xc high winds (santa ana winds)

[mmilano]

i have an xc scheduled for today, and although i haven't got the official briefing yet i hear that santa ana winds are forcasted today from the news. ( in southern ca, santa ana winds are when the winds are strong, blowing from the desert, over the mountains, to the coast )

my route is taking me from the coast, over the mountains into the desert and back.

any advice on flying in this? is it dangerous enough to call a no go? or is it not that big of deal? i'll be talking to my CFI in a couple hours about it.

 

[Richard]

i have an xc scheduled for today, and although i haven't got the official briefing yet i hear that santa ana winds are forcasted today from the news. ( in southern ca, santa ana winds are when the winds are strong, blowing from the desert, over the mountains, to the coast )

my route is taking me from the coast, over the mountains into the desert and back.

any advice on flying in this? is it dangerous enough to call a no go? or is it not that big of deal? i'll be talking to my CFI in a couple hours about it.

Yes, winds can be a very big deal. They can be dangerous. Discuss with your CFI. Odds are you are not going today. But don't despair, you will still have learned a valuable lesson.

 

[mmilano]

this is odd, i plugged the info into duats for the given time, and winds are predicted at 1-3 kts.

i'll give the weather briefer a call in a little bit to see what they say.

thanks for the info.

 

[Brian Austin]

I drove from Escondido to Phoenix yesterday via I-10, through Banning Pass. The winds were brutal, easily topping 30kts, coming from the northeast. They hadn't started in the south when I left at 11:00am, though.

 

[mmilano]

the briefer gave me this info for 1pm:

carlsbad surface: 020/8
twenty-nine palms surface: 290/7-12
winds aloft for 7500: 300/9
gusts through canyons and passes: 20-40

looks fine except for the canyons and passes .. is there a safe buffer to fly over the passes to avoid those gusts?

 

[Richard]

this is odd, i plugged the info into duats for the given time, and winds are predicted at 1-3 kts.

i'll give the weather briefer a call in a little bit to see what they say.

thanks for the info.

It's not odd at all. Even in an area of strong winds there may be pockets of calm to lt winds. This wind event (Santa Ana) can feature lt winds on the coastal plains even while there is LLWS and mod turb reported in the mtn passes which may be only 20-50 miles inland.

You didn't say where but the location and time you plugged into DUATS could explain the discrepancy.

If you are still intent on making the flight you may want to consider an alternate route which avoids the mtn passes. A flight up the coast would be good but watch out for placing yourself in the lee of mtn terrain. Even at alt you can expect strong down drafts of 800-1,200 fpm.

FYI: the high ridge which is producing these winds is expected to diminish as soon as this late evening. However, another ridge is currently moving in from the north which will cause winds to increase again after perhaps a one day interval. Also, from my observations, whenever a high moves over NV you can expect strong offshore winds throughout CA and strengthening in the southern portions of the state. That last is typically caused by topography.

 

[Richard]

the briefer gave me this info for 1pm:

carlsbad surface: 020/8
twenty-nine palms surface: 290/7-12
winds aloft for 7500: 300/9
gusts through canyons and passes: 20-40

looks fine except for the canyons and passes .. is there a safe buffer to fly over the passes to avoid those gusts?

2,000 above the highest terrain is often not enough. I've experienced strong up/down drafts as high as 7,000 above certain passes. The safest, surest buffer is to avoid those areas. Discuss this with your CFI.

Oh yeah, today's temp are forecast to be high. Lo RH with high temps and strong offshore flow in mtn regions produces (fill in the blank) ? Discuss this with your CFI.

 

[Michael]

Stay away from mountains if the winds are above 40 kts in a small plane. Thats just my advise from experience.

 

[grattonja]

From Colorado training, I know that CFIs up there don't fly light planes much when the winds exceed 20 knots in the passes. The ride starts to get rough real fast. But I don't know anything about Cal. coastal winds. Just beware those winds in the passes.

Jim G

 

[Richard]

Stay away from mountains if the winds are above 40 kts in a small plane. Thats just my advise from experience.

Even winds of 10-20 can produce strong winds in and around mtn terrain due to venturi effect and adiabatic lifting. Flying small a/c on instructional flights in areas of widespread winds of 20-50 is asking for a lot. Always higher wind speeds in the passes. Wind + terrain + convection = mod-severe turb and cut scalp from being bounced out of your seat with hedsets hanging off your cut nose and mic cord wrapped around your neck and yoke. Don't think I've done that.

 

[Jeff Oslick]

Let us know what your/CFI's decision was on today's flight. Personally, I wouldn't have done it, even in my 182. My 4800# pickup was getting blown all over the road this morning near Santa Ana. It did seem to calm down some later in the day, but I'd want to read a couple encouraging pireps (you do file these, right?) from my route before venturing out.

Even when the winds aren't that strong, I've experienced some severe downdrafts on the south side of the mountains during Santa Ana's. Santa Barbara can be particularly dangerous because the winds come down off the mountains and start rotating around from all different directions right at the airport - I've experienced some nasty wind shear at SBA a couple times, on days not as windy as today.

Jeff

 

[mmilano]

thanks for the posts. yes, the CFI said its a no go for the route and to plan it another day. i called back and asked if it would be ok to do a local flight with 9kt winds and he ok'ed it.

i just flew around for an hour. 1/2 hour i practiced basic manuvers, then did a couple touch and goes before landing.

awsome cross-wind landing practice!! winds were variable and creeped up to 13 kts by the time i started touch and goes, then before my last landing the tower called winds at 13 with gusts to 17 .. i decided to call it a day after hearing that one.

 

[Richard]

thanks for the posts. yes, the CFI said its a no go for the route and to plan it another day. i called back and asked if it would be ok to do a local flight with 9kt winds and he ok'ed it.

i just flew around for an hour. 1/2 hour i practiced basic manuvers, then did a couple touch and goes before landing.

awsome cross-wind landing practice!! winds were variable and creeped up to 13 kts by the time i started touch and goes, then before my last landing the tower called winds at 13 with gusts to 17 .. i decided to call it a day after hearing that one.

Cool, you got some time today. I still have this nagging question.

Did it take your CFI saying no before you decided not to go? I mean, what if your CFI had simply thrown it back at you by saying, whatever you think?

 

[mmilano]

no, like i was asking here, i didn't know if high winds in canyons and passes meant high winds at altitude over the canyons and passes as well. he told me no after i told him the weather brief.

this windy day was followed by a crash dream last night too. lol.. maybe that other dream thread provoked that one.

 

[SkyHog]

no, like i was asking here, i didn't know if high winds in canyons and passes meant high winds at altitude over the canyons and passes as well. he told me no after i told him the weather brief.

this windy day was followed by a crash dream last night too. lol.. maybe that other dream thread provoked that one.

eek. sorry man, not trying to scare the new pilots with my posts....I'll have to be more careful

 

[mmilano]

it's ok, i'm not the superstitious type anyway

so i was thinking today about the flight yesterday. i haven't talked to my cfi yet about it, but wth the higher winds, i was having to point the nose down pretty steep to keep my airspeed at 60kts.

i did have full flaps set. so since it was difficult to keep my speed up, and my nose was pointing so far down, i think i should have tried using less flaps. is that right?

 

[Jeff Oslick]

i did have full flaps set. so since it was difficult to keep my speed up, and my nose was pointing so far down, i think i should have tried using less flaps. is that right?

If runway length isn't a factor, I usually only use 20-degree flaps if the winds are gusty (more than ~5-7 kt gusts), or if the direction is variable. I also increase my approach and landing speed by about 4-5 knots. Net effect is to reduce the potential crosswind component and reduce the risk of stalling and dropping it in on the nosegear.

Jeff

 

[Michael]

If runway length isn't a factor, I usually only use 20-degree flaps if the winds are gusty (more than ~5-7 kt gusts), or if the direction is variable. I also increase my approach and landing speed by about 4-5 knots. Net effect is to reduce the potential crosswind component and reduce the risk of stalling and dropping it in on the nosegear.

Jeff

Jeff is right. With wind gusts, you should add half the gust speed to your approach, if the wind is 10 gusting to 20 thats a 10knot difference, you would add 5 kts to your approach.

 

[Richard]

it's ok, i'm not the superstitious type anyway

so i was thinking today about the flight yesterday. i haven't talked to my cfi yet about it, but wth the higher winds, i was having to point the nose down pretty steep to keep my airspeed at 60kts.

i did have full flaps set. so since it was difficult to keep my speed up, and my nose was pointing so far down, i think i should have tried using less flaps. is that right?

So much for the CFI-approved flight in 9 Kts.

 

[mmilano]

So much for the CFI-approved flight in 9 Kts.

i mentioned 9kts because that is what the metars reported before my departure. in my logbook i am endorsed for < 15kts. this is why i opted to call it a day when twr reported 13 gusts to 17.

 

[gismo]

it's ok, i'm not the superstitious type anyway

so i was thinking today about the flight yesterday. i haven't talked to my cfi yet about it, but wth the higher winds, i was having to point the nose down pretty steep to keep my airspeed at 60kts.

i did have full flaps set. so since it was difficult to keep my speed up, and my nose was pointing so far down, i think i should have tried using less flaps. is that right?

A lot of pilots operate that way (partial flaps for crosswinds) but IMO it's a bad idea. In most planes, the biggest increase in lift (and decrease in stall speed) comes with the first half of available flap deflection, and the second half mostly just increases drag. Therefore by using half or two-thirds of your plane's flap deflection you are mostly throwing away drag and drag is what gets you through the flight regiven where control in a crosswind is most difficult (just before to just after touchdown). My advice is to always use full flaps unless they are broken or you want to practice a no flap landing. If the crosswinds are pushing your ability to control the plane with full flaps, you can improve the situation slightly by using no flaps, but typically a better choice would be to find a runway more aligned with the wind.

 

[bbchien]

A lot of pilots operate that way (partial flaps for crosswinds) but IMO it's a bad idea. In most planes, the biggest increase in lift (and decrease in stall speed) comes with the first half of available flap deflection, and the second half mostly just increases drag. Therefore by using half or two-thirds of your plane's flap deflection you are mostly throwing away drag and drag is what gets you through the flight regiven where control in a crosswind is most difficult (just before to just after touchdown). My advice is to always use full flaps unless they are broken or you want to practice a no flap landing. If the crosswinds are pushing your ability to control the plane with full flaps, you can improve the situation slightly by using no flaps, but typically a better choice would be to find a runway more aligned with the wind.

Depends on whether or not the problem is sustained xwind or is gusts. The higher rollout speed on a no flap landing (1.3 Vs) allows more authoritative rudder but then doesn't help you once you're a gound vehichle with high speed side slide.

But when adding 1/2 the gust factor for gusts, that's more of a disruption of normal pilot technique when the gusts are high (20) and the airspeed is slow ( 1/2 of 20 =10 and 10 is a greater fraction of 60 rather than 70). It does however let you undeploy flaps if runway control becomes a problem (which I think is not a good habitual idea as one day you will retract the gear).

Going to a different runway or stowing the trip is indeed the answer.