High Speed Flight

[@twinkytwinklier4047]

It is very hard to find these kind of information. There's basically 2 types, one on the TV, where you spend 3 hrs of watching but you learn nothing new, and two on some PDF files, where all the goodies are writtin in technical words and you understand nothing whatsoever. THANK YOU FOR THIS VIDDDD

[@poh]

Thank you! and Welcome! :)

[@tristanfischer4296]

Are you sure about "Mach No. = LSS/TAS"? It should be TAS/LSS...

[@poh]

Oops big blunder! Thanks a ton will mention it in the description! Just didnt realize only! Sorry for that.. Thanks a lot for observing the same.

[@IronicArsenal]

Decreasing T/C also helps in increasing MCrit

[@Dorin1601]

Highly appreciated. Your video is amazing. I have an exam tomorrow, on POF. This is of help. Thank you!

[@poh]

You're welcome!

[@korrec1889]

awesome, effective and useful way of presenting the theory behind high speed flight with concrete examples.

[@poh]

Thank you!

[@gertverhoeven9102]

Hello, good explanation, but the graph LSS/T isn't correct. With decreasing T, the LSS will decrease. In your graph, the LSS will increase with a constant (low) T. Kind regards

[@poh]

Thanks a lot! I'm trying to improve on small bits and pieces. Appreciate that correction, just now checked. From now on my videos are going to be better scrutinized to eliminate all possible small errors. Cheers :)

[@beinghuman339]

please make video on wheel and undercarriage of aircraft

[@geoffreyblasco1693]

Could you do a quick video showing differences between bow wave, shockwave, and expansion wave? :D would make my life so much easier :D. Keep up the good vids!

[@boeing_737_neo]

I think when the speed over an aerofoil section increases from subsonic to supersonic , its aerodynamic centre moves from approximatelly 25% to about 50% of the chord. (can you correct me if i am wrong, thks)

[@jaxav8r]

I don’t understand how the center of pressure moves aftward when a shockwave forms. If lift decreases over the aft portion of the wing behind the shockwave, then lift on remains on the forward portion of the wing, yes? So ... if the lift over the wing moves forward, why would the CP mice aftward? That seems completely opposite.

[@poh]

At high speed there is a reversal that takes place. At shockwave formation there is actually a loss of lift temporarily due to break in the airflow because of the shockwave formation itself due to suction created at the rear of the wing. This is aggravated by the design of the wing which is generally swept back in nature.

[@tasnimewhida2573]

Think of it this way : as M = TAS/LSS mach is directly proportional to TAS, in the event that MACH is increased to M1 TAS must also be increased. Now the Lift formula (1/2 pv2 S CL) states that in order to maintain a constant lift, when TAS is increased CL must be reduced since all the other factors are constant. Now reducing CL implies a reduced AOA, and as AOA reduces the CP position moves aft

[@poh]

That's a great explanation! Thank you!

[@jaxav8r]

@@tasnimewhida2573 I don’t recall ever hearing anything about AoA changing during a shockwave in all the numerous things I’ve read and watched. You’re the first to ever mention the AoA changes Are you sure about?

[@tasnimewhida2573]

@@jaxav8r This is a case of understanding how the aircraft reacts in an impending stall, in this case it is a shock stall. So as the AC pitches down due to loss of lift capability since the flow is too turbulent and the boundary layer starts separating, the AoA automatically decreases and airflow is reenergized around the wing.

[@rahul_rawat1270]

Sir..one more question is that Aerodynamic centre generally not change..but in high speed how it changes

[@iva6486]

Well done. Such good explanation. Thanks

[@poh]

You're welcome! :)

[@poh]

+Iva Gobac You're welcome!

[@nikitanoronha3622]

Hi. Your videos are really helpful for me as i am preparing for my tech gen exam. But i wanted a video on Gas turbines as well please. rest all topis inhabe covered. it would be really helpful plzzz.. Thank u. 😊

[@poh]

+Nikita Noronha I'll be uploading them soon :)

[@nikitanoronha3622]

Planes Over Head thank u.. is it ok if u post by this week.. my exam is next week 😛

[@poh]

+Nikita Noronha Ouch it'll be little hard to do that within that time frame, don't want to give false hopes 😛

[@nikitanoronha3622]

Planes Over Head no worries..bt pls still try if possible..

[@poh]

+Nikita Noronha Will do :)

[@Imogene273]

GREAT VIDEO! WELL DONE

[@poh]

Thank you

[@msndolo2820]

The video was great can u please do one on propellers

[@poh]

+Anne Amina Ndolo There is one on propellers already.

[@edgarxavier493]

Do the A320 instruments give any indication of Mcrit, i.e if you approach it or exceed it?

[@poh]

Mcrit is not shown.

[@2908amit]

could you explain how LSS depends on t/c ratio please?

[@poh]

LSS depends only on Local Temperature of the air and nothing else.

[@RamKumar-to5ip]

in that place, it is TAS not LSS..

[@Realfoodreallife]

Hey, what vl be the difference in performance of jet engine and piston engine at high and low altitude??

[@poh]

+Dolridge Rumao Jet engine will perform better at high altitude. Piston engines are traditionally designed to perform better at low altitudes.

[@Realfoodreallife]

Does Mcrit affect the speed of the aircraft as it is concerned with the shock wave??

[@poh]

+Dolridge Rumao Yes ofcourse it does! Every aerofoil has its own Mcrit, and the speed of the aircraft depends at what Mach No. does it reach Mcrit, which indirectly affects TAS.

[@carolinendambuki7172]

mach number = TAS/LSS . Great vid though

[@poh]

Yes extremely sorry for that, I corrected that on the description and edited the video through sticky notes on the video! Thanks a ton! :)

[@obaidrehman395]

This is done for this chap high speed flight.

[@Realfoodreallife]

Can u plzz Jst explain the term sonic bang ??

[@poh]

+Dolridge Rumao Basically when your aircraft hits Mach 1, there is a loud noise since you've crossed speed of sound at the point in time!

[@Realfoodreallife]

Planes Over Head thanks

[@poh]

+Dolridge Rumao Welcome :)

[@kartik6925]

At mean sea level the speed of sound is 340m/s..in 15A its given 760m/h... How they are equals..its not possible...Its true 340m/s...but comparing it with 15A..its contradionary..

[@poh]

That is 340 meters per second and the other is 760 miles per hour. There is your difference.

[@meshary1996]

GREAT EXPIATION

[@poh]

+ALKHALEDI MESHARI Thank you.

[@poh]

+ALKHALEDI MESHARI Thank you.

[@rahul_rawat1270]

SIr i have read in book Mach no. = TAS/LSS Is it wrong written in book please reply Tomorrow is my exam

[@poh]

No it is correct, MACH is TAS/LSS only. I’ve mentioned the error in the description already.

[@rahul_rawat1270]

Planes Over Head@ but u have written LSS/TAS

[@poh]

Yes its an error, CHECK VIDEO DESCRIPTION

[@rahul_rawat1270]

Thanku sir

[@rehamooa.1704]

I think that mach no is tas/lss

[@poh]

Yes, the same is on the description!

[@vishalganeshe1823]

high speed in flight in I think mach no. formula is rong. because I check in Oxford book. thear is (mach no. =True speed/local speed of sound)but youer video in (mach no. =LSS/TS) so pleased details me

[@poh]

+Vishal Ganeshe I've corrected it in description already long back, kindly check.

[@achintgaur9751]

👍