The General Airplane Thread

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Dan
@Carlos In the second Red Flag video, what is the F-22 purging at 0:08?
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That is just smoke from the APU starting up. Fairly common for APU's to spit out a flame and a decent amount of smoke on startup. Heck, once I have seen one of our planes make a smoke ring come out the APU exhaust lol

*EDIT*
It is also possible that the F-22 might use a JFS, or Jet Fuel Starter, to crank up the APU. Basically it is a mini gas turbine that is used to spool up a larger gas turbine. It is generally faster than an electric starter for a jet engine. Older fighters had JFS's mounted directly to their engines, which cranked them up instead of using an APU or external compressed air.
 
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Venom800tt
That is just smoke from the APU starting up. Fairly common for APU's to spit out a flame and a decent amount of smoke on startup. Heck, once I have seen one of our planes make a smoke ring come out the APU exhaust lol
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I didn't even think about it being the APU. I would've guessed that the exhaust port for that would be at the rear instead of the side.
 
Swagger897
I thought there were gates you had to go through before you get next to the Polderbaan?
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LMSCorvetteGT2
@Carlos can you explain the Schiphol incident
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lxmmy
Quite intrigued in how the Porsche Macan got into that state.
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The small ditch is the only thing keeping you away. And this personnel entry with a fence:
porsche-macan-schiphol-02.jpg


The police haven't released a statement so I'm guessing the car is stolen and or the guy is out of the country already. No idea why they don't know where he is with all those cameras there.
 
LMSCorvetteGT2
What's with the x shaped winglets, that's interesting.
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I'm not up to date with winglets, and it seems a lot has been going on with them recently, but I think the basic idea is increasing effective wingspan. If you go both up and down, you're providing more wing to spread vorticity over and getting more of your potential pressure recovery.

There may also be some structural benefit as reducing the height in any one direction means less area to capture spanwise flaw and less moment arm for those forces to act on.
 
Exorcet
I'm not up to date with winglets, and it seems a lot has been going on with them recently, but I think the basic idea is increasing effective wingspan. If you go both up and down, you're providing more wing to spread vorticity over and getting more of your potential pressure recovery.

There may also be some structural benefit as reducing the height in any one direction means less area to capture spanwise flaw and less moment arm for those forces to act on.
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It's been explained I too wasn't up to date with the supposed wide array of winglet development myself. But yeah I figured it was due pressure manipulation over to the and bottom of the wing, but from the Boeing website it provides an increase in fuel efficiency by using such a method. Anyways thanks.
 
catamount39
The question is...will this ever appear on a fighter jet? :p
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No :D The Eurofighter Typhoon is a good example. Winglets seem to increase stability and reduce maneuverability. Less stable aircraft need less input from the pilot to maneuver. Aircraft responsiveness also increases when the aircraft is unstable. So intentional instability gets you a great maneuverable plane. The canards help the pilot control the plane like fly by wire.
 
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Carlos
No :D The Eurofighter Typhoon is a good example. Winglets seem to increase stability and reduce maneuverability. Less stable aircraft need less input from the pilot to maneuver. Aircraft responsiveness also increases when the aircraft is unstable. So intentional instability gets you a great maneuverable plane. The canards help the pilot control the plane like fly by wire.
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The winglets will actually help maneuverability by decreasing drag. Drag is one of the factors primarily limiting sustained turn rate, which is an important metric in fighter capability. However military aircraft may need to perform across a wide range of conditions, and for the winglets to be beneficial, they need to provide benefits across most if not all of the envelope. One big hurdle is supersonic flight, because the winglets just add more area to the plane, which can severely increase supersonic drag.

There have been a few military aircraft that have recieved benefits from winglet like devices though. I think the F-104 Starfighter had improved performance in some cases with wing tanks installed, because they would combat tip vortices. The Starfighter is an extreme example though, the wings had tiny aspect ratio (span/chord ratio).

ROCAF_F-104J_Right_View_20111009.jpg
 
Sustained turns come from high angle of attack, and winglets would factor into that with about a .000000359% reduction in overall drag. :) (Ok, I admit I came up with that number by throwing imaginary darts at an imaginary target 125,000,000,000 times and counted triple 20s.)

Also note that the spread feathers at the ends of a bird's wing, which inspired the winglets on airliners, are found on soaring birds, and not more active birds. Hummingbirds don't have them, for example. Winglets are effective in long, sustained, flat flight, which is not fighters.

If you're at an air show and see a jet turning (or just pulling up, which is how a plane "turns" when banked hard,) you can see the wingtip vortex leaving the wing at a strong upward angle rather than directly behind the wing, which is a visible representation of the angle of attack. The plane turns by presenting the flat of the wing to the air, which is DRAG!

16949067799_cf65e13d31_b.jpg
 
1:30 am post... Will be back to continue, but just got to fly in a few of Deltas level D simulators. Started out in a 777, then moved to a 737, and ended up in a 767 (favorite).

Still a bit dizzy, so I think going to sleep will be a bit difficult...
 
So yeah... A patient of my mom's work came in a few weeks ago and asked if I would be interested in coming up to Atlanta and getting in the simulators... The answer of course is yes.

Anyways, my sister, dad and I all went up last night at 11 pm and met him. First thing off the bat we hopped into a 777, which was somewhat unfortunate because I have no idea how to operate one. We tooled around in that for a few minutes, trying to set up an ILS approach for 09L at KATL, but that took forever so we tried to go to TNCM.

Well, they don't have that, nor did they have Pittsburgh. So after that we went to Amsterdam, took off from 36R and landed 18R. I was surprised with how much force you have to put in to manipulate the aircraft. It was cool however just to be able to manipulate the control surfaces and see it pop up on the lower display unit for the EICAS.

Then after that I wanted to go to something a bit more familiar to me, a 737. My dad hopped up into the left seat, and we tooled around near JFK. All I can say is my 16 year old sister was a little bit... wait no, a lot better than him. He thought he could approach LaGuardia at 290 so I had the gear out, speed brakes out, and lowered the flaps to about 15 30 degrees. Oh, another thing, the frickin speed brakes are nearly impossible to figure out how to use...

After that, I could sense he was done, as was my sister, and I hadn't gotten to sit left seat yet. So we scuttled on to the 767 and started at San Francisco, 28R. The aircraft was pretty much in a cold and dark state, and my dad was chatting along with the instructor. While doing so, I managed to setup a basic approach for a pattern around 28R, and an ILS landing, started up the APU, then the engines, and headed off.

Everything seems so different from my simulator at home to the simulators there. Just trying to manipulate some of the controls took me a while to understand. It's definitely put more of a light in my eyes however on the career I'd like to pursue, but it's going to be a long road ahead for me..
 
lol, not like you missed much either..

Looked at their YT page and they don't have much activity. Might be elsewhere on the interwebzzzz... What specifically is this add about?
 
Carlos
No :D The Eurofighter Typhoon is a good example. Winglets seem to increase stability and reduce maneuverability. Less stable aircraft need less input from the pilot to maneuver. Aircraft responsiveness also increases when the aircraft is unstable. So intentional instability gets you a great maneuverable plane. The canards help the pilot control the plane like fly by wire.
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Not to mention it'll play hell with your Radar Cross Section.
 

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