Forum: F-16 Procedures

When landing F-16, should the airbrakes be extend even when touching down? How much effect do they have when the aircraft is on ground? I heard that when brakes are extended throttle becomes less touchy, so its easier to control the throttle and speed when the airbrakes are extended ? I'm soon going to practice with Falcon 4 sim, so i might need some help Smile

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Elite 1K Joined: Aug 19, 2004 - 09:19 AM Posts: 1092

shc wrote:

When landing F-16, should the airbrakes be extend even when touching down? How much effect do they have when the aircraft is on ground? I heard that when brakes are extended throttle becomes less touchy, so its easier to control the throttle and speed when the airbrakes are extended ? I'm soon going to practice with Falcon 4 sim, so i might need some help Smile

The F-16 -1 flight manual recommends deploying speed brakes for landing. They retract a bit once your main gear touches the ground to avoid a tail strike, but yes... you should leave them open until you've slowed to taxi speeds.

and also a thing about flaring, why is it so critical to perform flare just before touchdown, i know its made to put the plane on the track more gently, but why wouldnt a pilot put his aircraft in flaring position more before the touchdown instead of flaring just moments before the touchdown ?

my question probably seems funny to you guys who fly real planes, but i gota ask somewhere and i guess i will find the best answer here. afterall, there arent stupid questions,...only stupid people:P

thanks alot raptor one.

shc wrote:

my question probably seems funny to you guys who fly real planes, but i gota ask somewhere and i guess i will find the best answer here. afterall, there arent stupid questions,...only stupid people:P

There arent many people who fly real planes on this website, its mainly mx and computer pilots....

The way I understand it, and I'm just a desk jockey so don't beat me up too bad if I'm wrong, but if you flare way early in the approach then you run a greater risk of stalling, and that would be bad, but if you flare at almost the last second, dumping alot of speed and energy right before the touchdown it makes the landing alot smoother and softer.

Last edited by Vulture on Jul 02, 2007 - 06:33 PM; edited 1 time in total

Raptor_One wrote:

shc wrote:

When landing F-16, should the airbrakes be extend even when touching down? How much effect do they have when the aircraft is on ground? I heard that when brakes are extended throttle becomes less touchy, so its easier to control the throttle and speed when the airbrakes are extended ? I'm soon going to practice with Falcon 4 sim, so i might need some help Smile

The F-16 -1 flight manual recommends deploying speed brakes for landing. They retract a bit once your main gear touches the ground to avoid a tail strike, but yes... you should leave them open until you've slowed to taxi speeds.

Actually, the airbrakes retract when the gear is down and locked in position, not when they touch the ground (that would be too late). In Falcon you can hear the airbracke retract a small amount as soon as the gear is completely extended. The airbrakes will cause excess drag which means you need to increase the throttle (increase the RPMs). The increase in RPMs is increased safety incase something happens and you need to perform a "Go-Around"/missed approach, or divert. You will have more thrust avaiable and attain full MIL or burner quicker (smaller spool time).

If you are aligned with the Center of the runway (moving down the runway centerline extended) achieve the 3 degree glide slope, and have the proper AOA 11-13 degrees, you need not flare at all. Just maintain those 3 parameters all the way to contact with the ground and once you contact stat to decrease the throttle to idle cutoff. It is important to note that this is not easy and you must contantly be working (making small changes, evaluating and making more changes) to avheive a smooth touchdown.

Last edited by Raptor_DCTR on Jun 30, 2007 - 02:44 AM; edited 2 times in total

Some of you are right and some of you have it half right. The SPEEDBRAKES are toggled with a switched on the throttle grip. They ARE NOT automatically retracted/extended with a landing gear retract/extension. There is a 43 degree limit switch built into the speedbrakes themselves that limits speedbrake position to 43 degrees on landing to prevent striking the ground. Once the jet jet is on the ground, a further toggle of the speedbrake switch on the throttle grip will open them to their full 60 degree position. The only way to control the speedbrakes is from the speedbrake switch on the T-Grip. They are not controlled as a landing gear function. As far as why they don't flare earlier in the appraoch, my guess is so they can see the runway. Can't really see the strip if you're holding that much AOA all the way in, common sense to me.

Salute!

Fixin-breath has it right.

Unless they have made a big change, the boards switch is spring-loaded.

With gear up, you hold the switch back until the desired amount of boards is reached.

Gear down restricts the max angle, as Fixin says. You can override the limit by holding continuous back switch, but if you let go the boards go back to the limit angle.

The Viper just doesn't wanna land. So any extra drag just before touchdown helps. The flare allows a slightly lower AoA on approach, then reducing throttle and raising nose slightly helps to kill speed and get a firmer touch. If you simply drive the sucker onto the rwy ala F-4, A-7 you'll bounce - I guarantee.

When gear touches, the LEf's will raise, killing some lift and increasing drag. That's the original FLCS programming, so it may be different now.

Hope this helps.

Gums

Elite 1K Joined: Aug 19, 2004 - 09:19 AM Posts: 1092

You guys are right of course. The landing gear being down limits the max angle for the speed brake. That's what I meant. Very Happy

Doh!

The F-16 bounces on just about every landing, whether it is a gentle 1 ft/sec sink rate or 10 ft/sec max sink rate. Reason is that the main gear has a short stroke and is very stiff. The gear geometry is such that wheel camber (lateral tilt) changes quickly as the gear strokes up. Too much camber and bad things happen to tires and wheels. So to control camber, the stroke is limited. Another reason for short stroke is to maintain enough clearance under the airplane for a centerline tank. Even so it is possible to ding a tank if the airspeed is too low, AOA too high, and sink rate near limit, seen it happen. Short stroke means you must have high stiffness to absorb landing energy. The shock strut has a dual stiffness capability. The first few inches are relatively soft. That helps to soften the impact a bit. Then the strut becomes rigid until the impact load is increased considerably. Taxiing is done on the rigid portion of the strut stroke. This prevents the airplane from rolling laterally during turns. Any rolling is due to tire compression only. Once the impact load is enough to overcome the rigid portion, the stiffness is much greater than the initial stiffness. In low sink rate landings (1 - 2 ft/sec) the rigid strut causes the bounce. In high rate landings, the strut is compressed past the rigid section, so the high stiffness section causes the bounce.

interesting, I never knew that about the gear.

thanks for answers people. looks like everything is answered. vulture pointed that flaring isnt necessary. In falcon 4 sim for me its impossible to land with a flare, because when i drop airspeed to 130 knots that low speed warning horn starts ringing and i always damage the aircraft on landing, so for me only flying it straight on the runway works. so i fly 160 knots, AOA about 11 and nose at about 8 and it works altough i cant achieve a smooth touchdown, the plane always bounces off the runway a bit.

however, whats the procedure in real life, is flaring a standard procedure and the thing that everyone does or its just an optional thing?

here's the f-16 landing video that i've found on youtube http://www.youtube.com/watch?v=Qsib1KkC ... ed&search=

it seems to me that pilot flares at the end and reduces the speed to 130 knots just before that touchdown, its the same in falcon 4 manual, but it doesnt work in the sim for me so i have to fly it right on the runway(and bounce off a bit in the proces).

Elite 1K Joined: Aug 19, 2004 - 09:19 AM Posts: 1092

You just need to practice. It's completely possible in Falcon 4.0... trust me, I've landed "by the book" in that sim thousands of times. You need to understand what you're trying to accomplish with a flare and how to actually flare. A flare is not an extreme maneuver... it's just a brief and subtle increase in pitch/AoA to bring you from your approach speed to your touchdown speed. When you actually land on the runway, your AoA should be no higher than 13 degrees. Even if you do a 13 degree AoA approach, you would flare up to a little above 13 degrees and then back down to 13 right before your main landing gear touch the runway. I actually prefer to land this way, but the flare is more difficult to pull off. Just practice... and make sure you understand how to properly land the jet in a general sense. In other words, know that you're really aiming for an AoA and not an airspeed. If you're trying to land at a certain airspeed instead of AoA, you've got things backwards. Your airspeed will be a result of the approach AoA you use (11 or 13 degrees) and your gross weight. It is what it is. Your touchdown speed will be about 10 knots slower than your approach speed, but don't focus on trying to slow your airspeed in the descent. Focus on trying to *gently* decrease your vertical velocity and making sure your AoA at touchdown is not higher than 13 degrees. You might have to use a little forward stick just before touchdown to get your AoA back below 13.

i've finally completely learned to land Very Happy

the problem was that i blindely followed the manual which said that speed should be 130 knots, and i always watched the speed instead of AOA ( i didnt how to use the AOA bracket so i rather watched the speed). 130 knots is too slow for a good landing in the game( guy who wrote the manual probably wrote as for real f-16 altough it might be that in-game mode is a bit different, atleast with landing speed). Finally i'm able to make real smooth, by the book landings. i put the runway on 2.5 degrees, put the flight path pointer on it, keep my aoa on 11 until the flare, then i decrease the speed to make AOA 13, and raise my nose a bit to keep it at 2.5 degrees. and thats it. i also tried to flare on the approach, and i did suceed in landing altough it was much harder because of low visibility and flying with nose of the aircraft high in the air.

Forum: F-16 Procedures

Airbrakes before landing