Good video. Just a clarification on the chart comparisons. When you said for example "increase by 115%" I think you mean 15% increase. An increase of 115% would mean doubling the distance plus another 15% but I knew what you meant 4:02
It’s a matter of comfort too, not just performance. The AC in most small planes is decorative at best, and after about 9am the turbulence and thermals pick up and flying just isn’t as fun. Flying in the morning/evening is simply preferable.
Here in Utah we have temperature swings from 15c to 41c in a matter of hours. Couple that with field elevations of 5,000 MSL or greater. You can get DA’s of 9,000 feet with runways at 4,000 feet. Not to mention mountains everywhere with mountain wave pushing you down. It can get very tricky very quickly.
Great video and summary of DA. I think regarding summer flying, another detailed video of the best way to monitor for popup thunderstorms and how to deal with them in flight say on a 2-3 hr flight. Do you divert and land to let them pass or do you fly around them. All options need to be considered based on time, fuel, and other weather obstacles. Thank you.
Great to see y'all back on UA-cam. First started watching your videos when I was training for private. Now instrument rated and I'm glad to see the longer format videos back.
yay! boldmethod is back! I have no idea you guys does YT shorts! I should take a look! But I just wanted to say I really like your older video! So I hope these new video will make a great comeback! Thanks for your teaching!
As someone who has flown turbines in and out of almost all of the CO high elevation airports, and his 182 to KAEG from the east coast, I believe you left out what is the most important consideration. Climb gradient is more important than rate of climb or time to climb. And that is affected much more than ROC with high density altitude, especially in mountainous high elevation areas. I concur, in the example given you have more options out of KGJT because you're not dealing with immediate high terrain if you head SW on V8, however this could have been a much more educational video dealing with, say an Aspen departure as befell a Bonanza in July 2021. I like the content, I'm just saying it could have gone further.
Excellent point. Also it's too simplistic to speak about DA alone as temperature and pressure altitude have independent effects on turbocharged and turbine engines. Those engines will not perform as well at 6,000 feet and 40 degrees C as they will at 10,000 feet and zero degrees, even though in both cases the DA is 10,000 feet.
@@igclapp Agreed! That same decrease in air density responsible for our lack of performance will also reduce the capability to carry away heat! Cooling is a function of air density primarily, not just air temp. Most aviators don't stop to think that although the engine may be seeing sea level manifold pressure, because of the heat of compression it is not producing sea level horsepower due to decreased air density in the intake charge(which intercoolers attempt to solve). In fairness, he DID touch on the fact that extended climbs at Vy may result in overheating in a turbo motor, thus extending the climb because of the necessity to accelerate to cruise climb speed(reducing ROC even further) or even perform a step climb. Also remember that although your engine may be outputting something close to S.L. horsepower, it is not producing S.L.thrust. Your propeller is an airfoil, and in the same way your wing is less efficient at higher altitudes, so your prop is less efficient at converting that reduced H.P. into thrust.
Whoa whoa whoa. You can’t just casually come back after 2 years! Kidding. Welcome back! Also, it’s not a “107% increase.” The new value is 107% of the previous or a 7% increase. You do correct verbiage later in the video. Question: 1) is it a valid experiment to climb to 7500 feet, level off, then climb at altitude adjusted Vyto see what your planes climb performance actually is at that altitude (and density altitude)? 2) have you thought of going to a subscription model for your app? In today’s content world, it’s hard to justify the per video cost, even though your content is phenomenal. But so is a lot else. But since you continue to put out new content and videos, a subscription might be a reasonable model.
Great video. Also keep in mind heat is enemy of any electronics and engines. I own my plane.... I will not fly in afternoon. And any airplane owner if u care about maint and repairs.
As a CFII here in Grand Junction, I can absolutely agree with this assessment! Get out there early and get it done before it's crazy hot! Climb performance is reduced greatly and it's difficult to maintain healthy CHT.
Love Bold method but... Where is the 172 inclusion? One of the most common trainers and maybe try looking at Vegas or similar, it absolutely makes a difference here in all stages of flight!!
Just a thought about mathematics and statistics. Saying “increases by 115%” really means you’re saying it is 2.15x the length of the original 1 unit of runway length, whatever it is defined as (let’s say 1000 feet). If you said it increases BY 15% so from 1000 feet to 1150 feet. Alternatively you can say takeoff distance is 115% of the morning/lower DA takeoff distance. Don’t want to be a stickler, but it’s an important point.
on top of that, humidity impacts additional performance. at 40C/104F 0% humidity vs 100% humidity, means at 100% you have ~97% molecules for wings and propeller, and for engine you have ~97% molecules times ~97% content of normal proportion of oxygen, so engine have 94% of performance. compared to 0% humidity.
I hate density altitude, especially when talking about high/low. "low density, Altitude" (means I'm at fl400), "low, Density Altitude" (means I'm sea level) . I always have brain fog how to think, low means: "it's: not enough molecules of air in the unit of space? or "it's: I'm lower compared to a real position in space)
At least you have an advantage when looking at those met charts labelled 700 hPa and so on. (when some of us may take a few seconds going "how high was that again?").
"low-density altitude" and "low density-altitude" is the correct punctuation. Commas don't make any sense in those phrases. But, I certainly understand the frustration as somebody with a physics background and starting pilot training later in life.
@@mytech6779 I know that allways means the same but my brain fighting. I always must brake and make sure I don't go on autopilot at that moment. For me phrasing "density altitude low/high" would be 100% clear always.
When I was a 737 classic and NG dispatcher, the AC on/off was part of the takeoff calculation. Default calculated with it on but if performance was marginal it could be recalculated off along with a special flag on the dispatch paperwork. (It was actually all of the bleed air for the airpacks not just the cooling subsystem.).
Boldmethod is back on UA-cam, hooray!
Good video. Just a clarification on the chart comparisons. When you said for example "increase by 115%" I think you mean 15% increase. An increase of 115% would mean doubling the distance plus another 15% but I knew what you meant 4:02
love your videos! glad you're back
It’s a matter of comfort too, not just performance. The AC in most small planes is decorative at best, and after about 9am the turbulence and thermals pick up and flying just isn’t as fun. Flying in the morning/evening is simply preferable.
Aleks!!!! Nice to see you!
Welcome back and Thank you guys. Very helpful and educational information.
Here in Utah we have temperature swings from 15c to 41c in a matter of hours. Couple that with field elevations of 5,000 MSL or greater. You can get DA’s of 9,000 feet with runways at 4,000 feet. Not to mention mountains everywhere with mountain wave pushing you down. It can get very tricky very quickly.
Great video and summary of DA. I think regarding summer flying, another detailed video of the best way to monitor for popup thunderstorms and how to deal with them in flight say on a 2-3 hr flight. Do you divert and land to let them pass or do you fly around them. All options need to be considered based on time, fuel, and other weather obstacles. Thank you.
This video has come out of thin air.
Great to see y'all back on UA-cam. First started watching your videos when I was training for private. Now instrument rated and I'm glad to see the longer format videos back.
Best aviation instruction content!
Good subject and most welcome instruction!
Good points with the unforeseen climb penalties. Something I've never thought of.
yay! boldmethod is back! I have no idea you guys does YT shorts! I should take a look! But I just wanted to say I really like your older video! So I hope these new video will make a great comeback! Thanks for your teaching!
❤ These are some excellent vlogs, as always ❤
As someone who has flown turbines in and out of almost all of the CO high elevation airports, and his 182 to KAEG from the east coast, I believe you left out what is the most important consideration. Climb gradient is more important than rate of climb or time to climb. And that is affected much more than ROC with high density altitude, especially in mountainous high elevation areas. I concur, in the example given you have more options out of KGJT because you're not dealing with immediate high terrain if you head SW on V8, however this could have been a much more educational video dealing with, say an Aspen departure as befell a Bonanza in July 2021. I like the content, I'm just saying it could have gone further.
Excellent point. Also it's too simplistic to speak about DA alone as temperature and pressure altitude have independent effects on turbocharged and turbine engines. Those engines will not perform as well at 6,000 feet and 40 degrees C as they will at 10,000 feet and zero degrees, even though in both cases the DA is 10,000 feet.
@@igclapp Agreed! That same decrease in air density responsible for our lack of performance will also reduce the capability to carry away heat! Cooling is a function of air density primarily, not just air temp. Most aviators don't stop to think that although the engine may be seeing sea level manifold pressure, because of the heat of compression it is not producing sea level horsepower due to decreased air density in the intake charge(which intercoolers attempt to solve). In fairness, he DID touch on the fact that extended climbs at Vy may result in overheating in a turbo motor, thus extending the climb because of the necessity to accelerate to cruise climb speed(reducing ROC even further) or even perform a step climb. Also remember that although your engine may be outputting something close to S.L. horsepower, it is not producing S.L.thrust. Your propeller is an airfoil, and in the same way your wing is less efficient at higher altitudes, so your prop is less efficient at converting that reduced H.P. into thrust.
Welcome back! 🎉
Glad to have you back!
Wow nice to see you back! 😀
I could not find better quality than your materials. Golden standard. All best and please continue.
Whoa whoa whoa. You can’t just casually come back after 2 years! Kidding. Welcome back!
Also, it’s not a “107% increase.” The new value is 107% of the previous or a 7% increase. You do correct verbiage later in the video.
Question: 1) is it a valid experiment to climb to 7500 feet, level off, then climb at altitude adjusted Vyto see what your planes climb performance actually is at that altitude (and density altitude)? 2) have you thought of going to a subscription model for your app? In today’s content world, it’s hard to justify the per video cost, even though your content is phenomenal. But so is a lot else. But since you continue to put out new content and videos, a subscription might be a reasonable model.
It’s been so long!! Welcome back 🙌
He’s back!
Great video. Conversation I frequently have with students and certificates pilots. I’ll point them to this video when the topic comes up again
Yeah! He's back again!❤💪
Great video. Also keep in mind heat is enemy of any electronics and engines. I own my plane.... I will not fly in afternoon. And any airplane owner if u care about maint and repairs.
It helps significantly with a J-3 cub at mile-high airports like KVEL.
A triumphant return to long form content.
As a CFII here in Grand Junction, I can absolutely agree with this assessment! Get out there early and get it done before it's crazy hot! Climb performance is reduced greatly and it's difficult to maintain healthy CHT.
Excellent presentation. Thanks
Love Bold method but... Where is the 172 inclusion? One of the most common trainers and maybe try looking at Vegas or similar, it absolutely makes a difference here in all stages of flight!!
Missed your vids
Where have you guys been?!?!?!
Is it 117% increase or 17% increase? I think you meant 17%
Welcome back
Just a thought about mathematics and statistics. Saying “increases by 115%” really means you’re saying it is 2.15x the length of the original 1 unit of runway length, whatever it is defined as (let’s say 1000 feet).
If you said it increases BY 15% so from 1000 feet to 1150 feet. Alternatively you can say takeoff distance is 115% of the morning/lower DA takeoff distance.
Don’t want to be a stickler, but it’s an important point.
Problem is picking aircraft with over sized engines. Aircraft with marginal propulsion would have a greater distance differential for takeoff.
on top of that, humidity impacts additional performance. at 40C/104F 0% humidity vs 100% humidity, means at 100% you have ~97% molecules for wings and propeller, and for engine you have ~97% molecules times ~97% content of normal proportion of oxygen, so engine have 94% of performance. compared to 0% humidity.
higher temperature higher difference. at 10C/50F difference is ~1% for molecules and ~1% lower proportion of oxygen content.
YAY!!!
Hey dude where have you been ??
I hate density altitude, especially when talking about high/low. "low density, Altitude" (means I'm at fl400), "low, Density Altitude" (means I'm sea level) . I always have brain fog how to think, low means: "it's: not enough molecules of air in the unit of space? or "it's: I'm lower compared to a real position in space)
At least you have an advantage when looking at those met charts labelled 700 hPa and so on. (when some of us may take a few seconds going "how high was that again?").
"low-density altitude" and "low density-altitude" is the correct punctuation. Commas don't make any sense in those phrases. But, I certainly understand the frustration as somebody with a physics background and starting pilot training later in life.
@@mytech6779 I know that allways means the same but my brain fighting. I always must brake and make sure I don't go on autopilot at that moment. For me phrasing "density altitude low/high" would be 100% clear always.
@@bartoszskowronski Maybe mentally rephrase it as "equivalent altitude"
Was the AC on in the AM & PM numbers?
When I was a 737 classic and NG dispatcher, the AC on/off was part of the takeoff calculation. Default calculated with it on but if performance was marginal it could be recalculated off along with a special flag on the dispatch paperwork. (It was actually all of the bleed air for the airpacks not just the cooling subsystem.).