Going supersonic in the vertical

[MasterBates]

Look at it this way.. It takes MOST of the power (thrust) of many jets just to get thru Mach 1.. And that's on wingborne flight. When you start needing a LARGE fraction of that power to support the aircraft (wings aren't in this "example") you just don't have the power excess.

We have things that CAN go supersonic in vertical flight. They are called ROCKETS.
And the mass fractions for fuel and T/W ratios are FAR different than airplanes.

And sadly, I was born 40-50 years too late to ride this bad mofo into orbit. That thing is the 426 Hemi of rockets.

 

[darrylcn]

um yeah about that...

really it dosent take a fighter pilot to explain why it can or cannot, it's an airplane they all fly the same...the only difference is that someone who actually flies it is going to have the final say bc they actually fly it...give me some numbers and i'll crunch some functions and prove it but since I don't own a poh nor do i want to go jail for trying to get one i figured i'd just ask a pilot who flies one.

Hey I wasn't badmouthing you, you and I are here for the same reason after all I just get bent when 'expert' guy starts throwing weight around because I get thrown in the same category by default.

PS, cool photo MB, I'm not even American and that's pretty patriotic lookin!

 

[BigIron]

I think it's only possible to do while flying in Ace Combat 6.

 

[CumminsPilot]

We have things that CAN go supersonic in vertical flight. They are called ROCKETS.
And the mass fractions for fuel and T/W ratios are FAR different than airplanes.

that has little to do with getting through Mach1, and much to do with getting into orbit or beyond...but you already knew that.

 

[Beans]

acclerating vertical isn't hard to believe at all...all you need is a t/w ratio over 1.00(which alot of military jets have)..what I find it hard to believe is having enough excess thrust to overcome the enourmous amount of parasitic drag that accumulates with high speed flight to the point were you can get to mach 1. not to mention the fact that you would still have a little bit of induced drag since you would be able to maintain a RW in the opposite direction resulting in lift...I guess really you'd have to be light as hell, clean, and an aft cg would definetly help.

Now we're in the compressible regime. Parasitic drag isn't the worst, but wave drag is when you're going transonic. Also, there are still zero total photos of F-18s flying supersonic in this thread.

Don't speculate. Read this book, and view some of these pages, then take the book and smack your idiot friend in the head with it.

Forward CG is always good. Even rockets like to have CGs close to the nose. Draw out your free-body-diagram and think about it.

 

[Flash]

I thought F-15's could do Mach 1 in the vertical?

That said, they ain't doing it at air shows.

 

[Okoboji]

well he said that the annoucer said it accelerated to .99 mach completely vertical and that if they were aloud to they would have pushed it to mach 1...he also claimed it did it right after t/o.

Negative Good Buddy. If you flew the fastest Hornet (A or C model with the higher thrust 402 engines), slick configuration, full afterburner in straight & level flight at 500' MSL, which would theoretically have you in the top-end neighborhood of mach 1.8 - you would immediately slow down when you raise the nose to vertical and will be subsonic in a matter of seconds.

The only a time an extreme nose-high F/A-18 can temporarily accelerate is when it starts from a low/slow position (i.e. after takeoff, or out of the high alpha demo pass) and has a light enough fuel load to provide a +1 thrust to weight ratio in full AB. With the altitude gain away from sea level comes a rapid performance loss, and there's no chance of reaching mach in the vertical (much less a 45 degree climb).

If you could remain at sea level conditions throughout the climb it would be different, but it's the altitude gain that makes vertical acceleration for aircraft unlikely that don't have the ridiculous thrust of a vehicle with NASA painted on the side. Every foot higher away from Earth and towards your aircraft's service ceiling equals diminished climb performance, and even the almighty F-22 cruising in full afterburner has an altitude at which a 1 degree pitch up from level will cause a loss of airspeed.

 

[darrylcn]

Good info Okoboji, I had no idea performance fell off so quickly. Makes good sense too, I always heard F-22s could accelerate while vertical, but I guess you'd be gaining alt so fast that any acceleration wouldn't get you through the number.

 

[Schnugg]

So if I put a C-172 on a giant treadmill...

 

[darrylcn]

I can't believe they even tested that myth on mythbusters, I thought they'd know that lift has something to do with wind over the wings, not rolling forward. I'm gonna have to search for WHY that topic's worn out, all I know so far is that it is. Anyone care to explain it? Thought so..

 

[UMichfly]

So if I put a C-172 on a giant treadmill...

And here I thought that this thread had already done all it could to make me want to stab myself in the eye with an icepick....

 

[Slammer2]

..I'm gonna have to search for WHY that topic's worn out...

+1

Is this Airwarriors? Awesome!

 

[a2b2c3]

I thought F-15's could do Mach 1 in the vertical?

That said, they ain't doing it at air shows.

I've heard the same thing...

 

[Beans]

I thought F-15's could do Mach 1 in the vertical?

That said, they ain't doing it at air shows.

Vertically down?

 

[Brett327]

This is another great example of a bunch of know-nothing aviation nerds trying to out do each other. Monkeys fucking a football. Morons.

Brett