Calculating G from landing Aircraft

[jkl]

Hopefully I have posted this in the correct section;

Can anyone help with the equation(s) & assumptions required to specifically calculate the landing G load of a modern jet aircraft.

I'm trying to calculate the G deceleration rate of an aircraft on landing based on the initial vertical descent rate on landing in feet per minute. For example a typical jet aircraft landing would give a decent rate around 200 feet per min at impact & a heavy landing would be around 700 feet per minute at impact so I want to find out the G load of the two.

Typical landing weight of 55,000kg & strut compression around 40cm as an approximation as it will vary with impact force. Also typical speed of 130kts at landing.

Looking for a simple way to start with decent rate in feet per minute & depending on certain assumptions, still air, strut compression, temperature & other assumptions arrive at the landing G load/impact force

cheers

 

[mfb]

Use SI units. 200 ft/min are roughly 1 m/s. If the acceleration during the 40 cm braking distance is uniform then we can calculate the acceleration via s=1/2 a t² = 1/2 v²/a or a=1/2 v²/s. Plugging in 1 m/s and 0.4 m gives 1.25 m/s². 1g is about 10 m/s² so 1.25 m/s² is about 0.13 g. A very gentle deceleration. With 700 ft/min you'll get a much larger value.