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#11
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In article , Todd Pattist
writes: The first time I tried this in my Ventus, I was flying along sideways with full rudder and level wings and heard a loud "BANG!" After my heart stopped thumping, I figured out that one of the gear doors had sucked open into the sideways airflow. :-) That happened to me once.Scared the hell out of me. Another scarey bang was in a Puchacz on the winch when the cover, which is over the rear seat adjustment bar, could not have been secure and flicked down and hit the side of the fuselage. This was about six inches from my left ear and was magnified by the megaphone shape of the hollow fuselage. A third was in a Bocian, also on a winch when the rear canopy, which slid backwards on rails, came unlocked, slid back and hit the rear stop. This one was probably the worst because, a) we were about 100ft and starting to rotate into full climb, b) in addtion to the "bang" as it hit the stop, there was a huge, disorientating rush of air, and c) it took a while to work out what had happened, take over from the pupil, (only his second or third winch take off) and get the nose down etc. However, one of the the worst I know of these type of incidents was a pilot at my club who owned a Carmem and lost the complete canopy at about 4000ft agl. It departing it caught his skull which bled profusely and a combination of blood and the wind causing his eyes to run, made it extremely hard for him to see. Once he worked out what had happened, his big concern was what else the canopy had hit, tailplane for example. He considered baling out but, having checked all controls decided to ride it down to the nearest field, successfully I am pleased to say. The farmers reaction to this bllod covered figure arriving at his door was, I understand, unprintable. Needlesss to say, all of the above (except U/c doors) occurred either as a result of poor take off checks or mechanical faults. Barney UK |
#12
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In article , Todd Pattist
writes: The first time I tried this in my Ventus, I was flying along sideways with full rudder and level wings and heard a loud "BANG!" After my heart stopped thumping, I figured out that one of the gear doors had sucked open into the sideways airflow. :-) That happened to me once.Scared the hell out of me. Another scarey bang was in a Puchacz on the winch when the cover, which is over the rear seat adjustment bar, could not have been secure and flicked down and hit the side of the fuselage. This was about six inches from my left ear and was magnified by the megaphone shape of the hollow fuselage. A third was in a Bocian, also on a winch when the rear canopy, which slid backwards on rails, came unlocked, slid back and hit the rear stop. This one was probably the worst because, a) we were about 100ft and starting to rotate into full climb, b) in addtion to the "bang" as it hit the stop, there was a huge, disorientating rush of air, and c) it took a while to work out what had happened, take over from the pupil, (only his second or third winch take off) and get the nose down etc. However, one of the the worst I know of these type of incidents was a pilot at my club who owned a Carmem and lost the complete canopy at about 4000ft agl. It departing it caught his skull which bled profusely and a combination of blood and the wind causing his eyes to run, made it extremely hard for him to see. Once he worked out what had happened, his big concern was what else the canopy had hit, tailplane for example. He considered baling out but, having checked all controls decided to ride it down to the nearest field, successfully I am pleased to say. The farmers reaction to this bllod covered figure arriving at his door was, I understand, unprintable. Needlesss to say, all of the above (except U/c doors) occurred either as a result of poor take off checks or mechanical faults. Barney UK |
#13
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In article , Todd Pattist
writes: The first time I tried this in my Ventus, I was flying along sideways with full rudder and level wings and heard a loud "BANG!" After my heart stopped thumping, I figured out that one of the gear doors had sucked open into the sideways airflow. :-) That happened to me once.Scared the hell out of me. Another scarey bang was in a Puchacz on the winch when the cover, which is over the rear seat adjustment bar, could not have been secure and flicked down and hit the side of the fuselage. This was about six inches from my left ear and was magnified by the megaphone shape of the hollow fuselage. A third was in a Bocian, also on a winch when the rear canopy, which slid backwards on rails, came unlocked, slid back and hit the rear stop. This one was probably the worst because, a) we were about 100ft and starting to rotate into full climb, b) in addtion to the "bang" as it hit the stop, there was a huge, disorientating rush of air, and c) it took a while to work out what had happened, take over from the pupil, (only his second or third winch take off) and get the nose down etc. However, one of the the worst I know of these type of incidents was a pilot at my club who owned a Carmem and lost the complete canopy at about 4000ft agl. It departing it caught his skull which bled profusely and a combination of blood and the wind causing his eyes to run, made it extremely hard for him to see. Once he worked out what had happened, his big concern was what else the canopy had hit, tailplane for example. He considered baling out but, having checked all controls decided to ride it down to the nearest field, successfully I am pleased to say. The farmers reaction to this bllod covered figure arriving at his door was, I understand, unprintable. Needlesss to say, all of the above (except U/c doors) occurred either as a result of poor take off checks or mechanical faults. Barney UK |
#14
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In article , Todd Pattist
writes: The first time I tried this in my Ventus, I was flying along sideways with full rudder and level wings and heard a loud "BANG!" After my heart stopped thumping, I figured out that one of the gear doors had sucked open into the sideways airflow. :-) That happened to me once.Scared the hell out of me. Another scarey bang was in a Puchacz on the winch when the cover, which is over the rear seat adjustment bar, could not have been secure and flicked down and hit the side of the fuselage. This was about six inches from my left ear and was magnified by the megaphone shape of the hollow fuselage. A third was in a Bocian, also on a winch when the rear canopy, which slid backwards on rails, came unlocked, slid back and hit the rear stop. This one was probably the worst because, a) we were about 100ft and starting to rotate into full climb, b) in addtion to the "bang" as it hit the stop, there was a huge, disorientating rush of air, and c) it took a while to work out what had happened, take over from the pupil, (only his second or third winch take off) and get the nose down etc. However, one of the the worst I know of these type of incidents was a pilot at my club who owned a Carmem and lost the complete canopy at about 4000ft agl. It departing it caught his skull which bled profusely and a combination of blood and the wind causing his eyes to run, made it extremely hard for him to see. Once he worked out what had happened, his big concern was what else the canopy had hit, tailplane for example. He considered baling out but, having checked all controls decided to ride it down to the nearest field, successfully I am pleased to say. The farmers reaction to this bllod covered figure arriving at his door was, I understand, unprintable. Needlesss to say, all of the above (except U/c doors) occurred either as a result of poor take off checks or mechanical faults. Barney UK |
#15
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We had one genius pull the canopy release on winch launch, then a week later do
it again with the new canopy. Fortunately he has moved on to smashing cars... BAToulson wrote: In article , Todd Pattist writes: The first time I tried this in my Ventus, I was flying along sideways with full rudder and level wings and heard a loud "BANG!" After my heart stopped thumping, I figured out that one of the gear doors had sucked open into the sideways airflow. :-) That happened to me once.Scared the hell out of me. Another scarey bang was in a Puchacz on the winch when the cover, which is over the rear seat adjustment bar, could not have been secure and flicked down and hit the side of the fuselage. This was about six inches from my left ear and was magnified by the megaphone shape of the hollow fuselage. A third was in a Bocian, also on a winch when the rear canopy, which slid backwards on rails, came unlocked, slid back and hit the rear stop. This one was probably the worst because, a) we were about 100ft and starting to rotate into full climb, b) in addtion to the "bang" as it hit the stop, there was a huge, disorientating rush of air, and c) it took a while to work out what had happened, take over from the pupil, (only his second or third winch take off) and get the nose down etc. However, one of the the worst I know of these type of incidents was a pilot at my club who owned a Carmem and lost the complete canopy at about 4000ft agl. It departing it caught his skull which bled profusely and a combination of blood and the wind causing his eyes to run, made it extremely hard for him to see. Once he worked out what had happened, his big concern was what else the canopy had hit, tailplane for example. He considered baling out but, having checked all controls decided to ride it down to the nearest field, successfully I am pleased to say. The farmers reaction to this bllod covered figure arriving at his door was, I understand, unprintable. Needlesss to say, all of the above (except U/c doors) occurred either as a result of poor take off checks or mechanical faults. Barney UK |
#16
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Bruce Greeff wrote:
We had one genius pull the canopy release on winch launch, then a week later do it again with the new canopy. I wonder how you manage to get a new canopy and install it so quickly. |
#17
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Where I'm having trouble is seeing why there is any difference between
sinking, level, and climbing. From the point of view of raf, these should all be same. I choose to set my longitudinal reference based on the fuselage, not the horizon. If I do this, the aircraft always has a sink rate, not relative to the ground, but relative to the projection of the fuselage centerline at a given time (T=0) and proportional to the angle of attack -- that is, the rate at which the aircraft "falls" away from this projection (dT). Since it shouldn't matter which reference frame I use to make my observations, my confusion arises with the suggestion that the pseudo-rolling moment reverses beetween sink and climb. As for the approach, it remains interesting. To help my understanding, I've been using a train. Imagine a sensor on a rail that only measures side force. A train going straight on level ground registers zero side force. As the rail bends though, the sensor would measure a side force proportional to the train's acceleration. However, a straight rail with a side pitch would register a force as well. When viewed this way, a train rolling on a straight rail with several degrees of side inclination could be said to be "turning." Of course, it isn't. Unlike a curved rail, no additional power is needed to maintain speed. (Note the limitations of my reference frame. I only see side force on the rail, not total force.) It's not exactly analogous, but it's a step in the right direction. |
#18
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In article , Todd Pattist
writes: The first time I tried this in my Ventus, I was flying along sideways with full rudder and level wings and heard a loud "BANG!" After my heart stopped thumping, I figured out that one of the gear doors had sucked open into the sideways airflow. :-) That happened to me once.Scared the hell out of me. Another scarey bang was in a Puchacz on the winch when the cover, which is over the rear seat adjustment bar, could not have been secure and flicked down and hit the side of the fuselage. This was about six inches from my left ear and was magnified by the megaphone shape of the hollow fuselage. A third was in a Bocian, also on a winch when the rear canopy, which slid backwards on rails, came unlocked, slid back and hit the rear stop. This one was probably the worst because, a) we were about 100ft and starting to rotate into full climb, b) in addtion to the "bang" as it hit the stop, there was a huge, disorientating rush of air, and c) it took a while to work out what had happened, take over from the pupil, (only his second or third winch take off) and get the nose down etc. However, one of the the worst I know of these type of incidents was a pilot at my club who owned a Carmem and lost the complete canopy at about 4000ft agl. It departing it caught his skull which bled profusely and a combination of blood and the wind causing his eyes to run, made it extremely hard for him to see. Once he worked out what had happened, his big concern was what else the canopy had hit, tailplane for example. He considered baling out but, having checked all controls decided to ride it down to the nearest field, successfully I am pleased to say. The farmers reaction to this bllod covered figure arriving at his door was, I understand, unprintable. Needlesss to say, all of the above (except U/c doors) occurred either as a result of poor take off checks or mechanical faults. Barney UK |
#19
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Chris OCallaghan skrev den 20 Feb 2004 05:53:14
-0800: Where I'm having trouble is seeing why there is any difference between sinking, level, and climbing. From the point of view of raf, these should all be same. I choose to set my longitudinal reference based on the fuselage, not the horizon. If I do this, the aircraft always has a sink rate, not relative to the ground, but relative to the projection of the fuselage centerline at a given time (T=0) and proportional to the angle of attack -- that is, the rate at which the aircraft "falls" away from this projection (dT). Since it shouldn't matter which reference frame I use to make my observations, my confusion arises with the suggestion that the pseudo-rolling moment reverses beetween sink and climb. When turning, the only rotation is about the vertical (earth-fixed) axis. Then take it to the extreme case of diving straight down (here defined as the longitudinal axis vertical). In that situation, all of the rotation will be around the longitudinal axis of the aircraft - i e roll. In turning flight with the fuselage level (longitudinal axis horizontal), all of the rotation will be around the yaw axis of the aircraft. In all the cases between these two extremes, part of the rotation will be around both the longitudinal and the yaw axis of the aircraft. The bank will mean some of it is around the pitch axis as well, which is a problem to be considered in, among other things, turn rate gyros. As for the approach, it remains interesting. To help my understanding, I've been using a train. Imagine a sensor on a rail that only measures side force. A train going straight on level ground registers zero side force. As the rail bends though, the sensor would measure a side force proportional to the train's acceleration. However, a straight rail with a side pitch would register a force as well. When viewed this way, a train rolling on a straight rail with several degrees of side inclination could be said to be "turning." Of course, it isn't. Unlike a curved rail, no additional power is needed to maintain speed. The equivalent to a banked railway track would be straight slipping flight. And in both cases, the normal force on the rail (the lift) will have to be larger if it is to keep the train/aircraft from accelerating downwards, and there will have to be a lateral (train/aircraft frame of reference) force as well, assuming that there are no other forces perpendicular to the direction of travel than the normal and lateral (to the wings/rail). Both these forces will add friction/induced drag and require additional power. Cheers, Fred |
#20
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Todd Pattist skrev den Fri, 20 Feb 2004
15:44:10 -0500: And, to answer his question on why there is a reversal between sink and climb, you need to go on and point out that with the nose pointed strongly down, the top of the outer wing is moving forward around the outside of the turn circle. With the nose pointed strongly up, the bottom of the outer wing is moving forward around the outside of the turn circle. Thus, a reversal at level. Good job! The same thing, but understandable in your version! Another example of why you should never let an engineer explain anything to do with his field of work. Cheers, Fred |
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