737 3/400 - Flaps 2 ?

[OLNEY2d]

For any 737 3/400 drivers out there...

Am often intrigued by the statement 'Flaps 2 has no practical application' occasionally seen in Handling notes.

What's the background ? Anyone agree/disagree? or like me use it on a regular basis (in an impractical fashion of course)!

[Seat1APlease]

It was the same on the -200 and then was carried over.

If ATC asked you to reduce to 180 then flaps 2 was a reasonable configuration, but I don't think it was used as a take off setting, although I stand to be corrected on that, and it didn't really help on approach as if you were flap one at 190 then you could select all the way through to five and go for 170.

In much the same way flap 10 (160) wasn't often used. All of this was before the rudder-over problems when all the flap speeds were increased.

[OLNEY2d]

180 kts

Indeed - have to say, it is usually in response to '180kts until 4 DME please' or similar - so spot on.

Just wondered if there was more to it, rather than it just being an unlikey configuration!

[Ennie]

I would agree with using Flaps 2 if asked to reduce to 180 on the 3/400.
Would give you a slightly higher nose up of course, but a little less drag than with Flaps 5.

[sjm]

B737-300/500

210/min clean
190/flaps 1
180/Flaps 5
170/Flaps 10
150/Flaps 15 (gear down)
140/Flaps 25
V ref+ 5/Flaps 30/40

I believe my company are one of the few companies using Flaps 10/170kts and Flaps 25/140kts.
The flaps 40 configuration sometimes results in the final vref speed for approach being higher than 140kts.
Never use flaps 2!

[Denti]

Dunno, we use the exact same flap speed schedule as posted by sjm (if below 53.070 kg, add 10kts above). Never use flaps 2.

[Gold Leader]

Trailing Edge Flap Asummetry

may be ( and this is just what i assume) one of the other reason u have flaps 2 is in case of an TE flap asymmetry. as the checklist suggests u to move the flap lever to the smallest indicated flap position.... which could be flaps 2 ! ! !

but then again i think the chances of that happening a zilchhh..

GL

[Contract Con]

Gold Leader,

I'm with you. I had always figured that is why it is there.

But as you say, havn't seen too many T/E Asy problems in the B733.

Plenty of L/E ones though

Cheers,

Con

[fireflybob]

Certainly on the B737-200 Flaps 2 was a scheduled flap setting for take off and, in certain situations, gave a better RTOW than Flaps 1 or Flaps 5.

When the 737-300 came along I recall that take off performance with Flaps 2 was not scheduled for one reason or another but maybe as the original intention was that pilots could be dual rated on the -200 and -300 and also for "commonality" the flaps 2 position was available.

[No Mate!]

FFB, are you sure what your'e saying is true?

NM

[fireflybob]

No mate!, absolutely - I flew circa 3,500 hours on the B 737-200 and 1,800 hours on the B 737-300 with Orion Airways - we were launch customers for the B 737-300 and many of our pilots were dual rated.

We did many take offs in the B 737-200 using Flaps 2.

Hope this helps.

[No Mate!]

FFB, thanks.

[CaptainSandL]

Flaps 2 was in normal use for Classics before year 2000. We used to work down through each flap position as follows:

Weight below 53,070kg
Clean 210
F1 190
F2 180
F5 170
F10 160
F15 150
F25 140
F30/40 Vref+5

The flap-speed schedule for positions 1 to 10 was increased in 2000 following the data about the crossover speed arising from the possible rudder related crashes (see http://www.b737.org.uk/rudder.htm for details). This made the flap 2 position redundant.

It is possible that we may return to the old flap-speed schedule (and hence use flap 2 again) after all aircraft have had the RSEP modification but I doubt it will happen.

S&L

[OLNEY2d]

Thanks all.

So it seems the statement regarding Flaps 2 'having no practical application' - has it roots firmly in potential flight safety issues. It was so emphatically stated that there had to be more to it - am slightly embarrased at not knowing that - but have learnt something.

Cheers

[A Very Civil Pilot]

It could simply be that it is easier for Boeing to use a part that is already certified (and there is probably a great big box of them sitting in Seattle somewhere), rather then design a new part without an F2 setting.

[flightleader]

Try this in the sim if you have a chance; Fail all flight controls,fly with only thrust and stab trim, the a/c will be very sensitive to thrust changes. However,if you take flap 2, it become more stable in pitch and makes it easier to fly.Probably due the the larger band of center of pressure over the wings. Have fun!

[safewing]

The scourge of intermediate flap

Having flown the 737/2/3/4/5

The Boeings have lots of small flap increments to minimise the ballooning effect caused by most other aircraft when the wing area is increased for a given speed.

Since the Boeings I have flown the F50,Bae146 and A320/321. All of these aircraft "balloon" when the second stage of flap is selected.

[I-2021]

Hello,

I sometime use F2 rather than F5 setting on the -200 on approach, especially when I have to fly an arc dme approach with a steep descent. On the classics, there is not a big diference with the same scenario (IMHO).