Vertical descent / Power to the rotor

GyroCyp

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. . . and if during autorotation, we could transfer ALL the engine power to the rotor, disengaging the prop, could we possibly survive a vertical descent?
 
There are so many ideas wrong in your question the least harmful answer is an old proverb:
It is better to remain quiet and be thought to be a fool than to open your mouth and remove all doubt.

Every landing in ever autogyro style flying machine is a " descent without power" all the way safely to the ground.
 
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GyroCyp;n1128343 said:
. . . and if during autorotation, we could transfer ALL the engine power to the rotor, disengaging the prop, could we possibly survive a vertical descent?

By definition autorotation is a rotor powered only by the wind.

If I applied power to the rotor in a gyroplane in a vertical descent it would spin in the opposite direction to the power required. Helicopters with powered rotors have tail rotors to manage this torque. Gyroplanes do not have tail rotors.

Speaking in general terms a vertical descent in a gyroplane happens at around 16 miles per hour (about the same as a parachute) so it is survivable. Most gyroplanes will not be reusable after the impact.

Again speaking in general terms a landing begun with some forward speed is preferable and can still be terminated with zero ground speed.

Please don’t hesitate to ask questions. That is how people learn.
 

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Tomgyro;n1128348 said:
There are so many ideas wrong in your question the least harmful answer is an old proverb:
It is better to remain quiet and be thought to be a fool than to open your mouth and remove all doubt.

Every landing in ever autogyro style flying machine is a " descent without power" all the way safely to the ground.

Not true... Landing with power is not unusual. I land that way most of the times...
And asking questions is a very good way to learn, as Vance points out...
 
XXavier;n1128354 said:
Not true... Landing with power is not unusual. I land that way most of the times...
And asking questions is a very good way to learn, as Vance points out...
There may be a word usage problem here. But XXavier I don't believe you make your landings with Power to the ROTORS as was implied in the first post.
 
Tomgyro;n1128355 said:
There may be a word usage problem here. But XXavier I don't believe you make your landings with Power to the ROTORS as was implied in the first post.

Your words were: **Every landing in ever autogyro style flying machine is a " descent without power" all the way safely to the ground.**

And, in reply, my words were: *Not true... Landing with power is not unusual. I land that way most of the times...*
 
Thanks for your replies guys. Exchange of thoughts/questions (right, wrong, irrelevant) is the name of the learning game.
Sooooo, provided we ignore, for the moment, the torque (opposite spin) issue, would we have been able to descent at a lower vertical speed?
 
GyroCyp;n1128367 said:
Thanks for your replies guys. Exchange of thoughts/questions (right, wrong, irrelevant) is the name of the learning game.
Sooooo, provided we ignore, for the moment, the torque (opposite spin) issue, would we have been able to descent at a lower vertical speed?

Well, yes... If you add energy to the rotor of a gyro in autorotating descent, in the form of increased RRPMs, the sink speed will be reduced.
 
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Only post-WWII gyros seem incapable of landing in vertical descent without crunching the landing gear. The 1930's autogyros had long-travel landing gear that allowed them to land from a vertical without damage. Such landing gear does require careful design, including a total vertical travel in the neighborhood of 2.5-3 feet, with significant "braking" occurring throughout the stroke -- and somewhere for the resulting heat to go.

A vertical descent in most modern gyros is unlikely to kill you, but the machine will be trash and there's a possibility of injury to the spine, and to other body parts as the blades wrap themselves up. It is not unheard-of for a folding-up rotor blade to strike and kill an occupant of a rotorcraft.

Even partial power to a gyro's rotor improves its efficiency and would slow down the descent, but there is the torque to consider. Dick DeGraw's designs have shown us that the torque resulting from partial power to the rotor is manageable with rudder, at cruise speed. The rudder essentially doesn't work in a vertical descent, though, unless a means of blowing air over it can be brought along.
 
When I was learning to fly gyroplanes I wasn't very good at landing and my motorcycle suspension background caused me to do the calculations and work out some design details.

I figured twenty five inches of travel on the mains and nineteen inches on the nose with lots of dampening and two rate springs.

Left and right mains were connected with a thing that looked like a anti-roll bar on a car to manage roll.

It appeared very doable to me.

As I learned to land; the allure of long travel landing gear on a gyroplane faded for me.

Mariah Gale was going to have twelve plus inches on the mains and ten inches on the nose.

I feel most aircraft suspension is very primitive.
 
Its not primitive Vance its non existence in most cases.
 
Knew someone years ago in Louisiana who had the engine quit on his Bensen over tall pine trees. He zeroed out his airspeed and came down vertically and survived. From what I remember he was not injured but the gyro was trashed.
 
Vance;n1128417 said:
I figured twenty five inches of travel on the mains and nineteen inches on the nose with lots of dampening and two rate springs. Left and right mains were connected with a thing that looked like a anti-roll bar on a car to manage roll.

Vance, did you estimate the weight of this approach? What was the planned construction for the anti-roll bar?

If the goal is to save the aircraft from damage, this approach might be useful, although the weight and drag, both below CG, could have stability downsides when the gear was extended. Larry's G-Force gear could remain fastened in the retracted position, and used for landing while in that position, then be deployed when an emergency arose, for those who did not need the extra travel for routine landings.

If the issue is saving the pilot's spine, there are techniques using layered foam and other collapsible materials in the seat and its supporting structure to absorb impact. Sport Copter has used this approach.

I read somewhere that limiting vertical impact shocks to 11-12g with proper alignment of the seat is appropriate to prevent most spinal injuries for a 25-year-old pilot, but that older pilots may suffer injuries at accelerations half that severe.
 
I'm curious what prompts the question. If you have power, why would you need a vertical descent? --Assuming of course that you would want to take off from the same location.
 
For the same reason that parachutists jump off a perfectly flying aeroplane. For the pleasure of it.
 
The first vertical descent of a heavier-than-air aircraft in history took place in Farnborough, the 31st October 1925, when a test pilot demonstrated one of the first autogyros, the C.6 The pilot was Frank Courtney, and he mentions the engine-off, vertical descent (from 1500 ft) in his memories, stating that the landing gear (no oleo legs yet installed) was badly damaged. According to Brooks (Cierva Autogiros) the sink speed was 16 ft/second, [960 ft/min] slower than in a modern, small gyro like the ELA, which I believe sinks vertically at 1500 - 2000 ft/min (that's an estimate. I don't dare to try...)
 
GyroCyp;n1128472 said:
For the same reason that parachutists jump off a perfectly flying aeroplane. For the pleasure of it.

No problem. I was just curious. From a practical perspective, the surface and surrounding area is generally larger for take off. And with power on, one can generally be quite accurate in the landing location, certainly within 200 feet, given the practical test standards are touchdown within a 150 foot area. --Anyway, the time I would want vertical decent capability to landing would be with an emergency power off scenario (particularly at night when you loose depth perception). But as others have mentioned, directional control can be a challenge with zero forward speed and no airflow across the tail.
 
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