B737CL DRIVER: Why no more FLAPS 25 during App?

[Silver Spur]

Come across this questions during PPC:

Why / whats the reason for going directly from FLAPS 15 to Landing FLAPS during approach? (in the past used to be flaps 25 then landing flaps)

Thanks
Ss

[STBYRUD]

This has been discussed before, here is the most recent discussion:
http://www.pprune.org/tech-log/461440-b737-flaps-25-approach.html
I suspect your company recently went back to using OEM procedures, Boeing doesn't mention it anymore except as a takeoff flaps setting - that still does not mean that you can't use it though ;) Light airplane, flaps 40 for some reason - the gap might be a little bit too large for comfort :)

[Sciolistes]

My guess would be that F25 speed can be at or less then Vref + wind corrections?

[BOAC]

I am sure it is just considered 'unnecessary'. Your theory could apply to F15 single-engined, and for all of these possibilities, 'airmanship' is expected to kick in.

[Sciolistes]

I would be surprised with the answer to Mr Spur's question was simple "because it is unnecessary" :) I would expect such a question to elucidate hitherto hidden knowledge and arm us with the extra wisdom needed to face the challenges of a dark and stormy night.

No pressure, Mr Spur :D

[Centaurus]

Unread 26th Dec 2011, 23:21 #32 (permalink)
Capn Bloggs

Join Date: Mar 2002
Location: Seat 0A
Posts: 3,235

Quote:
"8.0.2.3 A significant number of operating practices allow the discretion to the Commander to decide how the flight should be flown. These are characterised with the need to exercise sound judgement and prudent assessment and may be referred to as sound operating practises (included under the more general heading of airmanship during an earlier period).
There has been a trend within the industry to refer to all operating activity under the heading of SOPs or a desire to specify all procedures within such a concept. Such broadening of the scope of SOPs diminishes the merit and value of the concept and hence the need to highlight this differentiation."

This is a catch-all from another Tech Log thread. It would apply to the subject of using Flap 25 on the way down to using Flap 30/40. In other words there is nothing dangerous or wrong by using Flap 25. In fact, the original B737-200 FCTM showed the use of Flap 25 turning base on a visual circuit and my company used just that as well as on an ILS as part of going to landing flap. Certainly makes the transition to landing flap smoother which is surely a Good Thing. Captain's choice.:ok:

[despegue]

No more Flaps 25?!
Total bullocks. Nowhere is it says that one should not select F25 during configuration. It is a Flap setting that is allowed to be selected, JUST AS F2 by the way...
This has nothing to do with SOP but with airmanship and how you fly the approach.

[captjns]

It's there, and I use it all the time on the way to landing flaps.

If Vapp with wind correction is is greater than Flaps 30, then that's where the bug shall be set in preparation to taking final flaps for landing.

[BOAC]

It was quite strange actually - as my roster with Astraeus was as a 'Pollyfilla' (fill the gaps) I quite often found myself 'off' flying for periods of a few weeks. After one of these occasions the F/O (PF) called 'F30' from F15. It seemed to be safe, so I did it, and on the turn-round asked why. Apparently one of the new 'wunderkinds' had introduced it as 'the way to do it', so it kind of stuck. I had a personal 'NTO' on it, so no big issue. I continued myself with a F25 selection since there was nothing in the manual to say otherwise. Who cares really? There were bigger things to worry about.

A while back I retold the story of my trip as a new F/O with a 'previous' to Funchal when on one occasion the Captain briefed and 'did' a call for F40 from clean downwind. It worked perfectly.

[Denti]

As far as i know it was a change in the OEM SOPs. The supposed reason was to only use normal landing flap settings from F15 onwards. We have it as SOP now, however there is nothing against using intermediate flap settings like 2, 10 and 25 in the SOPs so those are still good. After all F25 (F10 as well) is a normal take off flap setting too, why not use it on approach?