Official Freewing F/A-18C Hornet 90mm EDF Thread

[Airguardian]

I'd love to read that!

[jetpltrich]

I attended a talk by Chuck Yeager years ago. He was discussing the instability designed into modern fighters to make them extremely agile.

He said (about the ship he was discussing…some F-xx fighter and I think it was the F-18);

Paraphrasing:
- There are redundant flight control computers. If they fail, you punch out. It is impossible to manually control the fighter. If you try to manually fly it, you will have success for only a VERY few seconds. -

—GG

In my initial class at Southwest Airlines the senior member of the class was a former Navy pilot who flew F-18's. He had a complete ADFCS failure of after launch off a carrier in an F-18A and managed to fight the plane to a shore station, I think NAS Norfolk. If I can find the story I will share.

Rich

[Evan D]

I flew my 7 year old C model yesterday, still in mint condition and flying awesome.

[Aros]

So THAT'S why I've had so many crashes with this model! No flight computers!!

[Airguardian]

Not mutually exclusive! ;)

[GliderGuy]

I attended a talk by Chuck Yeager years ago. He was discussing the instability designed into modern fighters to make them extremely agile.

He said (about the ship he was discussing…some F-xx fighter and I think it was the F-18);

Paraphrasing:
- There are redundant flight control computers. If they fail, you punch out. It is impossible to manually control the fighter. If you try to manually fly it, you will have success for only a VERY few seconds. -

—GG

[Airguardian]

I'm such a party pooper...

[Hugh Wiedman]

I'd say that's mostly due to the large side area of the Hornet's long nose (destabilizing), and that the Hornet's vertical stabs are small and placed very far forward, thus having little restoring (stabilizing) force, something that's further emphasized if you move the CG back.

Now, that said, it's not correct to say that the full scale F-18 design is 'unstable'. It may have some instability traits, but it is NOT unstable in the sense that an F-16, Su-57, F-22 or Eurofighter would be unstable. The full scale F-18, just like the F-15 is designed with a positive longitudinal static margin.

Or, as we say in the model aircraft community, they are nose heavy. You can easily see that from their horizontal stabs' position in high alpha flybies.

Then again, stability analysis can't be reduced to a single parameter, so all this is not to say that the F-18 wouldn't be a bunch to control if you turned the flight computer off. The same lateral stability problems we have on our models would also apply to the big sister. ;)

There you go again, bringing logic and facts to this discussion! Obviously the only thing unstable in this equation is my flying skills. Can't I just blame it on the aircraft instead of were it really belongs, on me?

[Airguardian]

I'd say that's mostly due to the large side area of the Hornet's long nose (destabilizing), and that the Hornet's vertical stabs are small and placed very far forward, thus having little restoring (stabilizing) force, something that's further emphasized if you move the CG back.

Now, that said, it's not correct to say that the full scale F-18 design is 'unstable'. It may have some instability traits, but it is NOT unstable in the sense that an F-16, Su-57, F-22 or Eurofighter would be unstable. The full scale F-18, just like the F-15 is designed with a positive longitudinal static margin.

Or, as we say in the model aircraft community, they are nose heavy. You can easily see that from their horizontal stabs' position in high alpha flybies.

Then again, stability analysis can't be reduced to a single parameter, so all this is not to say that the F-18 wouldn't be a bunch to control if you turned the flight computer off. The same lateral stability problems we have on our models would also apply to the big sister. ;)

[Hugh Wiedman]

Thanks for the kind welcome

Here's a picture of my work in progress, again printed the cockpit and detailed it (as this was my first go at it - I think it turned out ok, but I will do another one, and from my learnings with this one, the next will be better)

Agree that you should go with an EDF first as I'm not convinced this particular air frame is a good candidate for a turbine (more like the 90mm F22). But what I really recommend is using the 8S EDF that the F4/F16/F22 use. Although Motion doesn't offer this F18 in 8S, I converted both of mine and
Abso-freeking LOVE it. You also need a very responsive gyro in this bad girl and a somewhat rearward balance point to get it to really pop, as this airframe is naturally unstable which allows it to perform so well in combat (seriously controlled by a computer)! Talked with an F18 pilot once and he (maybe jokingly) told me that if his computer went down, he'd eject! I'm using the Spektrum AR 8360T Plus, which is much more responsive than their previous RX's. The nose wheel gyro in it is also a nice feature, especially if you fly off of "bumby" grass, as it easily gets knocked off course.

The only thing that's somewhat unusual with that gyro, and I've only found it in this airframe (not Mig/Su27/F4/F16/F22/A10) is that your gains on YAW must be very low (in the 7-10 range-when 40-50 may be more normal), otherwise it will fight you on a banked turn when using aileron/elevator only, as it tries to almost go into knife edge without turning and tries to climb. Thought it might be because of the twin rudders, but the Mig/Su27/A10/F22 don't exhibit that tendency, yet on those I still keep the YAW down to around 20.

[F106DeltaDart]

Where did you get it? Motion has never sold a 8S version as far as I know. Just PNP 6S and ARF+.

Picked it up locally. I believe it has the power system from the 8S 90mm F-4. He must have bought it as an ARF+.

[Evan D]

Where did you get it? Motion has never sold a 8S version as far as I know. Just PNP 6S and ARF+.

Just picked one of these up in the Blue Angels 8S version. Planning to convert it to use the Eflite scale gear from the 80mm, and redo the nose gears to be closer to the real thing.

[Aros]

I am crossing my fingers FW comes out with a new gen version of this bird.

[Elbee]

Just picked one of these up in the Blue Angels 8S version. Planning to convert it to use the Eflite scale gear from the 80mm, and redo the nose gears to be closer to the real thing.

Now that's a dream build with the Eflite LG.

Post the build pics when you are able.

Looking forward to this one.

Best, LB

[F106DeltaDart]

Just picked one of these up in the Blue Angels 8S version. Planning to convert it to use the Eflite scale gear from the 80mm, and redo the nose gears to be closer to the real thing.

[Aros]

Nice work!

[Elbee]

Thanks for the kind welcome)

Leighton63,

Your work looks great, that's a complex print and assembly.

Great livery choice, too.

Best, LB

[Airguardian]

Yep, a 90mm F-35A would be sweet too... I keep asking for one, but so far, no luck!



Good job with the cockpit work, BTW!

[Leighton63]

1st, welcome aboard!

Here's my biased opinion, for what it may be worth:

This Hornet is a tricky jet. Get a taste of what it's like first with the EDF. Decide later if you want to commit to a turbine upgrade. It's a lot of money for a quirky model that quickly becomes hard to see as it flies away, so I'd recommend against it.

As for the Zeus... I hate how that thing looks, so my recommendation is to put that X45 (or X52) into something else.

F-22s are great for turbine mods. ^^

Thanks for your opinion and tips on the jet - coming back to the hobby from some time away, and guess I've got swept up by the whole F18 thing (Top-Gun etc) - thought it would be a nice one to build in a turbine spec. I might check out the F-22, shame there isn't a 90mm F-35 out yet

[Leighton63]

Leighton63,

I agree with jetpltrich 100%.

Finish this as an EDF and make those decisions after you learn this jet.

Post pictures as you are able.

Very interested to see hoe your cockpit turns out.

Welcome to Hobby Squawk; glad to have you onboard, Sir.

Best, LB

Thanks for the kind welcome

Here's a picture of my work in progress, again printed the cockpit and detailed it (as this was my first go at it - I think it turned out ok, but I will do another one, and from my learnings with this one, the next will be better)