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-   -   Landing gear tilt angle difference between a B777 200LR & 300ER (https://www.pprune.org/tech-log/595088-landing-gear-tilt-angle-difference-between-b777-200lr-300er.html)

agg_karan 30th Jun 2017 18:57

JetII - the stow angle is 5 nose down (200LR) however the capability is -19 down. Question was which phase of flight it goes to -19?

What's more surprising is that in both pictures posted by me the only time 'ground' or 'touchdown surface' is shown is when the angle is -19. Rest images only a horizontal line is shown (to exaggerate a medium to differentiate the angle wrt zero datum)

Hence my doubt :)

underfire 1st Jul 2017 00:19

OT: I see that Boeing is looking to use the semi-lever design for the Max 10 to prevent tailstrike.

stilton 1st Jul 2017 06:03

How does that work on a single axle bogie ?

underfire 1st Jul 2017 07:52

Before,they were calling it telescoping, but at Paris, they are calling it a semi-lever or trailing link. Was thinking along the lines of the Embraer E2 landing gear, but not sure with this from Boeing.

737 MAX vice-president and general manager Keith Leverkuhn said in Feb 2017 ."Boeing has been evaluating multiple “good ideas”, including a shift from the 737’s traditional oleo strut to a trailing link landing gear design, A key criteria in the final decision (of the MAX-10) later this year will be the inherent reliability of the landing gear design,"

Keith Leverkuhn said on 2nd May about the -10 MLG: “The design focus is on the upper portion of the gear as it integrates with the actuator. In this area, within the tight confines of the existing wheel well, Boeing’s new design will do some “clever folding using a link mechanism at the top,”

"The lower section of the leg is also modified with an additional shock strut that fits inside the same forging. This moves the contact point aft a little bit. That’s fundamentally what we are doing and yes, it will look like a trailing link gear. We want to make it maintainable, reliable, and we are going to need that gear to get the performance we want out of the -10 but I’m confident in the solution set,”

Jet II 1st Jul 2017 14:03


Originally Posted by agg_karan (Post 9817437)
JetII - the stow angle is 5 nose down (200LR) however the capability is -19 down. Question was which phase of flight it goes to -19?

Rotation.

On rotation the aircraft rotates around the centre axle which then gives you the 'nose down' scenario - although you will never get to -19 in real life.

Jet II 1st Jul 2017 14:07

sounds more like an A330 style gear strut mechanism than a 777 SLG.


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