Delta Fins

[Flying Mechanic]

Heres a question for anyone Flying a Lear 45.........why do they have Delta Fins on the rear fuselage?

[Mad (Flt) Scientist]

They are for pitch axis charateristics in the stall, IIRC. (Not from flying them, of course)

[Will Rogers]

The "Delta fins" have two purposes (kinda):

1) It prevents the aircraft from entering a deep stall.

2) They dampen the dutch roll characteristics of the aircraft and is the reason that all Lear's with "delta fins" may be dispatched without a functioning yaw-damper. Also; on the 45 (I believe) and 60 it has eliminated the stick pusher.

will :)

[vmommo]

Basically a bandaid to compensate for a tail that is too small!!!!

Pick one or more of these reasons:

The design engineers made a mistake, and project engineering was not willing to spend the money to do it right.

The design engineers needed to save structural weight in the tail cone area (They did not want lead weights in the nose!).

The design engineers needed less drag (smaller tail), so marketing wouldn't have to lie quiet as much....

Tooling from a previous model was used for your model ($$$ savings).

The airplane could not meet certification stall or stability criteria without a band-aid.

And last but not least, Pete Reynolds thinks delta fins are cool!

This should about cover it!
:cool:

[Flying Mechanic]

Many thanks chaps for answers, it help me alot.