What happened here?

[frumpy]

 

Besides the CRM which is not too good, why didn't he clean up? VS was well positive,

but I don't see any reason why the gear was left down. I mean on a go-around cleaning

up the config is right after TOGA, isn't it?

 

 

[jojo2993]

Its the Windshear escape maneuver. 

As you can see: "Do not change flap or gear config until windshear is no longer a factor"

[frumpy]

Thanks!

I wonder - whats the rational behind this? Gear out, just in case I get pushed down and hit the surface?

Not changing the nose-down drag of the gear, so the nose does not get too high?

I mean I can imagine not changing flap position gives a speed margin if the speed drops,

but leaving out the gear... hmm.

[Morten]

Jan probably should answer this, but from what I understand, retracting the gear may cause temporary increased drag while the gear doors are open.

[Litjan]

35 minutes ago, frumpy said:

 Gear out, just in case I get pushed down and hit the surface?
 

That is the reason.

Jan

[Tom Stian]

I like this video about how to handle windshear and microburst. 

That guy have a lot of good lessons for different scenarios. The videos are a bit old, but so are the 733

 

 

[Morten]

From FAA advisory on windshear;

Quote

Maintain flap and gear position until terrain clearance is assured. Although a small performance increase is available after landing gear retraction, initial performance degradation may occur when landing gear doors open for retraction.  

 

[Litjan]

Yes - but this does not apply for the 737 as it has no geardoors that would extend when trying to raise the gear (all gear doors and fairings are already extended when the gear is extended). But I think they also keep the windshear procedures the same to maintain commonality with other types - so transferring to another aircraft would not require to relearn this procedure in such a substantial way.

Jan

 

[Morten]

1 hour ago, Litjan said:

Yes - but this does not apply for the 737 as it has no geardoors that would extend when trying to raise the gear (all gear doors and fairings are already extended when the gear is extended). But I think they also keep the windshear procedures the same to maintain commonality with other types - so transferring to another aircraft would not require to relearn this procedure in such a substantial way.

Jan

 

Right (except nose gear doors, and there is upwash there..), but also the gear itself will create more drag while being retracted (closer to the fuselage/wing) than extended, causing separation/interference drag etc. and this would take place during the time while the situation might be in it's most critical phase.  Even on the 737 you can feel the vibrations (atleast in the cabin) from this just as the gear leaves/enters the wheel well

[Litjan]

Thats true, Morten, I didn´t think about that!