Does Vy Decrease with Altitude? | Vx and Vy | Climb Performance

If you glance in your POH at a best rate of climb table, you may see that at higher altitudes, your Yv, or best rate of climb speed, is found at a lower indicated airspeed. Let's explore why by looking at changes in climb performance at higher altitudes.
Complete your training at flight-insight.com
Private Ground School: flightinsight.teachable.com/p/private-pilot-ground-school
Instrument Ground School: flight-insight.com/ifr
G1000 Course: flight-insight.com/g1000

[@Pagweb]

I like how this concept is explained so well in a 5 minute video. In the textbook is hard to a grasp of the concept.

[@flightinsight9111]

Thanks!

[@MikeAltogether]

This is quickly becoming my default KZbin channel for CFI material. You rock!

[@antiquehealbot6543]

I am CFI and CFII now but I still learn from your video. Thanks as always. I watch your channel almost religiously.

[@billmoran3812]

This is the best explanation I’ve seen of a very complex subject.

[@noagruber8028]

fantastic information here and so well explained thank you

[@jakew9887]

Great presentation. Thanks

[@raccoonair]

I do agree with Marcos, and the concept becomes even more complicated when you compare these graphs with the ones for jet engines.

[@AviAeroAsis]

Amazing video.

[@marcelbukuru]

Do a video on the subject of VFR on top vs VFR over the top Please!!

[@user-wv2ot4nq3w]

지렷다

[@maxramm7210]

Parasite drag doesn't reduce with altitude though... The proof is fairly simple. D =Cd x 1/2 x p x V2 x S of course p (forgive the stand in for rho) decreases with altitude, but Velocity (TAS) increases in proportion. We can prove this because 1/2 x p x V2 is actually the IAS formula. IAS remains constant with altitude and therefore so does drag, the reduced air molecules travelling faster reads the same as more air travelling slower. It might be helpful to think of it as D = Cd x IAS x S.

[@flightinsight9111]

True airspeed, not indicated, remains constant in this model.

[@maxramm7210]

@@flightinsight9111 but TAS does not remain constant with a reduction in air density? Look at any E6B calculator.

[@laranja9921]

And why does Vx and Vy decrease with more flaps? Is it because of more lift?

[@abhinavmadan1763]

Hey Flight Insight Kudos from India Dear sir Could you please clear my doubt that what will happen to Vx and Vy with extention of flaps in increasing manner?

[@shamu3838]

I’m sorry did you say something? Because I lost you at airspeed LOL I’m glad there’s not gonna be a quiz on this

[@talreichert]

Very nice video, but one thing is very weird. At 4:15, at the top of the graph, the identical Vx''',Vy''' airspeeds all of a sudden become different from one another when you switch to IAS. Same airspeed, same altitude, it should be the same both as TAS and CAS, and the difference between CAS and IAS ought to be quite small.

[@flightinsight9111]

Thanks! point taken

[@Anee988]

Is this what determines the aircraft service ceiling?

[@flightinsight9111]

In an indirect way, yes. Ceilings are related to excess power. At the absolute ceiling, there is no excess power and the climb rate is zero. At the service ceiling, the distance between the power available and power required curves is small enough that the aircraft's rate of climb is no better than 100 fpm.

[@slay47808]

fucking amazing graphics thank you

[@alk672]

Finally!

[@Factual_fortitude]

First

[@KC_FlightChief]

Congratulations