PDA

View Full Version : 737 SOP landing flap selected on downwind leg. Curious technique?


sheppey
30th Jan 2021, 08:48
Question out of curiosity, An Aussie domestic airline flying 737's has an SOP is to use idle reverse for landings to reduce maintenence costs as well as fuel savings. The same airline has a stated policy of selecting landing flap on the downwind leg of a circuit before turning base leg. The apparent reason is because pilots were having trouble looking out the window for the runway while judging the descent on base and final and keeping stable. Airlines having been flying jets for over half a century yet suddenly todays airline pilots seem to have lost the skill to fly a visual stable approach without resorting to full flap late downwind to aid them fly a stable approach. Fuel savings policy goes out the window. Full flap downwind would be a nasty time to have a bird strike and lose an engine.

Capt Fathom
30th Jan 2021, 09:26
Sounds like a beat up to me!

sundaun
30th Jan 2021, 09:38
That’s a skill I have certainly lost!

Capt Fathom
30th Jan 2021, 09:42
That’s a skill I have certainly lost!

What? Full flap on downwind with a bird strike and engine failure?

sundaun
30th Jan 2021, 09:51
Yeah, go round flap and toga are my focus from late downwind.

Koan
30th Jan 2021, 09:55
Our 737 same as I recall, in the manual.
99 percent of time ATC vectors you to LOC
they control the speed you manage flaps to follow.

Schnowzer
30th Jan 2021, 14:42
Question out of curiosity, An Aussie domestic airline flying 737's has an SOP is to use idle reverse for landings to reduce maintenence costs as well as fuel savings. The same airline has a stated policy of selecting landing flap on the downwind leg of a circuit before turning base leg. The apparent reason is because pilots were having trouble looking out the window for the runway while judging the descent on base and final and keeping stable. Airlines having been flying jets for over half a century yet suddenly todays airline pilots seem to have lost the skill to fly a visual stable approach without resorting to full flap late downwind to aid them fly a stable approach. Fuel savings policy goes out the window. Full flap downwind would be a nasty time to have a bird strike and lose an engine.

Makes sense to me, they land off every flight so idle reverse is valid whereas they probably fly a visual circuit once a blue moon. From turning final chucking out Flap on roll in will cost zippo fuel whilst the jet slows to Vapp but one Missed Approach would blow the idle reverse fuel savings for a month. If you lose a donk turn left or right and land.

JPJP
30th Jan 2021, 20:39
Meh. You’ve all lost ‘the edge’.

• downwind clean at 200kts.
• when you see 8 on the Descent page -
• scream “landing gear down, flap 10, bug ref”.
• kiss your giant Madonna medallion 3 times.
• roll unnecessarily hard into base turn.
• Configure. Further yelling in tongues optional.
• land, beautifully.
• Kiss your own fingers & medallion (3 times)

Done. :E

Judd
31st Jan 2021, 01:09
they probably fly a visual circuit once a blue moon. From turning final chucking out Flap on roll in will cost zippo fuel

If todays airline pilots are so helpless without the aid of the automatics that they cannot fly a normal visual circuit without resorting to gimmicks like landing flap downwind, God help them should they have a birdstrike in that configuration. I bet that's not practiced in the simulator in level flight and full flap.

Are pilots nowadays so welded to the autopilot they need to select full flap downwind to give time for the autopilot time to cope with the trim changes? . Really, isn't this just a case of the tail waggng the dog? Or is the real reason crews are worried that any out of tolerance parameters caused by poor handling ability is likely to trigger a flag in the QAR? Tea and bikkies, anyone?

The Boeing 737 FCTM held by the Townsville refueller, (remember him) states:

"Before turning base or initiating the turn on to base, extend the landing gear, select flap 15, arm the speed brake and slow to flaps 15 maneuver speed. Turning base leg, adjust the thrust as required while descending at apptoximately 600-700 fpm. Extend landing flaps before turning final." Not on the downwind leg (writer's comment)

Lookleft
31st Jan 2021, 01:38
In a 737 with full flap (especially if its flap 40) on downwind you would have to have at least 80% N1 just to maintain S&L! What sort of idiot would come up with this.

BraceBrace
31st Jan 2021, 10:15
Somebody who learned to fly on a Cessna and never wanted to learn to fly a swept wing jet with high BPR engines. Those "been doing it all my life like this-ideas" of pilots pop up more often than you think, and it only takes one of them to reach a "higher" position in the ranks to get this result. Nothing new...

Tee Emm
31st Jan 2021, 11:28
https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/555x450/737_december_1982_89b7c93643d91bff79f6026a994dad48bc0d9354.j pg
Original (1982) 737-200 from Boeing Pilot Training Manual (PTM). Note annotation Turning Final - Landing flaps. Why flying the 737-800 should be any different?.

zanthrus
31st Jan 2021, 15:04
TeeEmm, It isn't..

Consol
31st Jan 2021, 16:53
Somebody who learned to fly on a Cessna and never wanted to learn to fly a swept wing jet with high BPR engines. Those "been doing it all my life like this-ideas" of pilots pop up more often than you think, and it only takes one of them to reach a "higher" position in the ranks to get this result. Nothing new...
Couldn't put it any better. Possibly even management type who gave himself a scare once or just feels more comfortable flying a desk came up with this.
Aeroplanes have been around for nearly 120 years now so we have a fair idea how to operate them. When an operator has some strange procedure out of nowhere it implies that someone in management doesn't.

Best Rate
1st Feb 2021, 04:05
I would suggest, from experience, that the workload on the base leg is moderate in ensuring the jet is on the correct vertical profile and the landing checklist completed by 1000’ AAL, (as required by most operators now.)

Normally, as Flaps 40 are rolled out, and speed is being reduced to the final approach speed, landing checklist being completed, it’s time to turn base and commence descent. Therefore there’s rarely any sustained S&L flight at the end of The Downwind Leg with high thrust levels.

In the interest of stability, and avoiding unwanted ‘flagging of parameter exceedences’ (and overloading the PM at a rather condensed period of monitoring / assisting) , It’s quite prudent to be fully configured prior to turning onto the base leg (45 seconds After the abeam ldg threshold point in nil wind) “these days”.

(Also note the 1-1.5nm final, ie 300-450’ AAL - our company policy is wings level on final no later than 500’ AAL.) - like it or not, everything has been dumbed down / fat added since that diagram was published.

Eclan
1st Feb 2021, 05:19
In the interest of stability, and avoiding unwanted ‘flagging of parameter exceedences’ (and overloading the PM at a rather condensed period of monitoring / assisting) , It’s quite prudent to be fully configured prior to turning onto the base leg (45 seconds After the abeam ldg threshold point in nil wind) “these days”.

(Also note the 1-1.5nm final, ie 300-450’ AAL - our company policy is wings level on final no later than 500’ AAL.) - like it or not, everything has been dumbed down / fat added since that diagram was published.

You have justified the thread starter's original comment regarding the skill levels prevalent today.

I would suggest, from experience, that the workload on the base leg is moderate in ensuring the jet is on the correct vertical profile and the landing checklist completed by 1000’ AAL, (as required by most operators now.)

The same operators usually have an exception to their own stabilisation cut-off rule for a visual circuit obvious reasons.

Lookleft
1st Feb 2021, 08:27
What sort of idiot would come up with this.

You can all stop looking I think I found them:

Normally, as Flaps 40 are rolled out, and speed is being reduced to the final approach speed, landing checklist being completed, it’s time to turn base and commence descent. Therefore there’s rarely any sustained S&L flight at the end of The Downwind Leg with high thrust levels.
In the interest of stability, and avoiding unwanted ‘flagging of parameter exceedences’ (and overloading the PM at a rather condensed period of monitoring / assisting) , It’s quite prudent to be fully configured prior to turning onto the base leg (45 seconds After the abeam ldg threshold point in nil wind) “these days”.

Even in an Airbus, which is supposed to be as dumbed down as you can get , you are not fully configured with the checklist complete prior to turning base. If you are flying the aircraft properly you won't exceed any FOQA tolerances. The workload should not be anything a normal line crew can't cope with. I hope whichever company you work for has run this amendment to their SOPs by Boeing, who spent a lot of time and effort to avoid line pilots cocking it up, because there might be considerations that your company test pilots haven't considered. There was a legacy carrier who amended their landing procedures in order to save money and didn't consult the manufacturer. Guess what happened?

ACMS
1st Feb 2021, 08:58
Yes you are correct, but does it matter? Really matter?

With all this crap going in the World I’d be damn happy to be configured at 30 miles!!

And happy I had a job considering.......

Big picture boys and girls.

Occy
1st Feb 2021, 09:52
Yes you are correct, but does it matter? Really matter?

With all this crap going in the World I’d be damn happy to be configured at 30 miles!!

And happy I had a job considering.......

Big picture boys and girls.

couldn’t agree more, drag it in from 30 miles if you want, who f$#king cares! :ok:

fdr
2nd Feb 2021, 02:54
Golden Rule: those that pay make the rules.

It's their football.

If you object to the SOP, suggest a change with justification and some semblance of risk analysis. Manglers don't like the extra work though so don't expect too much thanks. You definitely won't get thanks if you determine that the SOPs are not for you and you "did it your way".

Configuring fully as you approach the base turn point, and completing the checklist so that everyone can enjoy the view and not stub their toes and ego's is not expensive on gas, 100 of those will still be less costly than one G/A and circuit due to being out fo the slot.

Manglement is obliged to manage, and the staff can always vote with their feet...

BraceBrace
3rd Feb 2021, 01:09
Configuring fully as you approach the base turn point, and completing the checklist so that everyone can enjoy the view and not stub their toes and ego's is not expensive on gas, 100 of those will still be less costly than one G/A and circuit due to being out fo the slot.

I’m still confused that 737 drivers would prefer selecting landing flaps in a level segment as opposed to descending and claim it’s more ’stable’ and demands even less skills...

Icarus2001
3rd Feb 2021, 02:31
99 percent of time ATC vectors you to LOC
they control the speed you manage flaps to follow.

Obviously OCTA - CTAF etc

If you object to the SOP, suggest a change with Not sure the ramblings of a poster on a forum constitute an SOP.

Some children are still off school this week.