Hi, I'd just like to say, for posterity's sake, that my father Donald Houghten invented the "wheel" you're using back in the 1960s. He was head of Safety Education at the FAA, so just like the safety education films he made ("One Eye On The Instruments", etc.) he never got credit for his work. He passed away in 2001, but I think he would be delighted that his wheel and films are still helping pilots!
thank you very much for explaining it perfectly. i use to use my cx2 and it gave me a huge pressure altitude it didn't even make sense this post made it simpler
For exam purposes (no altimeter available to read PA from) for a given true altitude or field elevation: PA = {(Sea Level Pressure - 29.92) x 1000} + true altitude or field elevation if on ground.
No, you stay at your indicated altitude. It means the performance of your air plane will be AS IF it were flying at a higher altitude (reduced performance).
Pardon my ignorance, but why is there no basic gauge that can automatically compute the given temperature, pressure alt, and what ever other info that is readily available to just give an instant density altitude reading!? I understand that in flight planning, the manual way is important but as a cross check for in flight??
Beatchild & The Slakadeliqs Have you ever hear about FMSC? That is the computer that doing all those calculations based out of what are you typing in it, like temperatures, altitudes and so on. This particular video is about using E6B, which is old fashion way the FAA wants the beginner pilots to know and understand those calculations.
Hi. Calculating the density altitude is simple but what does the result mean when I am flying? Should I now climb to 9000 ft to maximize aircraft performance?
hassaan zahid Cold air is denser, and hot air is less dense. As you rise in altitude the air gets thinner, but if it's not a "typical" day--and it rarely is--the air is going to be warmer or cooler than average. If it's warmer, the air will be thinner, just as if you are at a higher altitude than you're actually at. If it's cooler than average, the air will be denser, just as if you were at a lower altitude than you're actually at. Hence, "density altitude" the altitude it seems like you're at because of the air density. The reason it matters is that your airplane performs differently at different altitudes.
Yes; hard to believe! It means approx. 50 degre Celcius on ground that is 122 degre F. !!! As per ASHRAE Fundamentals, in Laredo, TX, just 0.4% chance to have more than 102 F. wich is 39 C. Anyways...just an example even not realistic!
Standard temperature at 5000' is 5°C, not 15. 15° is standard at sea level, and the standard lapse rate is -2° for each 1000', so 15° - 5000' / 1000' * 2° = 5°
Thank God for UA-cam and your tutorials.
Hi, I'd just like to say, for posterity's sake, that my father Donald Houghten invented the "wheel" you're using back in the 1960s. He was head of Safety Education at the FAA, so just like the safety education films he made ("One Eye On The Instruments", etc.) he never got credit for his work. He passed away in 2001, but I think he would be delighted that his wheel and films are still helping pilots!
It was invented by a US navy pilot named Philip Dalton in the 1940s
thank you very much for explaining it perfectly. i use to use my cx2 and it gave me a huge pressure altitude it didn't even make sense this post made it simpler
please keep making these videos i am a student pilot and this helps me so much!! thanks for the help!!
For exam purposes (no altimeter available to read PA from) for a given true altitude or field elevation: PA = {(Sea Level Pressure - 29.92) x 1000} + true altitude or field elevation if on ground.
Great explanation! Thank you!
thank you, I'm learning how to use my whiz wheel now, before I take my written mid Feb......I need all the help I can get!
That's correct, the example is supposed to simulate a "hot and high" condition where performance suffers significantly.
No, you stay at your indicated altitude. It means the performance of your air plane will be AS IF it were flying at a higher altitude (reduced performance).
Is that what these are ..someone told me they were prayer wheels .. Thanks anyway ..flight review coming up and I had forgotten how to calculate
Pardon my ignorance, but why is there no basic gauge that can automatically compute the given temperature, pressure alt, and what ever other info that is readily available to just give an instant density altitude reading!? I understand that in flight planning, the manual way is important but as a cross check for in flight??
Beatchild & The Slakadeliqs Have you ever hear about FMSC? That is the computer that doing all those calculations based out of what are you typing in it, like temperatures, altitudes and so on. This particular video is about using E6B, which is old fashion way the FAA wants the beginner pilots to know and understand those calculations.
Thanks for the upload! Great video!
Omfg! U just Saved my life lol THANK YOU!
Hi. Calculating the density altitude is simple but what does the result mean when I am flying? Should I now climb to 9000 ft to maximize aircraft performance?
can you please elaborate why its higher ? and density altitude shows what ??
hassaan zahid Cold air is denser, and hot air is less dense. As you rise in altitude the air gets thinner, but if it's not a "typical" day--and it rarely is--the air is going to be warmer or cooler than average. If it's warmer, the air will be thinner, just as if you are at a higher altitude than you're actually at. If it's cooler than average, the air will be denser, just as if you were at a lower altitude than you're actually at. Hence, "density altitude" the altitude it seems like you're at because of the air density.
The reason it matters is that your airplane performs differently at different altitudes.
what is sea level on a e6b?
I gather humidity is not significant enough to bother with?
It does effect the DA but as you said, not that much
why is 29.92 important?
Because density altitude is relative to ISA, i.e. 29.92 inHg (or 1013.25 hPa) at 15° at MSL.
Only the USA uses inches of Mercury. I see the issue now. Thanks.
Thats right whats wrong with that.In summer The Grand Canyon,Lake Taho,some places in Nevada etc have high altitude airports with very hot temps.
according to you example your altitude is 5000 ft and your temp is 40 celsius ? thats 104 degrees F.
Nice.. thanks!
Thank youu
With +40 C at 5000' it must be a really hot day!
Yes; hard to believe! It means approx. 50 degre Celcius on ground that is 122 degre F. !!! As per ASHRAE Fundamentals, in Laredo, TX, just 0.4% chance to have more than 102 F. wich is 39 C. Anyways...just an example even not realistic!
You act surprised. I wonder where you live but most of our days here in Austin Texas are that hot or hotter for about 5 months or more.
DA= (OAT-ST)x120 + PA
(40-15)x120+5000=8000
Standard temperature at 5000' is 5°C, not 15.
15° is standard at sea level, and the standard lapse rate is -2° for each 1000', so 15° - 5000' / 1000' * 2° = 5°
!!!