Chip is making progress with the Merlin Lite

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jazzenjohn

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The only ultralight plane I'm aware of that ran afoul of the speed restriction was the Sadler Vampire. It flew considerably faster than allowed.
 

Daleandee

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Back to the subject of the Merlin Lite:

Good video and seems the cost is fair enough when you consider that the kit is mostly built when received. Still have a bit of trepidation over them 2-strokes though ...
 

Chip W. Erwin

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Feb 16, 2020
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The only ultralight plane I'm aware of that ran afoul of the speed restriction was the Sadler Vampire. It flew considerably faster than allowed.
There are plenty of ultralights in the world market but I do not recall seeing anything like our new Merlin Lite wing. 32 feet high aspect ratio with a huge 3-hinge slotted Fowler flap. We comply with the Part 103 stall speed and can easily set the prop to comply with the top speed.
 

jazzenjohn

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Milan, Mi. U.S.A.
My ultralight has a considerably higher aspect ratio wing than the Merlin Chip, my span is 23' and my wing chord is a mere 7" ....😉 My comment was merely to suggest to work hard on the weight and not worry too much about the max speed limitation. That can be fixed easily later. Also, nothing in the regulation says it must be a BRS chute. You can use a pull out pilot chute and save even more weight and cost. Pull out pilot chutes offer the ability to throw out the pilot chute in a specific direction as opposed to a BRS type that is set by its fixed placement. That feature can be useful if the plane is in an unusual attitude or spinning during deployment. Tandem paraglider reserve chutes might be a possible avenue, where something rated at 220 KG might cost $1200 and weigh 5-7 pounds. You'd have to add the pilot chute, bridle, container, and all related attachment accessories to that figure which could make a big difference.
 

jedi

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My ultralight has a considerably higher aspect ratio wing than the Merlin Chip, my span is 23' and my wing chord is a mere 7" ....😉 My comment was merely to suggest to work hard on the weight and not worry too much about the max speed limitation. That can be fixed easily later. Also, nothing in the regulation says it must be a BRS chute. You can use a pull out pilot chute and save even more weight and cost. Pull out pilot chutes offer the ability to throw out the pilot chute in a specific direction as opposed to a BRS type that is set by its fixed placement. That feature can be useful if the plane is in an unusual attitude or spinning during deployment. Tandem paraglider reserve chutes might be a possible avenue, where something rated at 220 KG might cost $1200 and weigh 5-7 pounds. You'd have to add the pilot chute, bridle, container, and all related attachment accessories to that figure which could make a big difference.
Yes, but it is the aspect ration of the rotor disk that determines the induced drag. You have a LAR (Low Aspect Ratio) flying machine. The Aspect Ratio of a rotor is one.
 

BBerson

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Port Townsend WA
AC103-7 does not mention using " max continuous power" as a speed limiter.
The AC states: "cannot be capable of driving through the air in level flight at full power faster than 55 knots."

My experience is that less pitch just lets the engine rev higher but doesn't always limit speed.
The AC states: "a lower power setting, instead of using full power, is unacceptable."
Did the FAA find that a pilot limiting the engine rpm to " max continuous power" is an acceptable method of compliance with the top speed limitation?
 
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BBerson

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They accepted that method with the LSA Carbon Cub.


BJC
Yes, but maximum continuous power is in the definition of Light Sport only, not ultralight.

[Light-sport aircraft means an aircraft, other than a helicopter or powered-lift that, since its original certification, has continued to meet the following:

(1) A maximum takeoff weight of not more than—

(i) 1,320 pounds (600 kilograms) for aircraft not intended for operation on water; or

(ii) 1,430 pounds (650 kilograms) for an aircraft intended for operation on water.

(2) A maximum airspeed in level flight with maximum continuous power (VH) of not more than 120 knots CAS under standard atmospheric conditions at sea level.]
 

Daleandee

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Yes, but maximum continuous power is in the definition of Light Sport only, not ultralight.

(2) A maximum airspeed in level flight with maximum continuous power (VH) of not more than 120 knots CAS under standard atmospheric conditions at sea level.]
I thought I was the only one paying attention. You are exactly correct with regards to ultralight speeds. I'm sure if it's really close that the actual speed might be tough to determine and no one would really care.

I know when I was doing flight testing with my plane that my feeble attempts to get real accurate speed numbers were elusive. I'm not convinced the average builder has the equipment to get legitimate numbers. The other part for me was actually flying at sea level ... :pilot:
 

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