Skywatch From United States of America, joined Mar 2005, 921 posts, RR: 7 Posted (6 years 8 months 1 week 3 days 6 hours ago) and read 1947 times:
My thread about heavy aircraft made me wonder if increased payload on an airliner increases the wake turbulence. For example:
744A and 744B are going in for landing. 744A is empty and 744B is full of cargo. Do they both generate the same intensity wake turbulence? Does the intensity of wake turbulence depend on the overall weight of the aircraft, or the size of the craft itself? Thanks in advance for the answers!
727EMflyer From United States of America, joined Mar 2005, 547 posts, RR: 0 Reply 1, posted (6 years 8 months 1 week 3 days 6 hours ago) and read 1941 times:
Yes! Wake turbulence is a natural phenomenon, produced by every airfoil, whose strength is a function of aircraft weight, wing size/shape, and speed. The strongest turbulence is generated when the aircraft is slow, heavy, and operating in a clean configuration (gear up no flaps). There is lots of good information on this if you do a web search for "wake turbulence."
Loggat From United States of America, joined Feb 2000, 625 posts, RR: 0 Reply 3, posted (6 years 8 months 1 week 3 days 5 hours ago) and read 1885 times:
For a given airspeed, a heavier version of the same plane requires a higher angle of attack to generate the required lift. The byproduct of lift is induced drag. Induced drag increases as the angle of attack increases. Wingtip vortices (wake turbulence) increase in magnitude as angle of attack increases.
Also to note, wingtip vortices are always strongest on planes that have a large spanwise loading (ie. a large amount of weight for each foot of wingspan).
Hypothetically, if you put A330 wings (large span) on a 757, the wingtip vortices would be less intense (let's say that both pairs of wings weighed the same).
There are 3 types of people in this world, those that can count, and those that can't.
SlamClick From United States of America, joined Nov 2003, 10019 posts, RR: 76 Reply 4, posted (6 years 8 months 1 week 3 days 5 hours ago) and read 1896 times:
No.
But higher gross weight does.
A 757 with no passengers or cargo will still throw more wingtip vortex than a 737 with full passengers and bags. "Payload" is just one portion of the weight of an airplane.
Happiness is not seeing another trite Ste. Maarten photo all week long.
Skywatch From United States of America, joined Mar 2005, 921 posts, RR: 7 Reply 5, posted (6 years 8 months 1 week 3 days 4 hours ago) and read 1840 times:
So basically stating the facts, the only differing factors(given the same model of a/c)are the angle of attack and the extra thrust required to keep a heavier load aloft. Correct?
Loggat From United States of America, joined Feb 2000, 625 posts, RR: 0 Reply 6, posted (6 years 8 months 1 week 3 days 1 hour ago) and read 1795 times:
basically... yes
heavier you are, higher angle of attack needed for given airspeed, and more thrust required to overcome increased induced drag.
heavier you are for the same airplane model, the greater the wake turbulence created.
There are 3 types of people in this world, those that can count, and those that can't.
OldAeroGuy From United States of America, joined Dec 2004, 3092 posts, RR: 66 Reply 7, posted (6 years 8 months 1 week 3 days ago) and read 1783 times:
Quoting Loggat (Reply 6): heavier you are, higher angle of attack needed for given airspeed, and more thrust required to overcome increased induced drag.
Usually on approach, the angle of attack is constant for a given airplane because approach speed = (1G stall speed * 1.23) so as weight increases, stall speed increases and approach speed increases.
And although thrust also increases due to increased drag, it's the increased wing circulation (ie lift) that leads to increased wake turbulence.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
Sponsor Message: 
From United States of America, joined Mar 2005, 921 posts, 
From Canada, joined Mar 2001, 2776 posts, 
From India, joined Jan 2001, 29818 posts, 
Sponsor Message: 
Printer friendly format
