Western737 From United States of America, joined May 2000, 489 posts, RR: 0 Posted (11 years 2 months 1 week 3 days 8 hours ago) and read 2906 times:
As I grew up flying WA 737-247's, I vividly remembered WA's 737-247's leading slat functions during landing approach only till I looked at all other airlines' 732's and realized that WA 732's probably the ones of fewest 732 types that has leading slats function different from most of 732's. What I am trying to say that most 732 leading slats tend to have first 2 slats go down little bit further than end slat. While WA's 732 is opposite as thier end leading slat down more further than first 2 slats. It's only during landing, not during take off. Can anybody tell why is that? I cant find best picture of WA 732's landing approach with end leading slat so here this one.
OPNLguy From , joined Dec 1969, posts, RR:
Reply 2, posted (11 years 2 months 1 week 3 days 4 hours ago) and read 2795 times:
The Western aircraft that you pictured is an older -200 "Basic" version" as evidenced by the "sucker doors" on the engine cowlings, and the leading edge Krueger flaps (between engine and fuselage) that stop short of going all the way to the fuselage.
Boeing started making all 737-200s as "Advanced" (ADV) versions in 1971 or so, and the ADVs had numerous improvements over the Basics. The sucker doors disappeared, the engine cowlings got a little longer, and the leading edge Krueger flaps now went much futher towards the fuselage. As a result of all these aerodynamic improvements, permissible weights also increased.
I'll have to do some checking (with some retirees, since the Basic/ADV changeover was so long ago) to be sure, but I seem to recall that the #2, #3, #4 and #5 slats on the ADVs were re-engineered to deploy further in the "full extend" regime, thus matching the #1 and #6 slats (the most outboard). Looking at http://www.b737.org.uk/history.htm and scrolling down to the section on the ADVs, they mention the changes in slat sequencing as well.
I'll try to track someone down and post an update later...
Western737 From United States of America, joined May 2000, 489 posts, RR: 0
Reply 3, posted (11 years 2 months 1 week 2 days 22 hours ago) and read 2721 times:
Thanks OPNLguy for clear explaination on between pre-advance and advanced 732! I have been a big fan on 732 for long time, I didnt even realized that advanced 732 doesnt have sucker door on engine cowling!
HAWK21M From India, joined Jan 2001, 31808 posts, RR: 55
Reply 5, posted (11 years 2 months 1 week 2 days 11 hours ago) and read 2610 times:
The correct term should be Inlet cowl blow in door.
The Basic & Advanced slat difference is the staggering of the #1 & #6 slat which is slightly aft compared to the other slats in the Advanced version.
The reason for actuator of a particular slat moving before or after another depending on the pressure developed at that particular actuator & the friction present on the slat tracks.