Out of the Big Three WW2 bombers (B-17, B-24, Lancaster), was the Flying Fortress the most redundant?
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That sounds like a summing up about the Liberator's vices. Is there one of the B-17?
Although the Liberator's controls were heavy, I heard that it was quite agile for such a heavy, at least compared to the Fortress.
A high-aspect-ratio wing is advantageous to roll rate.
Searching for n2871g came up it being a former PB4Y-2 Privateer which was built with single tail
Shortround6
Major General
Thank you, sorry I wasn't clearer. It is tough going by pictures but it looks a bit taller than some other pictures.
It could be just the angle. I know a number of them got the R-2600 engines when they were converted for fire fighting. I don't know if they changed anything else.
It could be just the angle. I know a number of them got the R-2600 engines when they were converted for fire fighting. I don't know if they changed anything else.
Back in 2000 when there was many fires in the US west seen one start up and take off from Grey Bull Wyoming.
FLYBOYJ
"THE GREAT GAZOO"
And that high aspect wing didn't help when you lost an engine as documented in the story I previously posted.
Greg Boeser
1st Sergeant
Notice how nobody uses the Davis wing any more?
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Or Grumman blue paint?
They found a use
ThomasP
Senior Master Sergeant
re "A high-aspect-ratio wing is advantageous to roll rate."
In general in the WWII period, higher aspect ratio wings were at a disadvantage in roll rate when compared to lower aspect wings.
If we assume both wings are of approximately the same weight and everything else being equal (ie same basic fuselage, same effective wing area, same aileron area, manual-mechanical actuation, materials, etc), then:
1. The maximum roll rate of the higher aspect wing will be less than that of the lower aspect wing, due to roll induced drag forces acting against the direction of roll centering further out on the wing.
2. The higher aspect wing will be weaker in structure for the same weight, in the radial g and vertical g directions.
3. The higher aspect wing - in order to roll at the same maximum rate as the lower aspect wing - will require larger area ailerons to overcome the mechanical disadvantageous roll induced drag forces, which will result in higher pilot control forces, and higher roll induced drag forces while rolling.
4. If the ailerons are placed further out on the span to overcome (some of) the mechanical disadvantageous forces, such that it improves the roll acceleration to match or exceed the lower aspect wing, then the wing structure will have to survive greater bending and radial g forces, resulting in a heavier structure weight.
5. If the aircraft is required to lift the same useful load, the higher aspect wing will have to withstand higher bending forces in the vertical direction during flight, and withstand higher bending and g forces on landing. Some things can be done to reduce these forces at specific points/areas of the wing (such as moving the landing gear further out on the wing), but they all result in decreased roll acceleration or increased weight.
The only real increase in performance that a higher aspect wing offered in the WWII era was lower induced drag in the lower IAS regimes, ie cruise and for aircraft that did not approach the higher speeds where Mach compressive effects started to come into significant effect. This would be a max of about 350 mph with the technology and knowledge available at the time (I think) and if you exceed this speed, any reduction in induced drag would disappear, and above this speed induced drag would increase faster than for the lower aspect wing.
There could have been an advantage at "roll response" at lower speeds when low roll rates were used, such as precision in minor corrections during landing, but I have not read any mention in the hands-on/operational tests done in the WWII period.
In general in the WWII period, higher aspect ratio wings were at a disadvantage in roll rate when compared to lower aspect wings.
If we assume both wings are of approximately the same weight and everything else being equal (ie same basic fuselage, same effective wing area, same aileron area, manual-mechanical actuation, materials, etc), then:
1. The maximum roll rate of the higher aspect wing will be less than that of the lower aspect wing, due to roll induced drag forces acting against the direction of roll centering further out on the wing.
2. The higher aspect wing will be weaker in structure for the same weight, in the radial g and vertical g directions.
3. The higher aspect wing - in order to roll at the same maximum rate as the lower aspect wing - will require larger area ailerons to overcome the mechanical disadvantageous roll induced drag forces, which will result in higher pilot control forces, and higher roll induced drag forces while rolling.
4. If the ailerons are placed further out on the span to overcome (some of) the mechanical disadvantageous forces, such that it improves the roll acceleration to match or exceed the lower aspect wing, then the wing structure will have to survive greater bending and radial g forces, resulting in a heavier structure weight.
5. If the aircraft is required to lift the same useful load, the higher aspect wing will have to withstand higher bending forces in the vertical direction during flight, and withstand higher bending and g forces on landing. Some things can be done to reduce these forces at specific points/areas of the wing (such as moving the landing gear further out on the wing), but they all result in decreased roll acceleration or increased weight.
The only real increase in performance that a higher aspect wing offered in the WWII era was lower induced drag in the lower IAS regimes, ie cruise and for aircraft that did not approach the higher speeds where Mach compressive effects started to come into significant effect. This would be a max of about 350 mph with the technology and knowledge available at the time (I think) and if you exceed this speed, any reduction in induced drag would disappear, and above this speed induced drag would increase faster than for the lower aspect wing.
There could have been an advantage at "roll response" at lower speeds when low roll rates were used, such as precision in minor corrections during landing, but I have not read any mention in the hands-on/operational tests done in the WWII period.
Any idea where this bridge is?
buffnut453
Captain
Nassau County FL.
US-17 St. Marys River Bridge - HistoricBridges.org
Historic Truss Bridge in Rural Nassau County, Florida and Camden County, Georgia. This bridge is not only an impressive and locally rare example of a highway truss swing bridge, it was built for an important travel corridor.
historicbridges.org
I just googled "US-17" and "bridge" and it was the #1 pick.
My Google-Fu is strong!!! You must respect the Google-Fu!!!!!!!
Thumpalumpacus
Major
I am not trying to roll a B-24, there's just not that much beer in the world.
James River, Newport News Virginia. The B-24 was flown parallel to the (old/original) James River Bridge and came to rest within a few hundred yards of the Newport News Shipbuilding and Drydock Company. The flight originated at Langley Field (Hampton, VA), 6 1/2 miles away. Here are longer version videos of ditch test, conducted under absolutely ideal conditions, and the aircraft nearly broke up.
B-24 Ditching - Search Videos
B-24 Ditching - Search Videos
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Well Fu'ed! That place is not far from Jacksonville (where I reside). I thought it looked familiar but after looking at the map don't think I've been over it. Thanks for passing that along!Nassau County FL.
US-17 St. Marys River Bridge - HistoricBridges.org
Historic Truss Bridge in Rural Nassau County, Florida and Camden County, Georgia. This bridge is not only an impressive and locally rare example of a highway truss swing bridge, it was built for an important travel corridor.
I just googled "US-17" and "bridge" and it was the #1 pick.
My Google-Fu is strong!!! You must respect the Google-Fu!!!!!!!
From what I recall, the key to the Davis wing was that by sheer luck it happened to be better at maintaining laminar flow than previous wings (It was based on a teardrop shape modified to provide lift). The NACA 6-series essentially accomplished the same thing, which made it redundant, plus thick strong wings were not a good idea in the jet age. Thick wings like the Davis also have some undesirable characteristics such as "very high drag if the surface is roughened", which is why NACA advised Martin to make the 6-series airfoils on its XB-33 thinner.
I'm not sure to what extent the Davis did impact the Lib's crashworthiness, though I think we've all seen the video of a B-24's engine catching fire and the wing folding in half.
I love the B-24 and its odd looks myself, it's probably my favorite out of the three, but I sure as hell would not want to ditch or even belly-land in one. The Lady Be Good broke in two despite crashing at low speed and at a low angle onto a flat surface.
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special ed
1st Sergeant
- 5,162
- May 13, 2018
The "lady be good" crew survived the initial landing. They thought they were over water rather than desert. The fuselage breakup was at the classic B-24 locations.
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- #278
Thanks for the good explanation. The Germans happen to prefer higher aspect ratio because they prefer high roll rate (this I saw in publications) for their slash'n'dash tactics. But then again they also tended to build planes with comparably smallish wings overall and were willing to accept higher wing loads.
Especially Messerschmitt insisted on his planes to have abnormally wing loading early on.
This was due to his obsession for light build and focus on performance rather than pilot friendlyness.
Focke Wulf combat aircraft rolled well over most of the speed envelope and had quite sturdy wings as well as large ailerons.
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They parachuted, no one went down with the airplane. And one of them did die, though parachute failure cannot in any way be attributed to the B-24's characteristics.
Unclear if the landing would be smoother had they stayed onboard, since as I said, the plane came down at a pretty shallow angle, though they might have been able to flare better or keep the running engine from hitting the ground. Not criticizing their decision though, they didn't have all the information.
The B-24 is odd. There is footage of it coming back with significant damage (including an aircraft that has another B-24's vertical stabilizer stuck to its nose), but also footage of it crumpling up at the slightest hint of damage.
I'm not sure to which extent this is true, but I always figured a big factor was the shape of the fuselage. B-17s and B-26s have mostly-circular cross-sections and fair quite well in belly landings, B-24s are tall and skinny and break up easily. Of course, the B-17 is also helped by its low wing and semi-exposed wheels.
B-17 Ditching. The low wing design probably assisted in increased crew safety, opposed to B-24 ditching characteristics.
www.bing.com
b-17 ditching - Search Videos
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