potus From United States of America, joined Jan 2012, 14 posts, RR: 0 Posted (3 months 3 weeks 1 day 10 hours ago) and read 3814 times:
Hello all,
Does the Boeing 747-8 flare less than the Boeing 744 when landing? From the below video, it seems like the Boeing 748 doesn't flare much on touchdown...
CZ346 From China, joined Feb 2012, 45 posts, RR: 0 Reply 3, posted (3 months 3 weeks 1 day 9 hours ago) and read 3394 times:
Flare isnt exactly part of the landing checklist. Situational variables are mainly what determins it (wind, OAT, presssure, a/c weight, etc.). In my experience of flying the only design component that changes how I conduct my flare is a high wing vs. low wing a/c.
UAL747 From , joined Dec 1969, posts, RR: Reply 6, posted (3 months 3 weeks 22 hours ago) and read 2605 times:
Essentially, I would believe the maximum flare angle would be a touch less than the 744 just because it is longer. Same reason for the 77L vs. the 77W, but having an exact angle of flare is easy on paper, impossible in real world conditions. Many things change while a plane is landing that change the flare considerably. That said, I think overall, it would probably have a slightly less flare than the 744.
However, one thing I've noticed, and this may just be mean, but it seems that Airbus widebodies, excluding the A380, have a tendency to have a higher angle of flare than their Boeing counterparts. Anyone else notice this? In fact, I'd say that even before the flare, the angle of attack on approach is higher than those of Boeing.
DocLightning From United States of America, joined Nov 2005, 14050 posts, RR: 55 Reply 8, posted (3 months 2 weeks 6 days 14 hours ago) and read 2156 times:
Quoting wilco737 (Reply 5): Ask me again in a couple months when I have flown the 748i...
Go on. Rub it in more.
The best part of that video was where the CX 744F lifts as the 748 rolls out.
KAUSpilot From United States of America, joined Jan 2002, 1934 posts, RR: 43 Reply 9, posted (3 months 2 weeks 6 days 13 hours ago) and read 2131 times:
The flare is about the same........there is just less margin for error. There is no special tail strike warning system on the 747, including the -8, that I'm aware of.
Roseflyer From United States of America, joined Feb 2004, 7621 posts, RR: 51 Reply 10, posted (3 months 2 weeks 6 days 3 hours ago) and read 1948 times:
Quoting KELPkid (Reply 7):
Is there any tailstrike protection on the 748? I'd imagine it's probably much easier to scrape the tail on the ground in the
Yes there is tail strike prevention. The elevator will move if one is detected to be imminent without pilot input
If you have never designed an airplane part before, let the real designers do the work!
UAL747 From , joined Dec 1969, posts, RR: Reply 11, posted (3 months 2 weeks 4 days 2 hours ago) and read 1497 times:
Quoting Roseflyer (Reply 10): Yes there is tail strike prevention. The elevator will move if one is detected to be imminent without pilot input
Really? The aircraft taking control of such a maneuver during the most critical point of any flight seems a bit dangerous. What if you have a Tenerife type situation going on?
Roseflyer From United States of America, joined Feb 2004, 7621 posts, RR: 51 Reply 12, posted (3 months 2 weeks 4 days 1 hour ago) and read 1478 times:
Quoting UAL747 (Reply 11): Quoting Roseflyer (Reply 10):
Yes there is tail strike prevention. The elevator will move if one is detected to be imminent without pilot input
Really? The aircraft taking control of such a maneuver during the most critical point of any flight seems a bit dangerous. What if you have a Tenerife type situation going on?
The 747-8 has a pitch augmentation control system. It will activate if an overrotation or if excessive flare is detected as well as in a few other abnormal flying conditions. It is in series with the pilot controls, so the pilot will not feel it activating.
Such systems are relatively common and on almost all modern airliners. The 777 has such as system as well, but since the airplane is fly by wire, it doesn't have a physical actuator doing it, but rather it is factored into the control laws. The 747-8 uses a hybrid fly by wire system with mechanical cable controls for primary elevator control. The pitch augmentation system is a fly by wire system that provides additional limits on the airplane that are seen in other fly by wire systems. It activates to prevent tail strikes and stalls.
As with all Boeing architecture, the control laws can be overridden with pilot contols. The pitch augmentation system will create elevator down inputs to lower the nose if a tail strike is detected to be imminent, but it can be overridden if the pilot pulls further on the control column. It is similar to stalling the airplane. A 747-8 can be stalled, but it requires very high control column forces, ignoring a stick shaker and aural warnings, and counteracting the automated protection. A tail strike can be done on a 747-8, but it does require counteracting the automated protection.
If you have never designed an airplane part before, let the real designers do the work!
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