300 Horsepower, 737 Foot-Pounds of Torque

by Dean Sigler on 05/02/2016

Extra 330Ls have a long nose, usually cowling a Lycoming IO-540 or -580. The 330 EL, though, houses 14 battery packs of 18.6 kilowatt-hours each (according to InfoAvion, an Argentinian publication), all to allow the Siemens D-SP260 to flex its 300 horsepower muscle and demonstrate what 1,000 Newton-meters (737 foot-pounds) of torque can do for vertical rolls.

Flying Magazine thought that its display at AERO Friedrichshafen in Germany could be a harbinger of the future of emission-free airshow performances.”

Siemens intends to use the 330 EL for flight test and optimization of a electric propulsion system based on the 50 kilogram (110 pound) motor on display. Even the large battery array will give only about 15 to 20 minutes of wide-open airshow power, enough for a great routine, lacking only the airshow noise.

Batteries under glass highlight Extra 330 EL, sure to provide a little extra in performance

{ 4 comments… add one }

Peter Sund 05/03/2016, 3:13 am

Those 18.6 kWh must surely be the capacity of the entire pack?
Howard Handelman 05/03/2016, 4:26 pm

Lacking the noise? Well maybe the engine noise. Will they drive the prop tips to near or past Mach 1.0? For my aging ears, the really painful noise from those routines is from the prop. Maybe with all that power at low rpm it won’t happen? If my math is correct, 737 foot pounds of torque only needs 2135 rpm to make 300 HP.
David G Jones 05/13/2016, 6:02 pm

A very exciting development. I first did the ‘thumbnail’ numbers on the feasibility of an all-electric RB airracer about 4-5 years ago, and it looked promising.

Siemens announcement of the SP260 last year made it possible and just a matter of time, so it’s great to see it happening.

BTW: 260kw = ~ 350hp (not 300hp)

You also might want to check with Siemens re the battery specs – 14 packs of 18.6 kwh each would give ~ 260 kwh capacity, which would about 1 hour duration at max power.

Also with current lithium battery technology 260kwh would weigh around 800-1000kg, which seems unlikely.

15-29 minutes at wide-open power suggests the battery pack is somewhere around 75kwh.

The other possibility is that Siemens may be using lithium sulphur batteries, with a much higher energy density than conventional lithium ion batteries.
David G Jones 05/13/2016, 6:34 pm

A very exciting development. I ran the ‘thumbnail’ numbers on the feasibility of an all-electric RB airracer 4-5 years ago and it looked promising then.

Siemens release of the SP260 last year made it inevitable and just a matter of time, so it’s great to see them driving this exercise.

My guess would that an all-electric RB airrace could be happening around 2020.

BTW 260kw = ~ 350hp, not 300hp

The battery specs don’t look right either. 14 packs with 18.6kwh each would be around 260kwh capacity, which would an hour of endurance at wide-open power. 15-20 minutes endurance suggests the battery capacity is around 70-80kwh.

This would also make sense re battery weight – a 260kwh pack would weigh more than the all-up weight of a 330L.

The game changer for aeroelectric propulsion will be lithium sulphur batteries, with energy densities 2-3 times better or more than conventional lithium ion batteries.

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