same turn rate in a longer plane (ingnoring the ailerons), more surface area would be needed at the tail. But, exactly the opposite seems to be true. Can anyone explain these "tall tales"?
A320FO From Austria, joined Oct 2000, 211 posts, RR: 1
Reply 1, posted (14 years 5 months 1 week 3 days 22 hours ago) and read 919 times:
The size of the tail has a different reason. It has to do with the controllability of an airplane during a one-sided thrust loss (engine failure case). A longer fuselage needs a greater turning moment, increasing directional stability. Now the same plane with a shorter fuselage has to compensate this loss in stability. That is done with the larger tail surface. On the A321-A319 a one-sized tail is sufficient, but on the A318 it will be heightened by several feet.
Just a basic explanation.