# At what bank angle does load factor's effect on performance increase?

I had this question on my Part 107 exam today. After some thought, I opted for a) 15 degrees, since that is the minimum bank angle at which the load begins to increase. Was I right?

Load factors have a greater effect on both flight performance and loads on a fixed-wing aircraft as the bank angle increases beyond approximately?

a) 15 degrees
b) 30 degrees
c) 45 degrees

• I think this is an ill-posed question, it increases for any non-zero bank angle. So the question is what is considered 'enough' of an increase. Commented Mar 1, 2022 at 11:54
• What a stupid question. The exam question, I mean. God bless the FAA. I mean seriously. They could have said something like "increase 'significantly' by which we mean greater than 5%", or whatever else they wanted to say, but as written, it's just dumb, dumb, dumb. Commented Mar 1, 2022 at 17:35
• Seriously I am an actual pilot and have no idea what the right answer should be. Would tend to pick (b) though, assuming the question is asking about a noticeable increase. Though really the graph suggests the bank angle has to get up to 35 degrees or so before there's any increase that's likely to be noticeable to a pilot. Which seems more or less in line w/ my actual experience. So -- ??? Commented Mar 1, 2022 at 17:44
• Note that the load factor's effect on performance could largely be associated with an increase in stall speed, and the increase in stall speed is equal to the square root of the increase in load factor. My intuition that you'd need a bank angle of significantly more than 30 degrees to notice any significant increase in the stall speed associated w' steady-state flight (constant vertical speed). Even though you may perceive some slight increase in G-load at a slightly shallower bank angle. All in all a very subjective, and therefore lousy, question. Commented Mar 1, 2022 at 18:27

From the FAA Remote Pilot Study Guide chapter 4 comes the following graph:

From this graph I suspect they want you to notice that the slope really starts to pick up at around 30 degrees.

Edit: There have been several comments on the quality of the graph here. But note that this is their graph not mine. They make the graph and the test so I’d expect them to be at least internally consistent. However, the text accompanying the graph in the same section says,

Figure 4-2 reveals an important fact about turns—the load factor increases at a terrific rate after a bank has reached 45° or 50°.

So it’s very unclear what answer they want you to pick. But it’s probably not 15.

• Interesting that the load factor looks like less than 1 at 0° of bank on that graph. Commented Mar 1, 2022 at 17:36
• So the FAA cannot even plot an inverted cosine function properly? Sad! Commented Mar 1, 2022 at 18:28
• Yep, I take no responsibility for their choice of graphic….
– Jim
Commented Mar 1, 2022 at 19:01
• Should be approx 1.15 at 30 degrees -- but that's not what graph shows --!! Commented Mar 1, 2022 at 21:07

Actually, load factor (G's) required to maintain altitude increases as soon as you start to bank, but not linearly.

The cosine of the bank angle must give sufficient vertical lift.

At 0 degrees, this represents: 1 G vertical lift/cos bank angle = 1.000 G load factor

At 15 degrees: 1.035 G

At 30 degrees: 1.15 G

At 45 degrees: 1.41 G

So, don't be surprised if the answer is c. I would pick a. as well.