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Compared to most other fighters, the f-18 has a low sweep angle on its wing; 20 degrees compared to the f-16s 40 degree sweep and f-15s 45 degree sweep. Additionally the wing has a relatively high aspect ratio.

At first, I thought it was related to the requirements for taking off from a carrier, but the prototype YF-17 was originally designed as a land based fighter, and had a similar wing.

What are the performance trade-offs for this kind of wing on a fighter jet?

Edit: also is the sweep angle the reason the wing is mounted further back compared to something like the English Electric lighting?

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This could get complicated pretty fast. I'm not saying that because I know all the answers. Just that you ask questions that may have a lot of overlapping reasons.

The fighter could have been designed as land based while still having that 20 degree wing sweep(it was). Northrop had used that style of wing since at least the prototype N-156 which became the F-5s and T-38. The big difference in later Northrop aircraft and their respective prototypes are the much more prominent leading edge root extensions(LERX) providing better low speed stability and controllability.

What are the trade-offs? Less wing sweep usually limits top speed on the aircraft because of how the supersonic shock cone changes as speed increases, but does offer better low speed performance. It could also, in isolation, be worse at high speed maneuverability, but so many other factors play into this that saying so would be too reductive.

The low sweep is certainly a factor in why it is mounted so far aft, but may not be the only reason. Maybe the designers wanted good downward visibility from the cockpit. Maybe they had to elongate the fuselage to fit certain systems. The heart of it is probably as you said though. By shifting the wings further aft you shift the aerodynamic center aft and you typically want the aerodynamic center aft of the center of gravity to keep the plane stable.

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