Why are the engines on the F-18 so close??

[PropStop]

Speaking of horrible Hollywood renditions, anyone seen the premiere of that new TV series "Lost" ? I only saw the ad for it, but in it the plane gets its entire rear stab (tail) blown off by a bomb, yet somehow actually glides down to - and crash-lands on - an island. Yeah.......riiiighhhht.... What would really happen? Well, think Frisbee... or better yet, Rock.
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it wasn't a bomb, I don't think - it was CAT. The plane crash was pretty lame. The engine running on the beach after the crash and exploading sometime later was really really lame, but the show is actually very good. Can't have everything.

 

[Flash]

Flash- Come on give that battle staff some love. And so I still say it's "used" by both the AF and Navy

If you have ever flown with the AF you never 'use' their toys, only borrow for a little while. As for the battle staff, they are huge, just mushrooms sitting in the back. Oh wait, I used to sit in the back of a lumbering plane.....what does that make me?

 

[Broadsword2004]

Yeah, I couldn't believe that scene at the end of "Behind Enemy Lines" when Owen Wilson is being shot at with all that firepower from the European guy's men, and then he stops literally, and turns around, runs back, grabs the thing he forgot, then runs all the way back again, without taking a single round. I thought Hollywood did away with scenes that fake after the 1980s.

But then again anyone remember in "Rambo II" where Sylvestor Stallone, by himself, fights off a whole ton of Vietnamese troops (who miss him, but he hits them), then he steals a Huey helicopter, flies to where the hostages are being held, gets off, fights off more Vietnamese troops, frees the hostages, gets them all to the Huey, takes off, only to find a Russian attack helicopter after him, which looks like it is armed with more missiles then China has people. Somehow it can't shoot him down, but it still injures the Huey, so he goes down into a riverbed, then awaits the Russian chopper. It comes around and Stallone produces the trusty rocket launcher he'd had and fires through the windshield. He hits the the Russian chopper bullseye, and blows it to smitherines. Then he flies the Huey back to base.

As for Top Gun, I read an article saying the Navy pilots thought it was really cool that they were making a movie about Top Gun, but then when they saw how it was being manipulated, they complained. Either Jerry Bruckheimer or Don Simpson I think told them something like, "Look, this movie is about fighter pilots, but it isn't FOR fighter pilots. It's for your average families out there, and they don't know what you know." Now that is NOT a direct quote, but it is similar to what they said.

Did you know that originally, "Charlie," Kelly McGillis's character, was going to be basically, um....the equivalent of Chrissy from "Three's Company" (a dumb, but <supposedly> beautiful woman that Maverick fell for). But one of the women who had to approve the movie or something saw that and got really P.O.ed about it, and said if they didn't make Charlie a more realistic woman, she wouldn't approve it. So they made Charlie a sexy Ph.D. in astrophysics girl instead.

I never really liked "Top Gun" though. If anything, it made me NOT want to be a fighter pilot; I hated how Maverick was such a cocky-@$$, and how he wimps out in the aerial fight at the end on Iceman. Yeah okay, your friend died, but don't decide to go into a depression in the middle of a dogfight. At the end, Iceman says, "You can be my wingman anytime." If there ever was such an intense dogfight and I was in Iceman's position, the only thing that would have kept me from clocking Maverick across the face was, well, the consequences for such actions.

Schnuggapup, your explanation is a little confusing to a me right now, but my basic idea of how a plane turns was that the "horizontal rudders" rolled the aircraft somewhat, then the pilot used the rudders which actually turned the aircraft. Just the roll was needed since you can't just turn the aircraft with only the rudders...you'd need a roll first, then you can turn it, so it would be a combination of the rudders and the roll from the "horizontal rudders." Maybe that is totally wrong, that was my impression though.

 

[Jedj]

just move the stick, the FCC's do the rest.......except in a tomkitten, cause its old.

 

[HueyCobra8151]

We don't turn with rudders, they control yaw. We use asymmetric differential stabs or horizontal tails to roll the jet (a tiny bit of rudder) then when our lift vector is where we want to go we do a smooth pull with both horizontal tails taking an even bite to produce positive G and turn in an arc. Sort of a basic explanation, but I hope it helps.

He already cleared up that question Broadsword. You roll until your lift vector is where you want, and you pull back on the stick.

There are no "horizontal rudders" There are 3 basic control surfaces on a fixed wing aircraft. "Ailerons," "Elevators," and "Rudder(s)."

 

[Squid]

sure, three basic surfaces. what about stabilators, spoilers, slats, etc?

aren't chines the extension in front of the leading edge wing root on the hornet?

 

[46Driver]

If I remember correctly, there are "Primary Flight Controls" (rudders, ailerons & elevators) and "Secondary Flight Controls" (slats, flaps, everything else).

 

[Penguin]

Broadsword, I don't know about you, but before I started flying, all the aerodynamic terms thrown around this post would have been pretty confusing. I think you might get a better idea of what people are talking about with a very basic explanation of how airplanes turn in the air. Before everyone flames me here, I'm going to use basic terms that will hopefully make sense to someone who hasn't been around planes for years OR been through API.
First, airplanes move in three basic ways. 1. Roll: one wing moves up, the other moves down, think of a log rolling down a hill. This is controlled by ailerons, the control surface on the back edge of the wing. When the pilot pushes the stick left, for example, the left aileron moves up, and the right aileron moves down. This changes the airflow over the wing and the left wing rolls down while the right one rolls up.
2. Pitch: the nose of the plane moves up or down, usually causing a climb or descent. This is caused by the elevators in your basic airplane. Fighters and some exotic aircraft use a more complicated system, but ignore that for now. The elevators are the horizontal "tail" at the back of the airplane. Again, by changing the angle of the elevator by pulling back or pushing forward on the stick, the elevators move and strike the airstream differently, causing pitch.
3. Yaw:the left or right movement of the nose. I think this is what has been confusing you. The simplest form of yaw can occur when the plane is flying straight and level. If the pilot stomps on a rudder in straight and level flight, the nose of the airplane will swing in the direction of the rudder applied. Left rudder, nose swings left. Now the plane is still flying a straight course, but the nose is swung out to one side. This adds extra drag and has other more complicated effects, but you get the basic idea. The important thing to remember is this IS NOT how we turn the plane to a new heading.
To turn the pilot applies aileron input in the direction he wants to turn. This is where all that talk of lift vectors comes in. Above I mentioned that the ailerons are moved on the back of the wing into the airflow. This changes the lift produced by each wing. When the right aileron moved down, it causes more lift, so the right wing moves up and the plane rolls LEFT. Unfortunately, the extra lift also causes more drag on the right side (think of sticking your hand out the window of a moving car. The wind drag causes it to move backward). The extra drag on the right wing during a roll causes the nose to swing slightly to the right. This is adverse yaw, getting back to what was mentioned 40 posts ago. If you roll left, you don't want the nose swinging right, so you add a little left rudder to bring the nose back in line.
In summary, ROLL with the ailerons on the wing, PITCH up or down with the elevators (horizontal tail surface) and correct the YAW, or nose heading with the rudders, or vertical tails surface.
Hope this helps, and I apologize if I sound preachy!

Penguin

 

[Pitz]

I don’t know what an F-14 RIO is looking at during a cat shot nor an S-3 or E-2/C-2 pilot, but a Tomcat pilot is staring at his engine instruments. A loss of an engine at a high power setting and low speed, unless handled immediately and properly will result in the loss of the aircraft.

Those of you with multi-engine ratings know all about blue-line or Minimum Controllable single-engine airspeed. It is the minimum airspeed that the rudder can directionally control your multi-engine aircraft when an engine has failed. It can be a handful during or just after rotation while still at slow speed. Especially on big jets and of course on the F-14.

On the F-14, I know it’s hard to believe, but the pilot can’t hear the engines. The air conditioning system and helmet drown out all outside engine noise. This makes it especially tough during carrier landings too. So there is no aural indication while running down the catapult that an engine has failed, all there are is the little engine instruments down by the pilot’s knee that are used to get a warm fuzzy about the health of your engines.

Immediately, at the first indication of an engine failure, the F-14 pilot must begin to apply full rudder into to good engine so that he or she can control the aircraft at the end of the cat stroke. This is the only navy plane that I know of that this is so critical; the major reason is that they didn’t design the rudders large enough for the big engines at such a slow speed.

Now this allows me to explain why a fighter pilot does use his rudders quite a bit. Sure at high speed the use of rudder is almost non-existent, as is true in every airplane. And in the F-14 at high Mach numbers the use of rudder can result in an ugly kinematic departure which will rip the plane to pieces. So at high speed, rudders aren’t used much in any aircraft because turn rate is so slow and rudder is used to coordinate a turn, so a low turn rate requires minimal rudder input. A higher turn rate can be achieved with greater bank angle and vector placement alone. I recall during college when an SR-71 pilot talked to us, he illustrated how large his turn was in the SR-71 at high speed. He explained how it would take the states of Kansas and Nebraska to turn around in when flying at top speed. I don’t know what G he was limited to and what types of departures he had to worry about, but fast planes turn slowly and don’t need much rudder.

But slow speed flight requires a large use of rudders. Especially during a dogfight. Rolling Scissors and Horizontal Scissors are results of almost every dogfight. And they require huge amounts of rudder input from the pilot. Hard full throws, both ways with the rudders in absolutely imperative to turn the fighter quickly. The better the fighter pilot, the better his use of rudders during a slow speed fight.

So remember, as a fighter pilot you will be flying your aircraft at every edge of the flight envelope, and that means you will have to know when and how much to use every one of your flight controls. Engineers put the three major flight controls on an airplane for a reason, on some planes under ordinary flight environments you might not use all of them much, but in a fighter, you will use them all of the time because you will fly at the edges of the flight envelope.

 

[HueyCobra8151]

sure, three basic surfaces. what about stabilators, spoilers, slats, etc?

Sir,

I am not a pilot, and my knowledge is limited to working with helos and being an aircraft enthusiast, but I don't see how you can classify slats as a basic contral surface.

Slats serve to increase the lift generated by the wing and allow the aircraft to achieve a lower stall speed during take off and landing. I hardly see how that can be classified as a basic control surface. It has nothing to do with Roll, Pitch, or Yaw.

And aren't spoilers used to slow the aircraft down when it is landing? I don't see how that could be classed as a basic control surface either.

And I do not know what a stabilator is.

Broadsword, pilots use something like this (Turn and Slip Indicator) to gauge the turn:

When you roll, you apply rudder to keep the bubble in the middle.

 

[PropStop]

And aren't spoilers used to slow the aircraft down when it is landing?

they are used for that. Some aircraft, however, do not have ailerons (the B-52 for example). To turn they put the spoilers up on one side which spoils the lift on that side, dropping the wing and now you've got angle of bank and you're in a turn.

And I do not know what a stabilator is.

on aircraft like the f-18 the whole horizontal stabilizer moves vice just the elevator at the aft end of it. When the whole control surface moves and has no subcomponent (like the rudder or elevator) it is called a stabilator, because it serves the functions of the stabilizer and the control surface. Instead of changing the camber of the surface to create or spoil lift, stablilators change their angle of attack and litterally fly the tail up or down (or side to side) just like the main wing does. This is also called a "Flying Tail" and was a critical break through in highly maneuverable aircraft and transonic aircraft.

edit: here's a great page on this subject: http://www.grc.nasa.gov/WWW/K-12/airplane/stablator.html

 

[Squid]

I don't see how slats are a basic contral surface.

And aren't spoilers used to slow the aircraft down when it is landing? I don't see how that could be classed as a basic control surface either.

And I do not know what a stabilator is.

ok, ok, slats aren't a basic surface.

I guess I didn't explain fully. The spoilers I was referring to are the ones on the -14's wings, not the speed brakes on the empennage (and wing tips in the case of the prowler). I know schnuggapup can speak more to this... The ones on the -14's wings pop up (as they do on airliners if you've sat near the wing) and "spoil" the lift on either wing. this causes a roll much the same as the aileron does (one wing has more lift) at higher speeds.

oh, and stabilators can move independently for surviveability if something happens to another control surface, and for maneuverability.

edit: late as always with my post.

 

[HueyCobra8151]

Thanks for the information. I stand corrected.

 

[Whatsisname]

Something interesting to notice is that on full blower the F-22's engines put out more power than the SR-71's engines were capable of.

Operational, the F-15. The F-22 has a lot more though.
Below is the thrust for each engine
F-14-20,900 lbf
http://en.wikipedia.org/wiki/F-14
F-15-23,930 lbf and 29,000 lbf
http://en.wikipedia.org/wiki/F-15
F/A-18E/F-22,000 lbf
http://en.wikipedia.org/wiki/F/A-18E/F_Super_Hornet
F-16-23,840 lbf
http://en.wikipedia.org/wiki/F-16#F-16_C.2FD
F/A-22-35,000 lbf
http://en.wikipedia.org/wiki/F-22

 

[Lonestar155]

35,000 LBf is amazing! Unfortunatly the f-22 project doesnt look too steady. Something to note is that the f-22 does mach 1 without afterburners. :icon_smil