flying dog

Just to clarify - as it seems there is confusion: (yeah and probably on my side) V1 is your "GO/NO GO" speed for taking off. VR is the speed at which you rotate/take off. V1 is more a position on the runway, but..... If you are taking off you need to get to VR to take off. But this is greater than V1. Given rejected takeoffs are because of a problem happening and not because of some other reason. You get to V1 and exceed it. So you are committed to taking off, but for reasons unknown: you can't get to VR speed. You are not going to "obey" the fact that V1 is the "you are committed to takeoff" speed. Therefore I put it that VR should be less than V1 so if anything does happen you would be below V1. In my example you would get to VR before V1 so at VR, you take off and all is good. And you remain below V1 so you are complying with the less than V1 aborted take off speed.

Flightrite: Yes, I over think a lot of things. And I am asking not specifically for GA/Light planes. I am asking in the bigger picture.

> My aircraft at Archerfield could probs get to Vx before V1. Would you like me to check for you? I think I know what you mean, but.... If V1 is lower than VR and any/all other Vx... You can't. Sorry.

The first paragraph: I still beg to differ. Be it "engine out" or what ever. I think there is confusion there, but I'll leave that alone. So you are going down the runway taking off - or attempting to. V1 < VR You get to V1, but don't seem to get to VR. You are "stuck" between these two numbers. What are you supposed to do? You have exceeded V1 and are "supposedly" obliged to take off, but can't get to VR speed. VR should be less than V1 so there is a margin where if you can't/don't get to VR: you are below V1 - allowed to abort the take off. I'll now read the other posts.

Thanks. I maybe should have worked that out... But.....

Sorry: POH?

Yeah, I kinda get it. It just seems wrong how V1 is determined. Really VR < V1 by how I think. No good saying you have to take off (reason still not understood) before you reach VR.

Ok, 2 or more engines.... Still doesn't really address the remaining runway distance remaining (with 2 engines) and not getting to V1. You could be rolling down the runway slowly accelerating towards V1 and not getting there and only when you are about to run out of runway do you realise you need to abort. There was an example of this happening in NZ (I think) in a twin engine prop plane and the brakes were not fully released. They took off (JUST), retraced the wheels and then the wing caught fire. Plane crashed.

I get it that I don't fly those and the "rules" have existed for a long time and the "work". But do they? There are 3 important speeds needed when taking off: V1, VR and V2. Before I continue with this I'll digress slightly to when I was doing/trying to do the BAK. You are flying a plane at an airport and are going to take off. You need to know these things: 1 - QNH 2 - Temperature 3 - Wind speed and strength 4 - TODA 5 - TODR 6 - TOW Ok, so QNH and Temperature, fair enough. TOW - Take Off WEIGHT. Again: Fair enough. TODA - Take Off Distance AVAILABLE TODR - Take Off Distance REQUIRED The QNH, wind, temperature and TOW go through a table to give you your TODR. That has to be less than the TODA, or you will run out of runway. Kinda obvious. You can't take off on a 1,000 foot runway if you need more than 1,000 feet to take off. So, that is fairly self explanatory. But now things get interesting for me.... V1, VR and V2. V1 - Above this speed you MUST take off. (Confusing for reasons to which I shall address soon) VR - This is the speed at which you "rotate" the plane. That is: You take off. V2 - Minimum climb out speed needed. If you are slower than this: you are not going to continue flying. So, let's break this down a bit more: Your plane weighs... 500Kg. The wind is still. (Just to keep things simple) Your TODR is.... 800M (Arbitrary/random number) The runway is 1000M long. You get to the start of the runway and start your take off roll. And this is where it all falls apart for me. Let's say your V1 = 80 and VR = 100. You set off down the runway and the entire runway is ahead of you - good. You continue down the runway getting faster and faster... and faster. You get 800M down the runway but haven't got to VR speed (let alone V1 speed) and slam on the brakes. Where is your stopping distance required calculated? You are in a plane doing - say 70 kts - 800M down a 1,000M runway and decide to abort the take off. The STOPPING DISTANCE REQUIRED (I just made that term up now) is.... 300M. Guess what is going to happen. Problem as I see it: V1 is misleading. V1 should be replaced by a P1 - Point1 which indicates: YOU MUST BE FLYING BY NOW OR YOU WILL NOT STOP BY THE END OF THE RUNWAY! Also the fact that VR > V1 is also weird/strange/confusing. You have a "gap" between when you can take off and when you must take off. Surley VR should be LESS THAN V1, or more correctly: P1 And P1 is a point on the runway where if you reach it and are not flying, you MUST ABORT AND STOP. So the take off would be more like, you start (at the start) and accelerate down the runway. If you get to P1 before you get to VR, you abort the take off. The remaining runway distance is enough for you to stop. All things being good: You get to VR well before P1 and you are flying before you get to P1 on the runway. And - of course - P1 will vary from plane to plane and with different conditions. Temperature, wind, etc. Yes, it is more complicated to work out and "way back then" it may have been too difficult to calculate. But now, with computers coming out of every hole in "everything".... that isn't too difficult to do. So really looking back at the V1, VR and V2 speeds, and their association that: V1 < VR < V2 is really problematic. VR < V1 for starters. V2 and VR.... well.... I'm not sure. Thoughts? Who can help me get my head around why these are called what they are called and why.

Thanks. At the distance I thought it was a C130. It's a conspiracy! I tried to load "Flight Radar" (the app on my phone) and it wouldn't load. I wasn't supposed to see it. 😉

Well, I was walking to the shops and I'm sure it was. 4 big spinny things on a high wing plane. Alas I couldn't get Flight Radar to load quick enough to get more info. I am sure of the time as I tried to call someone I know who lives in your area who is also into planes. So I looked at the time I called them.

I was out shopping and heard a non-normal sound. Looked up. C-130 taking off. Heading NW over .... 5-dock/Concorde when I saw it.

Ah! That would do it. Thanks. And thanks Marty_d

I saw it on the news... It's a 4 engine jet. And it isn't a A380... So what is it? All I can think of is a 707, A340 or a DC-8.

ONETRACK: > Alan - You have to treat animals as animals, they're not humans, and they can't be given and follow instructions, as humans can. Ummmm..... I've seen animals that are more obedient than humans, and humans that make sheep look intelligent. So that statement isn't exactly true.

*&*(&$(! I'm in trouble then!

Yeah, ok, sorry. Got ahead of myself a bit.

I'll bite. How can that work? Sure: When they did the fence there was a 12 degree magnetic variation. That was then. Now it is 16.5. So the fence won't run to cardinal points. Be they magnetic or true.

That isn't an easy accent to shake though. Depending on .... Oh. Living in Oz for 60 years. Yeah, well I knew someone who was here about that time too. They had a heavy accent.

Well, if you fly in circles, you don't get to see that much. I know that. :)

Gee, I thought I was smart, and started to study navigation stuff.... try to get a degree or two. Seems I am not as smart as I thought. The compass has three hundred and sixty degrees. Shessh! I can't compete with that.

I have heard that name before but can't think where. But knowing me, it is probably a whole other "Mark Bennette" of whom I am thinking.

I am trying! I **AM** trying! But they are complicated things. And I believe costly pets as well.

I'm a bloke and single. Why would I read New Idea?

I saw on the news today that he (Mark) is taking a woman from Wadonga to QLD. He is in Bankstown. Good on you Mark!