A380 Aggressive Pitch Changes?
03-22-2009, 04:05 PM
#1
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A380 Aggressive Pitch Changes?
Hi All,
I was riding for the first time in the A380 this past week. I was headed from LHR to DXB on an Emirates 380. I noticed it seemed to be very aggressive in pitch changes. You could really feel them, I though perhaps it was the pilot. Then flying back from DXB to LHR the plane reacted the same way to pitch changes. They seemed overly aggressive and almost uncomfortable for a typical passenger flight. Anyone else been in a 380 and notice this? Any thoughts as to why?
I fly the 320 and it doesn’t react this way....
I was riding for the first time in the A380 this past week. I was headed from LHR to DXB on an Emirates 380. I noticed it seemed to be very aggressive in pitch changes. You could really feel them, I though perhaps it was the pilot. Then flying back from DXB to LHR the plane reacted the same way to pitch changes. They seemed overly aggressive and almost uncomfortable for a typical passenger flight. Anyone else been in a 380 and notice this? Any thoughts as to why?
I fly the 320 and it doesn’t react this way....
03-24-2009, 08:33 PM
#2
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Two Thoughts
DEW:
I thought the MegaBus used the same airfoil-section as the A-320; just more of it. But, if they used an airfoil-profile that is thinner (increased fine-ness ratio) in order to achieve higher critical Mach numbers, then pitch would have to increase more in magnitude to achieve a different Coefficient of Lift than what you are used to.
From your original post, though, I wasn't sure if you are talking about magnitude, or rate of pitch change.
The second thought: where were you in relation to the center of lift? If you were near the tail or nose (maximum length of moment-arm from the center of lift), you are going to feel a lot of up-and-down motion for even small pitch changes. I'm guessing on fuselage dimensions, but I would guess you could be 100 ft aft of the center of lift in the back of the plane, and 75-ish if you were in first-class.
Those moment-arms are double to triple that of the A-320.
I thought the MegaBus used the same airfoil-section as the A-320; just more of it. But, if they used an airfoil-profile that is thinner (increased fine-ness ratio) in order to achieve higher critical Mach numbers, then pitch would have to increase more in magnitude to achieve a different Coefficient of Lift than what you are used to.
From your original post, though, I wasn't sure if you are talking about magnitude, or rate of pitch change.
The second thought: where were you in relation to the center of lift? If you were near the tail or nose (maximum length of moment-arm from the center of lift), you are going to feel a lot of up-and-down motion for even small pitch changes. I'm guessing on fuselage dimensions, but I would guess you could be 100 ft aft of the center of lift in the back of the plane, and 75-ish if you were in first-class.
Those moment-arms are double to triple that of the A-320.
03-24-2009, 08:49 PM
#3
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I thought it would be the same as the 320 also, but it sure didnt feel like it. I was sitting in row 61 directly over the wing on both flights. During pitch changes, especially on top of decent, the magnatude was pretty high. You really felt the decent and it seemed to come on pretty sudden us well. I thought that the pilot was being aggressive for some reason and ATC perhaps asked to expidite from the top as we were preparing for DXB, but a week later the same thing when we approached LHR. If you were in the tail and not an experienced flyer you likely wouldn't like the feeling to much.
On a side note, I have never seen a wing flex like that!!! I took some pics I should post in the photos section. While sitting on the tarmac the gull is enough that you cannot see the end of the wing and only a portion of the winglet and niether engine is visible. On climb you can see a large portion of the outer engine and even some of the inboard. It was very cool to see.
VERY quiet climb too. The IFE showed us at .85 and once I noticed .86 so it is a lot faster than the 320 I am used to driving.
On a side note, I have never seen a wing flex like that!!! I took some pics I should post in the photos section. While sitting on the tarmac the gull is enough that you cannot see the end of the wing and only a portion of the winglet and niether engine is visible. On climb you can see a large portion of the outer engine and even some of the inboard. It was very cool to see.
VERY quiet climb too. The IFE showed us at .85 and once I noticed .86 so it is a lot faster than the 320 I am used to driving.
03-25-2009, 05:24 AM
#4
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After I posted last, I figured it must have a different airfoil than the -320, as .80 is a pretty slow top-speed for something that can fly halfway around the world. That would make some pitch changes bigger.
I would assume the speeds in the 380 are similar to the 747. Redline Mach in the 747 is 0.92, and we cruised anywhere from .83-.87 (.84 being most common).
Wing flex in the 747 and B-52 are legendary, with quoted ranges of +/-12 or so feet at the tips.
I would assume the speeds in the 380 are similar to the 747. Redline Mach in the 747 is 0.92, and we cruised anywhere from .83-.87 (.84 being most common).
Wing flex in the 747 and B-52 are legendary, with quoted ranges of +/-12 or so feet at the tips.
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