Turning G forces when descending

[Eric Marsh]

We are all taught the correlation between bank angles and g forces in level flight. For a long time now I've wondered what effect a climb or descent has on this. I've looked around for some sort of a formula but come up empty handed.

The reason I ask is that I've been trying to get a better understanding of what's happening on a descending turn to final and the effect on stall speed.

Can anyone provide a formula or something I can work with on this?

[Kyle Boatright]

If you're maintaining a constant rate of descent, it won't impact stall speed. Same thing for rate of climb, assuming you maintain a steady airspeed.

[Eric Marsh]

If one is turning into a bank without changing the pitch to compensate for decreased lift then the rate of descent should be increasing. That's the scenario I'm looking at.

Thinking about it, the in that case the amount of g's shouldn't change in the turn since the wings have 1 g of lift and with no change in pitch the aircraft would accelerate.

Thanks Kyle, that's what needed to get on track. Now to see if I can kill this thread.

[Mayhemxpc]

Hold on. Physics and common sense seem to offer a different answer. From personal experience, I know that my G-meter says 2G for a level turn at 60 degrees bank, but only about 1.5G for the same angle if I allow the nose to drop in the turn (e.g., top of a wing-over). Since weight (G-load) affects stall speed, the stall speed should be less.

I know that there are more experienced (or just more alert) people on this forum who will be able to provide more precise answers. I may even feel smarter or more alert myself in the morning.

[RetroAcro]

I think it's a fairly pointless exercise to try to think about what the "stall speed" is for all different possible combinations of bank angle, G-load, climb/descent, pitch angles, etc. There are too many variables, plus AOA is all that matters, not airspeed or bank angle. But for a given weight & balance condition of the airplane, and for a given G-load (of at least 1G), there is an airspeed at which the airplane will stall...and that's true only if the airplane is in perfect coordinated flight. The higher the G, the higher the stall speed. Bank angle, climb, descent, pitch angle, etc. is irrelevant.

[WLIU]

So if you are in a descending turn, with a constant "G", like any other descending maneuver, your airspeed will increase. With increased airspeed but constant bank angle and "G", the radius of the turn will increase with increasing airspeed. So you will fly a wider and wider spiral until you hit the ground....

Fly safe,

Wes
N78PS

[Kyle Boatright]

You're unloading the wing by allowing gravity to change your rate of ascent/descent. Just like when you do a push over from level flight, the G-load goes down when you allow the nose to drop through on a wing over...