Rudder to Break F-14 Intertia: Myth or Real?

[Horns]

I picked up the idea from somewhere (no idea where now) that the F-14 turns more effectively when adding a bit of rudder (in the direction of the turn) before starting to roll as opposed to using roll alone, and I believe the reason was that it was to do with combatting the Tomcat's high moment of intertia. I would like some opinions on whether this is correct and, if so, why it is effective. I believe the F-14's initial yaw rate is relatively good whereas its initial roll rate is fairly pedestrian, but how that factors in (if at all) I don't know. Maybe it's just to do with getting additional control surfaces involved to offset the lack of ailerons? No idea. All input welcome.

[speed-of-heat]

well co-ordinated rudder turns are a thing ... 

[zildac]

well co-ordinated rudder turns are a thing ... 

Indeed, they're called "coordinated turns" for a reason.

[average_pilot]

The natural reaction of an aircraft when starting a roll is to yaw in the opposite direction introducing some lag, so that preemptive compensation with the rudders helps reducing that. My instructor used to tell me to do that little bit of rudder before rolling. I think I didn't remember to do it not even once.

[Hiob]

It depends on the AoA, the higher the AoA the more rudder is needed instead (!) of ailereon to roll. In the tomcat this goes up to 100% rudder at very high AoAs.

This behavior is very emphasized in the Tomcat but not exclusive to her. 

I believe it is more a function of aerodynamics and has nothing to do with inertia - but I can't back that up with data.

Edited March 28 by Hiob

[average_pilot]

Yes, AFAIK is an aerodynamic effect. One wing is generating more lift that the other to induce the roll but also the one generating more lift becomes more draggy.

EDIT: A proper and more complete explanation in "See how it flies"

Edited March 28 by average_pilot

[Nealius]

Rudder coordination is nuanced. It's more important in props, gliders, and helos. In jets it's only a thing at higher AoA. Per T-38/F-5/T-45/AV-8B pilots I've talked with "stepping on the ball isn't a thing in jets," and those specific jets are just as analog as the Tomcat.

Unless at high AoA in the Tomcat I see no adverse/proverse yaw, and am able to fly smoothly, precisely, and coordinated without rudder usage by "flying the cross." In other words, not blending pitch and roll inputs. Trying to coordinate it as I would a warbird gives me worse results than simply leaving my feet on the floor.

A lot of people see "Tomcat needs rudder at high AoA" and completely ingore the qualifying statement of "at high AoA," and parrot a one-size-fits-all rule that doesn't actually fit all sizes. It doesn't help that the aircraft in question has a lot of lore and a kind of mysticism around it that makes it seem artificially special compared to other aircraft when--in this specific case--it isn't.  

Edited March 28 by Nealius

[average_pilot]

I think the OP is asking about using a bit of rudder right before even starting the roll to help initiating it, not turn coordination.

[Nealius]

2 minutes ago, average_pilot said:

using a bit of rudder right before even starting the roll to help initiating it

Used to think that way, but really noticed no difference in the end. I don't find the roll rate to be "pedestrian" as OP mentions, though.

[speed-of-heat]

OP are you turning off Roll SAS

[Horns]

10 hours ago, speed-of-heat said:

OP are you turning off Roll SAS

No, all systems on normal settings, nothing exotic.

[Horns]

11 hours ago, average_pilot said:

I think the OP is asking about using a bit of rudder right before even starting the roll to help initiating it, not turn coordination.

That’s what I was talking about, although it was good to be reminded about coordinated turns too.

12 hours ago, Hiob said:

It depends on the AoA, the higher the AoA the more rudder is needed instead (!) of ailereon to roll. In the tomcat this goes up to 100% rudder at very high AoAs.

This behavior is very emphasized in the Tomcat but not exclusive to her. 

I believe it is more a function of aerodynamics and has nothing to do with inertia - but I can't back that up with data.

 

Thanks for clarifying that this isn’t related to inertia, that was one of my main questions.

12 hours ago, average_pilot said:

Yes, AFAIK is an aerodynamic effect. One wing is generating more lift that the other to induce the roll but also the one generating more lift becomes more draggy.

EDIT: A proper and more complete explanation in "See how it flies"

 

Cheers for going into this further, the linked info was enlightening too.

11 hours ago, Nealius said:

Rudder coordination is nuanced. It's more important in props, gliders, and helos. In jets it's only a thing at higher AoA. Per T-38/F-5/T-45/AV-8B pilots I've talked with "stepping on the ball isn't a thing in jets," and those specific jets are just as analog as the Tomcat.

Unless at high AoA in the Tomcat I see no adverse/proverse yaw, and am able to fly smoothly, precisely, and coordinated without rudder usage by "flying the cross." In other words, not blending pitch and roll inputs. Trying to coordinate it as I would a warbird gives me worse results than simply leaving my feet on the floor.

A lot of people see "Tomcat needs rudder at high AoA" and completely ingore the qualifying statement of "at high AoA," and parrot a one-size-fits-all rule that doesn't actually fit all sizes. It doesn't help that the aircraft in question has a lot of lore and a kind of mysticism around it that makes it seem artificially special compared to other aircraft when--in this specific case--it isn't.  

 

Thanks for adding this. I was asking about this in part because my feet and legs aren’t good, so I wanted to check if I was mistaken about the value of using the rudder pedals (I don’t like twist sticks). While I’m now convinced that there is benefit to adding rudder (albeit not for the reasons I thought), it’s also good to know if it gets uncomfortable during a mission I might be able to eschew it without massive consequences.

Cheers for the responses everyone, they are all appreciated.

[speed-of-heat]

55 minutes ago, Horns said:

No, all systems on normal settings, nothing exotic.

One of the fence in checks for the tomcat is to turn roll sas off, for ACM, if the roll rate feels slow that might be why...

[Nealius]

Is roll SAS supposed to alter the roll rate? I can't tell a difference between on or off. 

[Spurts]

3 hours ago, speed-of-heat said:

One of the fence in checks for the tomcat is to turn roll sas off, for ACM, if the roll rate feels slow that might be why...

What does that actually do, I have yet to feel like it's needed.

[speed-of-heat]

I turns off the stability augmentation system for the roll, which moderates the stick input, making you able to roll faster, but also more likely to stall/depart as a result

[Horns]

8 hours ago, speed-of-heat said:

One of the fence in checks for the tomcat is to turn roll sas off, for ACM, if the roll rate feels slow that might be why...

 

16 minutes ago, speed-of-heat said:

I turns off the stability augmentation system for the roll, which moderates the stick input, making you able to roll faster, but also more likely to stall/depart as a result

Good to know, I'll try that, cheers!

[Lurker]

10 hours ago, Horns said:

 

Thanks for adding this. I was asking about this in part because my feet and legs aren’t good, so I wanted to check if I was mistaken about the value of using the rudder pedals (I don’t like twist sticks). While I’m now convinced that there is benefit to adding rudder (albeit not for the reasons I thought), it’s also good to know if it gets uncomfortable during a mission I might be able to eschew it without massive consequences.

Cheers for the responses everyone, they are all appreciated.

The Tomcat is a very Stick+Rudder jet. You can get away with flying it without rudder input as long as you are slow and deliberate, but as soon as you get into any kind of high G maneuvering (basically any kind of combat maneuvering) requiring both ROLL+TURN you will need a lot of rudder input to keep the jet stable without departing. When it was first released, suddenly there were a lot of virtual air jockeys who were used to fly by wire jets who couldn't wrap their heads around how to fly the tomcat without putting it into a spin as soon as they hit any kind of high AoA maneuvering. 

It's very challenging to fly properly compared to FBW jets, but also a lot more rewarding. It's definitely my favorite fixed wing aircraft in DCS by a long mile. 

Edited March 29 by Lurker

[Horns]

2 hours ago, Lurker said:

The Tomcat is a very Stick+Rudder jet. You can get away with flying it without rudder input as long as you are slow and deliberate, but as soon as you get into any kind of high G maneuvering (basically any kind of combat maneuvering) requiring both ROLL+TURN you will need a lot of rudder input to keep the jet stable without departing. When it was first released, suddenly there were a lot of virtual air jockeys who were used to fly by wire jets who couldn't wrap their heads around how to fly the tomcat without putting it into a spin as soon as they hit any kind of high AoA maneuvering. 

It's very challenging to fly properly compared to FBW jets, but also a lot more rewarding. It's definitely my favorite fixed wing aircraft in DCS by a long mile. 

 

Roger that. Makes sense that you'd need the extra authority in ACM or anything precise. If I'm going to give my feet a break I'll do that when speed of maneuver isn't an issue.

One of the things that appeal to me about the F-14 above other jets is that it's up to the pilot to stay within the flight envelope. Somehow FBW feels like a padded cell to me.

[Spurts]

4 hours ago, Lurker said:

When it was first released, suddenly there were a lot of virtual air jockeys who were used to fly by wire jets who couldn't wrap their heads around how to fly the tomcat without putting it into a spin as soon as they hit any kind of high AoA maneuvering. 

 

This was definitely me on release.  The funny thing is that now one of my favorite things to do in BFM is troll Hornet by flying slow at high AoA and doing it better than them.  I got comfortable with the Rudders, then comfortable with cross control stalls, then comfortable with safe use of the big flaps.  The Tomcat gives a pilot a lot of options.

[Jayhawk1971]

The only time I ever involuntarily departed the Tomcat was when I practiced using crossed controls (to increase the roll rate while at high AOA). Otherwise, I find the Tomcat handles very nicely in DCS. Even the A. Just don't yank the stick like a maniac, and it'll be fine.  

Anyone who wants to get into the Tomcat (and hopefully soon, the Phantom) after only ever playing in FBW jets (Viper, Hornet), my advice would be to "take a detour" via Warbirds or early jets (F-86). 

[Nealius]

I've actively TRIED to get into a spin and still not managed to get her to go into one. It baffles me how people are getting into spins.

[Panny]

On 3/30/2024 at 1:34 AM, Nealius said:

I've actively TRIED to get into a spin and still not managed to get her to go into one. It baffles me how people are getting into spins.

a good set up to do it:

Start at 20k ft MSL at 300IAS. Snap the stick left/right. At 90° roll violently add full aft stick in addition to your roll. Hold the stick full aft left/right until the plane enters a spin. 

[FR4GGL3]

Or sit the Tomcat on her Tail and climb straight up until you stall (not only going slow, really stand still or even fall down a bit). Then do what you shouldn't do: do a combined Input of Lateral and Rudder in the same direction. It will most likely fall into a flat spin.

 

/edit: have tried it several times. The Method that @Panny described works 100% everytime and is way better. You just need to hold the stick even if all your senses tell you to let it go.

If you want to force it with the straight climb into stall, you will need to do cross inputs on Lateral and Rudder.

Edited April 2 by FR4GGL3