lieberma
10-20-2004, 12:58 AM
Passengers say the darndest things....
First, understanding landings. When an airplane makes an approach into an airport, the pilot will 99.99 percent of the time want to land into the wind. The purpose of this is to slow the airplane down. We have "airspeed" and then we have "ground speed". My approach to a landing in my airplane is 72 mph. If there is no wind, then my ground speed is the same. If I have a 10 mph head wind, with the wind "blowing in my face", then my ground speed is 62 mph (72mph airspeed - 10 mph headwind). When the wheels touch the ground, that means I am doing 62 mph which makes for a shorter time to stop and turn off the runway.
Unfortunately, mother nature doesn't always blow the wind right down the runway. Sometimes the wind will blow across the runway. This is called a cross wind. Imagine driving down a highway on a windy day, where you feel the wind rock your car left and right. A car has the wheels on the ground that holds you on the road. You won't drift right or left, unless you let your mind do that ;)
An airplane doesn't have that extra liberty in the air of it's wheels holding it straight down the runway. If the wind is blowing right to left, then the pilot has to compensate for this by "steering" into the wind.
When you are sitting as a passenger, you may notice the airplane's wings rocking right and left, but if you watch carefully, you may notice the right wind lower then the left wing. (or vice versa) This is called a cross wind landing. Keeping in user friendly terms, pilots call this technique "crabbing" or "slipping" depending on the descent profile to the runway.
You may have experienced a "wierd" landing where one side of the plane touches the ground first, then the second side touches down. The pilot probably was executing a cross wind landing. Though not comfortable for the passenger, this is done so that the wind does not pick the airplane back up in the air.
So..... If you are ever on a flight where a pilot feels like he is wiggling and jiggling the plane, rocking the wings and doing everything that you may think defies the logic of landing, it is a good chance that it was a cross wind landing.
I participate in Usenet Newsgroups. Below, between the lines was posted by another pilot which I though you would enjoy after reading such boring stuff like explaining crosswind landings :airplane
-----------------
Just a funny little story...
I was landing a C172 the other day with the family aboard. We were on
final with a pretty decent cross wind from the right. I dipped the
right wing down a little, maintained track with opposite rudder,
touched down right main first, etc... You know, just the standard,
every day, boring, low-wing-into-the-wind approach. Turned out to be a
smooth & straight landing. As I was rolling out, the following
conversation with my wife ensued:
Me: "How's that for a nice landing, Heh?"
Wife: "Not bad, considering we helped."
Me: (confused) "You helped??"
Wife: "Yeah, obviously you had trouble keeping the wings level, so we
were leaning to the left."
I can't make this crap up.
-----------------
So, I will have to remember, if I want the passenger to lean on me, I will dip my right wing :wired
Hmmm..... maybe a good way to initiate a mile high club encounter. Lean right to lean left....:blush
Allen
First, understanding landings. When an airplane makes an approach into an airport, the pilot will 99.99 percent of the time want to land into the wind. The purpose of this is to slow the airplane down. We have "airspeed" and then we have "ground speed". My approach to a landing in my airplane is 72 mph. If there is no wind, then my ground speed is the same. If I have a 10 mph head wind, with the wind "blowing in my face", then my ground speed is 62 mph (72mph airspeed - 10 mph headwind). When the wheels touch the ground, that means I am doing 62 mph which makes for a shorter time to stop and turn off the runway.
Unfortunately, mother nature doesn't always blow the wind right down the runway. Sometimes the wind will blow across the runway. This is called a cross wind. Imagine driving down a highway on a windy day, where you feel the wind rock your car left and right. A car has the wheels on the ground that holds you on the road. You won't drift right or left, unless you let your mind do that ;)
An airplane doesn't have that extra liberty in the air of it's wheels holding it straight down the runway. If the wind is blowing right to left, then the pilot has to compensate for this by "steering" into the wind.
When you are sitting as a passenger, you may notice the airplane's wings rocking right and left, but if you watch carefully, you may notice the right wind lower then the left wing. (or vice versa) This is called a cross wind landing. Keeping in user friendly terms, pilots call this technique "crabbing" or "slipping" depending on the descent profile to the runway.
You may have experienced a "wierd" landing where one side of the plane touches the ground first, then the second side touches down. The pilot probably was executing a cross wind landing. Though not comfortable for the passenger, this is done so that the wind does not pick the airplane back up in the air.
So..... If you are ever on a flight where a pilot feels like he is wiggling and jiggling the plane, rocking the wings and doing everything that you may think defies the logic of landing, it is a good chance that it was a cross wind landing.
I participate in Usenet Newsgroups. Below, between the lines was posted by another pilot which I though you would enjoy after reading such boring stuff like explaining crosswind landings :airplane
-----------------
Just a funny little story...
I was landing a C172 the other day with the family aboard. We were on
final with a pretty decent cross wind from the right. I dipped the
right wing down a little, maintained track with opposite rudder,
touched down right main first, etc... You know, just the standard,
every day, boring, low-wing-into-the-wind approach. Turned out to be a
smooth & straight landing. As I was rolling out, the following
conversation with my wife ensued:
Me: "How's that for a nice landing, Heh?"
Wife: "Not bad, considering we helped."
Me: (confused) "You helped??"
Wife: "Yeah, obviously you had trouble keeping the wings level, so we
were leaning to the left."
I can't make this crap up.
-----------------
So, I will have to remember, if I want the passenger to lean on me, I will dip my right wing :wired
Hmmm..... maybe a good way to initiate a mile high club encounter. Lean right to lean left....:blush
Allen