Hardly noticeable, the fuselage of the 747 buckles a bit in front of the tailfin (the centerline is raised), beginning where the main cargo door is on a freighter and topping where the tailfin has its forwardmost point. I guess its due aerodynamic reasons, but as this to my knowledge is unique to the 747 I would like to know if that's the only reason.
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Re: 747 small "hump" in front of tailfin
I see no hump but the opposite : the fuselage gets "thinner" abeam the vertical fin and stabilizer to apply area rule (see https://en.wikipedia.org/wiki/Area_rule)
It's quite noticeable on the 737 : the bulky rearcone of the first 3 generations of 737 vs the one on MAXs (especially in the horizontal plane).
It's quite noticeable on the 737 : the bulky rearcone of the first 3 generations of 737 vs the one on MAXs (especially in the horizontal plane).
Re: 747 small "hump" in front of tailfin
It is just an aerodynamic fairing.
Re: 747 small "hump" in front of tailfin
I have very detailed factory drawings, believe me, the 747s fuselage is slightly raised there. Its very slightly, just about 1 degree, on a highres profile photo you can see it.
Re: 747 small "hump" in front of tailfin
na wrote:I have very detailed factory drawings, believe me, the 747s fuselage is slightly raised there. Its very slightly, just about 1 degree, on a highres profile photo you can see it.
Now I'm quite interested! Any chance you can share this drawing?
Edit : I see what you mean. We can kind of notice it on this picture as well, starting just aft of the sat antenna
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- Clydenairways
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Re: 747 small "hump" in front of tailfin
Yes hardy noticeable at all, never even spotted that myself. If you want the ultimate "buckle" then the 747SP is the obvious one.
Re: 747 small "hump" in front of tailfin
Think IIRC, the upper deck/hump on the 747 helps with area rule.That aft section is part of it it seems.....
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- 747classic
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Re: 747 small "hump" in front of tailfin
There was a PIP of the " Dorsal fin fairing", it was introduced around 1993/94 and even all our KLM 747classic's were modified in 1995 to obtain a fuel saving of 0,25 %.
Re: 747 small "hump" in front of tailfin
747classic wrote:There was a PIP of the " Dorsal fin fairing", it was introduced around 1993/94 and even all our KLM 747classic's were modified in 1995 to obtain a fuel saving of 0,25 %.
Are you referring to this one?
Thread on that here: https://www.airlinercafe.com/forums.php?m=posts&p=75291
I think the OP is asking about the fact that the top rear fuselage line goes up near the base of the stabilizer. You can see it in the picture that Caltech posted.
Re: 747 small "hump" in front of tailfin
CALTECH wrote:Think IIRC, the upper deck/hump on the 747 helps with area rule.That aft section is part of it it seems.....
Okay, I have to ask, what's with the radome. I realize radomes get swapped from time to time, but this is the first time I've seen it where the lines on the Battleship livery aren't even straight.
Re: 747 small "hump" in front of tailfin
Damn, that's hard to spot...what eyes...my guess is it's just an aerodynamic fairing to reduce drag in that area.
Ralph
www.GMTPilots.com
Ralph
www.GMTPilots.com
Re: 747 small "hump" in front of tailfin
LH707330 wrote:747classic wrote:There was a PIP of the " Dorsal fin fairing", it was introduced around 1993/94 and even all our KLM 747classic's were modified in 1995 to obtain a fuel saving of 0,25 %.
Are you referring to this one?
Thread on that here: https://www.airlinercafe.com/forums.php?m=posts&p=75291
The longer fillet was a change from end of 1993 (January 1994 delivery). Ln.1016 (now a freighter with UPS) still having the old tail as it was since 1969, ln.1017 (retired 2016) the new, longer one.
I think the OP is asking about the fact that the top rear fuselage line goes up near the base of the stabilizer. You can see it in the picture that Caltech posted.[/quote]
Thats right.
Re: 747 small "hump" in front of tailfin
LH707330 wrote:747classic wrote:There was a PIP of the " Dorsal fin fairing", it was introduced around 1993/94 and even all our KLM 747classic's were modified in 1995 to obtain a fuel saving of 0,25 %.
Are you referring to this one?
Thread on that here: https://www.airlinercafe.com/forums.php?m=posts&p=75291
I think the OP is asking about the fact that the top rear fuselage line goes up near the base of the stabilizer. You can see it in the picture that Caltech posted.
Believe the OP is talking about the rear fuselage bulge, not the dorsal fairing. The upper hump turned out to help with area rule.
Red line is the area in question.
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