Talk:Tractor configuration

There's a lot of talking about the use of guns on a plane. Off course, there is a relation, but I think that the last paragraphs are irrelevant to this article. Delete them?

One thing that's missing (both on this page and the push page) is the reason for the decline of the push configuration, i.e. the advantages of the tractor configuration. Request for expansion perhaps ?

Hirudo 06:56, 4 September 2005 (UTC)

Eh?
The intro says tractor configured aircraft have "the propeller facing forward...as opposed to the pusher configuration, in which the propeller faces backward...". The pusher prop is situated rearward on the aircraft but it faces forward. If it faced backward the aircraft would go it that direction. Moriori (talk) 02:10, 24 February 2014 (UTC)


 * No. "The direction a propeller faces does not determine the direction (strictly, the "sense") of its thrust - otherwise it would not be possible to have 'pusher' and 'tractor' propellers, which obviously face in the opposite direction ("sense"). The direction of the thrust produced by a turbine or a propeller is a product of the relationship between the left/right handedness of its pitch and the direction (clockwise or anti-clockwise) of its rotation. Contra-rotating propellers, for instance, (and this is true whether they are pushers or tractors) need to have opposite "handedness" (i.e. to have their pitch reversed) if they are to act in the same "sense". Which way a propeller "points" has nothing to do with the case. --Soundofmusicals (talk) 03:38, 24 February 2014 (UTC)
 * So.
 * An aircraft flying from our right to left has a propellor on the nose which faces {.
 * Aircraft does a 180 and is flying to the right so the prop is now pointing }.
 * We magically move the propellor to the rear of the aircraft which continues to fly to the right.
 * Is the propellor still facing forward of the aircraft, }, or is it facing backward, {, as our intro states?  Moriori (talk) 07:51, 24 February 2014 (UTC)


 * If the aircraft turns then the direction in which it is flying changes. But you can't just turn a propeller on an aircraft round, or move it to the back, and change the direction in which the propeller "propels" it. (Try reversing the propeller on a model aircraft if you don't believe me). You need to either spin it in the opposite direction, or reverse its pitch. If you do both, of course, (as you effectively do if you turn the propeller to face in the opposite direction) the two changes cancel each other, and the propeller continues to thrust the same way it did before. A tractor propeller "faces" to the front - that is not in itself why it "pulls" rather than "pushes", the pitch and direction of rotation need to be the right way round or the aircraft will indeed try to fly backwards. But that doesn't alter the fact that a tractor propeller "faces" forwards, relative to the rest of the machine. Nothing esoteric here - just using a common word in its usual sense. --Soundofmusicals (talk) 12:22, 24 February 2014 (UTC)
 * rutan.long-EZ.g-wily.arp.jpg have included info that would be obvious to anyone, such as when an "aircraft turns then the direction in which it is flying changes," which is straying from the point.
 * Let's revisit my original paragraph, but put it differently. Look at the aircraft in the image on the right. If we added an engine to its nose and transferred the existing propellor to that engine, would it not then move the aircraft forward? I am talking about the physical attitude of the propellor still being exactly the same as it is at the rear, with the same rotational direction and not being reversed (a la your model example). Wouldn't it function exactly the same whether mounted on the rear or front of the aircraft? (Please don't confuse the issue by introducing efficiencies, airflows, modifications needed, etc.) Moriori (talk) 02:27, 25 February 2014 (UTC)
 * If you want to change a pusher aircraft into a tractor you need to do the following:
 * 1. You have to take the propeller/engine combination off the back, turn it round, and face it in the opposite direction. A pusher propeller faces back (by definition, that's what a pusher propeller is). A tractor propeller faces front (by definition, that is what a tractor propeller is.
 * 2. Having moved the engine/prop combination to the front, the aircraft will still be "pushed" - i.e. it will try to fly backwards. Perhaps this is what is confusing you. Just turning it round hasn't actually changed anything - it still thrusts in the same direction. But it is now at the other end of the aircraft (facing in the opposite direction), so its effect on the machine has been reversed.
 * 3. What needs to happen is to reverse the thrust of the propeller, so that it pushes back (or "pulls"). Ask anyone who makes flying model aircraft (or an aeronautical engineer, of course). If a forward facing (tractor) propeller is going to do what a tractor aircraft does (fly behind its prop rather than in front of it) then it needs to have the appropriate "handedness". Depends on which way the engine turns whether it needs to be left or right handed - but it will be the other way round, i.e. the pitch will need to be reversed. You can get the same effect by putting in an engine that spins the other way - either by making it run in reverse, or fitting gears that make it turn the propeller the other way.
 * This ignores, as you mention, prop efficiency - there is more to the difference between a right and a left-handed prop than the direction you spin them! (Leading and trailing edges of the blades and so on). --Soundofmusicals (talk) 06:30, 25 February 2014 (UTC)


 * Think of (for instance) a big airliner coming into land - usually it loses speed after the wheels touch down by reversing thrust as well as putting the brakes on the wheels. In a propeller aircraft the reverse thrust comes from reversing the pitch of the propellers (in a jet they do something similar with the turbine, so that it blows air out the front, but that's nothing to do with our case). --Soundofmusicals (talk) 06:46, 25 February 2014 (UTC)
 * Answer the question. If a rear mounted propellor is moved to the front of an aircarft, will it still propel the aircraft forward? Yes or no. Moriori (talk) 07:35, 25 February 2014 (UTC)
 * 1. No. It wouldn't do anything at all unless you moved the engine too, and in that case it would push the aircraft backwards. You can set up that engine, with that propeller on it, anywhere you like, and it will still "fan" away from the engine. If there was a way you could somehow hang the engine out right in front of everything - including the propeller (an interesting engineering project) then yes - but then that would still be a pusher, because the force in the prop shaft would act by compression rather than tension. --Soundofmusicals (talk) 11:51, 25 February 2014 (UTC)
 * That's an awful lot of sidetracking there. Simplified. The prop faces forward in relation to the airframe regardless of whether the engine is behind it ("puller") or in front of it ("pusher"). After considerable googling I could find no adequate technical/expert reference for "the propeller faces backward" so I am removing it from the intro.  I believe my rewrite also markedely improves the intro. Moriori (talk) 03:01, 26 February 2014 (UTC)

We have already wasted far too much time on this one - the text as you have changed it is still fairly clear and might as well stand, at least for the moment. Of course the engine of a tractor is behind the propeller, while the engine of a pusher is in front of it. But you could say, on more or less the same grounds that you have been arguing on, that the propeller is always behind the engine, and always in front too - depending on which way the aircraft is facing. Which comes down to a statement of the original explanation, and goes to show how useless semantic gobbletygook is, especially when trying to explain something technical. Probably a clearer explanation would be something to the effect of "the propeller shaft of a pusher is compressed, while that of a tractor is stretched". If you could find a clearer way of phrasing that one it might even really be a "marked improvement". --Soundofmusicals (talk) 11:16, 27 February 2014 (UTC)
 * We haven't wasted too much time on this at all. You maybe, but definitely not me, because I have got rid of an embarrassing schoolboy howler which Wikipedia has presented to readers as fact for more than nine years. And as for "semantic gobbletygook" (sic), your statement  "the propeller shaft...of a tractor is stretched" beggars belief. Ka kite ano. Moriori (talk) 02:48, 28 February 2014 (UTC)

Deflector wedges
The use of deflector wedges when firing through the propeller could use further explanation and ideally an illustration. It isn't very clear how this works.Bill (talk) 23:57, 3 October 2015 (UTC)