KPA vs altitude in feet?

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fw2015

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fw2015
Hi;
Can someone tell me why departure controller gives expected altitude (after 10 min) in KPA most of the time, but about one in ten he gives expected altitude in feet.
I tried Google but couldn't find the answer there.

Thanks

FW
 
I occasionally get a expected altitude from departure but usually it is from clearance delivery. If I depart vfr, then dep. provides the clearance (if I am departing an airport near a class C airport), otherwise it's center.
I always get the e.a. in feet ie 15000' or flight level ie FL320. Not familiar with KPA.
 
fw2015 said:
Hi;
Can someone tell me why departure controller gives expected altitude (after 10 min) in KPA most of the time, but about one in ten he gives expected altitude in feet.
I tried Google but couldn't find the answer there.

Thanks

FW
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Would you prefer that he gives you the expected altitude in furlongs? :confused:
 
MikeELP said:
Would you prefer that he gives you the expected altitude in furlongs? :confused:
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It was not the scale I was questioning. It is just that sometimes it's flight level in KPA, and other times it's expected altitude in feet.
I'm not a pilot. A friend of mine is, and I listen on my scanner. OK.
 
Let'sgoflying! said:
I occasionally get a expected altitude from departure but usually it is from clearance delivery. If I depart vfr, then dep. provides the clearance (if I am departing an airport near a class C airport), otherwise it's center.
I always get the e.a. in feet ie 15000' or flight level ie FL320. Not familiar with KPA.
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OK, so it depends on who is talking to you. KPA is Kilo Pascals. It's used in meteorology to measure atmospheric pressure. 500KPA is a sort of standard level for weather forecasting.
 
In the United States, they give altitude in feet above sea level up to 18,000 feet; above that they give it as a flight level, which is the number of feet divided by 100 that an altimeter would indicate with its atmospheric pressure compensation set to correspond to a standard sea level pressure of 29.92 inches of mercury.

What country are you in?
 
Never heard of an altitude being given in KPA
 
Palmpilot said:
In the United States, they give altitude in feet above sea level up to 18,000 feet; above that they give it as a flight level, which is the number of feet divided by 100 that an altimeter would indicate with its atmospheric pressure compensation set to correspond to a standard sea level pressure of 29.92 inches of mercury.

What country are you in?
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I am in the USA. That is interesting. I am listening to radio from a local airport but near three major airports. If "expected" flight level after 10 minutes is say 400, that would correspond to 40,000 feet, assuming that the sea level pressure is 29.92 in hg?
What type of aircraft could climb to 40,000 feet in ten minutes?
It seems that I am missing something here.
 
fw2015 said:
I am in the USA. That is interesting. I am listening to radio from a local airport but near three major airports. If "expected" flight level after 10 minutes is say 400, that would correspond to 40,000 feet, assuming that the sea level pressure is 29.92 in hg?
What type of aircraft could climb to 40,000 feet in ten minutes?
It seems that I am missing something here.
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It means they are can expect to be cleared to climb to that altitude after 10 minutes, not be at that altitude in 10 min.
 
Not many, but when they issue the e.a., you don't have to be there in 10 mins, you are cleared to start climbing to that alt 10mins after departure.
 
Let'sgoflying! said:
......you are cleared to start climbing to that alt 10mins after departure.
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Only if there's a comm outage, otherwise you have to query ATC at the expiration of the expect time before making an altitude change (and to be clear I'm talking IFR). FWIW, I've always gotten higher no more than a few minutes after checking in with departure, but I expect that's due mainly because of where I fly out of .
 
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well yes, of course....but I am not sure how deep we can get into the details on this thread.
 
The initial altitude assigned after takeoff is usually below 5,000 feet above the airport. If the airplane loses communication ability the expect altitude clears the airplane to a cruising altitude. It puts everyone on the same page...the pilot knows it's safe to clinb after 10 min and the controller knows the pilot will climb at the ten minute mark. Gives them time to clear the airspace above the plane with no comms.

Any altitude at or above 18,000 feet in the U.S. will be given as a flight level. Drop the last two zeros and that's it. 25,000 feet would be FL250 with QNE set (29.92).
 
fw2015 said:
It was not the scale I was questioning. It is just that sometimes it's flight level in KPA, and other times it's expected altitude in feet.
I'm not a pilot. A friend of mine is, and I listen on my scanner. OK.
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Where are you hearing flight levels given in kilopascals on your scanner?

Or do you mean that you are mistaking something like "flight level 400" for 400 KPA?
 
I'm still trying to wrap my brain around Kilo Pascals as a unit of measure for altitude. Thats like saying a sea level airport's altitude is 29.92 in/hg (~ 10KPA)!!!???
 
fw2015 said:
Hi;
Can someone tell me why departure conparoller gives expected altitude (after 10 min) in KPA most of the time, but about one in ten he gives expected altitude in feet.
I tried Google but couldn't find the answer there.

Thanks

FW
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It's Flight Levels, not kPa. Below 18,000 ft, Altitude in ft as measured by local barometric pressure is used. The altimeter in aircraft can be adjusted for baro pressure, which ensures height over obstacles is consistent day to day.

Above 18,500ft, baro pressure is arbitrarily set to 29.92 in Hg / 760 mm Hg / 760 kPa. Why? Jets move too fast to constant reset the baro pressure and above that altitude terrain literally does not extend that high in America
 
warthog1984 said:
It's Flight Levels, not kPa. Below 18,000 ft, Altitude in ft as measured by local barometric pressure is used. The altimeter in aircraft can be adjusted for baro pressure, which ensures height over obstacles is consistent day to day.

Above 18,500ft, baro pressure is arbitrarily set to 29.92 in Hg / 760 mm Hg / 760 kPa. Why? Jets move too fast to constant reset the baro pressure and above that altitude terrain literally does not extend that high in America
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It's above 17,999 (17,500 practically) and your explanation is not why. 18,000 happens to clear all terrain in the continental U.S. allowing VFR traffic everywhere. In countries where terrain only goes to say 3,000 the transition level would be 5,000 or so. Fast moving jets having to reset their altimeters isn't a concern when establishing a transition level.


Also, consistent height over obstacles is poorly assured with a local baro setting. It's accurate at the airport and that's about it.

Lastly, 29.92 is hardly arbitrary. That is considered standard atmospheric pressure at sea level.
 
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Captain said:
The initial altitude assigned after takeoff is usually below 5,000 feet above the airport.
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Depends on the terrain, etc... around the airport. Out of here it's almost always maintain 3000 Expect <filed altitude> 10 minutes after departure.
Any altitude at or above 18,000 feet in the U.S. will be given as a flight level. Drop the last two zeros and that's it. 25,000 feet would be FL250 with QNE set (29.92).
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18,000 is the transition altitude in the US. The same principle applies elsewhere in the world but the transition altitude varies. In the UK for example where the highest point is just over 3000' has a transition altitude at 3000.
 
flyingron said:
Depends on the terrain, etc... around the airport. Out of here it's almost always maintain 3000 Expect <filed altitude> 10 minutes after departure.


18,000 is the transition altitude in the US. The same principle applies elsewhere in the world but the transition altitude varies. In the UK for example where the highest point is just over 3000' has a transition altitude at 3000.
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That's why I said "usually below 5,000"

Your second comment is addressed directly above your post. I'm guessing we both have this understood pretty well. :)
 
I only brought up the differing transitional altitudes around the world because the mentioning of pascals lends us to believe we were not talking about the US.
 
Thanks guys! You have more than answered my query. It was my mistake to assume that flight level was associated with atmospheric pressure in Kpa. I only made that assumption because I am studying meteorology, and knowing the height, or altitude of a pressure boundary is important in weather forecasting. When I heard the numbers on my scanner, I thought Kpa. It kind of made sense to me at the time, but now that you have explained it, I don't know why I made that assumption. My bad.

FW

Edit: I just realized that I made another mistake in my query: It's not Kpa, it's hpa, Hectopascals 1hpa = 100 pascals. Wow! guess I need to study some more.
 
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warthog1984 said:
Captain said:
It's above 17,999 (17,500 practically) and your explanation is not why.
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Except:
1) FL 190 is the first used flight level
2) do you even read? You just restated all my points without new info.
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1) Not true. FL180 is usable. Maybe not every day, but roughly half of them.
2) You had several wrong points. It's not above 18,500, it doesn't assure consistent obstacle clearance, 29.92 is not arbitrary and it's not to keep jets from adjusting their altimeters too much.
 
fw2015 said:
Thanks guys! You have more than answered my query. It was my mistake to assume that flight level was associated with atmospheric pressure in Kpa. I only made that assumption because I am studying meteorology, and knowing the height, or altitude of a pressure boundary is important in weather forecasting. When I heard the numbers on my scanner, I thought Kpa. It kind of made sense to me at the time, but now that you have explained it, I don't know why I made that assumption. My bad.

FW

Edit: I just realized that I made another mistake in my query: It's not Kpa, it's hpa, Hectopascals 1hpa = 100 pascals. Wow! guess I need to study some more.
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No problem, you just confused us for a minute. I've been to a place where the flight levels were given in meters and the altimeter setting in hectopascal instead of inches (Russia), but I had never seen altitude in hectopascals except on some winds aloft charts.
 
BTW, here's an article that explains nicely when and why FL180 is and isn't available. For anyone who might be fuzzy and wish a refresher...
 
And it's still to me Mount McKinley....

Obama can take his pen and phone and very gently place them where the sun will not shine.

Sorry, I know that's SZ stuff. :mad:
 
MikeELP said:
And it's still to me Mount McKinley....

Obama can take his pen and phone and very gently place them where the sun will not shine.

Sorry, I know that's SZ stuff. :mad:
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Why Ohio feels claim to name Alaska's mountains I'll never understand...see ya in the SZ. :)
 
MikeELP said:
And it's still to me Mount McKinley....

Obama can take his pen and phone and very gently place them where the sun will not shine.

Sorry, I know that's SZ stuff. :mad:
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The State of Alaska had already changed the name to Denali forty years ago. How do you feel about that?
 
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I also thought the name had been changed to Denali years ago and was surprised to hear the recent news. I haven't thought of it as McKinley in a long time.
 
MikeELP said:
And it's still to me Mount McKinley....

Obama can take his pen and phone and very gently place them where the sun will not shine.

Sorry, I know that's SZ stuff. :mad:
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Alaskans have wanted it named Denali since 1975. I would think that Alaska, not Ohio, should be able name Alaska's mountain. Anger at Obama is nothing more than pointless, petty party politics. :rolleyes2:

Besides I thought republicans were in favor of states rights. :rolleyes:
 
dmspilot said:
...Besides I thought republicans were in favor of states rights. :rolleyes:
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Only when Obama does something that infringes on them. When he does something consistent with states' rights, then they're against them.
 
MAKG1 said:
The McKinley memorial is one of only two possibly interesting things in Canton, OH. The other is the Timken factory. :D
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Isn't there something about the Wright brothers in Ohio?
 
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