Comments by "Gort" (@gort8203) on "“A Fun Airplane to Fly Because It Had So Much Wrong with It" – The Grumman XF10F Jaguar" video.

I would just like to note that the Me-262 is not the best example of early swept wing aircraft because its wings were not swept to increase its critical Mach number, but rather to change the distance between the center of lift and center of gravity. The original design had straight wings but the engine nacelles turned out to be heavier than anticipated, so the wings were adjusted to move them aft. It was simpler to change the wing angle than to redesign the fuselage and rearrange the structure and internal components. The wings ended up at the same slight sweep angle as the earlier DC-3 transport, which had slightly swept wings for the same reason.
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@thekinginyellow1744 Yes, the significance of the 163 is that it was a tailless flying wing. Actually, I don't think the wings of the 163 were swept to delay compressibility at all. I think they were swept for the same reason all flying wings without a horizontal tail are swept -- so the outboard portion of the wing is far enough aft to balance the nose down pitching moment of the wing and provide pitch control.
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@johnshepherd8687 The wing of the 262 was not swept to delay compressibility effects, it was swept to adjust the relationship between the center of gravity and the aerodynamic center when the engines turned out to be heavier than planned after the design was already established. The wings on the Dougals DC-3 were swept to the same degree for the same reason, and it didn't make that airplane any faster. I think the 262 was faster than the early Meteor, but the later Meteor with more thrust was faster than the 262. The P-80C was faster than the 262 on its single engine and straight wing. I don't think the 18.5 degree sweep of the 262 was a significant factor in the performance of the airplane.
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@johnshepherd8687 So it may have increased the critical Mach by 3% (16.8 mph). That is not significant even if the top speed was limited by compressibility rather than available power, which I have no reason to believe. With the Meteor and P-80 able to go faster with straight wings I don't see why it is necessary to credit the slight sweep of the 262 wing as responsible for its top speed.
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@thekinginyellow1744 I don't consider the Me-163 to have a delta wing, which is a sharply swept triangular wing like that of the F-106 or MiG-21, but simply a mild sweep angle. I can't find a reference for that angle, but I'm guessing it is not much more than 20 degrees. You don't see appreciable increases in the speed for critical Mach and peak drag Mach until around 25 degrees of sweep. A 30 degree sweep will increase those numbers by 8 and 15 percent respectively. I'm extrapolating a guess that the 18.5 degree sweep of the Me-262 would only provide improvements of 3 and 5 percent. I would be interested to see any hard numbers anyone may have. So I'm just guessing here, but I suspect that the wing sweep angle chosen for the 163 was the minimum necessary to provide the stability and control sufficient for good maneuverability. Increasing the sweep angle would have provided even more, but would also have reduced the climb rate of the aircraft, which was a critical performance parameter due to its design mission profile and limited fuel. Again, I would be interested in seeing any hard info on this.
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@johnshepherd8687 I don't see the evidence that the slight sweep of the 262 wing provided the dramatic effect you claim for it. The effect was slight, and the main point is that it was *inadvertant*. Happy holidays.
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This video made me notice that nearly all variable geometry aircraft had shoulder mounted wings, even before that arrangement became fashionable for fighters. I'm thinking it has to be more than coincidence. Structurally, it seems to me that a low mounted wing would be more efficient, especially for a carrier based aircraft, so perhaps this has an aerodynamic purpose. If anyone has any info please comment. All I can speculate is that the high wing with zero or negative dihedral makes the airplane less susceptible to variations in lateral stability as the wing angle changes.
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@KB4QAA Asking a question is not providing insight. What an asshole.
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David Rees Good question. With some variation, why not roughly the same place they go in an F-14 or F-111? Gear retracts into a different place than the wing pivot box, although if you could have the same basic structure carry both loads that would probably be efficient. Ordnance goes under the belly and fixed portion of the wing, and you can even have pivoting pylons on the swinging portion of the wing like the F-111 if you really need more pylons. This is all just speculation, which is why I'm just asking if anybody has any actual information about whether such a configuration was ever considered, and I'm especially interested in whether there are any lateral stability implications to a swinging low mounted wing.
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@davidrees7978 Yeah, I was not asking about this specific airplane, I'm interested in the general principles.
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@davidrees7978 Either I don't see the point you are trying to make, or it is not a logical one. You point to the Panther, a particular airplane, and state that its small size in comparison to others is a factor. I agree and say I'm not interested in that particular aircraft but in a general principle which may apply to others. Now you are trying to say what, that if that arrangement doesn't work in one particular instances it must hold for all others?
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@richardvernon317 Thanks. I knew there had been at least one with a low mounted wing but couldn't think of it at the time.
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@davidrees7978 Well, your last comment did seem to lead nowhere. But thanks for the well wishes and same to you.
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@richardvernon317 So it looks like my initial impression was incorrect. The shoulder mounted wings were all that came to mind at the time, but it seems VG wings have indeed been set at all heights. Thanks for clearing up the fact that there is actually no mystery here at all.
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@richardvernon317 Agree with all your comments, but perhaps it's not completely fair to characterize aircraft designers as lazy. I think most would love to start with a clean sheet of paper, but derivative designs are often proposed with a primary consideration of minimum cost or time to develop, so substantial changes to what came before have to earn their way on to the new model. I appreciate your comments.
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