[modern] Nitrogen and Aviation

Yes, I’m another in the aviation business. Just retired as Field
Support Engineer for Collins Avionics, and launched my own business
doing engineering and Certificaton projects.

The FAA has required nitrogen in all jet aircraft tires of US airlines
since something like 1963, and recommended, but did not require it for
foreign airlines operating into the US - until too late.

In 1985, a Boeing 727 arrived at the gate in Mexico City with a badly
dragging brake. There was a change of crews, and the new captain was so
anxious to get his family to Disneyland, he convinced the maintenance
crew not to delay the outbound flight to work on the brake. Mexico City
is at 7,400 feet elevation, and with a full load of pax, bags and fuel,
it takes a 727 just about all 13,000 feet of runway. Since the 727 will
climb at only 500 feet per minute until the landing gear and takeoff
flaps are up, the gear is retracted into the wheel wells right after

Tucked in the fuselage, out of the air stream, the dragging brake heated
the tire so much that the tire began vaporizing its flammable
components. It was just like a diesel engine: fuel vapor, high
compression, high temperature, and oxygen. The NTSB report of the crash
that killed all 170 pax and crew cited explosion of a tire as probable

A few years later, a similar fate befell a DC-8 in Saudia Arabia,
carrying pilgrims from the Hajj. Due lack of nitrogen at the airport, a
leaking tire had been serviced with air.

Ralph http://www.GraybeardAviation.com