Blown tires on takeoff

[riproren]

Since the new 2.4 NTTR update I'm experiencing a blown tire on almost every takeoff. I've had it happen anywhere from 150 to 200kts. Any body else?

 

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[mvsgas]

Is it in a specific airport?

At what weight? what is the aircraft configurations? weather?

[riproren]

Nellis. 2 bags. Perfect weather.

 

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[riproren]

Red Flag missions 2 and 3. I've flown them before and never had the issue.

 

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[mvsgas]

Will try to reproduce. So only two external tanks on the wings, no missiles, chaff/flare, gun ammo?

Does it happen on single missions on only in the Red flag campaign?

[riproren]

Sorry. Yes, full load out. Preloaded in Red Flag.

 

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[Sweep]

Since the new 2.4 NTTR update I'm experiencing a blown tire on almost every takeoff. I've had it happen anywhere from 150 to 200kts. Any body else?

 

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Try getting the nosewheel off the runway between 100 and 120 KCAS, see if that does anything. Should be holding 10 degrees pitch until you're off the floor, as well.

[mvsgas]

riproren,

I did not encounter any problems using normal takeoff (as stated by sweep ). Could it be that you where going to fast while still on the ground?

[=Mac=]

In May, 1983 an Israeli F-15d landed at 260 knots without blowing the tires. And, yes, at Nellis, one of the tires blows consistently now. (Loadout was 2, 2, and 4 ... I think... with two bags. Rotated at 120, lifted around 150 with one tire blown.)

 

Edited November 22, 2016 by =Mac=
Added the takeoff specs

[riproren]

Was it just an instant mission or a red flag? Just curious to know how to report.

 

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[Sierra99]

Not a redflag issue...happens all the time in F-15 since 2.0.4...Simple mission with 8 missiles and full tanks...Right tire blows about 130kias

[riproren]

Thanks Sierra. On a positive note, I've managed to grease every landing with the flat tire at Nellis. Sure is noisy though.

 

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[mvsgas]

Ok so, let's break this down,

- Has anyone tried what sweep suggested? Did it help?

- This has been said about several aircraft a multitude of times ( not about the tire but about it being at alpha stage); it is still a alpha, things will change. I do not know if this is the intended behavior or not.

- Next, I tried to duplicate it online on the Aerobatic Online Server (former VA) Clean aircraft (yes, I know it does not match the OP, but we will get to that in a minute) and could not duplicate during normal take off as sweep posted. I also tried in Groom Lake. Additionally, I tried with "full load out" in single player with bad weather and clear weather, quick missions and could not duplicate (CND).

Seems like high weight and ground speed are working here.

 

Now lets talk about this;

In May, 1983 an Israeli F-15d landed at 260 knots without blowing the tires...

 

And in 2008 one F-15 broke in flight;

http://www.washingtonpost.com/wp-dyn/content/article/2008/01/10/AR2008011003411.html

 

Mac,

- Now that we both posted something that happened once to a specific F-15; could we agree the an F-15 missing a wing, with no weapons nor external tanks, leaking fuel at a high rate would be considerable lighter that a F-15 as stated (by the riproren) with two wing tanks and a "full load out"?

- Could we also agree that during take off your speed goes up rapidly and during landing it goes down?

 

So a lighter F-15 should not have any problems, which again I tried and could not duplicate tire failure ( like I said, we got to it in a minute).

 

What we need is a way to duplicate it, but first I would like to wait for the answer to the first two questions;

- Has anyone tried what sweep suggested? Did it help?

Edited November 23, 2016 by mvsgas

[=Mac=]

Yes, I had seen the story about the F-15 longeron failure. I would imagine that ride was a wild one!

 

From what I can gather, the F-15's main mount is a 36x11R18 inflated to 300 psi. The empty weight of an F-15 is around 28,000 lbs but the maximum takeoff weight is about 68,000 lbs. These radials are designed and tested to handle these static loads as well as, at the 68,000 mark, overspeed conditions.

 

Yes, takeoff speeds are of the increasing type with much lateral loading mixed with normal high-speed loading. However, landing speeds begin with unusually high-speed loading mixed with extreme side loading (cross wind landings) and intense overpressures of slam-loading during impact landings (those infamous rough landings). The tread damage from landing tire friction (initial spin-up skidding from the instant of touch) has been inconsequential to the loading issues in tire failure. In essence, landing physics produce the most off-nominal loading in an aircraft tire. Today's F-15 tires (and those of the 1970's and 1980's) are tested with these extremes in mind. A normal, fully loaded, 150-knot takeoff should rarely cause a blowout, even in a wild side skid. Tire failure, during such a wild side skid, would be from tread wear-through only (assuming no tire side-impact events).

 

There is only the occasional story of a blowout on takeoff yet history is replete with stories of blowouts upon landings.

 

And, for me, no: I have not tried any other landing/takeoff tests to determine any cause. I flew on the Aerobatic Online server out of Nellis and had a takeoff blowout. I also flew a short single player takeoff out of Nellis and had a takeoff blowout. (I don't get to fly as often as most other sim pilots here. :(

[mvsgas]

11R18 are truck tires

AFAIK, F-15 has several different tires and several wheels depending on several factors

here is a F-15A tire.

 

 

https://docs.google.com/viewer?url=http%3A%2F%2Fwww.aerosuppliesinc.com%2FCatalogue%2FNumerical%2520Chapters%2FAero%2520Supplies%2520-%2520Catalogue%2520CHAPTER%25205%2520(431-504).pdf

 

Now,

And, for me, no: I have not tried any other landing/takeoff tests to determine any cause.

Any one ells?

Edited November 23, 2016 by mvsgas

[BIGNEWY]

I am a bit short for time at the moment, if someone can produce a short track ( as short as possible please ) showing the issue I will take a look

[NeilWillis]

https://forums.eagle.ru/showthread.php?t=177560

[Tackle]

I did a couple of TO this morning.

Test Setup:

New Mission, Default Settings, TO from Runway @Nellis, Groom Lake and Tonopah.

Started with 4*Sparrow, 4*Sidewinder and 2*Fuel Tanks - no Problem Standard TO*

Same Loadout but 3*Fuel Tanks - no Problem Standard TO*

Didn´t test Max. Performance TO.

At the very last test I set Temp. to 40° C and a 10kts wind at 33ft - no Problem either

 

Standard TO = Stick halfway back at 120kts, Rotate at 150kts, Hold around 10° and let her fly off the Runway.

 

So, works for me.

[NeilWillis]

I have a feeling it is down to a tightening of the allowable parameters rather than a bug as such.

 

The key to this is to keep your take off within realistic bounds. Don't go too fast before unsticking, and see if you still get issues.

 

If however you over speed on the ground you'll stress the tyres. Just like over stressing the airframe - at some point the wings will come off (in theory anyway, I haven't actually managed it - unlike the Israeli F-15 pilot!).

 

Likewise, landing may cause issues if you have an over-weight aircraft, or if your sink rate is excessive.

 

Personally, I think this may be a step in the right direction.

[mvsgas]

I am a bit short for time at the moment, if someone can produce a short track ( as short as possible please ) showing the issue I will take a look

 

:D

We need to start calling you; "The Wolf". From the movie Pulp Fiction.

You ain't got no problems [insert user name here], I'm on it. Go back in there, chill them out and wait for BIGNEWY, who should be coming directly.

[winchesterdelta1]

Have had the same issue in multiplayer. But i adapted so don't have it any more if a pay attention to it.

 

Happened to me after the latest 1.5 update.

 

Armament: Full load 6 AIM120C, 1 AIM-9, 1 AIM-7

Fuel load: Full internal fuel with 2 external tanks

Take off speed when this happens: Around 200 to 250 (not always) > Also happened once on 150 when i tried to pull up to soon. (maybe the weight was longer on the wheels)

Nose position on take off: Was higher then 10 degrees. Or when i pulled up faster then normal.

 

On landing i had no tires blown at all yet. I land around 150 knots.

It was always the right tire that blew up. Not any of the others.

Edited November 23, 2016 by winchesterdelta1

[riproren]

Flew the Red Flag mission tonight that I had the blown tire issues with, and followed the advice to rotate earlier. Slight back pressure at 100kts and a little more at 125 then airborne at 135. Not the most stable or smooth transition but no blown tire. Thanks for chiming in guys.

 

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[mvsgas]

I am glad sweep was able to help. Did you use T/O trim?

Edited November 24, 2016 by mvsgas

[riproren]

Yup. I think I pulled up a little bit too much once I got airborne and almost touched down due to loss of lift. Just need to trust it to let my speed build and let it climb slowly until around 200kts or more before applying back pressure on the stick.

 

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[BIGNEWY]

:D

We need to start calling you; "The Wolf". From the movie Pulp Fiction.

 

I like that idea made me lol

 

I am a bit short for time at the moment, if someone can produce a short track ( as short as possible please ) showing the issue I will take a look

 

We really need a short track, I and the ED team have tried to reproduce with no luck