Flaps 2 origin 737?

[Speedwinner]

Folks,

couldnt find something in the web:

When was the flaps 2 setting needed and which practical value does it have today and why doesnt boeing change that flapsetting? Cut it out? certification?


Thanks

SW

[d105]

The only occasions I've used Flaps 2 was on a very long final (15nm) where Flaps 1 just kept the speed at 230 but Flaps 5 would slow it down to fast.

[Agaricus bisporus]

Understand it has a maintenance function only. What, I dunno.

[Romeo E.T.]

optimum take-off flap from "old" Durban intl rny 06 full length was a flap 2 setting on the B737-200...don't always presume the approach and landing phase of flight.

[aterpster]

Romeo E.T.:

optimum take-off flap from "old" Durban intl rny 06 full length was a flap 2 setting on the B737-200...don't always presume the approach and landing phase of flight.

We used 5, 15, and 25 for takeoff, depending on runway length and elevation. Never 2, though; that must have been some huge ground speed at rotation.

[JammedStab]

Used Flaps 2 for takeoff on the 737-200 on a regular basis. For the long runways. Better climb limits. Flaps 5 for the shorter runways. Flaps 10 on gravel.

[Mach E Avelli]

Yep, flap 2 was very useful in the -200. Good trade between runway length and obstacle clearance. When Boeing built later versions they used a lot of existing components, so I guess the flap selection system was simply left there even though flap 5 generally became the better option with the higher thrust engines.

[Capt Chambo]

When was the flaps 2 setting needed....

Depending on our weight we used it on the 300/400/500 when ATC asked for 180Kts on the approach. We flew a fixed speed schedule in those days.

Never used it for take-off on either the classic or the -NG. And we never use it on the approach on the -NG.

why doesnt boeing change that flapsetting? Cut it out? certification?

I suspect that you have answered your own question

[john_tullamarine]

I've undeleted this thread. Please don't delete threads. If you have a REALLY important reason to do so, send me a PM and, if the reason is reasonable, I'll remove the thread.

Problem is that others have an interest in discussions and there is not much can happen that is more frustrating than having an interesting thread disappear on you ...

[BOAC]

Never 2, though; that must have been some huge ground speed at rotation.

- not so frightening, and certainly no worse than Improved ('going like a train') speeds - Flap 1 common for Classic take-offs where obstacles were the primary concern, but abandoned on the 737- 400 due to tailstrike risk. Used also on 200 and I assume 100. I was told it dated from 727 or even 707 (or even B17.......) from which the flap gate (and gear lever?) originates and rather than re-machine the whole thing Boeing left the gates as they are. If you use it, use the F1 manoueuvre speeds as I don't think any are published.

[Callsign Kilo]

Good for base leg into LGW in the NG when slowed to 180KIAS. Granted, we could use F5; however F2 doesn't get that much of an outing!!

[BOAC]

Ck - never tried it - does the speed tape respond?

[oxenos]

The early 737-200 had only 1, 5, 15, 25, 30 and 40 flap notches on the selector, so I don't think it came from the 727. It was referred to as having the basic wing.
Most of the Basic aircraft we had were fitted with dash 9 engines, and were a bit short on performance. It was often the case that F1 was very limiting on field performance, while F5 was very limiting on climb performance. On a shorter field, it would be a similar problem with F5 and F15.
I understood that the whole point of having F2 and F10, was to give a better choice in these conditions, i.e. F2 would be less limiting on field than F1,and less limiting on climb than F5, so that the available take-off weight would be higher.
The aircraft so fitted were referred to as having an advanced wing, and I recall that there were some other modifications, relating to the way the leading edge devices extended with different flap settings

[Denti]

If you use F2 on the NG the speedtape relables the F1 manouvering speed to F2 manouvering speed. Useful if you just want a tad more drag at the same speed.

[WallyWumpus]

I'm with Callsign K here, and not with Denti. On the -800 it allows us to slow to 180 if given by ATC, the F1 bug is often just above it, the bug does move down for F2.

Wally.

[Capt Chambo]

...but abandoned on the 737- 400 due to tailstrike risk.

We occasionally use Flap 1 on the -900. Ridiculous Vr's and a only 13" tail clearance.

Not for the faint hearted

[BOAC]

how many ***** has your lot experienced? I seem to recall the tail clearance on the 400 was a bit less at F1.

[Back Seat Driver]

On the 737-200, in some conditions, at near MTOW take-off speeds, Flaps 1 could exceed the brake energy limits (Vmbe). Flaps 2 take-off figures usually would accommodate the take-off. Faps 1 &(2) gave a better 2nd segment climb than F5/F15 on the -200. It is all revealed in the QRH Take-Off performance tables.

[oceancrosser]

how many ***** has your lot experienced? I seem to recall the tail clearance on the 400 was a bit less at F1.

It has been a long time since I flew the classics, but I seem to recall 10" on the 737-400???

We had a tailstrike on a -400 shortly after delivery of the first, with only scraped paint to show for it though. A tailstrike on landing produced some damage a few months later.

The tail clearance figures in the FCTM were changed shortly thereafter IIRC.

[c100driver]

We once had an old Boeing test machine that was a pre ADV B737-200. It had an ADV wing but everything else was an early model. We did use the the F2 selection for climb limited takeoff airports.

We use F1 at almost every airport on the B733.