FPV (Flight Path Vector) to Judge Flap, Approach, and Stall Speeds?

[adit]

Please excuse my lack of editing skills (original post is at the bottom; the clarified and added to part is immediately below):

Sorry if this is mostly redundant information.

Interesting that this subject creates little interest😊. New to the forum but as a grade 5 for some time and with 4500 or so landings, unable to remember how many years I’ve been using IF, and a PPL years ago, I’ll update this as my current self speaking to what my former self might have wanted to know, just so it appears in the search database. (Disclaimer: I know I’m not the best pilot on the block).

I’ve just read quite a few former posts that were less than enthusiastic about the realism or usefulness of the FPV. I sympathize, and I still turn it off from time to time - it certainly wasn’t in my training aircraft.

The big question: how can I get a handle on flying the aircraft within its capabilities with so many reference speeds to manage?: multiple flap settings, initial approach, over the threshold, safety buffer over the stall etc.

Multiply the above by changes in weight, and density altitude and the temptation and ability to transition to a large variety of aircraft, all with their own base characteristics.

I’ll quickly get out of the way, just listing some other uses:
The FPV is often discussed within the context of being a landing aid, especially but not limited to learning. It does that well. Also the FPV is of course a crosswind component indicator, but also visual vertical speed indicator - you can point it to clear mountains, monitor descent rate more immediately/intuitively etc.

But my key issue is the FPV as an AOA (angle of attack) indicator which gives feedback on how the aircraft’s flyability sits with your choice of flaps as airspeed changes, or targeting an approach speed that balances not too much energy with safety above stall.

So if dispensing with multiple speed charts to shuffle, you put on the test pilot hat just enough to fill in those details more intuitively.

How to practice this? Practice being aware of roughly how many degrees (vertically) the FPV is away from the nose indicator. Use the pitch marks to eyeball the angle. Assuming the typical AOA range is around 2 to 5 degrees, watch for when you start moving toward and maybe beyond 5 degrees - time to add flaps or keep your speed up. After a while this becomes an automatic process, and fun! (UPDATE: depending on reference source 5 degrees appears to be way low; the main point is being aware of what a reasonable range looks like from testing it out a bit)

AOA is of course what allows you “modulate” lift in relation to weight, which is what makes you ascend or descend. The stall is of course the limit on how much extra lift you can get out of that process.

Thanks.

Original message:

Hi, I’m wondering if anyone else uses the flight path vector as an aid to judging the airspeed envelope, especially if you’re the type that tends to hop around often to different aircraft types?

By judging airspeed envelope, I mean, a good airspeed zone to change flap settings, and as an extra gauge to roughly judge a safe margin above stall speeds?

And as an extra, descent rate cross check near landing, and vertical speed at touch down?

[Will_A]

All the time! It’s a super helpful tool when you don’t really know the aircraft’s specific speeds for each flap setting, etc. I actually use it for a bunch of my landings as well. The 737 is the only aircraft I can land by using the live flight deck.

And the FPV is super helpful for landings. Align it with the horizon and let the plane do the rest of the work 🙌

[adit]

Interesting your comment on the 737 in live flight deck. I’ll have to give that a go in comparison for landings, as I also find it very difficult generally to land in live flight deck view. I agree the FPV is a powerful tool but was curious if that’s the general view. Thank you.

[Will_A]

The reason I think the live cockpit is challenging is because you have much less of a “feel” through the screen. I’ve had relatively good luck with the 737 but I have no clue why.

Let me know how it goes!

[adit]

Thanks. In solo mode I tried live flight deck landings for several different aircraft on short final. I need to spend more time on this as my results were inconclusive in that environment - going to short final in solo makes it easier than on expert in a crosswind, with traffic waiting!