Abid
AR-1 gyro manufacturer
- Joined
- Oct 31, 2011
- Messages
- 6,254
- Location
- Tampa, FL
- Aircraft
- AR-1
- Total Flight Time
- 4000+ 560 gyroplanes. Sport CFI Gyro and Trikes. Pilot Airplane
It is obvious on this forum from comments etc. that many gyroplane pilots as well as CFIs don't talk about or even possibly fully understand the low to 0 G flight conditions that are without a doubt death sentence in a 2 bladed rotor system or even in weight shift trikes. Both these categories of aircraft have had their share of low G bunts, tumbles etc. Both suffered from gaining pilot population from airplane pilots who had the wrong response at the wrong time built into their muscle memory. Trikes have improved their record slowly with increasing training and specific training subjects around different ways that can get the pilot into trouble. Hopefully gyroplanes will catch up in reducing this kind of accident.
I wanted to simply start this specific discussion with parabolic flight which we all know is the classic example or way of creating freefall or sensation of 0 G.
First some facts.
You do not have to go to negative G to lose control
You don't even have to get to full 0 G to lose control.
You only need to get to low enough G to start to lose control and any sustained period of low G will create problems that are unrecoverable.
However, these just don't happen without pilot input unless you are flying in some severe turbulence like in a thunderstorm etc.
The biggest misconception among many pilots and even CFIs is that to create zero G you have to push the nose down from a steep climb up and then you get to zero G.
WRONG!
You get to zero G on your steep climb up, remain in zero G in the pushover phase and continue in zero G into the initial sharp descent.
The very beginning of the sharp climb up is where you can experience high G (1.5 to 1.8 Gs) and while you are still going upwards you begin to go towards low G and get to zero G while still heading up.
"Contrary to popular misconception, the 0 g freefall phase of flight begins as the aircraft climbs, and does not occur solely as the aircraft descends. Although the aircraft has upward velocity during the initial 0 g phase, its acceleration is downward: the upward velocity is decreasing"
Unless this simple fact is understood by all pilots and CFIs and actually conveyed to the students during training, the zoom climb showoff maneuvers that you see are not understood to have the danger that puts you right on the edge. The perceptive pilots know how to do the zoom climb without getting themselves in danger. Some of them (including me) also did not or do not know this fact but we are quick to perceive in our seats that things are starting to go the other way and do something to load the aircraft (which usually means make a banked coordinated turn). I certainly was not taught any of this in trike ground school by my BFI/AFI because he had no clue either but I did intuitively understand and feel that this was wrong and always either stopped the zoom climb smoothly or converted it to a sort of wing over keeping G forces. God knows I must have done 100's of zoom climbs smoothly and safely before I ever understood this and knew where I was going when doing these zoom climbs. Being a high time trike pilot/CFI and test pilot and a curious person I then had to find stuff to study what is actually happening in this parabolic flight and thankfully there are many things available to read about it. The math is there but that is not we as pilots have to really care about. We just have to conceptually understand where we get to 0 G because the popular belief is its on the down low.
This is why you will see comments from experienced gyroplane CFIs on some bunt over accident videos saying something to the effect of, well the pushover is not so drastic but he definitely lost control. Its simply because he was at zero G before he ever pushed over. There is a famous video from Japan of a bunt over where this probably applies in spades.
Here is the link to an article from where I have captured this picture. Hope this will help CFIs and pilots alike in discussing this subject during ground briefings. Again the understanding of the math is less important than understanding of the concept and what is generally happening.
I wanted to simply start this specific discussion with parabolic flight which we all know is the classic example or way of creating freefall or sensation of 0 G.
First some facts.
You do not have to go to negative G to lose control
You don't even have to get to full 0 G to lose control.
You only need to get to low enough G to start to lose control and any sustained period of low G will create problems that are unrecoverable.
However, these just don't happen without pilot input unless you are flying in some severe turbulence like in a thunderstorm etc.
The biggest misconception among many pilots and even CFIs is that to create zero G you have to push the nose down from a steep climb up and then you get to zero G.
WRONG!
You get to zero G on your steep climb up, remain in zero G in the pushover phase and continue in zero G into the initial sharp descent.
The very beginning of the sharp climb up is where you can experience high G (1.5 to 1.8 Gs) and while you are still going upwards you begin to go towards low G and get to zero G while still heading up.
"Contrary to popular misconception, the 0 g freefall phase of flight begins as the aircraft climbs, and does not occur solely as the aircraft descends. Although the aircraft has upward velocity during the initial 0 g phase, its acceleration is downward: the upward velocity is decreasing"
Unless this simple fact is understood by all pilots and CFIs and actually conveyed to the students during training, the zoom climb showoff maneuvers that you see are not understood to have the danger that puts you right on the edge. The perceptive pilots know how to do the zoom climb without getting themselves in danger. Some of them (including me) also did not or do not know this fact but we are quick to perceive in our seats that things are starting to go the other way and do something to load the aircraft (which usually means make a banked coordinated turn). I certainly was not taught any of this in trike ground school by my BFI/AFI because he had no clue either but I did intuitively understand and feel that this was wrong and always either stopped the zoom climb smoothly or converted it to a sort of wing over keeping G forces. God knows I must have done 100's of zoom climbs smoothly and safely before I ever understood this and knew where I was going when doing these zoom climbs. Being a high time trike pilot/CFI and test pilot and a curious person I then had to find stuff to study what is actually happening in this parabolic flight and thankfully there are many things available to read about it. The math is there but that is not we as pilots have to really care about. We just have to conceptually understand where we get to 0 G because the popular belief is its on the down low.
This is why you will see comments from experienced gyroplane CFIs on some bunt over accident videos saying something to the effect of, well the pushover is not so drastic but he definitely lost control. Its simply because he was at zero G before he ever pushed over. There is a famous video from Japan of a bunt over where this probably applies in spades.
Here is the link to an article from where I have captured this picture. Hope this will help CFIs and pilots alike in discussing this subject during ground briefings. Again the understanding of the math is less important than understanding of the concept and what is generally happening.
The dynamics of parabolic flight: flight characteristics and passenger percepts
Flying a parabolic trajectory in an aircraft is one of the few ways to create freefall on Earth, which is important for astronaut training and scientific research. Here we review the physics underlying parabolic flight, explain the resulting flight dynamics, ...
www.ncbi.nlm.nih.gov
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