# Density altitude kills...

Any CFI’s seen this video during their fight instructors flight review before this was release to the public?

liveleak.com/view?i=316_1249535759

I was shown this video in 2000 when I took Commercial ground school

Not sure if that has so much to do with density altitude as it does the ole’ axiom “don’t fly into a tight valley or canyon”.

I agree. I’ve always associated density altitude with planning for takeoff and landing performance - NOT enroute.

Damn! Hang on Ronnie!

AOPA was showing that video on their web site year before last. I don’t think you even had to be a member.

Think climb performance and how anemic it gets “with density altitude” while enroute" trying to out climb the terrain

I always do wonder if the density altitude remains the same throughout the climb or does the “gap between density and actual” get closer in values as you reach the cooler air at the higher altitudes (assuming no inversion)

In my simple way of thinking.

If my service ceiling is 14500, does that service ceiling drop with consideration of density altitude since the engine only cares how much “02” to ingest and hot air is less dense if the temps were above standard at the higher altitudes?.

OR

Field elevation is 3000, density altitude is 6000
At 12000, is the density altitude 15000 assuming standard temp is higher then standard at 10000? Would I be over my service ceiling based on density altitude calculations and should really fly no higher then 11000

Density altitude calculations needless to say is not my forte and truth be known, has not been a real factor in my flying since I generally have more then enough runway and then some where I fly.!

I’ve seen that mistake more than a few times.
The charts shows that you have enough runway to get off the ground, but not enough climb performance to get out of the valley.

Allen,

The density altitude is your pressure altitude corrected for non-standard temperature. It’s how high your normally-aspirated airplane thinks you are.

You can takeoff from a 3000’ MSL airport with a density altitude of 6000ft if the surface temperature is high enough.

As you climb, if the temperature drops faster than the standard lapse rate, then you could reach 6000’ and actually still be at 6000’ density altitude…the plane will perform the same on the takeoff, as it does in the air.

So, the density altitude during takeoff is not a iron-clad guarantee for what you’re going to experience as you get higher. It works the other way, too, particularly in an inversion. You might have standard temperature down low, but above normal temperature up high, resulting in a higher density altitude than your indicated altitude.

In short, you need to take the situation on its merits at the time. Check your OAT and your altimeter (while set to 29.92)…that’s what your plane is feeling right now.

Dayem, the things we learn… Never thought about this until the thread and something as simple as changing the altimeter to 29.92 Too cool.

I don’t ever remember doing this in training or if I did, it got lost in translation in my learning curve!

Thanks for this tip.

I remember back a few years ago, in Phoenix when the airport had OAT of 122, even tho KPHX is a long runway, there were limiting carry on luggage on long flights, and not topping off fuel tanks on short flights, it was only for 2 days, adn when there is not a cloud in the sky for 100 miles in all directions, its hard to tell the passengers the plane cant take off cause the weather… or because its too hot.