Hello everyone I'm working on this problem and I need some clarification.

A 40 tonne jumbo jet accelerates down the runway at 5 m/s^2. What must be the thrust on each of its four engines? What is the horizontal force that a 700 N pilot exerts on his seat?

I can calculate the thrust using F= ma. However I don't understand the second part of the question where it asks for the horizontal force that a 700 N pilot exerts on the seat. Do I have to subtract 700 N from the thrust? I need clarification

Your help will be much appreciated.