Can any production fighters exceed Mach 1 vertically

[Radical]

This is something I've been thinking about when looking at aircraft characteristics. From unclassified data, it seems like the MiG-29 is the fighter thats closest to exceeding Mach 1 in vertical climb rate with instantaneous speed of 330 m/s. Is it possible for a lightly loaded Typhoon or F-22 or PAK FA to go supersonic vertically?

 

[Orionblamblam]

As memory serves, both the YF-22 and YF-23 broke Mach 1 going straight up, prit near 20 years ago.

 

[Arjen]

Typhoon does it.

 

[Byeman]

F-15

 

[Steve Pace]

F-22 Raptor

 

[bob225]

Didn't the English Electric Lightning do it?

 

[Sundog]

You should also qualify your question. Do you mean at Take-Off Weight, with a full weapons load, or at any given fuel load and clean? Generally, if it's thrust to weight ratio exceeds one at sea level and up for maybe ten thousand feet, it shouldn't be a problem. I say that because thrust of the engine decreases with altitude, for your ref.

 

[Radical]

You should also qualify your question. Do you mean at Take-Off Weight, with a full weapons load, or at any given fuel load and clean? Generally, if it's thrust to weight ratio exceeds one at sea level and up for maybe ten thousand feet, it shouldn't be a problem. I say that because thrust of the engine decreases with altitude, for your ref.

If that's the case, then I'm curious as to why both the F-15 and F-16 has their rate of climb listed as 254 m/s.

Also, according to an F-22 pilot called "Dozer" the F-22 can do Mach 0.99 vertically at 20k ft. Here's an excerpt before his posts got taken down.

"At slower speeds the engines are not putting out maximum thrust, the more air flow there is through the motors the more thrust you're getting, so, for example, I did a takeoff where I was at about 570 knots at Edwards, I was prior to the end of the runway, not used to being that fast so I pulled up to 90 degrees nose high (single ship with my own tanker and first chance to try this with a Raptor so I decided to see what she'd do), and the mass flow at that point is close to producing max possible thrust, the a/c continued to accelerate in the climb to .99 mach passing about 20 thousand feet and then slowly began to decelerate - (unofficially according to the engineers I would have ended up around 65+ thousand feet on that day and broke every time to climb record we could think of for category & weight class -- and oh by the way, that wasn't a Streak Eagle or Flanker stripped down bare with weight removed, no external stores for combat configuration, etc., that was in a stock, off the line F-22, full of gas, combat configured with the internal weapons bay full - as an Eagle guy previous I was absolutely astonished, I hope someday we go after the official records because this jet will likely crush most of them. One last interesting point is that I did that going straight up after takeoff (that day I ended up blasting past my assigned altitude at Edwards of 29 thousand after takeoff, ended up at 31.5 AFTER a 5g pull to level out which at that weight and altitude should bleed energy fast but when I rolled out I was still at 330knots KCAS!!), but normally to get those altitudes they use a specific climb profile like the Streak Eagle did (I forget what it's called) climb at .9m to the mid 30 thousands, push over to accelerate to supersonic and then finish the climb profile to bust the records from there)."

 

[Bill Walker]

Any stated rate of climb is only valid at one weight, one airspeed, and one altitude. Without extra information, a single rate of climb number is kind of meaningless.

Going straight up at Mach 1 may not be the quickest way to get from sea level to your destination altitude. Most fighters will have a published climb schedule for the intended final altitude. For at least some aircraft, this can mean climbing subsonically to some medium altitude, then descending to go supersonic, and then continuing the climb at M1+ airspeed, but not striaght up. Along the way you will have various instantaneous rates of climb. The marketing guys may use an average rate of climb, or pick the best looking number at some arbitrary point in the climb schedule.

 

[Steve Pace]

I agree. Well said! -SP

 

[Delta Force]

Looking at engine thrusts and typical takeoff weights on Wikipedia (obviously not the best source) it would appear that the F-15, F-16, F-22 all have thrust levels higher than typical takeoff weight. An F/A-18 Hornet has a thrust/weight ratio slightly below 1.00, so it could probably achieve such a feat with a lower fuel load or after burning some fuel off during the flight. The Super Hornet and the F-35 can't even carry a full fuel load and achieve a 1.00 thrust/weight ratio, so they wouldn't be able to carry a useful payload and do the stunt.

 

[Bill Walker]

It is a bit more complicated than that. While going straight up at any speed there are aerodynamic forces as well as gravity to consider. From some quick free body diagram sketches, I think the best way to do this is to climb at the zero lift alpha, and accept the possibly higher drag. Or at least, that is the easiest to analyze. It that case, the required engine thrust to sustain non-accelerated flight becomes weight + drag. Obviously, the higher the airspeed the higher the drag.

You also have to ask, how do you get to M1+? Do you accelerate in level flight and then pitch up, or do you pitch up and then accelerate? Each will take a different amount of time, and you run the risk of running out of fuel before reaching M1. Again, a quick back of the envelope analysis suggests accelerating in level flight or even a dive to M1+, then pitching up, is the quickest way.

Doing the dive and pitch up, you could climb vertically at M1+ for a bit, but it may not be sustained. We need to keep that in mind when some fighter jock tells us he did it. I would believe the FTE in the back seat, but maybe not the jock. ;D

 

[Sundog]

The way they do it is by looking at the Ps diagrams and plotting the minimum time/maximum energy climb on them. As Bill has been stating, an F-15 could accelerate through Mach 1 going vertical, but that won't give it it's fastest/shortest time to climb to a given altitude.

There's good information here, on the F-15's Record Setting climbs that will show that information. Scroll down to almost the middle of the page to see the graphs.

 

[Delta Force]

Is it simply that there are no aircraft with a power to weight ratio where climbing straight up would make things go faster, or is it just because aircraft accelerate better in a straight line because they generate lift? Space launch vehicles don't have very high thrust to weight ratios but it's always faster for them to fly straight up. It's even more efficient for them to takeoff at a lower level of thrust while they punch through the atmosphere closer to the ground. Of course rockets generate very little lift, so they can't easily fly in a straight line while they build up speed.

 

[Bill Walker]

As Sundog pointed out, rate of climb, in rockets or airplanes, comes from excess power (Ps). That is the engine power not needed to keep you in steady flight at a constant altitude. In a rocket, you need thrust = weight + drag to keep in steady flight. If you have wings, the power required for steady flight will be a function of airspeed, altitude and weight. From power required curves you can find an airspeed that gives you maximum excess power for any weight and altitude (excess power = power available - power required). That is the airspeed that will give you the best rate of climb. From some of the F-15 curves in Sundog's link, that airspeed may start out at M1+ at lower altitudes but appears to decrease with altitude.

Climbing straight up at M1+ will have some drag. If (as I theorized) you are doing this at a zero lift angle of attack (slightly nose down, relative to flight path) to stay on a vertical flight path your drag (and therefore your power required) will go up, compared to horizontal flight at the same speed, so your excess power goes down. Rate of climb comes ONLY from excess power, no matter which way the airplane is pointed.

Of course, it all depends on what your mission is. I think Sundog's F-15 data shows minimum time to altitude, a more realistic military mission might be to arrive at altitude with some useful speed, so that could have a different climb schedule.

Sounding rockets may go straight up, but orbital rockets quickly transition to angled flight, so they can develop horizontal speed at the same time they are climbing. Again this is the mission: arrive at altitude AND orbital speed. There are the added factors of quickly decreasing weight as the rocket climbs, and decreasing drag, even at higher speeds, as you get up into the thinner atmosphere. I will let the rocket guys comment on how all that effects rate of climb and climb schedules. But I think your initial climb, in the thicker atmosphere, will be at relatively low airspeed (certainly right after takeoff), so you have lots of excess power even going straight up.

Now, for bonus points, who can explain why the Pegasus rocket has wings on the first stage, but not on the second stage?

 

[gtg947h]

Now, for bonus points, who can explain why the Pegasus rocket has wings on the first stage, but not on the second stage?

To make the pull-up maneuver right after the drop.

 

[Bill Walker]

Half credit. Anyone else?

 

[archipeppe]

Lockheed F-104 in clean configuration.


I remember one impressive take off F-104S-ASA long ago (it was 1997) at Grazzanise Italian AFB, followed by a vertical zoom climb followed by the typical "bang".


When it happened the only thing that one could see of the 104 was its A/B bright spot....

 

[TomS]

Half credit. Anyone else?

First stage wings also do provide some lift early in flight.
Second stage uses thrust vectoring rather than aerodynamic controls, because there's not enough air at the altitude where the second stage fires (~200,000 ft)to make aero controls worthwhile.

 

[Bill Walker]

Close enough .

By using the carrier aircraft to get the wing up to altitude and speed without using any rocket fuel, the Pegasus can then use aerodynamic lift to support the weight right after dropping, so more excess power is available to accelerate and to climb at the same time. Within a short time the air is becoming too thin for the wing to help much, so, as TomS says, the wing is gone with the first stage and the Pegasus becomes a conventional guided missile.

Without the carrier aircraft, a great deal of rocket fuel would have been used to get up to a speed where the small wing could help.

This may be on next week's quiz. ;D

 

[stuarty771]

You should also qualify your question. Do you mean at Take-Off Weight, with a full weapons load, or at any given fuel load and clean? Generally, if it's thrust to weight ratio exceeds one at sea level and up for maybe ten thousand feet, it shouldn't be a problem. I say that because thrust of the engine decreases with altitude, for your ref.

To break the sound barrier the thrust has to exceed the weight and the drag at Mach 1.
I don't think what you've written there covers that. Given that some jet fighters can't climb vertically at all (Tornado), it's a very high level of power

 

[Sundog]

You should also qualify your question. Do you mean at Take-Off Weight, with a full weapons load, or at any given fuel load and clean? Generally, if it's thrust to weight ratio exceeds one at sea level and up for maybe ten thousand feet, it shouldn't be a problem. I say that because thrust of the engine decreases with altitude, for your ref.

To break the sound barrier the thrust has to exceed the weight and the drag at Mach 1.
I don't think what you've written there covers that. Given that some jet fighters can't climb vertically at all (Tornado), it's a very high level of power

Many modern fighters like the F-15 and F-16 have T/W ratios that are much greater than unity at Sea Level and they are optimized for low drag, because, wait for it, they're supersonic fighters. The F-22 can easily do so.

 

[1635yankee]

This is something I've been thinking about when looking at aircraft characteristics. From unclassified data, it seems like the MiG-29 is the fighter thats closest to exceeding Mach 1 in vertical climb rate with instantaneous speed of 330 m/s. Is it possible for a lightly loaded Typhoon or F-22 or PAK FA to go supersonic vertically?

When going up or down?

 

[sferrin]

This is something I've been thinking about when looking at aircraft characteristics. From unclassified data, it seems like the MiG-29 is the fighter thats closest to exceeding Mach 1 in vertical climb rate with instantaneous speed of 330 m/s. Is it possible for a lightly loaded Typhoon or F-22 or PAK FA to go supersonic vertically?

When going up or down?

How does one climb down?

 

[paralay]

Compared with conventional AL-31F, the afterburner thrust of the R-32 engines was increased to 13600 kgf[1]. Two such engines, together with a small maximum take-off weight of the aircraft, provided a thrust-to-weight ratio of at least 1.93 kgf / kg. Thanks to this, the aircraft was able to overcome the sound barrier in vertical climb mode

 

[Ainen]

Compared with conventional AL-31F, the afterburner thrust of the R-32 engines was increased to 13600 kgf[1]. Two such engines, together with a small maximum take-off weight of the aircraft, provided a thrust-to-weight ratio of at least 1.93 kgf / kg. Thanks to this, the aircraft was able to overcome the sound barrier in vertical climb mode

The author specifically said 'among production aircraft'.
And this particular requirement more or less leaves us to full profile(including supersonic) acceleration-optimized aircraft - i.e. [earlier] mig-29, Eurofighter, and F-22.

 

[stuarty771]

You should also qualify your question. Do you mean at Take-Off Weight, with a full weapons load, or at any given fuel load and clean? Generally, if it's thrust to weight ratio exceeds one at sea level and up for maybe ten thousand feet, it shouldn't be a problem. I say that because thrust of the engine decreases with altitude, for your ref.

To break the sound barrier the thrust has to exceed the weight and the drag at Mach 1.
I don't think what you've written there covers that. Given that some jet fighters can't climb vertically at all (Tornado), it's a very high level of power

Many modern fighters like the F-15 and F-16 have T/W ratios that are much greater than unity at Sea Level and they are optimized for low drag, because, wait for it, they're supersonic fighters. The F-22 can easily do so.

But not many fighters can attain supersonic speed vertically I'm guessing. There's more to accurate statements of aircraft performance than saying snidely 'wait for it, they're supersonic fighters'
How much greater than unity is required?
You can be snide to me (an ex aircraft performance engineer) if you know the answer.

 

[F-2]

F-16 block 50 can climb 1200 feet per second while maintaining a 7.5 degree

22000 lb clean

View topic - F-16 vs MiG-29 energy maneuverability from test report • F-16.net

Military aviation forum since 2003, with high quality discussion focusing on the F-16, F-35 and F-22 jet fighters and the C-130.

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[stuarty771]

F-16 block 50 can climb 1200 feet per second while maintaining a 7.5 degree

22000 lb clean

View topic - F-16 vs MiG-29 energy maneuverability from test report • F-16.net

Military aviation forum since 2003, with high quality discussion focusing on the F-16, F-35 and F-22 jet fighters and the C-130.

www.f-16.net

Thanks
We know the Lightning could attain this, so what was its thrust/weight at SL say?
For comparison an F14 weighs ~200kN at SL (empty). Theres a drag rise on the Internet showing a CD of 0.04 so that's wave drag of about 150kN, suggesting a SL thrust/weight of 1.75 (assuming the units match). I don't think the F14 had that.

 

[F-2]

F-16 block 50 can climb 1200 feet per second while maintaining a 7.5 degree

22000 lb clean

View topic - F-16 vs MiG-29 energy maneuverability from test report • F-16.net

Military aviation forum since 2003, with high quality discussion focusing on the F-16, F-35 and F-22 jet fighters and the C-130.

www.f-16.net

Thanks
We know the Lightning could attain this, so what was its thrust/weight at SL say?
For comparison an F14 weighs ~200kN at SL (empty). Theres a drag rise on the Internet showing a CD of 0.04 so that's wave drag of about 150kN, suggesting a SL thrust/weight of 1.75 (assuming the units match). I don't think the F14 had that.

My journey started in the 15, after many years transitioned to the F-16, and when my unit was inactivated in 2006, I was selected and transitioned to the F-22. The F-22 was where I ended my career.

This is my opinion and based on personal experience. The block 30/40/50 F-16 (GE equipped) has the best acceleration of the three I mentioned. Those jets would jump out to their maximum quick and could probably go beyond it if were not for the fixed intake and the canopy. In all my years of flying, nothing beat the F-16 (GE) for acceleration. period. It was a screamer and it was one of the best ACM platforms I ever flew.


I'm a newbie, limited to three post....lol, so hence the edit

Sorry Gents, should have mentioned low altitude in A/A config. The F-16C (GE) will surprise you with its acceleration. An old Eagle driver like me was quickly impressed on my first few rides. I never flew it, but I hear that the-229 F-16 is a sage burner also. I know allot of Viper drivers who flew the older Pratt versions, and the difference was substantial between the two. I can just speak the GE equipped block onwards.

Here is a little tidbit that will get you guys all riled up. The F-15A/C (flew both) were not particularly fast at low altitude, above 30 and that changes. Ready......I've flown a lot of Eagles and not a single one of them would accelerate in the vertical straight from brake release, I know, we've tried. I know some of you guys on here will figure out why, but I'll give a hint.............denser air at low altitude, T/W ratio versus decreasing thrust. A specially modified Eagle (think Streak) but me and my compatriots never got a line Eagle to do it.....lost quit a few beer bets on this.

I say this and this only about the 22 (opsec). It's a generational leap above anything currently flying anywhere in the world. It brings a whole different aspect to air combat. F-35 excluded, of course.

F-16.net View topic - F-16 vs F/A-18

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All the big mouth GE and 229 powered vipers have unbelievable subsonic acceleration.

 

[1635yankee]

This is something I've been thinking about when looking at aircraft characteristics. From unclassified data, it seems like the MiG-29 is the fighter thats closest to exceeding Mach 1 in vertical climb rate with instantaneous speed of 330 m/s. Is it possible for a lightly loaded Typhoon or F-22 or PAK FA to go supersonic vertically?

When going up or down?

How does one climb down?

The thread title just specified vertically.