737 Landing Gear Question

[Rick G]

Why is it that on the Boeing 737 the main gear wheels and tires are left exposed on the wing underside when retracted with no landing gear doors to cover them? Doesn't this result in a lot of unnecessary extra drag and / or turbulence in this area? To me, this design seems kind of WWII-ish. You would think that in this day and age that the entire gear would be enclosed when retracted.

I can't remember, but did the Boeing 727 also have this style of main gear where the wheels and tires were left exposed like this?

Are there any other modern era jetliners out there that are flying around with any of their landing gear still exposed even when retracted?

Rick G.

[Peter Kesternich]

The 737 main landing gear is designed to minimize drag. For example the outer wheels have caps to create a smoother surface.
If I recall correctly, the idea was to save all the weight and movable parts (causing maintenance) that are involved with gear doors. Originally the 737 started out as a short range airliner with very frequent stops so the additional drag wouldn't weigh in so much. I am pretty sure that if there was substantial savings in drag or fuel consumption involved in designing a door for the main landing gear on the 737, somebody would already have done it.

The ATR-family has a similar design on the main landing gear and as far I know is the only major airliner family with this kind of system.

[bob m]

The A320 design closes in the retracted wheels, but I think Boeing got it correct back in the sixties with the exposed side walls. K I S S

Bob

[MCM]

Also remember that the 737 was designed in days where fuel costs were not the most important thing in an operation. Gear doors and actuators add weight, and the fuseage isn't all that big. Would you make the entire aircraft fuselage bigger to fit it all in?