uplinker,
No: there are no tip vortices.
Certification: the bending moment of the wing is increased substantially with a winglet, Boeing had to 'prove' the forces under circumstances, especially with speed brakes, so that the forces were in bounds of the wing design, and additional reinforcement was not required (ie re-cert of the ac)
Winglets are a balance that must be considered, when deciding to purchased them, or in fact offer them.
In offering them, its a doubled edge sword, as an add on, you are basically stating shortcomings in the wing design of the aircraft. Much like the advertised increased benefits of the air system of the 787, vs your current platforms.
To compound the issue, offer a completely different winglet design on the 737MAX....
As stated before, the airflow over the top of the wing, as the section decreases, becomes turbulent, creating drag.
The winglet design moves that turbulence outward, creating less drag, and allows for a decreased angle of attack on the wing.
This has the most benefit on the beginning of the enroute phase of flight.
As the fuel load decreases, and the required angle decreases, the benefit of the winglet decreases vs the minimum required for level flight.
Last edited by FlightPathOBN; 21st Jun 2012 at 01:10.