Nitrogen...

[Steven B.]

Re: Nitrogen...

Just curious, when did FAA begin requiring nitrogen? Did an incident require it? Inquiring mind--- Thanks! Steve

[Domenic T.]

Re: Nitrogen...

Mike,
And here all the time I thought you were in the fuel business? Although I didn't get a engineering degree I was required to know all aspects to do my job. Every system, physics of, and then went on to learn how to repair all that made a aircraft fly. I am only repeating what was told in my class and what I actually did. Nothing else, you don't have to believe a word I say. If you want to verify my credentials google up my name using A as my middle initial.
Engineers said that it was impossible to go over 350 theyMPH on the ground! Someone that couldn't read blew that away.
Things are a little different in the field than they are on paper.
I'm not trying to play the game that mine is bigger than yours, I am sharing life experiences and what I needed to learn to pass tests issued by the Government. Maybe they are all wet in their thinking but they trusted me to fly their late President and his wife for years. So some of what I learned worked or maybe I just fooled the he?? out of them.
With all do respect to what you know and your achievements I am off this post. I have used your suggestions in the past and will still consider using them in the future.

DOM

[Michael W.]

Re: Nitrogen...

Just curious, when did FAA begin requiring nitrogen? Did an incident require it? Inquiring mind--- Thanks! Steve

Only 'recently' mandated in 1987 although in common use long before that. Most regulatory authorities around the world issued a similar document

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/55850E6389EFBA3C8625695B006723A3?OpenDocument&Highlight=87-08-09

I belive what prompter the AD (Airworthiness Directive) was this event with a 727

http://aviation-safety.net/database/record.php?id=19860331-1

FL310 is 31000 feet altitude.

The root cause was an overheated brake assembly which in turn heated the tire to the point that it exploded. This would have happened irrespective of whether it had been filled with air or nitrogen, but at 31K feet the surrounding air in the wheel well would not have otherwise supported combustion. The air in the tire is thought to have increased the intensity and duration of the ensuing fire.

[Edward B.]

Re: Nitrogen...

The best thing about a nitrogen fill are the green valve stem caps that proudly proclaim the fact that the owner has more money than brains.

[John D.]

Re: Nitrogen...

Keep in mind air is 78% nitrogen anyway...http://en.wikipedia.org/wiki/Atmosphere_of_Earth

[Duke W.]

Re: Nitrogen...

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/55850E6389EFBA3C8625695B006723A3?OpenDocument&Highlight=87-08-09

http://aviation-safety.net/database/record.php?id=19860331-1

Exellent research on the subject, Mike!

What surprised me is that the explosion was apparently initiated by reaction of the oxygen in the tire with "volatiles" from the tire inner liner, so the explosion was chemical and not due to tire structural failure. Then the available oxygen from the tire combined with the heat released from the exothermic reaction ignited fuel from the ruptured fuel line.

Up to about 10 years ago Mexicana had an ancient 727 that took off daily from LAX for Mexico City in the wee hours of the morning that generated a lot of noise complaints. Even though the JT8Ds supposedly had "hush kits", that thing was LOUD, and I usually heard it at my house, which is 5 miles due south of the LAX tower.

They finally had to get rid of that PoS when Stage III noise requirements were fully implemented at LAX.

... same thing with a FedEx 727 that took off from Long Beach for San Jose and passed right over my house at 3000 feet. Fortunately it was only 10 PM. You could set you watch by it.

Duke

[Joe L.]

Re: Nitrogen...

Exellent research on the subject, Mike!

What surprised me is that the explosion was apparently initiated by reaction of the oxygen in the tire with "volatiles" from the tire inner liner, so the explosion was chemical and not due to tire structural failure. Then the available oxygen from the tire combined with the heat released from the exothermic reaction ignited fuel from the ruptured fuel line.

Up to about 10 years ago Mexicana had an ancient 727 that took off daily from LAX for Mexico City in the wee hours of the morning that generated a lot of noise complaints. Even though the JT8Ds supposedly had "hush kits", that thing was LOUD, and I usually heard it at my house, which is 5 miles due south of the LAX tower.

They finally had to get rid of that PoS when Stage III noise requirements were fully implemented at LAX.

Duke

Duke------


You don't have to worry about any 727's anymore. I don't think there are any flying in the US and very few worldwide. It's not noise that killed them, though, it's fuel consumption. Plus, they require a 3 person flight crew. They're no longer "economically viable".

However, there are still quite a few MD-80's still flying with later versions of the JT8D, though.

By the way, there are very few 3 person flight crew commercial airliners still flying. The only ones I can think of are the DC-10's still operated by Federal Express (no passenger DC-10's are flying worldwide), a few 747-100 and 200 still operated by a few "2nd tier' air freight operations, and a few DC-8's still operated by ATI.

[Joe C.]

Re: Nitrogen...

Dom-

I was in the commercial airline business for 31 years working in the engineering, design and customer support areas of world's largest manufacturer of gas turbine engines. Got to see and learn a few things over the decades.

You may refuse to believe what's being said but it's simple indisputable physics- inside or outside the airline business.

Hi Mike,
Did you work for GE, Rolls Royce, Hamilton Standard or some other?
With all due respect, how long did you work in the customer support area?

"FL310 is 31000 feet altitude.

The root cause was an overheated brake assembly which in turn heated the tire to the point that it exploded. This would have happened irrespective of whether it had been filled with air or nitrogen, but at 31K feet the surrounding air in the wheel well would not have otherwise supported combustion. The air in the tire is thought to have increased the intensity and duration of the ensuing fire."

@ Mach 0.85, and small amount of O2 present in an exploding tire would be immediately displaced by the very thin air in the stratosphere which, although of very low density is still approx. 78% nitrogen and 21% oxygen.

[Michael W.]

Re: Nitrogen...

I worked for none of the above Joe.

If you wish to dispute the wording of the FAA findings, please be my guest. Good luck with that and please send us a postcard.

[Peter S.]

Re: Nitrogen...

Hi Mike,
@ Mach 0.85, and small amount of O2 present in an exploding tire would be immediately displaced by the very thin air in the stratosphere which, although of very low density is still approx. 78% nitrogen and 21% oxygen.

Joe,

Are you taking into account explosive velocity? This is a much greater velocity than mach 0.85, and the air in the tire is much denser than the air in the stratosphere. Proximity of the tire to the fire and if it is even exposed to mach 0.85 air would be critical knowledge to make any kind of guess as to the ability of the tire's air to dissipate.

Just playing devils advocate, my experience in the aviation industry is limited to my loading zone and skymiles.

[Michael J.]

[Michael W.]

Re: Nitrogen...

Very entertaining thread, and I am glad to see there is something more misunderstood than ethanol…….

Fixed it for you.

[Leif A.]

Re: Nitrogen...

Very entertaining thread, and I am glad to see there is something more controversial than ethanol…….

Never intended to start a fire storm, but it sure is great to hear everyone's experiences and opinions. Now, about that ethanol thing...just kidding

[Jim L.]

Re: Nitrogen...

After reading the whole thread, I've decided to use in the tires of my cars nothing but pure N78.

[Michael G.]

Re: Nitrogen...

After reading the whole thread, I've decided to use in the tires of my cars nothing but pure N78.

That's a big risk, Jim, what if the ideal gas law is repealed?