Some nice shading work with the pencil there, especially on the cowling and the wing ribs. Now, I hope you don't mind me doing this, because it is intended to help you rather to be negative criticism, as I would hate for you to spend a lot of time on a painting only to spot this down the line, so here goes...
Take a look at this that I knocked up quickly based on your image, which should hopefully help you a bit with getting perspective totally nailed on:
On an illustration, any object will have three perspective vanishing points, one into the far distance, one vertically, and one off to the side, these being the three dimensions, and any object in the same orientation as another will have the same vanishing points too, such as two aeroplanes in formation for example. I've only drawn vanishing point lines for two of the vanishing points on that thing because the vertical vanishing point only really becomes relevant when drawing ojects with a good deal of height, such as tall buildings and things like that.
Anything that is parallel with anything else on an object (such as the leading and trailing edges of a square wing) will have the same vanishing point, which is where the extended line from such things will meet at the horizon. Thus you have to have such things able to follow an extended line to the horizon if they are to appear as though parallel in your drawing. You've got the front to back (direction of flight) vanishing point pretty spot on in your drawing, and I've drawn a few extended blue lines which show that. Where you need to tweak things a little, is in the other perspective plane, which I've shown in red. On the enlargement of the tail section, I've highlighted where the leading edge of the horizontal stabiliser is slightly out with regard to the main wings, and where the hinge line of the elevator is similarly out by a smidge (the yellow lines following your stabiliser which I've added indicate why it is out by a little bit, as they do not match the red lines going to the vanishing point). As you can see, it's not out out by much, but it's enough to make the rear stabiliser look like it is a bit askew.
Think of a sniper firing from a location right on the horizon: wherever he aims, the bullets will appear to fan out as they come toward you, but they will all appear to come from the same point on the horizon. A vanishing point on a two dimensional drawing, attempting to emulate three dimensions, works a bit like that. Another good example is straight railway lines going off into the distance with telegraph wires running parallel to them. The telegraph wires will have the same vanishing point as the railway lines, the cross bits on the telegraph poles will have the same vanishing point as the crossways sleepers on the railway line.
If you tape your illustration to a big drawing board or a wall, you will be able to plot the vanishing points from a part of your drawing that you are happy with (it might be quite a distance, and you can use a bit of string or something to do it). Anything which should appear parallel in the same dimensional plane should also disappear off to that same point if you extend a line from it. Once you are used to that, you'll find that you can do that sort of thing mentally and with quite surprising accuracy too.
Be careful not to let things such as wing dihedral angles or fuselage taper throw you off when doing stuff like that, and instead plot your lines from known parallel locations or items, such as the wingtips, wing ribs, or wing roots. Wings with a dihedral angle will of course have their own separate vanishing points, since they will not be in the same parallel plane as a horizontal stabiliser for example, that's where things get tricky!
As I say, hope you don't mind me pointing that out, as it is intended in the best way, to help you get a painting you will be happy with. You are clearly very good with a pencil, so I look forward to seeing what you do with a brush very much indeed.
Al