B737NG: High stage bleed valve & Cat3
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B737NG: High stage bleed valve & Cat3
Hi,
our MEL restricts our ops to Cat1 when the high stage bleed valve is INOP.
It mentions Boeing SR 1-292534973.
I don't see any relation?
Tnx for answers!
our MEL restricts our ops to Cat1 when the high stage bleed valve is INOP.
It mentions Boeing SR 1-292534973.
I don't see any relation?
Tnx for answers!
Last edited by JeroenC; 1st Nov 2013 at 17:00.
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I couldn't made it. Maybe regarding that bad weather conditions, high pressure compress might be occur(280 kPa or more), where requiring a high stage bleed. But my theory is pure speculation, as we are able to CATIIIb in any kind of inoperation of bleed valves(not the 737 though).
Last edited by Westnest; 1st Nov 2013 at 17:39.
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Says about High Stage Valves (-300/-400/-500/-700/-800) that two are installed, one may be inoperative for dispatch:
(M) One may be inoperative locked closed provided a minimum of 60% N1 is maintained on associated engine during flight in icing conditions.
No restrictions on CAT III at all, neither IIIa nor IIIb.
(M) One may be inoperative locked closed provided a minimum of 60% N1 is maintained on associated engine during flight in icing conditions.
No restrictions on CAT III at all, neither IIIa nor IIIb.
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Copy-and-paste:
9. High Stage Valves: C 2 1
(M)(O) One may be inoperative locked closed provided a minimum of 60% N1 is maintained on the associated engine during flight in icing conditions.
NOTE 1: Both high stage valves required to be operational for CAT3 operation (Ref: Boeing SR 1-292534973)
Nice he, all these different MELs for the same hardware?
9. High Stage Valves: C 2 1
(M)(O) One may be inoperative locked closed provided a minimum of 60% N1 is maintained on the associated engine during flight in icing conditions.
NOTE 1: Both high stage valves required to be operational for CAT3 operation (Ref: Boeing SR 1-292534973)
Nice he, all these different MELs for the same hardware?
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The only connection is with icing conditions.. How are you going to keep >=60% on the throttles with a light a/c if doing a CAT IIIa Autoland? How often do you do a CAT III above 10° C ?
Last edited by Jetpipe.; 1st Nov 2013 at 21:58.
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I see what you mean. But Cat3 are F40 mandatory. Only when you're very light you need < 60%. But indeed you cannot actively control thrust manually on Cat3, maybe that's the issue.
Strange that other operators don't have the restriction on Cat3 then?
Is there anywhere I can access these Boeing SRs?
Strange that other operators don't have the restriction on Cat3 then?
Is there anywhere I can access these Boeing SRs?
