F-14 landing characteristics on land bases behaviour problem/issue on the current FM.

Or, you are just transferring your wishes upon someone flying at an air show who is putting on a show. It was not SOP to make the Cat bow to a crowd at the end, but it was done at every airshow I saw an F-14 at. Big difference between fleet day-to-day flying and an airshow demonstration flight. Please dude, drop it. You have received your answer and been shown you can do it if you learn to fly. Stop answering every post, I beg you. End of rant//

Just stating an observation and no, not every airshows the Tomcat pilots land like that...nothing wrong with stating an observation.

The thread moderator can lock this thread, then. I'd welcome it.

As you can see, about six inches from dragging the burner cans in that video, which is why it wasn’t done. Big trouble for the pilot if he/she hit the cans and required a dual engine change. Aero braking isn’t as effective as nose on deck, aft stick with spoilers extended and brakes.

F14 had good anti skid. Also, there is no reason to “baby” the landing gear. It’s Grumman for heaven’s sake.

For those who are interested, assuming dry runways, brakes are most effective for stopping a jet. Spoilers dump lift to make the brakes more effective, it isn’t the drag from the spoilers per se.

Also, in general, reverse thrust is less effective than brakes.

As you can see, about six inches from dragging the burner cans in that video, which is why it wasn’t done. Big trouble for the pilot if he/she hit the cans and required a dual engine change. Aero braking isn’t as effective as nose on deck, aft stick with spoilers extended and brakes.

 

F14 had good anti skid. Also, there is no reason to “baby” the landing gear. It’s Grumman for heaven’s sake.

 

For those who are interested, assuming dry runways, brakes are most effective for stopping a jet. Spoilers dump lift to make the brakes more effective, it isn’t the drag from the spoilers per se.

 

Also, in general, reverse thrust is less effective than brakes.

Did the cat have good brakes? As in, did they bite rather well on shore ops? In DCS it seems like I really dont have to use brakes ever, just put her down full aft stick and steer with the stabilators. Comes to a stop rather quickly.

And by the way, do you happen to recall the pitch limit for a tailstrike? +/- the buffer ofc.

Did the cat have good brakes? As in, did they bite rather well on shore ops? In DCS it seems like I really dont have to use brakes ever, just put her down full aft stick and steer with the stabilators. Comes to a stop rather quickly.

 

And by the way, do you happen to recall the pitch limit for a tailstrike? +/- the buffer ofc.

Yes, the brakes coupled with anti-skid were fine. Aft stick as mentioned, was very effective in adding aerodynamic drag. It was very powerful, obviating use of brakes. When you landed ahead of a wingman, you let the aircraft roll accordingly, to give him room as needed.

This could be ticklish when landing ashore with carrier pressure in the tires, which was around 350 psi. You are landing on bricks, and had to be careful with braking under those conditions to avoid locking and flat spotting and blowing a tire in a skid.

NATOPS cautions to not exceed 15 units or 10 degrees pitch during a minimum descent rate landing (required when landing with fuel in the drop tanks for example). On a non- flared landing, the limit was 17 units.

It interesting that the AOA test produces 17 units as the test reference. We heard, unconfirmed, that the initial approach AOA was designed to be 17 units to meet landing speed specifications, but it resulted in poor over the nose visibility and marginal burn can clearance, so it was changed to 15 units early in the test program. Who knows?

The issue with aero-braking was the burner can clearance, and running over arresting gear with the mains exacerbated the issue. Field arresting gear, depending on the type, sometimes had rubber donuts affixed to raise the cable enough for consistent hook engagement. As the main tires ran over the cable, the donuts would compress and bounce back, lifting the cable into the air just in time to damage the burner cans.

Dual engine change, mishap report, pilot in deep kimche...

It is a near-certainty that the ground friction in DCS is too high. My comparison comes from the DCS F-5 and the MILVIZ T-38 in P3D.

The former is laughably finicky to aerobrake in terms of keeping a stable pitch attitude on touchdown and landing roll. There's this sudden bucking forward that coincides with main gear touchdown, so you have to anticipate and compensate for that and probably cause some pilot-induced oscillations in the process.

The latter, you barely have to think about it. You touch down on-speed, the nose stays where it is, and you just gradually bring the stick full aft as the stabilators lose aerodynamic authority.

It is a near-certainty that the ground friction in DCS is too high. My comparison comes from the DCS F-5 and the MILVIZ T-38 in P3D.

 

The former is laughably finicky to aerobrake in terms of keeping a stable pitch attitude on touchdown and landing roll. There's this sudden bucking forward that coincides with main gear touchdown, so you have to anticipate and compensate for that and probably cause some pilot-induced oscillations in the process.

 

The latter, you barely have to think about it. You touch down on-speed, the nose stays where it is, and you just gradually bring the stick full aft as the stabilators lose aerodynamic authority.

Funnily enough the Viper and all the FC3 jets have this modelled correct. Viper friction seems roughly authentic as well.

The fact that you need above 80% rpm to keep the jet rolling also does indicate some exegarrated friction.

The FM developers and testers have already concluded or said that this Friction problem is an ED related issue and at current they nor ED has any plans to rectify it any time soon. So there we have the answer...that maybe some day, hopefully, it can be rectified.

And before others say about the F-14 NATOPS SOP procedure of landing and not do an aerobrake, its clearly stated that it is NOT recommended..but they did not use urgent wording like forbidden, and we STILL see SOME pilots in airshows doing just the opposite and doing those aerobraking at land bases.

The Mig 29 risks a tail-strike coz of its design and cannot do a high AoA aerobraking risking an engine "can"/tailstrike. But some pilots still do it and in tandem release the brake chute. Too much AoA and risk a tailstrike.

I suppose, most Navy carrier pilots don't see the point or use of an Aerobrake and they do land somewhat like they do in the carrier even in land bases. Since carrier based jets have strong landing gears. I guess they dont see the point of much on going easy on the landing gears.

Only some jets so far are easy to aerobrake in DCS and more possible. Some require LOTS of practice, but can be done. The hardest so far is the Mig 21 (need a LOT of practice, can be done). Near impossible is the Hornet with full flaps (maybe the suspension modeled is too soft), but for some reason the W.brake are poor on Hornet and F-16 (Too much AoA on F-16, you risk hitting the extended speedbrakes).

F-14 in DCS is like Mig 21, but needs a LOT of practice, you can aerobrake, but not keep it long enough like in one of the recent videos of an F-14B doing it. Again...it can be done, Just that the drag of flaps, spoilers and Speedbrake seems more and the extra friction acting up. F-14 comes to a stop very fast in DCS. Runway length is not much of problem.

So, the problem is exaggerated friction from ED side, at least that's what most third party devs have said so far and they did say its quite complicated to correct it or not their prime priority.

For those who are interested, assuming dry runways, brakes are most effective for stopping a jet. Spoilers dump lift to make the brakes more effective, it isn’t the drag from the spoilers per se.

So few people appreciate the simplicity of friction. Its all about the Normal force. Engineering 101, if you want to stop shorter, or corner faster, increase the "Down Force".

Same reason I retract flaps on roll out. 1, I want to stop flying and 2. it makes the tires more frictiony, which in turn makes the brakes more effective.

This may be a silly question: if friction is about the downforce, why pull back the stick to increase braking in the 14, I'd have thought you push the stick forwards to increase down force. Does pulling back the stick increase downforce on the mains better?

This may be a silly question: if friction is about the downforce, why pull back the stick to increase braking in the 14, I'd have thought you push the stick forwards to increase down force. Does pulling back the stick increase downforce on the mains better?

Maybe, depending where the CG is but it also aids as an airbrake (aerobraking). It's a huge surface deflecting into the windstream. I'd also be careful with the downforce with tire life and wear considered. For the most part the spoiler brake should create the sufficient lift-dump and downforce needed for braking.

This may be a silly question: if friction is about the downforce, why pull back the stick to increase braking in the 14, I'd have thought you push the stick forwards to increase down force. Does pulling back the stick increase downforce on the mains better?

I imagine it's because the drag generated by pulling the stick aft is larger than the friction due to downforce generated by pushing the stick forward.

This may be a silly question: if friction is about the downforce, why pull back the stick to increase braking in the 14, I'd have thought you push the stick forwards to increase down force. Does pulling back the stick increase downforce on the mains better?

DCS world F-14...yeah we know it stops efficiently. Maybe the drag on the spoilers is more or how it affects the F-14 here.

As for, in real life, we seen air show. We gotta ask the pilot on WHY he'd need to aerobrake and keep the nose up attitude? (like we see those F-15s do for example). There are vids posted here F-14 pilots of both models and their pilots doing aerobraking with the nose up, yes, with spoilers engaged, flaps full and speed brakes deployed.

I dont get how spoilers work in DCS. Do the spoilers come up when we cut power to idle or when the nosewheel touches the ground? In vids seen here, spoilers are seen even with nose up attitude, as in nose wheel still not in contact with the ground.

This may be a silly question: if friction is about the downforce, why pull back the stick to increase braking in the 14, I'd have thought you push the stick forwards to increase down force. Does pulling back the stick increase downforce on the mains better?

Of course aft stick increases downforce! Just look at that the control surfaces are doing when you pull aft stick, it's obvious.

It's only when the stabilators produce so much downforce that the nose gear lifts off the ground and the AoA increases that the lift of the wings overcomes this downforce!

Of course, in an aircraft with canards, it's the opposite, stick forward for downforce.

This may be a silly question: if friction is about the downforce, why pull back the stick to increase braking in the 14, I'd have thought you push the stick forwards to increase down force. Does pulling back the stick increase downforce on the mains better?

Well slowing down is the result of many forces acting upon the aircraft. You have to use superposition to analyze each component and it's effects.

At low speed induced drag is going to be greater than parasitic drag (ignoring parachutes). The elevons will induce a considerable amount of drag. Spoilers on the other hand can't induce drag, because its not creating lift. As Victory said, they reduce the lift of the wing by disrupting the highspeed airflow over the wing. The parasitic drag component they create is not as effective at lower speed.

To your question is, doesn't pushing the stick forward create "downforce"?

As Airhunter mentioned, it depends on the Center of Gravity along with the center of aerodynamic lift. While it is true that in straight and level flight the elevon will raise the nose by creating negative lift in the back thereby pivoting the aircraft around the aerodynamic center, which increases AOA and therefor generate an increase in lift. Pushing the stick forward creates the opposite.

In this scenario though, you are on the ground. The wings stopped generating sufficient lift to fly. Pushing the nose forward will not reduce the AOA. Now lift generated by the wings is only a matter of velocity (after we deployed spoilers and perhaps raised flaps). So we'll eliminate that component from our analysis.

What you are left with is a beam scenario supported by only 2 points and a force acting on the counter-lever. If we consider your mains the pivot point, pulling back on the stick will unload the nose gear, which in turn means your main gear now has to support more of the total mass. Remember only the mains have breaks. Pushing the stick has the reverse effect so while you create "down force" the force is acting on the nose gear, which has no breaks and unloading the mains which reduced your break's effectiveness.

Yes. I do agree this does not take into account wear and tear on the wheels (which is also the reason formula 1 wheels are so wide even though friction has nothing to do with surface area), but essentially they are also cheaper to be replaced as are breaks unlike engine nozzles and the like.

Point is Aerobraking is not very effective other than if you had a really long runway, an aircraft that landed at higher speeds (such as delta wings and hot shot Iranian/airshow pilots) and/or a penny pinching CO that didn't want to replace breaks and tires a lot, but got to blame the pilot if a tail-strike occurred.

What you are left with is a beam scenario supported by only 2 points and a force acting on the counter-lever. If we consider your mains the pivot point, pulling back on the stick will unload the nose gear, which in turn means your main gear now has to support more of the total mass. Remember only the mains have breaks. Pushing the stick has the reverse effect so while you create "down force" the force is acting on the nose gear, which has no breaks and unloading the mains which reduced your break's effectiveness.

Well, if you completely unload the nose gear, not only do the mains have to support the entire weight of the aircraft, according to Newton's third law of motion they must also counteract whatever downward force the stabilators produce to unload the nose gear.

It's exactly like a car with a spoiler, and the very definition of "down force".

This may be a silly question: if friction is about the downforce, why pull back the stick to increase braking in the 14, I'd have thought you push the stick forwards to increase down force. Does pulling back the stick increase downforce on the mains better?

There are different schools of thought on this, and it also depends on your specific aircraft’s characteristics. On one hand, pulling back on the stick will shift more of the aircraft’s weight to the main gears and make braking more effective. On the other hand, with close proximity to flying airspeed, pulling back can also increase the AOA just enough to put significant lift on the wings which decreases wheel brake effectiveness and can cause you to become airborne very briefly (dangerous). That’s why it’s so important in an airplane without spoilers (F-5, T-38, F-16, etc.) not to just yank the nose up to like 12 degrees upon main gear touchdown.

Without flight tests, it’s tough to say quantitatively what is the best technique for stopping in the shortest distance. In the case of the F-14, I nearly always plant it on-speed, let the nose come down, and gradually pull to full backstick at the same rate airspeed decelerates toward 100 KIAS, and then steadily increase wheel brake pressure. And I do not retract the flaps; that causes the spoilers to retract. Never had a problem stopping the plane in time.

It *is* worth saying that aerobraking is a technique for reducing wear on the brakes. It is not a short field/minimum run landing technique.

Thanks all for the great responses! Much appreciated.

So, why they aerobrake is pretty much understandable since MOST land bases have long runways and F-14 along with spoilers will stop better than say, an F-15 or F-16.

As to WHY we even see SOME pilots do it? Maybe they'd want to go easy on the landing gear. I mean, if you HAVE a long runway and you have the CHOICE to go easy on the gears, then most have been seen to do it. There is no harm in going easy on the gears and brakes, IF you do have long runway to use.

As for tailstrike risk. Just look at the Mig 29 for example! Its got a taller nose gear and it cannot do a high AoA aerobrake as it certainly would risk a tailstrike. But we still see pilots doing it. Most of it does look they'd have a tailstrike.

F-14 spoilers do provide downforce and extra drag effect. How it works in DCS and how it activates seem different. Drag effect of spoilers on is very noticeable.

Well, if you completely unload the nose gear, not only do the mains have to support the entire weight of the aircraft, according to Newton's third law of motion they must also counteract whatever downward force the stabilators produce to unload the nose gear.

 

It's exactly like a car with a spoiler, and the very definition of "down force".

I use quotations because the technical term is Normal Force and down is a construct of your reference system. The other problem is what people perceive as down force (such as pushing the stick forward), when in reality the points representing load distribution along the beam, with the force vectors, are a little more complex.

And yes. I would agree that force would be in addition to the weight of the aircraft. Which is all the more reason to pull back and not push over.

I would note that I said on roll out which is after the aircraft has stopped flying and nose has already come down which is exactly as Chuck describes.

I remember in flight school there were more instructors that wanted you to stall the aircraft onto the runway instead of flying it onto the runway. It doesn't intuitively make sense to intentionally make the plane fall out of the sky. Its something that only clicks when you've practiced a lot and become so familiar with the aircraft to flare and hold a few inches above the runway until it decides on its own to land. The upside being that you don't bounce your landings which is both bad for your ego and worse your plane.

So yes some pilots do aerobraking even if they dont have to. You can do it, if you know the plane well enough (like demonstration pilots for instance), but the risk of a tail-strike is too great for the regular naval aviator to do. They land on carriers where brakes aren't even used and they don't flare in contrast to AF pilots. So you just can't compare the two. Why do the Iranians seem to do it? Easy. Spare parts and they do it every-time the fly. Even though they its not as exaggerated as the airshow videos. Landing onspeed in the Tomcat is already pretty slow with the low sweep angle and barn door flaps. Its just not worth it to showboat for Penny B.