Tomgyro
Member
Kolibri you have become your Alabama gyro CFI. He repeated things he had learned from people he respected and trusted. In his own eyes he was right no matter what others tried to tell him. He knew that the RAF could be flown "tail-less" or stabilized by just proper flying techniques. You applied what you experienced with him and listened to others. You sincerely try to help make the gyro community safer. BUT the time has come for you to reevaluate some of the things you have "learned" that are either "half truth" or outright false teachings.
You said, " They know not what they do". Well, neither do you.
For the second time in two years, the video link to a stock Bensen being barrel rolled has been posted to this forum in response to your equating the ability of one pilot to roll one machine to the assumption that makes for a better engineered gyro. You still don't get it. Jim had a special childhood growing up. In his own words he kept pushing the family gyro steeper and steeper until he went over. One pilot. For all the Aussie muster pilots with thousands of hours swooping and zooming, I don't see them looping or barrel rolling that make or model of machine. History lesson time. In the early days of flight the maneuver we know as a stall spin was an unrecoverable event. After many deaths the designers and flight instructions gave us a repeatable recovery procedure. For decades it was taught in initial flight training. We are not yet there with a two blade tetering rotor system in an inverted or greatly lowered "g" flight condition. That's the reason for the No Aerobatic Flight limitations. It has nothing to do at all with the structural integrity of the airframe and flight components.
I know personally that the AR-1 was first on paper and in computer engineering software evaluated for flight loads and failure factors such as fatigue before the first choice of structural materials was considered. Think about that for a moment. Let it sink in. Why sink in ? Because when it has been said to you over and over in a nice way you have missed it. Just like your old Alabama CFI again. Now, once the loads were laid out the materials were selected. Yes 4130 has good on paper numbers. Weight and strength in line with the requirements but.....a very big but....it was not available in those sizes in a documented certified source in commercial quantities. Stainless steel in the weight and strengths needed are available with traceable certification at prices and quantities that allows manufacturing with room left for possibly making a profit on the finished machine.
So, quoting your prior post, "I very specifically criticized stainless steel masts" shows your lack of knowledge about the subject. I don't personally know your educational background. But I do know Abid Farooqui's Engineering education and his professional work in aviation leading to making other types of flying machines safer. I know he has been the lead engineer on several aircraft getting their Type Certification. If Abid designed the one piece stainless mast, then I have no fear trusting mine or my family's safety to that use of material. You are wrong in your assumptions about one piece stainless steel mast in this machine.
Dr. Bensen pushed for "tail-less" airframe and self instruction. For whatever legal advice or personal pride that was accepted as "truth" for 25 years. There are many good pilots in their graves because of this dogma. There have been fewer modern era crashes due to tail feather size and location. This leads to another misconception on your part. And again I quote you, " to dismiss the structural strength needed in a low positive-G maneuver is to ignore, for example, the issue of mast flexing". Truth is in a low positive-G maneuver there are less forces on the mast than in a normal G range. In normal flight traditional physics works like this: the weight and aerodynamic drag of the gyro are offset by the lift of the rotor. The lift line goes in a direction mostly parallel to the mast. In a sudden low G situation like the high speed zoom up followed by a leveling control input, the upward inertia of the gyro lowers the apparent weight of the machine and pilot ( that light in the seat feeling) but the rotor is still producing lift in an upward and slightly rearward direction. If unchecked the rotor will in a split second tilt rearward often with enough movement to chop off the tail. Since any turn in any aircraft produces higher G forces (weight) the proper flight instruction is to turn at the top of a climb adding "weight" to the rotor to balance the lift being produced. There are no or so small as to be not a factor mast bending forces in a low G situation.
Good engineering puts tail surfaces large enough and far enough back from and vertically from the center of gravity to aid in limiting those momentary contol inputs that some machines need just to fly straight and level. However, there is a group thought that less dampening of the machine is " better" for mustering or circuits around a pattern. There is a group thought that dampening is safer for pilots. I know that on a cross country machine I enjoy the trim and sit back aspects of a non-divergent machine. This leads to the ASRA rules via way of the Arrowcopter and the British rules. That machine is the eye candy of the modern gyro era. It is fast. It goes cross countries. Plural intended. It is maneuverable in the hands of good pilots. It has over 700 hours of logged flight test times with data points and standards met. However, someone's opinion in the British rules department is that since it is divergent above about 70 knots as I recall it is limited by placard to slow flight to be certified. That's the point being made about Aussie rules. Some are good but like the British one, other rules are opinion based.
You have some very good and specific knowledge about some areas of gyros and gyro safety. I'd never talk down to you about rod ends. That has been a great addition to the knowledge base for all gyros.
Don't become that person that takes away from or leads astray others. Abid, Chuck,Eddie,Vance,Jason, all spoke these same ideas but in a much less blunt way.
And now your final quote, it's in your tag line area:
When an honest but mistaken man learns of his error, he either ceases to be mistaken - or he ceases to be honest.
You said, " They know not what they do". Well, neither do you.
For the second time in two years, the video link to a stock Bensen being barrel rolled has been posted to this forum in response to your equating the ability of one pilot to roll one machine to the assumption that makes for a better engineered gyro. You still don't get it. Jim had a special childhood growing up. In his own words he kept pushing the family gyro steeper and steeper until he went over. One pilot. For all the Aussie muster pilots with thousands of hours swooping and zooming, I don't see them looping or barrel rolling that make or model of machine. History lesson time. In the early days of flight the maneuver we know as a stall spin was an unrecoverable event. After many deaths the designers and flight instructions gave us a repeatable recovery procedure. For decades it was taught in initial flight training. We are not yet there with a two blade tetering rotor system in an inverted or greatly lowered "g" flight condition. That's the reason for the No Aerobatic Flight limitations. It has nothing to do at all with the structural integrity of the airframe and flight components.
I know personally that the AR-1 was first on paper and in computer engineering software evaluated for flight loads and failure factors such as fatigue before the first choice of structural materials was considered. Think about that for a moment. Let it sink in. Why sink in ? Because when it has been said to you over and over in a nice way you have missed it. Just like your old Alabama CFI again. Now, once the loads were laid out the materials were selected. Yes 4130 has good on paper numbers. Weight and strength in line with the requirements but.....a very big but....it was not available in those sizes in a documented certified source in commercial quantities. Stainless steel in the weight and strengths needed are available with traceable certification at prices and quantities that allows manufacturing with room left for possibly making a profit on the finished machine.
So, quoting your prior post, "I very specifically criticized stainless steel masts" shows your lack of knowledge about the subject. I don't personally know your educational background. But I do know Abid Farooqui's Engineering education and his professional work in aviation leading to making other types of flying machines safer. I know he has been the lead engineer on several aircraft getting their Type Certification. If Abid designed the one piece stainless mast, then I have no fear trusting mine or my family's safety to that use of material. You are wrong in your assumptions about one piece stainless steel mast in this machine.
Dr. Bensen pushed for "tail-less" airframe and self instruction. For whatever legal advice or personal pride that was accepted as "truth" for 25 years. There are many good pilots in their graves because of this dogma. There have been fewer modern era crashes due to tail feather size and location. This leads to another misconception on your part. And again I quote you, " to dismiss the structural strength needed in a low positive-G maneuver is to ignore, for example, the issue of mast flexing". Truth is in a low positive-G maneuver there are less forces on the mast than in a normal G range. In normal flight traditional physics works like this: the weight and aerodynamic drag of the gyro are offset by the lift of the rotor. The lift line goes in a direction mostly parallel to the mast. In a sudden low G situation like the high speed zoom up followed by a leveling control input, the upward inertia of the gyro lowers the apparent weight of the machine and pilot ( that light in the seat feeling) but the rotor is still producing lift in an upward and slightly rearward direction. If unchecked the rotor will in a split second tilt rearward often with enough movement to chop off the tail. Since any turn in any aircraft produces higher G forces (weight) the proper flight instruction is to turn at the top of a climb adding "weight" to the rotor to balance the lift being produced. There are no or so small as to be not a factor mast bending forces in a low G situation.
Good engineering puts tail surfaces large enough and far enough back from and vertically from the center of gravity to aid in limiting those momentary contol inputs that some machines need just to fly straight and level. However, there is a group thought that less dampening of the machine is " better" for mustering or circuits around a pattern. There is a group thought that dampening is safer for pilots. I know that on a cross country machine I enjoy the trim and sit back aspects of a non-divergent machine. This leads to the ASRA rules via way of the Arrowcopter and the British rules. That machine is the eye candy of the modern gyro era. It is fast. It goes cross countries. Plural intended. It is maneuverable in the hands of good pilots. It has over 700 hours of logged flight test times with data points and standards met. However, someone's opinion in the British rules department is that since it is divergent above about 70 knots as I recall it is limited by placard to slow flight to be certified. That's the point being made about Aussie rules. Some are good but like the British one, other rules are opinion based.
You have some very good and specific knowledge about some areas of gyros and gyro safety. I'd never talk down to you about rod ends. That has been a great addition to the knowledge base for all gyros.
Don't become that person that takes away from or leads astray others. Abid, Chuck,Eddie,Vance,Jason, all spoke these same ideas but in a much less blunt way.
And now your final quote, it's in your tag line area:
When an honest but mistaken man learns of his error, he either ceases to be mistaken - or he ceases to be honest.