2 hours ago, bobcat999 said:

Tom Cruise seems to have a centre tooth in that video picture.  I can't unsee it now!   

hahaha had me staring for a minute too...🤣🤣🤣

4 hours ago, bobcat999 said:

Tom Cruise seems to have a centre tooth in that video picture.  I can't unsee it now!   

THAT'S funny! It does indeed look like a center tooth.

On 5/25/2022 at 9:58 PM, Kyuss said:

You're going from a 20° pitch up to a 20° pitch down in one maneuver. Pulling sustained negative G's like that would have all your blood going to your brain and there's nothing you can do like when you pull positive G's to keep the blood going to your feet. So I don't necessarily think it's "required" but then you're going to be burning a lot more fuel in that stage of the flight as you level off and then descend to gain speed at a much slower rate.

i have not flown this aircraft yet,

but from what i have seen,
It seems to me that the 20° pitch down is only used to cross the sound barrier

(from mach 0.9 to mach ≈1.2)

then you have to pitch up to 10°, and the aircraft will quickly and effortlessly reach mach 3.

That does not mane any sense to me, why would you need to pitch down such an aircraft, designed for speed, just to cross to cross the sound barrier? 
 

btw, i am not 100% sure, but i think i read somewhere that the pilots of the SR-71 were not allowed to fly inverted.

On 5/25/2022 at 3:33 PM, virtuali said:

Maybe because it also requires to push down 20 deg to gain speed, so it's supposed to be flown inverted to not suffer from negative Gs.

This makes sense - you would have to do the same with any jet fighter, such as the F16.  No way you would just push the nose down for a quick descent.  You would flip inverted and pull, then flip back when not generating much G.

Son of blackbird… UAV

https://en.wikipedia.org/wiki/Lockheed_Martin_SR-72
 

 

Edited May 28, 20224 yr by Khashoggi

Negative g overload (red out) is much more dangerous to the human body (stroke/retinal damage) than a grey out or positive g overload.

Can you use the Darkstar on a normal flight outside the challenge? Would love to fly this on Vatsim!

The reason for the inversion has nothing to do with gs. You're inverting at subsonic speeds. If the negative gs at that speed were dangerous, airliners would have to invert when descending. Which admittedly would make commercial air travel a lot more entertaining.😉

I saw somewhere that you have to invert the Darkstar because the engines are on the bottom and you'd block airflow in the pitchover but that doesn't make sense either because you pitch down at the end of the flight without inverting. I suspect the inversion is just to give you something "cool" to do.

Btw the Blackbird did not invert but it did at least sometimes dive to go supersonic. The maneuver had the high-tech proper military name of "dipsy-doodle." Diving helped burn less fuel while pushing through the transonic shockwave. Once it was supersonic there was much less resistance to overcome.

The high-G turns and other maneuvers performed by fighter aircraft during dog-flights and other high-performance maneuvers are, for the most part, accomplished at subsonic speeds (otherwise you wouldn't be able to turn tight enough).

The Gs generated at these subsonic speeds can generate enough positive Gs to cause black-out and (if improperly performed) enough negative Gs to cause red-out (or even kill you).  That's why you always invert to maintain positive G-forces rather than negative.

You, of course, do not fly airliners in this manner, and it's not necessary to do so.

On 5/29/2022 at 10:31 PM, Kyuss said:

Think of it like cars that run for topspeed on the Bonneville salt flats, they need a push start because of the really long gearing needed for top speed. The engines are designed for high speeds in much the same way. There is also a bit of a wall in the transonic range.

 

19 hours ago, eslader said:

I suspect the inversion is just to give you something "cool" to do.

Btw the Blackbird did not invert but it did at least sometimes dive to go supersonic. The maneuver had the high-tech proper military name of "dipsy-doodle." Diving helped burn less fuel while pushing through the transonic shockwave. Once it was supersonic there was much less resistance to overcome.

i am aware of the wall in the transonic range, but is it that strong? is an average jet fighter subject to the same struggle to break the barrier of sound?

i agree, the inversion is here to spice things up, otherwise the flight would appear boring to many people.

38 minutes ago, Sceli said:

 

i am aware of the wall in the transonic range, but is it that strong? is an average jet fighter subject to the same struggle to break the barrier of sound?

i agree, the inversion is here to spice things up, otherwise the flight would appear boring to many people.

The average fighter jet doesn't need to make it all the way across the Soviet Union unescorted before refueling. 😉

 

 

This sounds like a made-up game challenge, which is fine, but I don't think has any real-world use. 

The negative-g avoidance theory only holds if you need to perform this pitch attitude change pretty rapidly. There's no reason you can't lower the nose at a reasonable rate from 20 degrees nose high to 20 degrees nose low without going anywhere near negative.  Even 0.8 positive G is a reasonable pitch-down rate, and an unload has the added benefit of reducing induced drag, if a speed increase is the goal. 

Edited May 30, 20224 yr by Stearmandriver

Aside from sharing its name with a good song from Crosby Stills & Nash, the Darkstar is fun enough that I actually added it to my NeoFly fleet where it's priced out at an extremely reasonable $2.5M.  Sounds crazy but it would pay for itself after 10 coast-to-coast light cargo missions.  Unfortunately my hopes of being the world's fastest freight dog were dashed because Neofly doesn't recognize the engine start, I'm guessing because it's wanting to see the scramjets light off as well.  

Edited May 31, 20224 yr by Stoopy

I don't think it has to so with the plane. It's about the human flying it. my understanding is when you fly inverted the g forces will force the blood TO your brain, when you are upright it forces the blood out of the brain. If you invert the g forces to force your blood into the brain, then you re roll and the forces then start pushing the blood back into the brain. So I believe the point is you invert to take negative gs and then flip back over sending blood back to the brain, keeping your blood flow in check during accelerated g forces. If you simple stay up right during the entire acceleration you would pass out. So the inversion then re orientation keep you accelerating without losing conciousness. I could be wrong but I do believe this is the logical reason. It's about being able to achieve the speed intended without killing the pilot. It's not about what the aircraft can do it's about what the person in it can handle. This is just my theory based on what happens to your body during such intense acceleration.

 

 

Did it without inverting. Can’t feel G’s in the Sim!  Cheers.