Density Altitude - The Triple H Effect
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- เผยแพร่เมื่อ 10 ก.ย. 2018
- What causes density altitude and how does it affect my airplane? Find the answer to these questions and learn a quick and easy step to ensuring maximum aircraft performance when density altitude is a factor in your area. Learn more here: www.aopa.org/training-and-saf...
Here are the main takeaways:
• Fly light
• Determine proper mixture
o Advance the throttle
o Lean mixture until RPMs increases and peaks
• Fly indicated airspeeds
• Use long runways
• Watch airspeed and trends
• Anticipate quicker deceleration
To download the video for offline learning visit the link below, click on "safety Videos" and select the video you want to download. www.aopa.org/training-and-saf...
Will probably never fly a plane in my life, but somehow I'm becoming an expert in aviation safety
Ivan Mazeppa that’s how I was then one day I went to an airport and asked some questions. Now I’m flying lol. Trust me. Try it.
In the 1970s I got the 172 up in the air from a grass 2000ft airstrip. My dad built the airstrip in the early 70s using a brush hog, road grader, chain saw, and a lot of blood sweat and tears. We lived on a 49 acre farm and he couldn't run the airstrip east-west because it wasn't long enough so it ran north-south. He named the airstrip J&B Sky Ranch for Joe and Betty my mom and dad. I believe the airstrip is still registered with the FAA but you wouldn't want to use it since its not used for planes anymore and has grown into a field of high weeds when I drove by there last week.
Thankful to be learning to fly in 7000-8000+ DA in Utah. I feel well prepared to expect realistic performance from my plane because of this.
I feel the same way. Just got my PPL in Reno. A former CFI of mine said that if you can learn to fly in Reno (winds, mountains, higher elevation, etc) then you can fly anywhere. I’m sure it applies even more so in your situation.
One of the best DA explanations and procedures videos I've ever seen.
As usual, top notch production
back in the 80s the UK had a number of very hot summers. a lot of pilots had problems with density altitude issues. now hot summers are common the problem has gone away. but for a short time it was something that messed a lot of people up. thankfully no accidents, at that time, seem to have this issues as a factor. but it is something a lot of people just don't give much thought to.
I'm currently taking lessons in 29 Palms. The field elevation is 1,800 ft. Sunday's DA at 9am was 4,300ft with thermals in the pattern. My CFI says I'll be a better pilot for having learned to fly out in the desert.
Hey I did my training at KTNP as well! Ha. Yup. Brutal out there, especially in the summer. I remember my CFI and I taking off in my PA-28-140 and it was 115⁰ with 5,200' DA. Field is 1,888' MSL! Thermals are nasty also.
You definitely learn to lean for take off real quick.
If you're the guy with the turbo skylane, I met you yesterday 😂
Thank you so much for the well produced and executed video!
Great video! Thanks for the hard work
Good pre-flight mixture check advice.
Interesting about humidity and also good tip about finding max power lean setting
Awesome video, thanks!
best video as far as the content goes
Good tip on accelerating in ground-effect during take-off. Another tip is to not overuse flaps on T/O, more flaps is not better. The (technical) increase in lift is not worth the slower acceleration. You want to get to Vx as fast as possible.
Why Vx ? May not be needed
Excellent info on an important subject.
Your initial graphic showing air and water molecules is misleading. The air molecules are much bigger that the water molecules, that's important. ie O2 and N2 vs H2O. Wet air has less density than dry air.
(that's not a criticism, the video is great)
Yes - and the reduced density is due to the fact that water molecules are not only smaller but also lighter than oxygen and nitrogen molecules. For the same total pressure there will be the same total number of molecules in a unit volume of air, but in humid air, some of those molecules will be lighter water molecules.
Molecular weight is important, not "size."
I think the graphic illustrates that the mass is less for a given volume -- the number of molecules at constant temperature and pressure is constant -- because the molecular weight of the h20 vapor is 18, 16+2, displacing either a nitrogen molecule n2 of 28, 14+14, at 78% or oxygen molecule O2 of 32, 16+16 at 21% (plus or minus.) I won't pretend to do the chemistry, but .78 x 28 + .21 x 32 = 28.5 replaced by 18 means rising humidity results in decreasing density . : )
The rest of the illustration and explanation is valid: less density is less lift and less drag, less propeller performance, less engine power, less thrust. If the aircraft weight is constant, give or take fuel burn while retaining a 1 hour reserve in , and the air density is falling ... well, once it reaches that corner of its thrust and lift performance envelope, so will the plane. : )
@@sbreheny "same total number of molecules in a unit volume" right! high five for high school chem teachers!
The hot humid environment of Vietnam caused a lot of problems for the Huey’s especially in the highlands
I'm a maniac subscriber of this channel:)
Big emphasis on the difference between air speed and ground speed. You can't rotate and keep yourself from stalling based on what your GPS says. Air speed is based on the molecules coming into the pitot tube, which is really what measures and determines our speed with respects to air density. Are there GPS units that can calculate or estimate air speed? I would assume so. Anyone? Would suck to lose a panel or have a clogged pitot tube and not be able to know your true air speed under extreme conditions.
A multi-sensor air density computer is well within the capabilities of modern tech, the problem with general aviation is that it's too small a market to do it cost-effectively. A pitot tube is a cheap and dirty solution, that's why it's readily available.
A GPS unit would need accurate wind data to estimate your airspeed. Where would it get that?
@@ewthmatth Good one It cant Well said
You were doing great until you mention true airspeed. Change that to indicated airspeed. Gps only knows ground speed. And we all know GS is used for time to distance only.
It's scary the amount of Pvt drivers that really don't understand DA & TAS!
Best example for having a turbo aircraft.
"Just more horsepower" is among the top 5 reasons why Detroit lost ground to Japan and Europe. Take a ride in a high performance sailplane to get an appreciation of the other tools in the toolbox besides just the hammer. Your wallet and increased TBO will thank you.
Could of included how extreme cold temperatures will throw altitude off.
Dynon Skyview show DA ..very handy
When 'Density Altitude' becomes 'Destiny Altitude'.
Great job. What ever happened to the Accident analysis videos?
I think they're still making them, but it looks like it takes an astronomical amount of man-hours to produce one of these videos. Be patient, I bet there will be more.
Blancolirio is another technical accident analysis channel you might be interested in!
@@memomorph5375 Yea I watch him Thx
All three, Heat, Humidity, and Altitude effect engine hp, but I assume only Heat and Altitude effect lift?
wouldn't lower SLP also affect density altitude? lower slp, higher temp, higher rel hum, is the hidden deadly trifecta, that sadly many pilots overlook.
Why not just call it air density? And do turboed engines, which can produce the same amount of boost at most altitudes, do better than non turboed engines?
I don't understand why setting the proper mixture is such an inaccurate activity. An AFR meter could really help setting mixture exactly. If there is a concern with lead fouling of the sensor, AFR can be calculated with some accuracy by dividing air mass flow and fuel mass flow. Air flow can be calculated with engine speed, manifold pressure, and manifold air temperature (we call this speed/density mass flow calculation in the automotive industry). Volumetric efficiency can be determined by the engine manufacturer very easily. My point is, it's not a very large leap to get a good air/fuel ratio measurement from information already present in an aircraft.
Finding Lean of Peak is always an inacurate activity... DA is a big factor here.
It is done fairly accurately via leaning to peak rpm. Any other gains in a more precise method would be so minimal that it would probably not be worth the time since it is going to change again in a minute. Also most aircraft do not have a manifold pressure gauge or manifold temp but oat would probably be good enough. Another method is to lean to peak exhaust gas temp
Most single-engine aircraft engines are still basically 1940s technology.
Something this video didn't mention is that fouling tends to be a problem at high altitude, where the usual rule (see your POH) is to lean for taxi to avoid fouling, and we're taught basic techniques to alleviate fouled plugs, and to take off with a leaned mixture instead of full-rich.
But that only works during run-up, not in flight.
And dont forget high density altitudes are due to low density air
He keeps saying "high density altitude" but doesn't he mean "low density altitude" because it's caused when the air is lower density than usual?
yeah but video is right as high refers to altitude here not density though we are talking about lowering n increment of density but with respect to a given altitude.
I have experience poor climb in hot weather
I like the abort rule 😀
. excellent I almost became a tree trimmer in a Cessna at Lake Tahoe 7000 feet and 90 degrees.
Who else is watching this video as a result of the 1984 plane crash video from Nick Crowly
As if flying were not complicated enough.
this video would've been better if you showed how to calculate it?!
Triple H.
I thought this was about the wwe superstar
good info but can't download therefore useless fro LT learning
Hi Kirby, thanks for your interest in our videos! Our safety videos, including this one, are available for download via the link below. To download: click on this link (www.aopa.org/training-and-safety/air-safety-institute/safety-to-go-downloads), select "Safety Videos" from the drop down menu, scroll down to the "Density Altitude" video and click on the download button. The video will auto-play, just click on the three dots in the lower right-hand corner and select download. If you have any questions let us know, thanks!