LLWS

[wind_shear]

A question for the experienced pilots. What is your determining factor on making the go/no go decision with non convective LLWS? Airmet for LLWS along route of flight with or without Airmet tango for moderate turbulence from sfc-xyz, LLWS in the TAF below a specific altitude at departure/destination/alt airport (personal minimum) we know LLWS is capped at 2000ft AGL. Will you cancel your flight based on just one of these? a combination?

 

[Sac Arrow]

Kinda depends on the plane I think. Small planes deal with low level wind shear better than big ones.

 

[PaulS]

Depends, LLWS at altitude is generally a non issue for small piston planes unless it is associated with mod to severe turbulence. On final it can make things sporty, but if you watch for it and it's not excessive, you can easily deal with it. Airliner on final can be a different story.

 

[wind_shear]

Kinda depends on the plane I think. Small planes deal with low level wind shear better than big ones.

Good point, we can just use a C172, C182, or the Piper equivalent for this example

 

[Sac Arrow]

Good point, we can just use a C172, C182, or the Piper equivalent for this example

As stated above, barring severe turbulence, it's generally a non issue for the planes you cite, but certainly something to be aware of.

 

[Jeff Oslick]

The problem with the "not a problem enroute" theory is if you have a problem and need to land.

I went up once when LLWS happened to me. Ended up in a 45+ degree bank at 300' AGL after takeoff in a 172, and that 45 degree bank was essentially instantaneous. This was winter flying in New England (New Bedford, MA).

Nope, not doing it again. That was 25 years ago, and I've cancelled at least a few flights due to LLWS since then. This event and riding a thermal near Palm Springs were the only times I've ever felt like I did not have complete control of the plane I was flying.

 

[PaulS]

I'll fly a heavier airplane in winds I wouldn't want to be in a 172 in. That's why it depends. In the SR22 up to +10 - 5 or vice versa generally isn't an issue, just keeps you on your toes on final. Would not want to do that in a 172. We get shear here in New England quite a bit. Most of the time it's a little bumpy and makes the airspeed indicator jump around when you see it. Usually it's gusty and you have a gust factor in your approach speed. At altitude during cruise, unless it's associated with turbulence, you barely notice it, in a heavier airplane.

 

[Clip4]

There are a lot of factors, day vs night, runway orientation, width and length, trees, buildings, terrain proximity to the runway producing mechanical turbulence, aircraft near gross weight or near zero fuel, pilot fatigue, currency/proficiency, mission.

 

[RyanB]

Will you cancel your flight based on just one of these? a combination?

Depends, if it’s just a local joy ride or something, I’d cancel most definitely. If I’m trying to get home and all other conditions are favorable, than I’d fly it.

Depends, LLWS at altitude is generally a non issue for small piston planes unless it is associated with mod to severe turbulence.

That would just be considered wind shear, as LLWS doesn’t occur at altitude. The pedantic in me had to mention this.

 

[PaulS]

Depends, if it’s just a local joy ride or something, I’d cancel most definitely. If I’m trying to get home and all other conditions are favorable, than I’d fly it.

That would just be considered wind shear, as LLWS doesn’t occur at altitude. The pedantic in me had to mention this.

LOL

 

[WannFly]

Depends on the type of LLWS for me. 50 kts from W when winds are from S on the ground at 400 AGL for a joy ride? No thanks.

25 kts under same circumstances at 1000 AGL, I will go.

Anything above 15 kts from completely opposite direction - no.

Up till few months ago I used to cancel a lot more than I do now. Now when I see LLWS warning I dive into the wind aloft and if I think it’s mostly stable or not from opposing directions, I will take a call and mostly go.