Fast Tyre Fill

Product Specification Table
Gas Nitrogen 99.999% Pure
Pressure 0 – 400 psi / 0 – 27 bar
Flow Rate 50 cfm / 1400 Litres/Min
Hoses 2 x 50ft / 15 metre
Tank Coding DOT 4–L
Tank Capacity 75 Gallons / 300 Litres
Length 124 ins / 315 cms
Width 60 ins / 152 cms
Height 54 ins / 137 cms
Weight 3250 lbs / 1474 Kg

Pressure Guage

Servicing an aircraft with the Fast Tyre Fill

Servicing an aircraft with the Fast Tyre Fill

Aircraft Tyre Inflation Unit Fast Tyre Fill “FTF Unit”

McNaughton Dynamics Limited has developed the FTF Unit, an exciting new aircraft tyre inflating unit for use on military and civil aircraft. This innovative design provides large amounts of low-pressure Nitrogen gas from a liquid Nitrogen tank, for charging aircraft tyres from their storage pressure of 30 psi / 2 bar to their operating pressure of 220 psi / 15 bar.

Designed to be very simple to operate, the self–pressurising FTF unit fills approximately 80 Boeing 737 tyres quickly from 30 psi to 220 psi, without the potential hazards of cylinder trolleys.

The machine is filled with 300 Litres of Liquid Nitrogen which is stored in a 400psi / 27 bar cryogenic tank. Some of the liquid is boiled off and used to pressurise the tank so as to provide a continuous supply of pressure to fill the tyres. After the tank is pressurised, the remaining liquid is vaporised into gas by aluminium heat exchangers, warmed to ambient temperature and delivered to the control panel for distribution to the tyres through two separate hoses and control valves. Each of the two systems is fitted with 50 ft / 15 metre extendable hoses with a gauge, relief valve, shutoff valve and quick release Schrader tyre adaptor fitted at the hose end.

The choice of 400 psi / 27 bar as the gas delivery pressure enables the tyres to be filled both quickly and safely. As the burst pressure of an aircraft tyre is four times the normal operating pressure, the “FTF Unit” unit can charge tyres safely without any chance of bursting the tyres. The unit is protected by three relief valves and a burst disk so the delivery pressure cannot rise above 500psi / 34 bar. As the burst pressure of the tyre will be above 800 psi / 55 bar it is completely safe.

Features and Benefits


The FTF Unit saves time by changing the tyres quicker and eliminating the need to handle cylinders. The unit is filled either once a week or up to once every three weeks depending on usage. This is done by a Liquid Nitrogen delivery vehicle and takes about 15 minutes. There is no pressure raising time as the Nitrogen is always available. Just one valve has to be opened to supply gas to the end of the hose.


The FTF Unit takes up much less space than the 20 cylinders it replaces and can be stored outside in all weather. It occupies 52 square feet or 4.8 sq metres only, and can easily be moved manually or with a towing vehicle.


The cost of gas generated from liquid is less than cylinder gas. There are no costs associated with storing, transporting or changing heavy (80 Kg) gas cylinders and no empty cylinders have to be returned.


The FTF Unit is designed with the minimum number of components. We have even managed to design out the pressure regulator – a major source of problems – by storing the Nitrogen at the Tyre filling pressure. The machine is based on a tried and tested military unit of which over a thousand were produced for service all over the globe. The hose end components are rated to high pressure so as to make them more robust for flight line service.


The FTF unit is protected by no less than three relief valves and one burst disk and is unable to generate enough pressure to burst aircraft tyres. All the hoses are rated at high pressure even though only low pressure is delivered. The tank is designed to DOT 4–L standards and can be operated for life without the need for annual testing.