View Single Post
Old Dec 29, 2012, 04:07 PM
ShoeDLG is offline
Find More Posts by ShoeDLG
Registered User
ShoeDLG's Avatar
Germany, BW, Stuttgart
Joined Mar 2012
1,081 Posts
Quote:
Originally Posted by bigjohn View Post
I think you know less about aerodynamics than you think you do.
A Computational Fluid Dynamics study early in the FA-18E/F development program indicated the possibility of a Mk 84 series bomb yawing (nose outboard) upon release from an inboard wing station such that its fin would impact a targeting pod mounted on the inlet. The FA-18E/F program was extremely risk averse, and a hasty decision was made to cant the pylons outward to "unwind the spring" to reduce the probability of such an impact. It turns out that the stores configuration this "solution" was intended to address is hardly ever flown (Super Hornets are frequently flown operationally with the inboard pylons removed). The result of this design decision is significant reduction in top speed when carrying stores, and a significant increase to the fatigue life impact of catapult shots and arrested landings. I've flown the Super Hornet with empty bomb racks on the canted pylons and watched the max Mach number go from about 0.93 to about 0.98 after selecting full afterburner (increasing total thrust from about 25,000 lbs to about 40,000 lbs). I've flown the same profile with empty pylons and accelerated above Mach 1.25. I've spent many hours while commanding an FA-18E squadron deliberating over how best to configure Super Hornets to preserve operational flexibility while minimizing damage to the wing spars from cats and traps. All just to mitigate the effects of an ill-conceived design decision.

I believe I am qualified to offer the canted pylons on the FA-18E/F as an example of "reducing the performance of an airplane, for no particular gain".

Perhaps you know less of my grasp of aerodynamics than you think you do... NOTAC.
ShoeDLG is offline Find More Posts by ShoeDLG
Last edited by ShoeDLG; Dec 29, 2012 at 07:25 PM.
Reply With Quote