vertical descent

ronr

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just wanted to know, can a Bensen do a power off vertical descent ?
I didn't know if it has a large enough rudder keep from rotating without any prop thrust or forward airspeed.
 

WaspAir

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Keeping the H-V avoid region in mind is a bigger safety issue IMHO. Rotation need not be a deal breaker.
 

Resasi

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just wanted to know, can a Bensen do a power off vertical descent ?
I didn't know if it has a large enough rudder keep from rotating without any prop thrust or forward airspeed.
Yes. It can.
 

Tyger

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You're not going to be wanting to do a vertical descent all the way to the ground. That being the case, a little bit of rotation well above the ground should not be a big issue, should it?
 

EI-GYRO

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Even in a true (zero airspeed) vertical descent, there should be sufficient thrust from an idling motor to control yaw. If there isn't, a little burst of throttle should be sufficient.
You can also descend vertically with a little throttle and a little backstick to balance it. That will give you more rudder control.
A good yaw string is your friend.
 

All_In

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Keeping the H-V avoid region in mind is a bigger safety issue IMHO. Rotation need not be a deal breaker.
I've not seen a height velocity graph for any gyro.
How could I create one for the AG915?
My best guess would be the forward airspeed when you lose rudder authority???
But in real life, if I have a 10-knot headwind I have rudder authority at zero forward airspeed.

 

All_In

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Data point for the AG915. It can do 20 MPH forward airspeed in zero winds vertical descents and point the nose down with the engine off at 100 AGL and be at 65 (best glide) in about 60 feet. If I keep the nose down at 60 feet I'm at over 80MPH when it's time to flare and would ballon up or float down the runway until 65MPH.
 

Vance

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I've not seen a height velocity graph for any gyro.
How could I create one for the AG915?
My best guess would be the forward airspeed when you lose rudder authority???
But in real life, if I have a 10-knot headwind I have rudder authority at zero forward airspeed.

There is a height/velocity diagram in the Rotorcraft Flying Handbook and likely one in your POH.
https://www.ronsgyros.com/Gyro_Handbook.pdf
page 19-3

In my opinion it is an important safety consideration for any rotorcraft pilot.
 
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Vance

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Data point for the AG915. It can do 20 MPH forward airspeed in zero winds vertical descents and point the nose down with the engine off at 100 AGL and be at 65 (best glide) in about 60 feet. If I keep the nose down at 60 feet I'm at over 80MPH when it's time to flare and would ballon up or float down the runway until 65MPH.
This would be inside the shaded portion of the height/velocity diagram.

In the most basic terms it says if you are much below 300 feet above the ground at zero indicated air speed and lose the engine you may not have a successful landing.

If you are below 100 feet at 35mph indicated air speed and you lose an engine you are right on the edge of trouble.

Flying in the shaded area of the height/velocity diagram is a contributing factor in many gyroplane accidents.

The height/velocity diagram is for pilots of average ability.
 
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All_In

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This would be inside the shaded portion of the height/velocity diagram.

In the most basic terms it says if you are much below 300 feet above the ground at zero indicated air speed and lose the engine you may not have a successful landing.

If you are below 100 feet at 35kts indicated air speed and you lose an engine you are right on the edge of trouble.

Flying in the shaded area of the height/velocity diagram is a contributing factor in many gyroplane accidents.

The height/velocity diagram is for pilots of average ability.
We first tested, at altitude, the distance needed to reach 65MPH with full fuel and two people and it is 60 to 75 feet in the AG915 depending on density altitude.
With CFI's I was pulling out of them at 100 feet AGL and NEVER had to add power to reach 65 = best glide landing speed.

I have doubled that to 200 feet when there is no instructor.
The problem is after 100 feet it becomes practicing normal 65MPH best glide landings.

Not sure how that will teach me the sight picture needed in a real engine-out emergency when less than 300 feet above the ground.
 

wolfy

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Even in a true (zero airspeed) vertical descent, there should be sufficient thrust from an idling motor to control yaw. If there isn't, a little burst of throttle should be sufficient.
You can also descend vertically with a little throttle and a little backstick to balance it. That will give you more rudder control.
A good yaw string is your friend.
Yaw string is one of the most important instruments on a gyro.
If low level and doing vertical descents you absolutlely need to know when your starting to get reversed airflow. If it catches you unaware and you start to spin at low level and panick and kick the wrong rudder pedal the spin will increase and get ugly quickly.
Experiment with altitude to learn about the reversed rudder control.

wolfy
 

Tyger

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Just remember, practising landings with the engine at idle is NOT actually to be the same as landing with a real engine out.
 

WaspAir

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I've not seen a height velocity graph for any gyro.
How could I create one for the AG915?
My best guess would be the forward airspeed when you lose rudder authority???
But in real life, if I have a 10-knot headwind I have rudder authority at zero forward airspeed.

Rudder authority has nothing to do with it. You need at least a certain total energy onboard (potential energy from height and kinetic from airspeed and rotor rpm), to ensure a safe landing, allowing for conversion from one form to the other. The avoid region of the H-V diagram indicates where the total energy is likely to be insufficient.
 
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dabkb2

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just wanted to know, can a Bensen do a power off vertical descent ?
I didn't know if it has a large enough rudder keep from rotating without any prop thrust or forward airspeed.
I have done a vertical decent after a Mac attack, Mine did not want to rotate. If you are trying to practice for a engine out, my suggestion would be to try and land with as little ground speed as possible. Let me try and explain this, you need to keep 45mph on your glide slope and if you are over a decent landing spot go ahead and land normally. If you are over less than friendly terrain you want to land with as little forward speed as possible. Flair a little higher and try and get to 0 ground and air speed about 1' to 2' above the ground and just settle in. It will hit hard but it's better than hitting something that will stop a wheel and flip you over.

One of my engine out's I had to do a vertical decent to land starting at over 100' and had minimal damage. It was in soft sand so that might have helped.

If you are just doing a vertical descent with power it is fun to kick in a little left rudder and slowly spin.

Fly safe speed and altitude are your friend.
 

Gyro28866

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I've not seen a height velocity graph for any gyro.
How could I create one for the AG915?
My best guess would be the forward airspeed when you lose rudder authority???
But in real life, if I have a 10-knot headwind I have rudder authority at zero forward airspeed.

"But in real life, if I have a 10-knot headwind I have rudder authority at zero forward airspeed."

NEGATIVE!!!

Don't confuse Airspeed and Ground speed.
If you are a "0" Zero Indicated AIR Speed, then you will have (so to speak) a negative Ground speed; in other words - you will be traveling over the ground at 10 kph backwards. Because you are indicating your airspeed in relation to the airmass which is moving over the ground.
However, if you are "looking down" and have a "0" zero ground speed, and are basically stationary over a fixed point. Then your ASI will be showing "10 kph IAS"; which is your velocity within the airmass.
Don't confuse Air Speed and Ground Speed; but do understand the relationship between the two.

Hope this helps.
 
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