Secret to fighter design

[War Eagle 1]

Ok so I see people making all kinds of fighters type aircraft that look really great and fly really great. What is the secret. If I build 100 fighters, only one will be of quality design.

What I look for is…

Fast (early hits 340m/s below 200m)

Tight turn (flys circles around the VAB)

Stable (won't lose to much speed in a turn and doesn't flip out when turning)

realistic design (self explanatory)

decent fuel amount (gets me to the north eastern Island and back)

Low part count (no more that 120 parts total)

My current fighter (PG-38 Banshee) is a prime example of what I expect in a fighter design, but I have no idea how I did it. Complete mystery to me

Edited September 18, 2015 by War Eagle 1

[SpaceplaneAddict]

Small, lot's o' engine. Skinny wings. Follow that. You're clear.

At least, that's how I did it.

[War Eagle 1]

Small, lot's o' engine. Skinny wings. Follow that. You're clear.

At least, that's how I did it.

Im gone need something a bit more complex than that

[Bubbadevlin]

I found one of they keys to a good fighter is to have ALOT of wings, that way your velocity will change more rapidly as you turn, allowing you to turn faster

[Slam_Jones]

It has a lot to do with CoM/CoL alignment. You want them basically on top of each other to have it maneuverable, yet stable. You'll have to tweak it to find the right balance for your design, but it's a big factor.

[War Eagle 1]

It has a lot to do with CoM/CoL alignment. You want them basically on top of each other to have it maneuverable, yet stable. You'll have to tweak it to find the right balance for your design, but it's a big factor.

That much I got

[almagnus1]

It all boils down to how effective your control surfaces are at moving the plane in flight, how fast you're going, your CoM/CoL, and your TWR.

Stupidly high TWRs means you basically have fins on an engine, but the craft is oh so maneuverable, assuming the control surfaces actually bite.

[War Eagle 1]

What I really want to know is why they went back to the soup atmosphere in 1.04. 1.0 was so much better

[The_Rocketeer]

Refining a design, a lot. My first attempt at anything practically never works. Even when I've got something nice, I'll try swapping intakes or engines, or switch a short fat control surface for a long thin one and see what happens, try a high-wing rather than a low-wing, try a bit of dihedral/anhedral, etc.

Having said all that, one of my very favourite planes I've built is a Harrier-style VTOL. Like the Harrier it's not the quickest flying or the lightest, but damn if you can't pull of some amazing stunts with those VTOL jets fired up, not to mention the sheer awesome factor of a perfect vert take-off or landing.

[Sanic]

Larger wings will get you better range due to greater lift. Make sure to give the wings a dihedral (upward) sweep to help maintain attitude even with SAS.

[March Unto Torment]

It's worth experimenting with forward-swept wings. I've reached outright absurd levels of manoeuvrability using those.

[Hodo]

Depends on if you are using FAR or not what will affect your fighter design. Also what you are looking for in the aircraft.

To many people get locked into this concept that fighters are all turn fighters. But several fighter aircraft in the world are designed with the idea that they will kill their target long before it comes to a turn fight. The F-15C Eagle comes to mind, same for the MiG-31.

Others like the F-101 Starfighter, were again designed as energy fighters, boom and zoom, if you will. Same for the MiG-21.

In my designs I think of what its role is going to be before I start. Then I work from there, sometimes I can come up with some OUTSTANDING designs, other times I come up with complete absolute junk.

I have a save file filled with over 50 fighter aircraft designs, this is not including my SSTO fighters, or SSTO aircraft.

[Feradose]

I want maneuverability, I use high, swept wings with anhedral, and forward swept tailplane, and double rudders. CoM must be behind CoL by a tiny amount, and the fighter has to be wider than its longer. For speed, two of the turborams are enough, mostly. CoT should be below CoM to assist in turning, and airbrakes are a must. I use FAR, so I have to fiddle with wing placement in very fine settings according to graphs.

Outcome is usually a fighter that turns 15°-20° a second at mach 2 and pokes for mach 3 at sea level.

[soulsource]

While I'm definitely not the right person to ask about plane design - I cannot land most of the contraptions I come up with, at least not on the runway - I thing that the Basic Aircraft Design guide is a good starting point, as it explains how to get an aircraft maneuverable or stable.

[n.b.z.]

How you did it:

1. already mentioned: above all else, you must have gotten CoL / CoM just right.

2. that thing looks way too good to fly bad.

[Aegeas]

Flight Test.... Flight Test.... Flight Test...

You have to flight test and keep changing your wing positions until you have the desired balance between maneuverability vs stability.

I've seen it discussed on these forums that the COL is really just a rough indication and to do it properly there would need to be a wind tunnel in the SPH because lift changes depending on air speed and atmospheric density etc. So COL is just a good starting point but to get it perfect you have to flight test and experiment.

As was stated above:

COL close to COM = maneuverability

COL far behind COM = stability ("doesn't flip out when turning")

Also while in the SPH empty it completely of fuel and see how much the COM moves around. Some badly designed planes will end up unstable as the fuel drains.

The two best flight tests I can recommend are:

1 level flight - flat out until hitting terminal velocity - if the plane doesn't flip out or roll funny then you have a good balance of COL and control surface authority.

2 vertical stall - fly straight up until stall then turn engines off - see what the plane wants to do naturally, if it falls nose down that's good, if it falls tails first that's bad - a plane that wants to keep falling tail first in a free fall is prone to flipping at speed.

Do these two test under two conditions, 1st fully fueled, 2nd empty of fuel.

If the plane passes the two tests under both conditions you are on the way to making a good plane.

Also read (as linked above) Basic Aircraft Design - Explained Simply, With Pictures its really good the blokes put a lot of effort into making it thorough but easy to understand.

If you have a design that you are happy with the aesthetics but not happy the the flight performance then link the craft file and a lot of people here will be able to give suggestions as to what the cause is.

Edited September 25, 2015 by Aegeas