Punctured tires on takeoff (that may seem like punctured tires on landing) [with fix included]

[RafaPolit]

Hey friends!  I just wanted to share this in case someone else finds it useful.

I have been flying the F-16 with heavy bomb loads, and, upon returning from mission I would always land and find my tires got punctured (flat tires).  I kept thinking I was landing too hard, forgetting to put the anti-skid switch correctly, not selecting the right CAT I or III.  Even when doing PERFECT landings, I ended up with punctured tires.  

So, as the trained classical pianist that I am, I went and practiced landing after landing after landing... all great.  No punctured tires.  Went back to the missions, again punctured tires.

If someone is facing this, this NOT happening on landing, these are being torn up AT TAKEOFF!

Turns out that I was not rolling strong enough if the runway was long, and "waiting" for the F-16c to take off naturally.  At around 220 kts, you can hear the tires disintegrate.  I actually thought this sound was the back fins scratching through the runway (thinking I was pitching too hard), so I started using less and less attitude pitch up during take off, which in turned ended up presenting even more punctured tires.

So, long story short: in case you are seeing this, the solution is to correctly roll up at max 160 knots or so (less if without load) and keep the correct pitch attitude so that the plane takes off before the tires disintegrate under your but. 

 

Hope this helps someone, best regards

Rafa.

[Dragon1-1]

This is correct, and a known quirk of the Viper. The F-16, much like Mirage, needs to "unstick" from the runway, and will not fly itself off like most others do. If you expect it to do this, it'll result in blown tires on either aircraft. Weirdly, despite learning the Viper at an early age, I did it a few times to the Mirage when I was starting out on it. That's just how those planes are, due to their aerodynamic configuration they're actually generating a little downforce when rolling on all three wheels, not to mention in the Viper the FLCS will keep you at 1G unless you tell it otherwise. They won't lift on their own no matter how fast you go. Once you overcome that force by pulling on the stick, the nose will immediately jerk into the air (important to watch out for the tailstrike then) and the ship will almost immediately begin to climb. Some aircraft are just that way, it depends on aerodynamics and on how the aircraft sits on the landing gear.

[Fulgrim]

160 feels a bit too slow.

I'm taking off at 190/200kts fully loaded without puncturing a tire. 

[=475FG= Dawger]

While I cannot speak directly regarding the F-16, 210 knots is maximum tire speed for every jet I ever flew. 

[Dannyvandelft]

160 feels a bit too slow.
I'm taking off at 190/200kts fully loaded without puncturing a tire. 

160 is right.

Sent from my SM-G960U using Tapatalk

[Chain_1]

8 hours ago, Fulgrim said:

160 feels a bit too slow.

I'm taking off at 190/200kts fully loaded without puncturing a tire. 

160 may be good, and it may not be.  Rotation speed will depend on aircraft gross weight and weather conditions.  Power setting and pitch angle also play a factor.

[Dragon1-1]

The Viper is peculiar in that once it rotates, it will lift off more or less immediately unless you really jumped the gun (and even then, it doesn't take long). If you're heavy, it might be 170 or so (the other sim manual says 165 is typical for a combat-laden jet), but either way, once it unsticks, up it goes.

[TobiasA]

Slowly pull the nose up to 10 degrees. That's it.

[RafaPolit]

13 hours ago, Fulgrim said:

160 feels a bit too slow.

I'm taking off at 190/200kts fully loaded without puncturing a tire. 

Yeah, that's about right.  160 was the max weight initial rotate speed, you usually take off at 180 or so.  I read somewhere that you should rotate about 15 or 20 knots before the actual takeoff speed, and, as mentioned, that depends on the weight of the jet. Still, at MAX weight, 180 or so is the maximum speed, so I rotate at 160.

[Tholozor]

IIRC it's rotation at 10 knots below calculated takeoff speed for non-afterburner takeoffs, 15 knots below for afterburner takeoffs.

[Frederf]

Indeed 10 and 15. It takes some time to rotate and the airplane will accelerate during the maneuver.

Liftoff is the goal speed, rotate is the estimated action speed to anticipate.

Liftoff attitude is 8-13 degrees. Goal is to have a positive pitch rate during liftoff so lift is increasing by function of acceleration and AOA rate. This provides the quickest transition between W>>L to L>>W.