22.18 Straight and Level Flight

22.18.2 Explain the four forces acting and the conditions required for steady straight and level flight.

When we talk about an aircraft maintaining straight and level flight, it means that the aircraft is flying in a steady and horizontal path without any changes in altitude or heading, achieving a state of equilibrium.

In other words, the aircraft is neither climbing nor descending and is flying in a straight line without any turns or banking.

It's like keeping the airplane on a level "autopilot" mode, where it maintains a constant altitude and flies in a straight line without any deviations.

In steady straight and level flight, there are four main forces at play.

Lift

The first force is lift, which is generated by the wings and opposes the force of gravity.

Weight

The second force is weight, which is the downward force acting on the aircraft due to gravity.

Thrust

The third force is thrust, which is the forward force generated by the engines or propellers.