Since you've received your Lesson 7 critique previously and have opted to take me up on my offer to be able to submit a new set of vehicle constructions, this is going to be a shorter, more focused round of feedback, specifically targeting advice I think can help, and addressing the question you included in your post about the airplane.

So jumping right in, one of the biggest things that I think is making this work more challenging for you is a question of space. That is, how much space you've given to the vehicle construction on the page, and in turn choices in how to approach the drawing that may have further increased the difficulty of working with a limited amount of room.

Looking at this motorbike for instance, it's taking up less than a quarter of the space available on the page, and so you end up having to work within pretty steep constraints, and having to pick through much tighter subdivisions, making it harder to distinguish between them. While we're never going to be able to make complete use of all of the space on the page, we can definitely set up our bounding boxes with allocating as much of that space to our use as we can, and that will help spread the clutter out and make things more readable.

Furthermore, opting to fill areas in with various kinds of shading, hatching, etc. as well as going back over all of your linework to add additional thickness (as opposed to approaching that line weight in the more limited fashion discussed here in Lesson 1, which I had mentioned in my feedback on your original Lesson 7 submission) can further contribute to just how much is packed into a small space. I understand that at times the intent is to allow the drawing to stand out from the subdivision lines for the sake of clarity, but this approach to achieving that works on the basis of making the vehicle itself always stand out more, and therefore making it harder to discern those subdivisions. Conversely, the approach we encourage being much subtler simply makes it easier to focus on the individual aspects of the construction. It gives our brains enough information to organize what it's looking at, and pull the vehicle apart from its underlying construction, but while still allowing that construction to be perceivable for when we need to continue working with it.

In effect, in trying to make the vehicle more visible, you tended to make things more haphazard and messy, which worked against you. That's not to say the underlying constructions are bad - as far as I'm able to make them out, they're fine. You're just too eager to create an end result, a rendering, that can be shown off, rather than first and foremost treating these drawings as the spatial reasoning exercises that they are.

While the aggressive line weight is certainly still present, I do think that this one is generally more successful for the purposes of being an exercise. It demonstrates really thorough, mindful subdivision, and shows that you thought through the various relationships, gradually carving pieces out from the larger block and refining the shapes as you went. It demonstrates the clear focus on precision very nicely.

As to the plane you were asking about, since you included two different planes amongst your detailed vehicle constructions, I'm somewhat unclear on which was the one you were focusing upon. That said, setting aside the advice I've offered in terms of ensuring you have more room to work, and not going back over your drawings with shading, I think both were pretty well constructed, though I do see that with both the viewing angle was altered. For the purposes of our lessons, I don't consider that a problem or a mistake, for the simple reason that Drawabox is not an observational drawing course.

That is to say, we don't focus on reproducing reference images exactly as they are - rather, our focus is on understanding how the things represented in the photos exist in space, how they can be broken down into simpler forms. The purpose being of course to be able to change the viewing angle, or even make structural alterations to the object itself. So part of your confusion here could simply be coming down to what the methodologies we've been practicing focus on, and what they don't.

When it comes to observational drawing, the techniques used actually tend to shift back to understanding what it is you're trying to reproduce as it exists in 2D space. It focuses on the relationships between different elements of the structure as they are seen from that specific angle. So for example, these notes I've drawn on top of your reference are the kinds of things one would also be taking into consideration, if the goal is to draw the vehicle specifically from that angle. But again - that's not the purpose of this course, and we specifically avoid things that require more focus being put on the 2D elements, as this can lead to confusion as we try and focus on 3D spatial reasoning.

As far as what this course covers, you're applying that stuff well. Yes, you could stand to give yourself more space, to skip the shading/rendering and aggressive use of line weight, and you'd probably benefit from a full set of ellipse guides to avoid having to freehand all of your ellipses (which is prohibitively expensive for most, and for our purposes here still not really required), but when it comes to the concepts we're teaching, you've developed those spatial reasoning skills well.

Now, I'll be marking this lesson as complete again, and since official critique is offered at a price point that is subsidized (cheaper than what it costs us to provide it without credits being allowed to expire), I think your best bet moving forward will be both to continue making use of advice from other students on the discord server, but also to take some time to reflect on what exactly it is you want to be able to create, so you can focus your efforts on the skills that are relevant towards those goals.

So if your intent is very much to be able to reproduce the photo references you see, then investing resources into developing your observational skills, even taking courses to that end, may well be worthwhile. But if that's just something that bothered you because of how those particular constructions weren't turning out in the way you wanted, but aren't actually that closely tied to the goals and the things you're learning to draw in order to create (your own projects, designs, illustrations, etc) then I wouldn't let that distract you.

Ultimately the 50% rule - which I assume you've been adhering to throughout the course - serves as a guide, by showing us what we're interested in investing our time into, and where our skills fall short in accomplishing those things as we would like to be able to in the future. In turn, this points towards areas we might study to shore up those skills.