You are a tough crowd :) Recall that the vast majority of training doesn’t even cover accelerated stalls, and in fact most training aircraft aren’t even authorised to carry out accelerated stalls. Practising 1-g stalls, usually to first indication, doesn’t really allow a good exploration of the V-g envelope. As a consequence, a large majority of flight crew may not be as well versed in the V-g diagram as they might think?
I believe it may also be known as a Klecher diagram, but Google hasn’t been my friend and I can’t find the name of the aerodynamicist who devised it.
most training aircraft aren’t even authorised to carry out accelerated stalls.
Huh? You can roll into a 60 degree bank then pull a stall in anything. That’s 2G. More than that would require some creativity, I agree.
@johnh yes, checked the PA28 and C172 and didn’t find it as a limitation. The practical test standard PPL or CPL doesn’t require the manoeuvre and it is only taught in theory, usually.
Rolling G manoeuvres to an accelerated stall are not typically practised in civilian flight training outside of aerobatics and UPRT.
Will look for some POH where accelerated stalls are in the limitations.
The practical test standard PPL or CPL doesn’t require the manoeuvre and it is only taught in theory, usually.
I did a 45 degree bank stall in my 182, when I was experimenting with the “impossible turn” (at altitude of course). Turns out it is very benign, much more so than a wings level stall. There is masses of buffet (practically none wings level), and altitude loss holding the stall at just below the accelerated stall speed is no worse than flying for longer at Vs+10 !
But I agree that I never flown this with an instructor other than in aerobatic flight.
The FAA talks of POH prohibitions and limiting to flaps up (flaps reduce the g envelope) and 45 degree bank with IAS below Va.
I just stumbled on this video. As it has been an eye-opener to me, I thought I’d share.
Thank you. I don’t remember seeing that diagram before and it was very interesting to see familiar concepts expressed in a different way.
Much appreciated!
Colm
RobertL18C wrote:
As a consequence, a large majority of flight crew may not be as well versed in the V-g diagram as they might think?
I don’t think the average GA pilot will get that much info of this diagram. It’s mostly a diagram by designers, for designers. I’m a bit confused about the naming also. This is a V-n diagram, and has always been a V-n diagram. Maybe by including the gust lines it becomes a V-g diagram ? The interesting parts of the gust lines are the equations leading to the lines, not the lines themselves, at least for GA aircraft with highly varying wing loading. Of course, some discussions about the gust lines in relation to the
stall curve could be done, but isn’t in the video.
Conventionally the load factor is either n or g, the g is not for gust factor. A purist would use n. The gust lines are relevant for defining limit speeds and Vc and Vb, not sure that relevant for Vs.
Not sure it is for ‘designers’? The V-g diagram is in effect a representation of the type’s airframe limitations and arguably most relevant to pilots?
RobertL18C wrote:
The V-g diagram is in effect a representation of the type’s airframe limitations and arguably most relevant to pilots?
Without a g meter, how would you ever know where on that diagram you are, or have been? Aerobatics, perhaps, but even there the only important thing in this respect is max G, not where in that diagram that max G occurred.
