Electric SSDR Motor Glider

[John.Roo]

Hello!
The SSDR seems to me like interesting category allowing new designers to make nice prototypes. English is not my native language so I would like to ask few questions to understand basic rules.
MTOM with parachute is 315 kg, stall speed max. 65 kmph / 35 kts - OK. But is there any request for Empty Weight or maximum wing loading?
Quick explanation why I ask - in the document is mentioned rule from 2007 with EW 115 kg and wing loading not more than 10 kg/m2. I hope this is not included in 2016 definition in SSDR.

Sample weight balance sheet "from top".
MTOM = 315 kg
Pilot - 110 kg
BRS - 8 kg
Airframe - 120 kg
= I have available 77 kg for propulsion.
Motor, controler, prop - 20 kg
Battery - 50 kg (10 kWh)
Wiring, connectors + small reserve - 7 kg

I can imagine to make simple light electric airplane, but not with wing load 10 kg/m2

Have a nice day!
Martin

 

[hole in the ground]

Martin,

I think you are right in that there used to be a wing loading requirement, though my recollection is that it was an OR not an AND requirement. However this does not appear in more recently published documents. That said I’m trying to track down a definitive doc but surprisingly non-trivial.

Here is another one from 2018:
https://www.bmaa.org/files/til_045_ssdr_handbook.pdf

 

[Basil]

The origional SSDR rules didn't produce very practical aircraft. The current rules have no wing loading requirements, only the 35kt max stall in landing configuration. This has been met with wing loadings up to 40kg/m2 and full span flaperons and a moderately high lift section or 30kg/m2 or less without.

 

[John.Roo]

Martin,

I think you are right in that there used to be a wing loading requirement, though my recollection is that it was an OR not an AND requirement. However this does not appear in more recently published documents. That said I’m trying to track down a definitive doc but surprisingly non-trivial.

Here is another one from 2018:
https://www.bmaa.org/files/til_045_ssdr_handbook.pdf

Perfect - thanks for info!
So seems that I will start to dream a little bit as well

 

[John.Roo]

The origional SSDR rules didn't produce very practical aircraft. The current rules have no wing loading requirements, only the 35kt max stall in landing configuration. This has been met with wing loadings up to 40kg/m2 and full span flaperons and a moderately high lift section or 30kg/m2 or less without.

Thanks for this confirmation.
I agree - 10 kg/m2 is far too low...

35 kts stall speed + MTOM 300 (315) kg + nice flight characteristics are allowing more interesting constructions

 

[hole in the ground]

House move stuff has delayed progress for the last little while. I am still progressing this in slow time though.