Pete737

Real quick, I'd like to relax a bit with my F-18 this coming weekend and slow her down. What should I be looking for? How will she tell me she needs more heat? How is the envelope from the point where she starts acting up to a stall? Im just looking for advice during the clean config.

Thanks, Pete

invertmast

My Feedback: (23)

Since every airplane is different, the only true way to find out.. take it upstairs and do it. Stall characteristics in all of the configurations available (or at the least the ones you plan to use that flight) is one of the things that IMO should be done on the first flight.

From what i've seen/read. The hornet just starts to descend at a high rate.

Aero65

My Feedback: (2)

Is it a Super hornet or Classic hornet, and what model is it?

My experience is with the Skymaster Classic and Super hornets. If your CG is aft you have to watch for pitch up when slow, the lex on the super has allot of area and tends to overpower the other surfaces at high aoa, slow speeds. If not arrested right away it will usually spin.
The classic just kind of mushes then enters a high rate if decent at high aoa, and can also spin at aft cg's, although allot less likely to do it.
As you get too slow the planes tend to get wobbly, and you might see some yaw diversions right before departure, however if it gets that far it might be too late at low alt. Drag comes on pretty fast as the aoa increases just be ready for it with some throttle. Most of the hornets I have flown can fly very slowly with power on, and are pretty well behaved if you get the power on soon enough.

erbroens

Talking about my experience with the SM F-18C: Usually all goes well until it starts to pitch up on its own, making it desacelerate and stop flying very quickly... all this at the same time the wings begin to "rock" and and the nose tries to bite it´s tail.

This simptoms where greatly reduced after installing gyros on rudder and aleirons on it. But even so I land it with some power and a moderate angle of attack, never trying to "stretch" a glide on the final approach.

Enrique

David Searles

My Feedback: (49)

DITTO!

The stall characteristics can vary greatly depending on your cg point. The only way to know what your jet will do is to experience it, at a safe altitude. Properly balanced though, my experience is that they just stop flying and descend at a frightening rate. At that point you've gotta be quick to get added thrust back into the equation to avert disaster!

David S

Bryce Watson

My Feedback: (6)

This is what happened to me once with a Superhornet, a number of factors contributed to the situation below, most notably, first flight on a brand new slower spooling turbine which I had been used to, and ultimately overall, pilot error in forgetting to reset the elevator to flap mix from prior trials with the ailerons being lowered along with the flaps which required more up elevator (3/4)up, and simply being behind the power curve. As you can see in the video the jet remains controllable, but begins to wing rock and becomes a bit pitch sensitive. As mentioned by David above, the descent rate will increase fairly rapidly. Believe it or not, I began to increase power toward full at the beginning of this video because I could sense the jet getting a bit slow. The turbine installed at the time took approximately 11s from idle power (which is where I was due to a slightly high approach) to max thrust. After this flight I sent my turbines in to have them upgraded to faster spooling versions and my models with those turbines in them (including the SuperHornet) have been a joy to fly ever since, especially due to the turbine spool times on those engines being approximately 5.1 seconds from idle to full thrust.

Bryce

[youtube]http://www.youtube.com/watch?v=bV9uXHl2P0k[/youtube]

Aero65

My Feedback: (2)

Wow Bryce thats a great example of behind the power curve!

Has happened to most of us for sure, thank you for sharing that video. That sure is a sinking feeling waiting for spoolup, bummer.
I have done the departure spin deal myself, got away with it once. Flat spun it in the other.

Bryce Watson

My Feedback: (6)

Ooops! I forgot you were looking for the characteristics in the clean configuration. See that,I screwed up again, pilot error.


Well, it's been my experience that the Superhornet will pretty much behave the exact same way in the clean config as well. I almost lost it here in the picture below when I got a bit too slow releasing the centerline drop tank (off to the left in the picture). The jet began to wing rock because the nose was so high, quick push of down elevator just as the jet began to depart to the right with simultaneous application of full throttle (thank you 2.2 seconds from half!) and she was flying again. Still trimmed the weeds on that one.

Bryce Watson

My Feedback: (6)

I know the feeling Duke, just imagine if that was our job.

[youtube]http://www.youtube.com/watch?v=26quJFBvuX4[/youtube]

Pete737

I really appreciate the help guys.

Thanks for the videos Bryce.

At least I know what to look for now.

Pete

yeahbaby

My Feedback: (21)

haaaa haaa +1 fastest way to deplete a bottle of LOx

great vid by the way and a perfect example of a time when you need to ask yourself....."why am I below 1/2 throttle??" in the dirty configuration.

some have mentioned it previously already but the only way to regain control is to lower your AOA, with enough altitude and a rapid increase in power you'll be able to fly out of it, lack of either and well....you get the idea.

you'd be amazed how big a tumbleweed looks when you're staring straight down at it while falling like a turd off a tall camel!!! haaaaa

don't be skeerred, she'll hang on her tail all day long just stay ahead of her with power.

cheers
buck

Bryce Watson

My Feedback: (6)

Now Buck, as we all know, in aviation, there's always more to the story.

Being that I had just dumped a F-15 with the exact same engine about 30 minutes before that flight, ironically trying to avoid landing and having a collision with a fellow pilot and friend who was back taxiing his big F-18 on the runway. I was a bit ground shy due to the slow spool time and loss of a jet I had just experienced, thus I was flying a little high on the approach with the SuperHornet, juusst in case I found myself in that situation again, (things were going a bit out of order that day.) I learned some lessons with those experiences, and from that point on, I tend to fly a bit lower and with power, no matter what the configuration.

[youtube]http://www.youtube.com/watch?v=jmHDVsD-6wo[/youtube]

[youtube]http://www.youtube.com/watch?v=MuNGq_ZNXtA[/youtube]

erbroens

ditto.. been there, done that!


BTW, great video Bryce.. excelent demonstration of a bug bite! thx for posting it.

Bryce Watson

My Feedback: (6)

No problem, just figured those experiences may help someone someday in the future. Really doesn't matter what kind of jet you're flying, any kind of stall, compressor, or aerodynamic, is [link=http://www.youtube.com/watch?v=hAOoRtPr5Kk]not a good feeling.[/link]

Bryce

basimpsn

My Feedback: (5)

Hey Duke F-18 Test pilot . Well i saw this before,, Flat spin at the top of a loop [X(]. Manage to get out of it and recover. But Ive seen two crash on youtube and still cant understand what cause them.

[youtube]http://www.youtube.com/watch?v=goqf32HBA-g[/youtube]
[youtube]http://www.youtube.com/watch?v=4hewCJFYj2g[/youtube]

David Searles

My Feedback: (49)

Spark's crash was insufficient airspeed, pure & simple. Tried to haul it off the ground before adequate airspeed had been obtained. Stall & crash.

The second flight appears as though the bug was tail heavy. Even after he got off the elevator, right after take off, the jet still wanted to climb. As such again he couldn't build sufficient airspeed, stall & crash.

Also it rarely makes sense to do first flights fully loaded with armament! Without all that extra drag, he might have been able to stabilize that jet, but with the bombs he didn't have enough thrust to continue to accelerate airspeed. Also it looks as though as the bug began to stall he pulled back on the stick to try to keep it flying.[:@] Should have done the exact opposite. Push the nose over and get the AOA down and give it time to build more airspeed.

David S

erbroens

More bug bites! this is what I was talking about the plane pitching up by itself, rocking the wings and trying to bite it´s tail.. this happens on my plane when It stalls, but never at takeoff.


Seems that in both videos the plane was with the cg too aft making the plane slow down too much while the pilot was trying to correct it.

KC36330

that pretty much sums up my experience as well, when you start noticing yourself relaxing the stabs to maintain the same AOA it's time to add power.

jseppanen

Sorry more ot....

Not my vid, but saw it live. It's nice every time!!!

Finnish AF takinkg all out of the 'small' C-version Bug...

http://www.youtube.com/watch?v=EznXmyijh9c

Aero65

My Feedback: (2)

Hey Basimpsn

How you doing?

Agree with David, once those bug's got slow and the aoa got up there the drag just got too great. Bummer for those pilots, one thing the F-18 can slow down in a hurry when things get dicey. Notice that you can see some uncommanded yawing right before departure, thats your clue your about a nano second away from departure. (If of course you didn't pay attention to the sluggishness of the controls or the wobbly flight before that occured.) If you don't do what Buck said earlier lower aoa, and get some speed it's not going to be a good day.

Unfortunatly for the people in the video, they were in bad shape right from the start, again bummer.

Pete737

After the jet has entered this environment, How effective are the control surfaces?

David Searles

My Feedback: (49)

When the wing stops creating enough lift to support the aircraft, the control surfaces essentially become useless for anything other than creating additional drag. The extreme pitch-up you sometimes see on bugs that are in the process of departing controlled flight is caused by the extreme drag created by the typical full up elevator input the pilot is inputting contrasting with the final vestiges of lift still being created by the LEX's. If allowed to stall or depart without that input, the bug will typically just drop straight ahead.

When the wing stops flying it will sometimes drop to the side of the wing with higher drag. When the pilot attempts to counteract this with opposite aileron input, since the wing is no longer creating adequate lift, the aileron input just adds increased drag and over she goes. I think their is a pretty good explanation of this, probably better than mine, given by the Test Pilot instructor on video three or four of the series on Test Pilots.

David S

John Redman

My Feedback: (8)

I love the thread headline. What is a bug? Have to say after 20 years of military aviation I never heard the F-18 called a "bug". Must be a modeler's name for the Hornet. I would love to see Buck's face when you introduce him to someone stating he is a former "Bug Driver".

Buck - any comments? I know he is currently working overseas and may not have interenet access in his location.

David Searles

My Feedback: (49)

John,

I think it comes from the original factory scheme on the F-18 that had the little Hornet "bug" on the side of the fuse. I use it simply to go along with the thread's ID.

David S

yeahbaby

My Feedback: (21)

haaaaa....I asked the same question a few years ago.