# FAA minimum climb rate?

#### bigbobhi

##### Newbie
Hello, I'm new to this forum but it looks great! I'm wondering if anyone knows where to find the rules for determining minimum (and max) climb rate for certification of a gyroplane design?

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"Certification" is an important word here. There are very few Standard Airworthiness gyroplanes that would be subject to climb rate / climb gradient requirements from FAA (14 CFR 27.65 (a)(2) et seq.). Most are licensed as Experimental Amateur Built instead. No in-flight performance testing is typically done for an Experimental Airworthiness Certificate, just construction methods and quality inspections, and builder's log review.

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Thank you!

So if there is no specific certification requirements, and therefore no minimum lift requirement, then can the rate of climb be less than the typical 1000 fpm, for a lower, say, 300-400 fpm be acceptable for a heavier payload?

For example, how can one determine if the same rotor can support the weight of four people instead of two people at the expense of climb rate.

Most blade manufacturers can tell you the maximum loading intended for their product (depending on diameter, chord, etc.), so you can follow their recommendations for gross weight.

Thanks. Apart from the structural strength of the blades from the manufacturer’s Max Allowable Loading. It would be good to know how to calculate what the aerodynamic performance limits are to determine what max load is for various climb rates. Do you know of any calculator programs that can give you the lift for a rotor diameter + chord + number of blades?

eg I understand a typical 28' 2-blade rotor can produce 4tons of lift at jump-take-off rpm. Hard to imagine such lift can be produced as that's about
5 times the gyro weight

I understand a typical 28' 2-blade rotor can produce 4tons of lift at jump-take-off rpm. Hard to imagine such lift can be produced as that's about
5 times the gyro weight
Most jump take off gyroplanes do not use a two blade rotor.

During a jump takeoff the rotor blades are not pitched for autorotation and the lift is temporary.

It would likely save time if you would just ask straight out about what you are imagining.

Not sure what you are looking for. Maybe these two Excel spreadsheets by Chuck Beaty(sp) will help a little.

#### Attachments

• Rotor MPH.zip
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• Rotor Performance.zip
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Most jump take off gyroplanes do not use a two blade rotor.

During a jump takeoff the rotor blades are not pitched for autorotation and the lift is temporary.

It would likely save time if you would just ask straight out about what you are imagining.
Thanks Vance

Not sure what you are looking for. Maybe these two Excel spreadsheets by Chuck Beaty(sp) will help a little.

Bob, be aware that the climb rate of a gyro is affected by a number of factors. The weight of the machine which varies, with the amount of fuel, the number/weight of people, cargo, along with the air density, which varies with the outside air temp at time of TO and the elevation of your departure airport.

These are all calculate for the time and place of departure then checked against appropriate performance charts all those then going into calculating a likely climb rate.

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