F-14 low speed prowess vs Other Aircraft

[Cobra847]

Alternatively you can attempt snap rolling to bump your instantaneous roll rate by quite a margin, you need to be careful not to depart the plane or cause asymmetrical airflow in the engines by inducing too strong lateral inputs (i'm talking about the TF30 powered Tomcat here, i have never read if the F100 powered Eagles had issues with large side slip at high alpha).

 

Or stalling the engine(s) by rapid throttle movements.

Tricky endeavor.

[captain_dalan]

Or stalling the engine(s) by rapid throttle movements.

Tricky endeavor.

Yep, some aviators claim they would just plug the throttles at full military power or afterburner and leave it there during hard maneuvering. One manual i've read says the compressor stall probability rises exponentially as the throttle nears the idle setting, but is at minimum near the full mil. power and above.

Edited March 13, 2015 by captain_dalan

[BlackLion213]

First of all excellent post Nick. I was wondering if you like to explain a lite bit more on how the F-15 can offset the flat scissors maneuver because of the roll rate. I know the F-15 has superior roll rate, but I didn't know that the F-14's roll rate was so bad that it would actually mater. On the Air show demos that are uploaded on net, when both planes do a 180° roll in turns i can't seem to notice more than a second difference in F-15's favor. :)

 

Sure, roll was always one of the primary weak points of the Tomcat (I like to call it a "lesser strength ;) ). There are two parts to it: firstly the max rate of roll is a bit slower than most modern fighters; secondly initiating and ending roll is slower and less precise than most fighters as well. Especially with the risks of excessive yaw (with the TF30 mostly), many pilots will take a (Very) brief pause to stabilize the roll before initiating pitch. After a few reversals, especially against something with really good roll and digital flight controls (think F-16), the difference is noticeable.

 

It also took the OpEval team a while to sort it out the Tomcats roll in general. The very first (pre-production) Tomcats had A LOT of trouble with roll. Sometimes at lower speeds, the aircraft could not complete a full 360 deg before roll rate would peter out. Not sure why it was an issue, but this book discusses it a bit:

http://navyreservewebsite.blogspot.com/2012/03/roger-ball-odyssey-of-john-monroe-smith.html

(It's a great read for many reasons!)

 

It might have been an issue of masking the control surfaces as Alpha increased and the tendency towards adverse yaw (nose moving away from centerline in the opposite direction of the roll - watch "Cougars" carrier approach from Top Gun for a visual). The nose might have countered the forces applied by the control surfaces.

 

In any case, this got better on fleet aircraft, but many fleet pilots disengaged roll SAS to speed up the roll rate during combat. When VX-4 tested the Tomcat against the MiG-17 and MiG-21 (Op: Constant Peg aircraft), they found the Tomcat handily out-turned the MiG-21, but during flat scissors the MiG-21's rapid roll rate offset some of the benefit. This would prove to be true against many fighters. The difference doesn't look huge, but there is an additive effect after multiple reversals. It's much better during rolling scissors because the Tomcat can use it's tremendous pitch rate in combination to swing the nose into position.

 

What a Tomcat wants most is a one-circle flight at low altitude against something that either has an AOA limiter or lesser AOA performance, then it can run it down! More pitch, less roll.

 

Again, these things matter a bit, but the ability to keep a visual on the enemy and anticipate your opponents move matters most. During Desert Storm an EF-111 managed to fly a Mirage F.1 into the ground, I think that says it all.

 

-Nick

[GGTharos]

There was an eagle hounding that mirage.

[BlackLion213]

Yep, some aviators claim they would just plug the throttles at full military power or afterburner and leave it there during hard maneuvering. One manual i've read says the compressor stall probability rises exponentially as the throttle nears the idle setting, but is at minimum near the full mil. power and above.

 

Yes, I've heard the same. Low revs are not your friend with the TF30.

 

The uncoupled low-pressure compressor (which has a large diameter and heavy fan blades) will lag behind the rest of the engine during acceleration and deceleration of the other compressors. If it lags behind too much, it will functionally block airflow and starve the rest of the engine (like Asthma). First, the thrust drops, then the turbine inlet temperatures spike because the air-fuel ratios are all screwed up (too much fuel, too little air). This can lead to flame out or fire.

 

This is part of the reason the TF30 also has really slow throttle response, the center of the engine is trying to indirectly accelerate that big, heavy low-pressure compressor.

 

The solution is to advance or retard the engine slowly so the first low-pressure compressor can keep up. If you slam forward the throttles at low RPM, the high-pressure compressor and turbine rapidly accelerate (with the 2nd stage low-pressure compressor-turbine) and the heavy 1st stage low-pressure falls way behind. Airflow is blocked and badness follows.

 

The stall margins is also built into this mess. Most engines need to strain a bit during side-slip or high alpha as they force air to "bend the corner" into the intakes. But with the TF30, the coupled part of the engine has to draw extra hard - both forcing air through the uncoupled low-pressure compressor and into the intakes. Sometimes it's too much work for the coupled engine and out she goes...

 

That said, the design is very fuel efficient and is greatly helped by dense air. At low altitudes and high-speeds, the engine makes impressive power. Hence it worked pretty well in the F-111 that either cruises, flies fast, or flies low (or both). But in the end, it proved to be a terrible engine-airframe combo for the Tomcat.

 

However, the TF30 does make simulation flight very interesting/entertaining...

 

Hope this isn't too long.

 

-Nick

Edited July 3, 2015 by BlackLion213

[BlackLion213]

There was an eagle hounding that mirage.

 

EF-111 crew still won an air medal and credited with a kill.

 

-Nick

[GGTharos]

Yes, they did a very good job, and in the end, IIRC they got half the kill and the eagle driver got the other half.

[turkeydriver]

Yes, they did a very good job, and in the end, IIRC they got half the kill and the eagle driver got the other half.

 

thanks for the info!

Edited March 14, 2015 by turkeydriver

[GGTharos]

Yes it did. An eagle had locked onto that mirage and is hard to tell whether the pilot was trying to evade the eagle's radar, or if he was target fixated, or distracted by both. Thus both crews for half a kill.

[BlackLion213]

Yes it did. An eagle had locked onto that mirage and is hard to tell whether the pilot was trying to evade the eagle's radar, or if he was target fixated, or distracted by both. Thus both crews for half a kill.

 

Thank you for the back story this makes sense.

 

You' hope that EF-111 wasn't out totally on it's own!

 

-Nick

[turkeydriver]

Yes it did. An eagle had locked onto that mirage and is hard to tell whether the pilot was trying to evade the eagle's radar, or if he was target fixated, or distracted by both. Thus both crews for half a kill.

 

Thank you for insight.

[Hummingbird]

Min radius sites not preclude MAX G. Air show rules do.

 

A min radius turn is not carried out at the aircraft's max g limit, it is carried out flying at and maintaining the aircraft's optimum corner speed, and here the F-14 is noticably superior to the F-15. (At low altitudes at least)

 

In terms of max g and instantanous turns, well obviously the F-15 is better with its' 9 G rating. (Although I've been told that the F-14 was capable of withstanding 9 G easy)

[dekiplav]

A min radius turn is not carried out at the aircraft's max g limit, it is carried out flying at and maintaining the aircraft's optimum corner speed, and here the F-14 is noticably superior to the F-15. (At low altitudes at least)

 

In terms of max g and instantanous turns, well obviously the F-15 is better with its' 9 G rating. (Although I've been told that the F-14 was capable of withstanding 9 G easy)

 

I think that F-14 is beater than F-15 and F-16 in instantaneous turns at any altitude.:smartass:

[Hummingbird]

I think that F-14 is beater than F-15 and F-16 in instantaneous turns at any altitude.:smartass:

 

If there were no limit load factors, yes :) However every aircraft has a limit load factor (safe G rating) that it shouldn't exceed, and this was officially lower for the F-14.

[dekiplav]

Sure, roll was always one of the primary weak points of the Tomcat (I like to call it a "lesser strength ). There are two parts to it: firstly the max rate of roll is a bit slower than most modern fighters; secondly initiating and ending roll is slower and less precise than most fighters as well. Especially with the risks of excessive yaw (with the TF30 mostly), many pilots will take a (Very) brief pause to stabilize the roll before initiating pitch. After a few reversals, especially against something with really good roll and digital flight controls (think F-16), the difference is noticeable.

 

It also took the OpEval team a while to sort it out the Tomcats roll in general. The very first (pre-production) Tomcats had A LOT of trouble with roll. Sometimes at lower speeds, the aircraft could not complete a full 360 deg before roll rate would peter out. Not sure why it was an issue, but this book discusses it a bit:

http://navyreservewebsite.blogspot.com/2012/03/roger-ball-odyssey-of-john-monroe-smith.html

(It's a great read for many reasons!)

 

It might have been an issue of masking the control surfaces as Alpha increased and the tendency towards adverse yaw (nose moving away from centerline in the opposite direction of the roll - watch "Cougars" carrier approach from Top Gun for a visual). The nose might have countered the forces applied by the control surfaces.

 

In any case, this got better on fleet aircraft, but many fleet pilots disengaged roll SAS to speed up the roll rate during combat. When VX-4 tested the Tomcat against the MiG-17 and MiG-21 (Op: Constant Peg aircraft), they found the Tomcat handily out-turned the MiG-21, but during flat scissors the MiG-21's rapid roll rate offset some of the benefit. This would prove to be true against many fighters. The difference doesn't look huge, but there is an additive effect after multiple reversals. It's much better during rolling scissors because the Tomcat can use it's tremendous pitch rate in combination to swing the nose into position.

 

What a Tomcat wants most is a one-circle flight at low altitude against something that either has an AOA limiter or lesser AOA performance, then it can run it down! More pitch, less roll.

 

Again, these things matter a bit, but the ability to keep a visual on the enemy and anticipate your opponents move matters most. During Desert Storm an EF-111 managed to fly a Mirage F.1 into the ground, I think that says it all.

 

-Nick

 

 

Thanks! :thumbup:

Edited March 14, 2015 by dekiplav

[Basher54321]

A min radius turn is not carried out at the aircraft's max g limit, it is carried out flying at and maintaining the aircraft's optimum corner speed, and here the F-14 is noticably superior to the F-15. (At low altitudes at least)

 

In terms of max g and instantanous turns, well obviously the F-15 is better with its' 9 G rating. (Although I've been told that the F-14 was capable of withstanding 9 G easy)

 

 

Below a certain speed neither will be hitting 9G - and AOA can become the limiting factor regarding nose rate and GOR. However over that certain speed it will likely be G limited.

 

Like a lot of older jets without G limiters there is a chance it will see higher G over the limits - (examples of Mirage IIIs pulling 12 Gs etc in desperate situations) but likely major air-frame damage if sustained.

 

So for example if the pilot is going to hit the ground he aint gonna care about writing the jet off!

[Hummingbird]

Below a certain speed neither will be hitting 9G - and AOA can become the limiting factor regarding nose rate and GOR. However over that certain speed it will likely be G limited.

 

Like a lot of older jets without G limiters there is a chance it will see higher G over the limits - (examples of Mirage IIIs pulling 12 Gs etc in desperate situations) but likely major air-frame damage if sustained.

 

So for example if the pilot is going to hit the ground he aint gonna care about writing the jet off!

 

Yes, absolutely.

[turkeydriver]

If there were no limit load factors, yes :) However every aircraft has a limit load factor (safe G rating) that it shouldn't exceed, and this was officially lower for the F-14.

 

An F-14s min radius turn, depending on weight and air density, is typically around 330-360kts. That's a "NATOPs" min radius turn- both engines operating at the same setting, "legal" flaps, etc.

 

This discussion then turns into rate vs radius.....enter Boyd...yadayadayada. At those slow speeds you have entered the Tomcat's world. However, no Tomcat is ever going to follow an F-16's 9g turn and match its rate and radius at the same time. It could fly faster and try a bigger radius with equivalent rate, or a slower speed match the rate with a smaller radius.

 

Note that while the tested F-14s demonstrated +9g/-5g, this didn't give a jet that's going to last for 6000 hours. It caused a LOT of excess maintenance. The wing sweep programming(mach sweep programmer) was changed from the first jets, where it was scheduled for maximum lift and caused too much bend in the wings, to maximum Ps. So your F-14, though underpowered in the A variant and not able to rebuild energy as quickly as an F-15, does sustain energy very well as long as the fight doesn't involve a lot of vertical at heavy weights.

[GGTharos]

I just did a min radius turn in the fc3 f-15c in about 15sec. Of course technique may have been a bit different.

[Hummingbird]

I just did a min radius turn in the fc3 f-15c in about 15sec. Of course technique may have been a bit different.

 

Game < Reality

[GGTharos]

It's quite well modeled, so you shouldn't hold much hope of being able to use that excuse - besides, are you claiming it isn't modeled as well as an F-14 would be? It's also not at all surprising, about an average for most modern fighters.

 

To be more clear, the F-15C PFM has been checked against a LOT of RL data. The min radius turn isn't exactly edge of the envelope stuff, so it's not a good candidate for naysaying at this level of flight model.

Edited March 14, 2015 by GGTharos

[Hummingbird]

The story of a legendary F-14 pilot and the gun kill on an F-15 that could sell Tomcat to Japan

 

By Dario Leone

 

Aug 18 2014

 

 

Known and unknown stories of a legendary F-8 Crusader and F-14 Tomcat pilot

 

Look at the picture above.

 

It’s a 8” x 10” frame of a 16 mm gun film shot which shows an F-15 Eagle locked through an F-14 Tomcat Head Up Display, at 250 feet, with piper on the Eagle’s pilot, gun selected, master arm on.

 

Even if the photo itself is already very interesting, the story behind it, is by far more fascinating. In fact the naval aviator at the controls of the Tomcat was a real legend in aviation history.

 

As explained by Alvin Townley in his book Fly Navy, maybe other pilots have scored more kills, held higher ranks or more prestigious commands, but few living aviators embody the untamed nature of aviation like the one of a kind legend known to decades of F-8 Crusader and F-14 Tomcat pilots: Joe “Hoser” Satrapa.

 

Skilled rifleman since young, Joe joined the Navy with the aim to fly a jet fighter to continue his interest in guns, an interest that guided him after the flight school graduation, in 1966, when he was called to opt for the F-4 Phantom or the F-8 Crusader. The Phantom had no guns and Satrapa thought: “No guns? What kind of aircraft is this with no guns?” and he immediately chose the “Last Of The Gunfighters” as the Crusader was dubbed by it aircrews.

 

But the “Satrapa legend” began the day he gained his call sign, Hoser (but he is also known as “Da-Hose” or “D-hose”), during a mission at the gunnery range in which he was flying in the tail position in a flight of four Crusaders. He cut off the preceding aircraft as they approached the target and started shooting from two thousand feet up, one and a half miles out hosing off all his bullets in one pass. After having seen it, his flight leader J.P. O’ Neill told him to return to the airfield at El Centro and the same night O’ Neill had the final say on the incident when he nailed Satrapa: “Lieutenant junior grade Satrapa, for hosing off all his bullets in one pass, will hence forth be known as Hoser. That’ ll be five bucks.”

 

Hoser became famous also during the Vietnam War as a fearless F-8 pilot who regularly carried a good forty pounds of lethal ordnance, leaning toward small automatic weapons and hand grenades, in case he was suddenly compelled to leave his aircraft and face an entire platoon of North Vietnamese Army regulars.

 

His interest for guns continued when he transitioned to the F-14 Tomcat. But as explained by George Hall in his book Top Gun – The Navy’ s Fighter Weapons School, Hoser knew also some things about the element of surprise.

 

During the AIMVAL/ACEVAL (the Air Combat Evaluation/Air Intercept Missile Evaluation) fighter trials that put the F-14s and the F-15s against the F-5Es to test new weapons and tactics which took place from 1974 to 1978 at Nellis Air Force Base, Hoser (assigned to the VX-4 evaluators) was put in a 1 V 1 against an F-5.

 

As the two combatants sat side-by-side on the Nellis runway, awaiting tower clearance for takeoff, Hoser looked over at his opponent, reached his hand up over the control panel, and mimicked the cocking of machine guns in a World War I Spad. A thumbs up came from the other cockpit, meaning that guns it would be, the proverbial knife fight in a phone booth, forget the missiles.

 

Both jets took off.

 

As soon as they reached the assigned area, the fighters set up twenty miles apart for a head-on intercept under ground control. Seven miles from the merge, with closure well over 1,000 knots, Hoser called “Fox One”, a Sparrow missile away, scoring a direct hit.

 

As they flashed past each other, the furious F-5 driver radioed, “What the hell was that all about?” “Sorry.” said Hoser, “lost my head. Let’s set up again. Guns only, I promise.”

 

Again the two fighters streaked towards the pass, again at seven miles Hoser called “Fox One.” The F-5 driver was apoplectic.

 

Hoser was first back to the club bar, nursing an end of the day cold one as the flushed Aggressor stomped in. “Hoser, what the hell happened to credibility?” asked the F-5 pilot. Hoser replied “Credibility is DOWN, kill ratio is UP!”

 

This story became very popular around Topgun, but even more important is the lesson learned that came from it: from 1 V 1 to forty-plane furball, expect anything. But never expect your enemy to be a sweet guy.

 

Still, Hoser’s best experience during the AIMVAL/ACEVAL most probably came after the end of the trials. Even if Tomcat and Eagle drivers could not engage each other, Hoser and his RIO Bill “Hill Billy” Hill with Dan “Turk” Pentecost and Frank “Fearless” Schumacher onboard the second F-14, went 2 V 2 against a couple of F-15 instructors from 415th Training Squadron (415th Flight Test Flight).

 

As told by Hoser to airwarriors.com “All pre-merge heat and radar missiles didn’t count. It was GUNS only at the merge.”The two Tomcat split the fight into two 1 V 1 with one F-14 high and the other low with fair lateral separation. Once Hoser and Hill Billy closed for a 250ft, gun kill on their Eagle, a minimal communication over the radio took place as Hoser recalls. Hoser: “Where are you Turk?”Fearless:”Right above you Hoser” Hoser: “We got two cons! Who’s out front? “Turk (mildly offended): “Who do ya think?”

 

Both Eagles were gunned, “knock it off” was called, and the Tomcats RTB’d with a 500 knot, 6.5g, half second break at Nellis.”

 

But there was something more, as explained by Satrapa:

 

“Knowing the gun camera film would be destroyed by the Nellis Photo lab, it was covertly sent to a secret contact at Grumman for processing. Bout a month later, December 6, the door slams open and General Knight, with 2 of his staff, doggie wobble heads entered demanding to know “who and where are Hoser and Turk?” Falcon (J.W. Taylor), OinC (who was the Officer in Charge) stepped up asking if he could be of assistance. The General responded with, “Your fighter jocks have no idea how their playful antics affect important political decisions!”

 

Well, as General Knight proceeded to explain, Japan had contracted for twenty one F-15s, but an article in Aviation Week had talked about the F-14 being superior to the Eagle. With gun camera film to prove it, Japan was considering buying F-14s instead.”

 

The General wanted and received all copies of the gun camera film, the TVSU/VCR (the Television Sensor Unit and the Voice Cockpit Recorder) and audio recordings on his desk the following day, but few months later Hoser asked to Falcon: “Hey Falcon, I know ya got a copy of that 16mm gun film…. how bout it?” JW returned few moments later with a copy of the film from which the original Tomcat gun camera image you can see in this article comes.

 

 

SOURCE:The Aviationist » The story of a legendary F-14 pilot and the gun kill on an F-15 that could sell Tomcat to Japan

[Hummingbird]

It's quite well modeled, so you shouldn't hold much hope of being able to use that excuse - besides, are you claiming it isn't modeled as well as an F-14 would be? It's also not at all surprising, about an average for most modern fighters.

 

To be more clear, the F-15C PFM has been checked against a LOT of RL data. The min radius turn isn't exactly edge of the envelope stuff, so it's not a good candidate for naysaying at this level of flight model.

 

Are you saying that the ingame flight model is like reality?

[pyromaniac4002]

Are you saying that the ingame flight model is like reality?

 

That is the objective.. It's not 100% but in the heart of the flight envelope, like with a minimum radius turn, you can consider it a pretty damn reliable representation of the real deal. At the edges is where it's much more difficult.

[Hummingbird]

That is the objective.. It's not 100% but in the heart of the flight envelope, like with a minimum radius turn, you can consider it a pretty damn reliable representation of the real deal. At the edges is where it's much more difficult.

 

Pretty certain that the F-15 can't complete a min radius turn in 15 secs ;)

 

The nimblest of WW2 fighters, the A6M2 Zero took 16.5 sec to complete one.