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Iflydogs

Pre-takeoff checklist
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Iflydogs
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Iflydogs said:
Ran into a pilot who used some kind if clock reference system to figure crosswind component. Why don’t you just memorize the sine tables? I asked. He had never heard of it. Submarine officers use them to figure torpedo firing angles in their head, as a check against the computers. When I took my written exam I never used the E6B, did it all
In my head. I wrote a paper on it and put it on my website as a “reader magnet”, if you are interested in it, DM me. It is very simple and based upon the fact that at low angles, the sine is equal to the angle in radians. And accurate enough to shoot torpedoes, and pass the written.
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I remember the key ones for xw and then mentally interpolate.
30deg wind angle = 50% of the wind speed will be XW component
45deg = ~70%
60deg = ~85%
Any angle over 60 and I can assume it's full xw.

That's enough information to let me know if the landing is doable or not :)
 
30. 45, and 60 are memorized during trig anyhow. Namely 0.5, sqrt(2)/2, and sqrt(3)/2 respectively. Since 60 is .866, for flying, just use the whole wind velocity as xwind component.

30 -> 0.5
45 -> 0.7
60 -> 0.9

For all intents and purposes
 
I use those tricks in the air to see if it's in the acceptable range. On the ground, I'll look at the X Wind computed by F Flight.
 
I have that xw chart printed on my kneeboard. I’m pretty sure it’s still calibrated.
 
Iflydogs said:
Ran into a pilot who used some kind if clock reference system to figure crosswind component. Why don’t you just memorize the sine tables? I asked. He had never heard of it. Submarine officers use them to figure torpedo firing angles in their head, as a check against the computers. When I took my written exam I never used the E6B, did it all
In my head. I wrote a paper on it and put it on my website as a “reader magnet”, if you are interested in it, DM me. It is very simple and based upon the fact that at low angles, the sine is equal to the angle in radians. And accurate enough to shoot torpedoes, and pass the written.
Click to expand...
You find it hard to remember 30° is 50% and >60° is 100% for crosswind and think memorizing the sine tables is easier? Really?

I wonder why the aircraft manufacturers bother putting a chart in he AFM?
 
ArrowFlyer86 said:
I remember the key ones for xw and then mentally interpolate.
30deg wind angle = 50% of the wind speed will be XW component
45deg = ~70%
60deg = ~85%
Any angle over 60 and I can assume it's full xw.

That's enough information to let me know if the landing is doable or not :)
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Same here. In fact, if it's between two angles, I use the sine of the larger one.
 
Ashara Keliyn said:
I use Taylor series expansion, in my head of course. So much easier to do simultaneously while shooting an instrument approach, navigating with VORs, running through checklists, switching between frequencies, talking to controllers...
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You left out looking up threads on PoA to optimize your ADM. :rolleyes:
 
I haven't calculated an exact crosswind since I took my written, to be honest. I usually just take a rough guess, rounding up, at what I expect the component to be based off the 30* =50%, 45*=75%, and 60*=100% "chart", and then make any adjustments as needed while flying. But I don't fly near the limits, either. I would be a lot more exact if I did.
 
SkyChaser said:
But I don't fly near the limits, either. I would be a lot more exact if I did.
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'Cause, you know, if you try to take that C150 off at 1650 pounds and two ounces you will fall from the sky. :rolleyes:
 
billsgs126 said:
'Cause, you know, if you try to take that C150 off at 1650 pounds and two ounces you will fall from the sky. :rolleyes:
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*runs off to check sarcasm thread to see if I'm about to reply seriously to a post meant to be sarcastic...* :goofy:

I was thinking more of my own personal limits in regards to crosswinds, but you never know...those two ounces might just be the straw that breaks the camel's back! ;)
 
What runway is the wind favoring, fly the centerline, if there’s too much and there’s no better runway, divert and chill for a while.
 
SkyChaser said:
I haven't calculated an exact crosswind since I took my written
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Same with me. I figure if I am at full rudder travel, full aileron, more than 10 inches difference in manifold pressure, (in a twin) can't bank and/or crab anymore as well as can't hold center line then there might be a tad too much cross wind.
 
ateamer said:
What runway is the wind favoring, fly the centerline, if there’s too much and there’s no better runway, divert and chill for a while.
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Just sayin' there are no clearly definable absolutes. Every abstract value is an approximate point on a continuum interacting with every other point on the continuum.
 
SkyChaser said:
*runs off to check sarcasm thread to see if I'm about to reply seriously to a post meant to be sarcastic...* :goofy:

I was thinking more of my own personal limits in regards to crosswinds, but you never know...those two ounces might just be the straw that breaks the camel's back! ;)
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If you're worried about those two ounces you'll sweat them out before you reach Vr.
 
billsgs126 said:
Just sayin' there are no clearly definable absolutes. Every abstract value is an approximate point on a continuum interacting with every other point on the continuum.
Click to expand...
Getting a little X wind Zen going there……
 
I admit I never calculate an exact crosswind.

1. I haven’t flown a plane that can’t handle a 20 knot crosswind in reality. So unless the wind is > 20 knots I know I’m good. If it’s > 20 knots I’d reconsider the flight in the first place and calculate the crosswind if I decided to make the flight anyway, but I’d still be doing a rough estimation.

2. Around where I typically fly there are so many airports with varying runways that if I tried to land and had to go around due to a crosswind, I could find an airport I could land at safely pretty easily.

3. I don’t fly tail wheel aircraft. This is really the same as #1 but just a specific example.
 
I’ve found that I’ve used the most rudder on landing on days that the wind data did not indicate there would be a strong crosswind. The wind close to the surface is just not nice and reliable, plain and simple. You just never know what you’re going to get so be prepared for anything.
 
about the only reason I use fltplan go

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I've been spoiled by my old lancair. Crosswinds pretty much didn't matter. It just wasn't affected by them very much. I once landed at a towered field after dark in very strong crosswinds. They told me they all came out to watch me land because I was the first plane to land there all day long due to the wind.
 
eman1200 said:
about the only reason I use fltplan go

fe8cc0d81d511192a7b3a19571fa505f.jpg



64629bf77416189af542332c26cf18aa.jpg



da29663f0abbcbbbd74c775518accb2e.jpg



59349c080a675df5e372e4ccedc0163e.jpg
Click to expand...

Wouldn’t it be simpler to memorize the sine table and do a calculation in your head?

PRO TIP - If you’ve memorized the sine table, you don’t need to memorize the cosine table, too. Just remember that the cosine is equal to the square root of (one minus the square of the sine).
 
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