727 krueger flaps

[allflight57]

Hi, I was wondeing why in a lot of pictures of 727s parked they have the krueger flaps extended but everything else on the wing is clean. Does anyone know the reason for this? Here are some pics to show what I am talking about...

http://www.airliners.net/open.file/1232761/L/
http://www.airliners.net/open.file/1230065/L/
http://www.airliners.net/open.file/1229400/L/

Tyler

[Wodrick]

Like many things in life they droop without hydraulic pressure !

[bflyer]

HI

krueger flaps need hydraulic system 'A' to keep them in the stowed position..when the aircraft is parked , system 'A' hydraulic pumps which are engine-driven no longer pressurize the system, hence the gradual pressre loss..hence the drooping of the krueger flaps

[con-pilot]

There was or is a mod that can be added to the system to keep them retracted. I know a few corporate operators added the mod but I don't know of any airline.

[BelArgUSA]

Flaps "sagging"

That problem, leading edge flaps hanging is common to various Boeing models. Funny thing, in the Douglas DC-8, a similar problem exists with the trailing edge flaps, if planes are parked for awhile, without hydraulic pressure. It is not uncommon to see the trailing flaps "sagging" down and aft, some "10, 20 or more" as position. However, the DC-8 has no "leading edge devices" like Boeings have. The problem with Kruger flaps in i.e. the Boeing 727, is that "little birds" are keen to build well protected nests in these areas.
xxx
So you might get an omelet when you power the hydraulic systems...
xxx

Happy contrails