Skywest X-wind Limit

TUCKnTRUCK said:
We have ref speeds that get up to 150 knots. We then don't have brakes for 5 second. If a gust excess what the ruder can compensate for it all goes to the nose. If the nose steering cuts out, you've got nothing.


-typing on my phone, sorry for the grammar
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I can see how that big(ger) tail and long arm could put a lot of leverage on the nose wheel. I can also reflect and remember that bigger equals better in winds due to inertia or whatever you want to call it. I'll just take your word for it... unless they start putting some 8:50s on the Q and landing it on ice slicked runways. ;)
 
Screaming_Emu said:
WTFO? Please explain.
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My guess is anti-skid... some aircraft have an anti-skid computer that has to sense that the wheel is in rotation for x number of revolutions prior to allowing the brakes to be utilized... this way even if you land with your feet on the brakes, in theory of course, you won't pop or flat spot tires.
 
Gonzo said:
I was just asking because we have a hard limit of 30kts including the gust. The ZW CA jumpseater said it was above their x-wind limit of 27kts. PCNL didn't even try to land. FYI: the wind was 270@37G46 landing runway 21.
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SteveC said:
39 knots at 90 degrees to the runway? [ clarifying ]
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According to my wind component chart from the Airway Manual, Chap. 3 (Ops. Specs.) for SouthernJets:

Wind Component:

- Maximum gust velocity and least favorable direction will be used to compute the crosswind component.

If you enter the chart at 46 knots (maximum gust velocity) and follow the curve around for 60 degrees (difference between 270@37G46 and runway 21) you come up with a headwind component of approximately 24 knots.



Perhaps this is what they were using to determine their legality to land?

It is my understanding that Max Demonstrated Crosswind limits pertain to direct 90 degree crosswinds. If I am wrong in that understanding please let me know!


Kevin
 
Gonzo said:
I was just asking because we have a hard limit of 30kts including the gust. The ZW CA jumpseater said it was above their x-wind limit of 27kts. PCNL didn't even try to land. FYI: the wind was 270@37G46 landing runway 21.
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9E has a limitation of 27 knots for Dry, 22 Wet and 15 contaminated (snow, ice, slush, etc.)
 
Screaming_Emu said:
WTFO? Please explain.
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The Megga Dash waits to see WOW, 35kts at all wheels (nose excluded), and then 5 seconds. If those arn't met, the anti skid just says no. ( if you hold one off in an xwind, your 5 seconds start once the other are down)

Thats why sometimes Q landings are like... nothing... nothing...nothing... brick wall! pilots get on them right away.. nothing happens so they press harder. Suddenly they engage, and you go right into full anti skid. It's not really comfortable... but it also means we have no differential braking for steering. When our NWS fails, we have a free nose wheel, and a touchy, hard to use, carbon brake system to steer.

Nose wheel steering inop for us is a 3 leg mel, and I know a lot of guys that won't take it at all. It really becomes a safety issue if there is any x-wind etc.

For the fun of it, touching down at 62,000 lbs, with ICE speeds means we are doing almost 260 ft/sec... as I see it : (148kts*1.69"kts to ft/sec")*5= 1250ft without brakes = FUN
 
TUCKnTRUCK said:
The Megga Dash waits to see WOW, 35kts at all wheels (nose excluded), and then 5 seconds. If those arn't met, the anti skid just says no. ( if you hold one off in an xwind, your 5 seconds start once the other are down)

Thats why sometimes Q landings are like... nothing... nothing...nothing... brick wall! pilots get on them right away.. nothing happens so they press harder. Suddenly they engage, and you go right into full anti skid. It's not really comfortable... but it also means we have no differential braking for steering. When our NWS fails, we have a free nose wheel, and a touchy, hard to use, carbon brake system to steer.

Nose wheel steering inop for us is a 3 leg mel, and I know a lot of guys that won't take it at all. It really becomes a safety issue if there is any x-wind etc.

For the fun of it, touching down at 62,000 lbs, with ICE speeds means we are doing almost 260 ft/sec... as I see it : (148kts*1.69"kts to ft/sec")*5= 1250ft without brakes = FUN
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Wow...only an engineer could come up with something like that. Thanks for the explanation. Understandable on people being hesitant to take anything with the NWS inop. I've had one landing where the NWS went inop on touchdown (after a gear problem) and it was fine at high speed but a little squirrely towards the end. That and having to be towed to and from the runway...that's just embarrassing.
 
With the winds given in the example, I don't see anything illegal, even with the conservative 27 knot direct xwind limit the CRJ has (which I think is more restrictive than the Jungle Jet's). Our limit does not take into account gusts, but I normally include them anyways as you can be damn sure the FAA will if I ever get blown off the side of the runway.
 
BobDDuck said:
With the winds given in the example, I don't see anything illegal, even with the conservative 27 knot direct xwind limit the CRJ has (which I think is more restrictive than the Jungle Jet's).
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Not all operators have a hard 27kt limit for the CRJ...

I can't believe they wouldn't take gusts into account for a limitation, though. That's insane...I'd rather have steady 30kts than 25 gusting to 35 for sure.
 
We only have a Xwind limit for poor braking action and FO landings. The restriction on FOs at SKW is one the most retarded still on the books.
 
GaTechKid said:
We only have a Xwind limit for poor braking action and FO landings. The restriction on FOs at SKW is one the most retarded still on the books.
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Last flight, getting home, after the reported winds, "your controls." ;)
 
Swept-wing turbofan + tail-mounted engines + 5-second spool time = annoying in crosswinds. When I was teaching in the sim, it only took about 8* of bank for a wingtip strike on the RJ. Our books said 27 knots, but like BobD's didn't include gusts. That being said, our operations manual stated that no landing should be continued should a gust factor exceed the aircraft's limitations. Talk about having your cake and eating it too!
 
TUCKnTRUCK said:
The Megga Dash waits to see WOW, 35kts at all wheels (nose excluded), and then 5 seconds. If those arn't met, the anti skid just says no. ( if you hold one off in an xwind, your 5 seconds start once the other are down)

Thats why sometimes Q landings are like... nothing... nothing...nothing... brick wall! pilots get on them right away.. nothing happens so they press harder. Suddenly they engage, and you go right into full anti skid. It's not really comfortable... but it also means we have no differential braking for steering. When our NWS fails, we have a free nose wheel, and a touchy, hard to use, carbon brake system to steer.

Nose wheel steering inop for us is a 3 leg mel, and I know a lot of guys that won't take it at all. It really becomes a safety issue if there is any x-wind etc.

For the fun of it, touching down at 62,000 lbs, with ICE speeds means we are doing almost 260 ft/sec... as I see it : (148kts*1.69"kts to ft/sec")*5= 1250ft without brakes = FUN
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Wait...nosewheel steering is something that can actually be MEL'd? I would never have guessed that.
 
C150J said:
Swept-wing turbofan + tail-mounted engines + 5-second spool time = annoying in crosswinds. When I was teaching in the sim, it only took about 8* of bank for a wingtip strike on the RJ. Our books said 27 knots, but like BobD's didn't include gusts. That being said, our operations manual stated that no landing should be continued should a gust factor exceed the aircraft's limitations. Talk about having your cake and eating it too!
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5 seconds to spool those things? Sheesh, were they made in 1953 or what?
 
broncoav8r said:
9E has a limitation of 27 knots for Dry, 22 Wet and 15 contaminated (snow, ice, slush, etc.)
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Right from our CR2 OM

Max demonstrated is 27kts on a dry runway, however...the following are limitations:

Wet Runway: 27kts
Contaiminated runway with braking action less than good: 15kts
Captain has less than 100 hours PIC in Type (CR2): 27kts

So...with that being said, certainly a number of opportunities to land the thing in crosswinds >27kts during regular operations.

33 is my highest, wasn't a highly enjoyable approach, but it felt all the same below 40ft.
 
TUCKnTRUCK said:
The Megga Dash waits to see WOW, 35kts at all wheels (nose excluded), and then 5 seconds. If those arn't met, the anti skid just says no. ( if you hold one off in an xwind, your 5 seconds start once the other are down)

Thats why sometimes Q landings are like... nothing... nothing...nothing... brick wall! pilots get on them right away.. nothing happens so they press harder. Suddenly they engage, and you go right into full anti skid. It's not really comfortable... but it also means we have no differential braking for steering. When our NWS fails, we have a free nose wheel, and a touchy, hard to use, carbon brake system to steer.


Nose wheel steering inop for us is a 3 leg mel, and I know a lot of guys that won't take it at all. It really becomes a safety issue if there is any x-wind etc.

For the fun of it, touching down at 62,000 lbs, with ICE speeds means we are doing almost 260 ft/sec... as I see it : (148kts*1.69"kts to ft/sec")*5= 1250ft without brakes = FUN
Click to expand...

This may be a totally obvious answer...but if the airplane waits to engage brakes until it senses WOW and 35kts at each main gear, how does it know when its taxiing. In other words, if your taxiing at 10 knots I'm assuming you can still engage brakes since there is WOW, but how does the airplane know i'ts ok to brake, even though you haven't met the 35 knot requirement on the mains? Does that make sense?
 
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