Why does the Darkstar in MSFS have to invert itself?

[Dillon 2,197]

On 5/25/2022 at 3:22 PM, abrams_tank said:

Ok, this is bugging me more and more. For the new Top Gun Maverick downloadable content, if you download it, you get the Darkstar, which is a top secret plane, that can reach Mach 9. When you fly the mission for the Darkstar in MSFS, at one point, you are required to invert the plane.

I can't for the life of me, figure out why the Darkstar needs to be inverted.  Did the SR 71 require inversion as well, in order to reach its top speed?  What is the scientific reason, that the Darkstar needs to be inverted? I'm sure it's related to physics, but I can't really figure out why inverting it is necessary, in order to reach the top speed of Mach 9.

PS. I don't think the inversion for the Darkstar has anything to do with the original Top Gun movie where Tom Cruise inverts his plane.

I thought it silly so I didn't bother doing this as I'm sure this wouldn't be required in the real world.  Low and behold I found after 30,000ft if you point the nose down and gain speed you get the same result.😶  This is a case of monkey see monkey do... You don't need to invert the aircraft, this was something suggested and people followed like lemmings the same maneuver.😌  

[Sceadu 117]

On 5/25/2022 at 10:05 PM, abrams_tank said:

While this is a fantasy aircraft, Skunk Works from Lockheed Martin, the same team that developed the SR 71, had input on creating this Darkstar: https://www.thedrive.com/the-war-zone/skunk-works-helped-create-the-darkstar-jet-for-top-gun-maverick

So I think at least for the larger details, the physics and design of this, probably have merit. Of course when it comes down to the smaller details, it’s not fleshed out yet (if the smaller details were fleshed out, the Darkstar would be real).

One thing you can be certain of is if the Guys at Burbank publicly state they had a hand in a flight sim representation of a hollywood film depiction of secret hypersonic reconnaissance aircraft  then it aint too close to what they really built (assuming they even built an SR71 replacement)

[deepstar 38]

NASA:

https://flightsim.to/file/34045/darkstar-nasa

 

[CommandProMC 0]

The plane inverts after reaching 20k feet at mach 0.9. The inversion occurs to allow a pull down maneuver to take place, putting the plane into a dive where it breaks the sound barrier. I think the inversion is there so that the plane does not suffer from negative 1.2 Gs.

[Tuskin38 6,520]

On 5/30/2022 at 7:08 PM, Stearmandriver said:

This sounds like a made-up game challenge

It isn't.

[Stearmandriver 2,296]

2 hours ago, Tuskin38 said:

It isn't.

How so isn't it? Why can't the nose simply be lowered at a reasonable rate? When you're in an airliner, it doesn't roll and pull to get the nose down and "avoid negative g", right? 

[Tuskin38 6,520]

1 hour ago, Stearmandriver said:

How so isn't it? Why can't the nose simply be lowered at a reasonable rate? When you're in an airliner, it doesn't roll and pull to get the nose down and "avoid negative g", right? 

Because an airliner isn't trying to go Hypersonic.

The dive is to build up speed to break the sound barrier and inverting has to do with the Gs. It's been explained in previous posts in this thread on how it makes sense.

Edited August 11, 2022 by Tuskin38

[Glenn Fitzpatrick 3,798]

This thread sort of reminds me of my younger days playing table top Dungeons and Dragons where people would argue for days about the real world physics behind magical enchanted great swords.

[Sceadu 117]

8 hours ago, Tuskin38 said:

Because an airliner isn't trying to go Hypersonic.

The dive is to build up speed to break the sound barrier and inverting has to do with the Gs. It's been explained in previous posts in this thread on how it makes sense.

...and stearmandriver already explained that the speed build up can be performed via a push over that hardly generates negative G, it might take 10 seconds longer to do it that way rather a dramatic inversion followed by a pullup which in reality is something only done during  combat or aerobatic routines, so does that extra 10 seconds  reaching the required pitch down for speed gain matter?...no of course not there isnt a bogey on your 6 and nobody is watching you up there to impress, its simply a gimmick to make flying a fantasy aircraft in a flight sim seem a little more interesting

[bobcat999 8,483]

1 hour ago, Sceadu said:

...and stearmandriver already explained that the speed build up can be performed via a push over that hardly generates negative G, it might take 10 seconds longer to do it that way rather a dramatic inversion followed by a pullup which in reality is something only done during  combat or aerobatic routines, so does that extra 10 seconds  reaching the required pitch down for speed gain matter?...no of course not there isnt a bogey on your 6 and nobody is watching you up there to impress, its simply a gimmick to make flying a fantasy aircraft in a flight sim seem a little more interesting

I have seen fighter pilots roll over and do this rather than push too much negative G.  In fact, I do this in DCS when I am at altitude and need to get down quickly.

In something like an F-16, it would be 9G positive, but negative much lower, probably no more than -3G, but even this wouldn't be good for the pilots head!    As G-suits only work one way as we know, to squeeze the blood to the upper body on lots of positive G.

So what I am saying basically is that it can be a valid manoeuvre, but mainly for the pilot rather than the aircraft limitations.

[Stearmandriver 2,296]

21 hours ago, Tuskin38 said:

Because an airliner isn't trying to go Hypersonic.

The dive is to build up speed to break the sound barrier and inverting has to do with the Gs. It's been explained in previous posts in this thread on how it makes sense.

Correct, and in the goal of *accelerating*, you're better off doing a gentle unload (lowering the nose) which reduces drag and improves acceleration rate. A roll and pull loads the wing further, generating drag and actually working against your quest to accelerate. 

I teach aerobatics. I wouldn't say anyone really loves negative Gs, but -1 or -1.5 is no big deal at all.  I mean, everyone knows what -1g feels like... we've all hung upside down by our legs from a tree branch at some point, right? 

A gentle nose down push could be anywhere from airline-style that almost remains 1g, to something a bit more aggressive like .5g that significantly reduces induced drag on the aircraft, while still keeping everything positive for engine systems etc. (Though any aircraft intended for a roll and pull is aerobatic and therefore would have inverted systems.)

This IS a gamey construct. Which is fine, but let's call it what is is. Rolling and pulling would accomplish nothing in this type of operation. 

[Rogen 1,087]

Came across this SR-71 Pilot's Story on how slow he had flown in the SR-71.

Cheers

Quote

As a former SR-71 pilot, and a professional keynote speaker, the question I'm most often asked is "How fast would that SR-71 fly?"

I can be assured of hearing that question several times at any event I attend.

It's an interesting question, given the aircraft's proclivity for speed, but there really isn't one number to give, as the jet would always give you a little more speed if you wanted it to.

It was common to see 35 miles a minute. Because we flew a programmed Mach number on most missions, and never wanted to harm the plane in any way, we never let it run out to any limits of temperature or speed.

Thus, each SR-71 pilot had his own individual “high” speed that he saw at some point on some mission.

I saw mine over Libya when Khadafy fired two missiles my way, and max power was in order. Let’s just say that the plane truly loved speed and effortlessly took us to Mach numbers we hadn’t previously seen.

So it was with great surprise, when at the end of one of my presentations, someone asked, “what was the slowest you ever flew the Blackbird?”

This was a first. After giving it some thought, I was reminded of a story that I had never shared before, and relayed the following.

I was flying the SR-71 out of RAF Mildenhall, England , with my back-seater, Walt Watson; we were returning from a mission over Europe and the Iron Curtain when we received a radio transmission from home base.

As we scooted across Denmark in three minutes, we learned that a small RAF base in the English countryside had requested an SR-71 fly-past.

The air cadet commander there was a former Blackbird pilot, and thought it would be a motivating moment for the young lads to see the mighty SR-71 perform a low approach. No problem, we were happy to do it.

After a quick aerial refueling over the North Sea , we proceeded to find the small airfield. Walter had a myriad of sophisticated navigation equipment in the back seat, and began to vector me toward the field.

Descending to subsonic speeds, we found ourselves over a densely wooded area in a slight haze. Like most former WWII British airfields, the one we were looking for had a small tower and little surrounding infrastructure.

Walter told me we were close and that I should be able to see the field, but I saw nothing. Nothing but trees as far as I could see in the haze. We got a little lower, and I pulled the throttles back from 325 knots we were at.

With the gear up, anything under 275 was just uncomfortable. Walt said we were practically over the field—yet; there was nothing in my windscreen.

I banked the jet and started a gentle circling maneuver in hopes of picking up anything that looked like a field.
Meanwhile, below, the cadet commander had taken the cadets up on the catwalk of the tower in order to get a prime view of the fly-past.

It was a quiet, still day with no wind and partial gray overcast. Walter continued to give me indications that the field should be below us but in the overcast and haze, I couldn't see it..

The longer we continued to peer out the window and circle, the slower we got. With our power back, the awaiting cadets heard nothing.

I must have had good instructors in my flying career, as something told me I better cross-check the gauges.

As I noticed the airspeed indicator slide below 160 knots, my heart stopped and my adrenalin-filled left hand pushed two throttles full forward.

At this point we weren't really flying, but were falling in a slight bank.

Just at the moment that both afterburners lit with a thunderous roar of flame (and what a joyous feeling that was) the aircraft fell into full view of the shocked observers on the tower.

Shattering the still quiet of that morning, they now had 107 feet of fire-breathing titanium in their face as the plane leveled and accelerated, in full burner, on the tower side of the infield, closer than expected, maintaining what could only be described as some sort of ultimate knife-edge pass.

Quickly reaching the field boundary, we proceeded back to Mildenhall without incident. We didn't say a word for those next 14 minutes.

After landing, our commander greeted us, and we were both certain he was reaching for our wings. Instead, he heartily shook our hands and said the commander had told him it was the greatest SR-71 fly-past he had ever seen, especially how we had surprised them with such a precise maneuver that could only be described as breathtaking.

He said that some of the cadet’s hats were blown off and the sight of the plan form of the plane in full afterburner dropping right in front of them was unbelievable. Walt and I both understood the concept of “breathtaking” very well that morning, and sheepishly replied that they were just excited to see our low approach.

As we retired to the equipment room to change from space suits to flight suits, we just sat there-we hadn't spoken a word since “the pass.” Finally, Walter looked at me and said, “One hundred fifty-six knots. What did you see?” Trying to find my voice, I stammered, “One hundred fifty-two.”

We sat in silence for a moment. Then Walt said, “Don’t ever do that to me again!” And I never did.

A year later, Walter and I were having lunch in the Mildenhall Officer’s club, and overheard an officer talking to some cadets about an SR-71 fly-past that he had seen one day.

Of course, by now the story included kids falling off the tower and screaming as the heat of the jet singed their eyebrows.
Noticing our HABU patches, as we stood there with lunch trays in our hands, he asked us to verify to the cadets that such a thing had occurred.

Walt just shook his head and said, “It was probably just a routine low approach; they're pretty impressive in that plane.” Impressive indeed.

Little did I realize after relaying this experience to my audience that day that it would become one of the most popular and most requested stories.

It’s ironic that people are interested in how slow the world’s fastest jet can fly. Regardless of your speed, however, it’s always a good idea to keep that cross-check up…and keep your Mach up, too.

There were a lot of things we couldn’t do in an SR-71, but we were the fastest guys on the block and loved reminding our fellow aviators of this fact. People often asked us if, because of this fact, it was fun to fly the jet.

Fun would not be the first word I would use to describe flying this plane. Intense, maybe. Even cerebral. But there was one day in our Sled experience when we would have to say that it was pure fun to be the fastest guys out there, at least for a moment.

It occurred when Walt and I were flying our final training sortie. We needed 100 hours in the jet to complete our training and attain Mission Ready status.

Somewhere over Colorado we had passed the century mark.

We had made the turn in Arizona and the jet was performing flawlessly. My gauges were wired in the front seat and we were starting to feel pretty good about ourselves, not only because we would soon be flying real missions but because we had gained a great deal of confidence in the plane in the past ten months.

Ripping across the barren deserts 80,000 feet below us, I could already see the coast of California from the Arizona border. I was, finally, after many humbling months of simulators and study, ahead of the jet.

I was beginning to feel a bit sorry for Walter in the back seat. There he was, with no really good view of the incredible sights before us, tasked with monitoring four different radios.

This was good practice for him for when we began flying real missions, when a priority transmission from headquarters could be vital.

It had been difficult, too, for me to relinquish control of the radios, as during my entire flying career I had controlled my own transmissions.

But it was part of the division of duties in this plane and I had adjusted to it. I still insisted on talking on the radio while we were on the ground.

Regardless, this game has been very fun to play

 

 

Edited August 12, 2022 by Rogen

[CommandProMC 0]

On 8/11/2022 at 3:56 PM, Stearmandriver said:

How so isn't it? Why can't the nose simply be lowered at a reasonable rate? When you're in an airliner, it doesn't roll and pull to get the nose down and "avoid negative g", right? 

An airliner can't sustain 0G for the amount of time you need to be pulling them, and neither can the darkstar; it's not a fighter jet like some people say. It's closer to an SR-71.

[Tuskin38 6,520]

Adobo said they talked with people knowledgeable in hypersonic physics to help develop the sim’s version of the Darkstar. So the inverted dive may have come from them.

I will note the inverted dive was not in the movie, the Darkstar in the movie just kept flying straight until hitting Mach 10.

Edited September 14, 2022 by Tuskin38

[Stearmandriver 2,296]

10 hours ago, CommandProMC said:

An airliner can't sustain 0G for the amount of time you need to be pulling them, and neither can the darkstar; it's not a fighter jet like some people say. It's closer to an SR-71.

Where do you get the idea that simply lowering the nose will result in anything near zero g?  That's my entire point about an airliner - they manage to pitch down many times on every single flight without anyone experiencing anywhere near zero g... more like .95g, right? 

Again, if the goal is acceleration, lowering the nose to unload the wing is actually more efficient than rolling and pulling; an unload (not to zero g, but ANY amount of unload) actually reduces drag. 

This is 100% a game construct; there's no legitimate reason for an aircraft on this profile to roll and pull. 

Even in the movie (which of course contains very little aviation reality of any kind), they do show Mav *pushing* the stick forward for a little extra speed.