Vx vs Vy climb technique & Startup and Run up tips.

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AKar
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Re: Vx vs Vy climb technique & Startup and Run up tips.

Post by AKar »

Oracle427 wrote:Essentially, Mr. Deakin is suggesting performing a cruise climb to pattern altitude. That will cover a lot of ground, though you will be climbing at a good pace
I recall in one of his writings he had either tested or calculated how much farther away you'd be at given altitude using his technique, it wasn't that much I think. However, I've got to dig up the article some time, not that I had much to comment, except that in gliders the extra speed, due to tow plane's typically higher climb speeds than what training gliders' best L/D speed tends to be, is extremely useful in case of the rope failure as it gives one some extra energy to 'bleed' while reacting to the situation, determining the course of action and establishing a proper glide attitude. Especially I'd think that would be so in case of an actual emergency - I've only done some 'simulated' rope failures where it is released by instructor.
DHenriquesA2A wrote:He does however in my opinion anyway, have a tendency toward an approach with his writing that goes to war with Lycoming on their recommendations every once in awhile :-)
He really seems to do that. I like it! :mrgreen:

If nothing else, it brings more technical knowledge available and spreads that with discussion.

-Esa

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Nick - A2A
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Re: Vx vs Vy climb technique & Startup and Run up tips.

Post by Nick - A2A »

Thanks chaps for the insights. :) I did actually try the technique John Deakin described in the A2A 182T and it felt rather odd to say the least. It takes a while to reach 120 knots at the lift-off attitude and it did feel I was squandering altitude whilst hurtling along rather quickly close to the ground: a serious consideration when there are obstacles and noise-abatement procedures as Oracle pointed out.

Having said that, in the 182 at least, I've found that if I delay rotating by 10-15 knots or so, the P-factor (etc.) induced yaw is less pronounced and the take-off 'feels' like it would have been a bit more comfortable in the real thing. This tends to mirror some of John's comments in the article. However, even leaving the runway surface at just about 70 kias, climb out at 80 seems to come naturally (at flaps 0 or 10 anyway) and this is in line with the published Vy I believe. The Vx initial climb is something I guess I don't tend to practice unless we're talking a flaps 20 short field take-off; otherwise it seems to take a fairly substantial yank on the yoke to get the airspeed where I want it.

I guess what I'm saying in a roundabout way is that a Vy climb tends to 'feel' a bit more comfortable to me for a normal take-off, even in the sim. From a safety point of view, I guess it got the advantage of giving me a tiny bit more reaction time to get the nose down in the event the engine looses power. In other words, I'm less vulnerable to Mr Deakin's "pile of flaming wreckage" "red area" as he puts it...

Cheers,
Nick
A2A Simulations Inc.

William Hughes
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Re: Vx vs Vy climb technique & Startup and Run up tips.

Post by William Hughes »

I perform a Vx climb on an aircraft once so I know what it looks like, and then not again after that. A Vx climb in a lightly loaded high performance single piston is a rather extreme attitude and freaks out the passengers. I have generally followed the lift off when it wants to fly, nose down till well into green, positive rate climb, gear up, and trim at something comfortable over Vy that still allows for good visibility over the nose.

Keep in mind that there are other factors in engine management, other aircraft, maneuvering, and the like that come into play. In general, getting altitude sooner is better in case something goes wrong, but strict focus on the numbers could lead to other problems...

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