F-14 Tomcat, Horsepower vs. Thrust 

That's one of the coolest stories I have ever heard.

Can depend quite a lot on inlet design. An F-16 gets like 10-15% more static thrust from its F-100 than an F-15

Surely there must be some ram air effect, especially at supersonic speeds where the air must be slowed to sub sonic intake speeds and hence compressed?

@@gavindavies793 There is massive ram effect with airspeed. The additonal airflow will result in increased fuel flow (thrust) until the fuel system can no longer support the demand, or the inlet can no longer provide slow enough (subsonic) air to the engine.

@@baileyparadis1815 That ram effect overcomes the thrust that would otherwise be lost with increasing speed due to the smaller ratio between inlet and exit velocities. The graph on Page 118 of AFNA illustrates this, and here is some of the text that graph illustrates: The turbojet engine is essentially a thrust producing powerplant and the propulsive power produced is a result of the flight speed. The variation of available thrust with speed is relatively small and the engine output is very nearly constant with flight speed. The momentum change given the engine airflow develops thrust by the following relationship: Ta=Q(V2-V1) Since an increase in flight speed will increase the magnitude of Vi (inlet velocity), a constant thrust will be obtained only if there is an increase in mass flow, Q, or jet velocity, Vs, When at low velocity, an increase in velocity will reduce the velocity change through the engine without a corresponding increase in mass flow and the available thrust will decrease. At higher velocity, the beneficial ram helps to overcome this effect and the available thrust no longer decreases, but increases with speed. The propulsive power available from the turbojet engine is the product of available thrust and velocity. Since the thrust of the turbojet engine is essentially constant with speed, the power available increases almost linearly with speed. In this sense, a turbojet with 5000 Ibs. of thrust available could produce a propulsive power of 3,000 h.p. at 325 knots or 10,000 h.p. at 650 knots. The tremendous propulsive power at high velocities is one of the principal features of the turbojet engine.

@@gort8203 Are you familiar with the NASA engine sim?

What i hear they help with the transonic region of flight

Thanks, and I like Mr. Ward Carrol's channel as well.

PLEASE do yourself a favor and get a joystick (a cheap used logitech X52 pro will do just fine..... its what i use.... and it has more than enough buttons for the F14) . and then buy DCS f-14 . . yes, i know that 50 to 60 dollars per plane is expensive but you can still fly with // shoot down players who are flying other jets . and the planes WITH OUT clickable cockpits are 10 bucks (f-15, su-25t, su-27, mig 29, ETC) . . . like..... you will spend WAY WAY WAY more time learning, flying, and fighting the 50-60 dollar jets than you will playing ANY new FPS game released today COD/BF can be beat in 20 hours..... Single player AND multi player . but DCS...... you will get 100 hours in, and still be learning new tricks and tips . . . the amount of work and EXACT detail and simulation that goes into these 50/60 dollar jets is just insane you can only pay for what YOU want to fly (again, you can still fly in the same sever with jets you dont own..... on your team or not on your team) . like.... they got the sea level airspeed EXACT on the F-14a its THAT hard core of a simulation . . . . . but if you dont want to learn something for 5 hours before you even know it well enough to take off (let alone land and/or get a radar lock, IFF and shoot missiles) or you dont like waiting 5 mins every time you die for the NAV system to align (plus another 5 to 10 for the engines and systems to boot up) . then DCS is not for you . . but if you LOVE knowing you could LITERALLY jump into a REAL!!!!!!! F-14/FA18/F16/A-10c..... start it up, take off, shoot shit, and land . then DCS is for you . . . . . . also..... dont join multiplayer..... when you dont know how to land... or tell which jets are friendly and enemy on your radar..... the community is AMAZING..... and they will take hours out of their day to teach you . but joining a server as a "noob"..... and team-killing 2 people, before making a crater in the runway because you crashed on landing which means EVERYONE who tries to take off will crash.... due to your aircrafts wreckage and crater . you are GOING to get nasty messages . . . no one wants to wait 10 mins for the NAV to align again...... simply because they got TKed by a dude who didnt use the tutorials or even TRY to learn the jet . . treat it as 80% as serious as real life........ and you will have a VERY fun time and make a TON of friends

also..... but the F-15 first its 10 bucks and will teach you 99% of how to take off/land...... how the radar and IFF works...... how the missiles work.....ETC . and if you decide that you like the game...... THEN pay the 50 or 60 bucks for the "big" jets

This video is for you engineering types. Not much history in this one, mostly just technical stuff.

@@GregsAirplanesandAutomobiles which is also great! and necessary to be honest - there is not much of this stuff on youtube and some sources are either hard to come by or just hard to read and explain, yet you do a stellar job with regard to simplifying things when necessary but in a way that does not warp the general idea behind those complex processes.

@@GregsAirplanesandAutomobiles As an old engineer the "mathy vids" get my vote, the power / work conundrum I'm very happy with , on aerodynamics lift and manifold pressures I've still got three thumbs . Which ever way you measure it , your tutelage is worth a dozen Top Gun 2's for us Tomcat junkies. Thank you Greg , and please keep feeding us the gold stuff.

@@GregsAirplanesandAutomobiles a nation can survive foreign enemies but cannot survive treason from within or words to that effect ..Why would the USA(the Australian military /governments destroyed their upgraded F111 fleet) 'governments',military deliberately take out of service essentially its 2 most important air superiority assets ie the Navy F14 and USAF F111s ...thus along with the F35 nonsese handing air superiority over to China,Russia as was always the money power plans ...

Very cool story! Though I wonder if the weak point would be on the airframe, not on the chain.

“The loudest noise I have ever felt” Good description, jet exhaust is sensed by more than just the ears.

​@@TurboHappyCar F-14A's launch with full afterburner, both engines, and they stay til they're released, no chains. The chain would not break, the airframe would not break. No guarantee on padeyes in concrete though. It's probably a bad idea because if one engine just shut down, the sudden lack of thrust or tq from one side on the frame could move the aircraft left or right. Maybe. Realistically it's an unnecessary risk and wasteful to spin both up like that. I'd bet there's similar rules for F-15 turns, as well... unless it's only on the Tomcat because of wider engine spacing. F-15 had less problems with flat spins due to engine failure because the engines were closer together.

I seriously doubt the anchor chains were less strong/durable than the launch holdback bar that held the aircraft back on the catapult on the carrier.

I was wondering about that, I don't believe that was covered in the video. I may have missed it, that was a lot of information.

Thanks Bill.

My Dad flew F-4’s in Nam and Eval after.. After retiring from USN he worked on the Tomcat

29,500 ft. time to climb in 60 seconds. Set altitude record at 98,557 ft. Air Force flew to mach 2 on its first flight. Aerodynamics were surprisingly good owing to its area rule fuselage Maneuverability ok due to things like its vari ramp intakes , leading edge slats etc.

I would love to see a Greg video(s) on the Phantom. 👍

Good luck finding a brick with a glide ratio of 7. That's not worse than most fighters.

Maybe this evaluation of aircraft handling is relative to smaller, lighter, slower and / or earlier types.

I second this, as well as the opposite (how do you figure how much thrust a prop plane has when stopped?). Something I've always wondered and could be interesting to discuss.

Propeller aircraft is measured in SHP via the twist in the torquemeter shaft. How much force it takes to twist a shaft. Thats the way is measured on the c130j, i guess it is the same with the osprey and other propeller aircraft.

@@fsendventd You could chain it down with a big spring scale in the chains (these days you would use a load cell) and crank it up to see the maximum reading you could get on the scale. This would actually be useful information to know for, say, a carrier launch.

For me the loudest was a hovering Harrier with full water injection

@@gavindavies793 I think the F-22 finally beat the Harrier, according to my "ahhhh" scale at the Miramar Air Show. 😂

@@TurboHappyCar well, we could try to beat all by getting my work's museum collection to fire up one of their Walter rockets from the Me163 Komet , but I don't think they'd have enough stof lying around lol

@@gavindavies793 INDEED it blasted up the Turf, thanks for reminding me @ wings over houston

@@gavindavies793 indeed Awesome also. Wings over Houston in OCT was fantastic Pre days of Mr Obamas cuts!

Thanks DZ.

That is correct, speed is a key factor here.

I've heard the same. Would love to see some research into this by Greg The Mighty.

That’s just rumours. The fastest the F-14 ever went was 2.34 Mach in early testing. As for the B model the F110s actually work in a different way to the TF30. To generate more thrust the GE pushes more air. The PW gets hotter. Thus at high altitude the TF30 actually produced more thrust but was less efficient. With the thin air the F110 doesn’t have as much air to push. The F-14D can’t actually make 2.0 because it doesn’t have the extendable glove vanes at all. Without them no F-14 can get past 2.0 Mach. The glove vanes bring the centre of pressure of the jet back within limits at high speed. Otherwise it creeps back and creates a nose down pitching moment. This increases the speed and pushes the centre of pressure further back and the jet enters an unrecoverable dive. All A and B models had the glove vanes welded shut. Sorry to be a party pooper but no Tomcat ever got past 2.34 Mach.

@@dat581 That is exactly why I'd like Greg to dive into it in more detail, pull research documentation and see what the test pilots had to say. It would be interesting to see if the Tomcat with TF-30's could actually overspeed like that. What would be really interesting (I'm just dreaming) is to see a Tomcat with technology the SR-71's engines used to make it mach 3+. Who knows how it works handle high AoA, though. Would love to see a huge thrust F-14 with a big AESA radar, stealth considerations, potential mach 3+, yadda yadda. One can dream....

@@speedycpu The F-14 is never going to stay above 2.3 for long without melting. The TF-30s have been proven to 2.5 in the F-111 and they are essentially the same engine with different nozzles. The F-111, which is a slicker airframe than the F-14, would only get to 2.5 when clean and with the engines in very good condition. A timer starts above 2.0 and the jet has a limited time before it melts. The F-14 is made from similar materials. As for the SR-71 engines that would be pointless for several reasons. The primary reason is the F-14 rarely got above 1.4 in service. It was actually limited to 2.0 by the Navy. The ramjet is also not suitable for a fighter at all. Most people would be surprised how much of a dog the SR-71 was until it got up to cruising speed. Most fighters could easily out accelerate it. People love to quote the top speeds of jets but they are actually one of the more irrelevant statistics in service. The F-35 is limited to 1.6 Mach because that’s what the USAF wanted. The jet has the aerodynamics and thrust to easily make 2.0 but it would need new intakes. The reality of fighters is quite a bit different to how they are portrayed as you can tell from Greg’s videos!

@@dat581 I read the SR climbed out at 400+ so thats impressive . Thats not the first time I've heard of F14 glove vanes shifting lift . A poster on a vlog who sounded legit'ish (said he was a military pilot or something) stated the F35 WITH STORES under the wings will out accelerate a clean F16 when ask about F35 performance . Now it there is any truth to that Fat Amy is maybe not so fat . I know it has the most powerful engine but a clean viper is a rocket .

Think the c.a.d.c was made by garret airesearch, en.wikipedia.org/wiki/Central_Air_Data_Computer

@@exup18 70s and instruction pipeline? Ahead of it's time I would say.

Once I sat in a cube next to a guy who wrote some of the F-14 code. He had worked on other planes too. He said that the F-14 was the most carefully engineered of them all.

We need an ex RAF Greg for that

@@guyk2260 Astounding aircraft. Magnificent!

Thanks Enigma. I feel quite lucky.

That's nice to hear. Thanks.

That would be an interesting video. However if I make another video featuring the Tomcat I'm going to start with something related to the propulsion or electrical systems.

@@GregsAirplanesandAutomobiles good idea, i read somewhere that some of the first microprocessors in the world were used in the Tomcat.

lol, that won't be happening!

AgentJayZ's channel is quite good.

If you have any interest in machining and the like you might also take a look at 'Rotary SMP'. He is an aircraft mechanic by trade, and always manages to spend a couple of minutes on some aside that is aircraft engine related in his videos. The most recent one spent a couple minutes showing the attachment methods for an airliner jet engine.

I hope you like it. It's quite mathy. I even had to do a tiny bit of trigonometry.

@@GregsAirplanesandAutomobiles haha I can always guarantee when you make a disclaimer regarding the technicality of a video, it's going to be a good one!

I am too, I'm playing it a fair amount these days.

@Kirk Wolfe what I mean is that the power of a piston engine is directly related to the torque and rpm of the engine itself, but the power of a jet is related to the thrust of the engine but the speed of the whole vehicle, not the rpm of the turbine.

There is velocity of the mass-flow of the jet exhaust which can be used to determine power, even when stationary.

@@andrewdynes5300 I am not arguing that there is no way to measure power from the jet engine itself. I am saying that it is confusing to people because of the way power is defined and measured in IC vs jets. Piston engines appear to have intrinsic power because of the way bhp is defined and measured, so people assume jets do as well. But as we see in the video, it's all about how you define power.

Hi Raptor. In the second paragraph of the description, I make it clear that this video is intended to convey certain concepts using the F-14 as an example and not really an F-14 video. Of course I also answer the question posed in the thumbnail inside of the 30 second mark, so I think I'm good there. Great point about the Saab. The Cessna 208 is indeed great at holding that speed until the last moment, it's a wonderful airplane.

Get too close for missiles and switch to guns.

I'm glad you noticed that, I put it in there for a reason.

He was a RIO, not a pilot, but that doesn‘t in any way detract from his superb channel. It’s a must for anyone interested in the F-14 or naval aviation.

F-86 > Mig 15 Because; All-flying stabilizer. The Russians obviously read NACAs research reports from the early 1940s on streamlined bodies with internal flow. Because they ended up making a nearly identical aircraft to the Saber, while they obviously missed several key advances that were unpublished and kept top secret between the reports they had access to and the launch of the F-86.

@@TheJustinJ Even with the flying tail, the MiG still had an edge in maneuverability. It also had a higher ceiling and climb rate allowing it to pick its fights. The two aircraft were almost a match speed wise, though the F86 was slightly faster. The F-86 had a much weaker gun package (the USAF was still fixated on the.50 cal). However though the 23mm/37mm cannon mix on the MiG gave dispersion issues, any hit on a Sabre was bad news (some 20mm cannon armed Sabres were tested in Korea with very good results). What really gave the Sabre an edge, was the radar assisted gun sight (which the Soviets quickly copied from downed Sabres).

Hi Admiral, great tip about the NVidia card. I may do that and start including DCS footage in my videos. I will get the Jug and probably the Mossie. Right now my time is taken up with the three modules I have. I love all three.

Thanks Finlay.

Thanks for visiting my channel. I'll do exactly that. I have never talked about turbo fans in detail and a lot of people are asking for that. I do have some videos about jets, and of course a lot about piston engines.

The rocket in the tail was to meet FAA engine out climb requirements. The engine didn't have auto-feather, it had something called NTS which was close but not really an auto-feather. The funny thing is, when the rockets became non maintainable due to a lack of parts, the FAA all of the sudden said they weren't needed anymore. Not only that, now you could carry more weight WITHOUT the rocket because they added the weight of the removed rocket to the payload.

@@GregsAirplanesandAutomobiles Thanks for that info. Dad never used it so he couldn't really describe what the experience was like. Typical FAA. "Now you can carry more payload since we removed the safety system." I knew quite a few great guys who worked for the FAA in the 1980s. Including the one who approved the Phoenix Air Race where an off field crash in a Super Corsair(?) on GM testing track property caused him some grief. Bureaucracies like the FAA, ATF, FBI, CIA, DEA, DHS, ad Nauseum just bloat and degrade from inertia and entropy over time.

You're exactly right, they rot from within, sometimes due to "regulatory capture" (an actual term in economics) which is exactly what's happened to the FAA, at least in my opinion.

Yes, the person with the wrench may be able to apply just as much torque as the engine, but will not be able to apply that much torque AND spin the wheel at high RPM.

I think also the reason why jet can accelerate a flying object past this compresssibilty barrier is that the trust it creates is made of very high velocity air mass compared to propeller. The impact of say 300 kts of airstream created by forward speed compared to the exhaust air speed of the jet engine is far less than the same speed with a propeller aircraft. BTW propeller is kind of the same as a jet if you think about creating trust by way of accelerating an air mass (be it behind a propeller or a trust tube) Also this is why modern airliners cannot fly as fast as early jet airliners, because modern airliners jet engines became more and more like propeller engines (fan up-front) and less jet engines (simple core jet) and their exhaust velocity is thus far less. They are optimized for the speed they operate at.

Agreed-the main issue with the TF30 powered F-14A was not necessarily its thrust to weight ratio but rather the engines poor stall margin. Most pilots that flew the F-14A felt that given its fuselage and wing design that the TF30 provided adequate thrust. The reliability of the TF30 in air combat maneuvering though was another matter. Despite the increase in thrust that the F-110 engines offered in the F-14B & D variants. The F-14A with the TF30’s could still out perform them in certain high speed regimes of the flight envelope. There was a phenomenon called a “ram effect” that benefited the TF30 in that scenario. I would love to hear an informed explanation regarding this.

Thanks Brain, and Merry Christmas to you and yours.

lol, I suppose it does!

@@GregsAirplanesandAutomobiles Thanks 😊

When F-14 stays with full afterburner at brakes it does contribute to the total propulsive power of the aircraft carrier. However, it is not much as the speed of the carrier is slow. From the physics point of view, it is the same as connecting directly jet engines to the ship. As soon as it is released, thrust works only on the plane, and no more boost for the carrier is provided :) I did some math and assumed F-14 static thrust equals 186kN (2*93kN) and the power of the Nimitz aircraft carrier is 194MW (acc. to wiki), then at 30knots F-14 contributes only ~1,5% of the total propulsive power of the ship. The thrust created by the four screw propellers of the Nimitz is absurdly 12600kN. A lot of simplification is taken like 100% screw efficiency, but it gives some comparison. BTW: working with metric units makes this analysis significantly easier as you do not need to remember any static factors like 325 or whatever. Power [W] = force [N] * speed [m/s]

The Royal Navy used propeller driven fighters to manoeuvre aircraft carriers in Valetta, Malta. So, not going forward but docking.

@@davewolfy2906 Cool