Go Back  PPRuNe Forums > Flight Deck Forums > Rumours & News
Reload this Page >

Electric Islander

Rumours & News Reporting Points that may affect our jobs or lives as professional pilots. Also, items that may be of interest to professional pilots.

Electric Islander

Old 17th Oct 2018, 19:46
  #1 (permalink)  
pzu
Thread Starter
 
Join Date: Jul 2002
Location: N Yorkshire, UK
Age: 72
Posts: 464
Thumbs up Electric Islander

pzu is offline  
Old 17th Oct 2018, 20:22
  #2 (permalink)  

"Mildly" Eccentric Stardriver
 
Join Date: Jan 2000
Location: England
Age: 72
Posts: 2,929
It makes sense to introduce an electric aircraft on the routes around the Orkneys. A big difference between the short hops with a small aircraft and trying a 737 size on longer routes. My guess is it will work.
Herod is offline  
Old 17th Oct 2018, 21:09
  #3 (permalink)  
 
Join Date: Jan 2008
Location: Blighty (Nth. Downs)
Age: 72
Posts: 2,052
So a two-minute sector (or perhaps a couple) followed by how long a recharging period?

PS: Is this thread restricted to septuagenarians?
Chris Scott is offline  
Old 17th Oct 2018, 21:32
  #4 (permalink)  
 
Join Date: Jun 2003
Location: PUDBY
Posts: 684
I don't understand how this will work. I thought the Islander was powered by the noise the engines make?

(And no, not quite there yet myself, a few years to go).
n5296s is offline  
Old 17th Oct 2018, 22:34
  #5 (permalink)  
Gnome de PPRuNe
 
Join Date: Jan 2002
Location: Too close to Croydon for comfort
Age: 55
Posts: 5,738
Originally Posted by Herod View Post
It makes sense to introduce an electric aircraft on the routes around the Orkneys. A big difference between the short hops with a small aircraft and trying a 737 size on longer routes. My guess is it will work.
We won't charge you if you're wrong...😊
treadigraph is offline  
Old 18th Oct 2018, 04:39
  #6 (permalink)  
 
Join Date: Feb 2008
Location: USA
Posts: 93
Originally Posted by Chris Scott View Post
So a two-minute sector (or perhaps a couple) followed by how long a recharging period?

PS: Is this thread restricted to septuagenarians?
Serious back of the envelope calculation here with a little real world data thrown in:

Islander with 2x 300HP engines = approx 400kW peak power output

Lets assume that the whole 2 min sector is flown at full power to be nice and pessimistic...so 13.3kWh per sector.

Now the complete battery assembly for the Tesla Model3 is pretty representative of the bleeding edge of EV battery technology and it comes in at 168Wh/Kg.
The total mass of the ~75kWh battery pack in a Model3 is approx 470 Kg. Empirically I can tell you that my Model3 charges from say 20% to 80% in about 40 minutes from a DC fast charger.

That passes the smell test for me, it seems very practical for this particularly odd air route.
ion_berkley is offline  
Old 18th Oct 2018, 04:53
  #7 (permalink)  
 
Join Date: Jan 2008
Location: Denver
Posts: 961
Yes, the Islander is a pretty flexible little test-bed. There have been ducted-fan, turboprop and 3-engine mods. And minimal systems power-&-complexity overhead required: no pressurization, retractable gear, spoilers, or such.
pattern_is_full is online now  
Old 18th Oct 2018, 05:35
  #8 (permalink)  
 
Join Date: Apr 2008
Location: UK
Posts: 336
Originally Posted by n5296s View Post
I don't understand how this will work. I thought the Islander was powered by the noise the engines make?

(And no, not quite there yet myself, a few years to go).
The noise doesn't come from the engines, their cores are far too small to make that din.
msbbarratt is offline  
Old 18th Oct 2018, 05:49
  #9 (permalink)  
 
Join Date: Apr 2008
Location: UK
Posts: 336
Originally Posted by ion_berkley View Post
Serious back of the envelope calculation here with a little real world data thrown in:

Islander with 2x 300HP engines = approx 400kW peak power output

Lets assume that the whole 2 min sector is flown at full power to be nice and pessimistic...so 13.3kWh per sector.

Now the complete battery assembly for the Tesla Model3 is pretty representative of the bleeding edge of EV battery technology and it comes in at 168Wh/Kg.
The total mass of the ~75kWh battery pack in a Model3 is approx 470 Kg. Empirically I can tell you that my Model3 charges from say 20% to 80% in about 40 minutes from a DC fast charger.

That passes the smell test for me, it seems very practical for this particularly odd air route.
There are some downsides. The battery is heavier than the equivalent fuel tank. The power cables are heavier than the equivalent fuel lines. The motors are heavier than the equivalent gas turbines, and can't sustain max power for as long either (efficiency in a motor conflicts with cooling it with air). The batteries don't get lighter as they discharge. Charging times are longer than refueling times (but maybe irrelevant given other operational factors).

A lot of these downsides go away or become irrelevant if you consider the electricity to be free (solar, wind, etc). One way or another we seem to be heading kinda in that direction, but it's a long way from free still.
msbbarratt is offline  
Old 18th Oct 2018, 06:32
  #10 (permalink)  
 
Join Date: Oct 2009
Location: North West UK
Posts: 520
Charging also available from wing and fuselage covering of solar cells. This would have a modest but not negligible benefit on range and charging times.
Espada III is offline  
Old 18th Oct 2018, 06:41
  #11 (permalink)  
 
Join Date: Jun 2001
Location: FNQ ... Still!
Posts: 3,339
I thought the Islander was powered by the noise the engines make?
Electric Engines!
​​​​​​​Who would have thought the day would come when an Islander could sneak up on you!
Capt Fathom is online now  
Old 18th Oct 2018, 07:00
  #12 (permalink)  
 
Join Date: Jul 2010
Location: Asia
Posts: 523
The 300hp version had fuel injection, there was also a 265hp carburettor varient.

​​​​​​The route could be a proving ground for trying out the new technology which could find its way into simple single engine types.

Obviously at the moment it's not a viable replacement for piston engines though.
krismiler is offline  
Old 18th Oct 2018, 09:32
  #13 (permalink)  
 
Join Date: Jul 2016
Location: Broughton, UK
Posts: 67
Just one question, how would you fly it out to the Islands from the Mainland, if you require 30 minutes reserve capacity..?

edit... Would their nearest engineering base be Aberdeen, to do the initial installation..?

Last edited by scifi; 18th Oct 2018 at 11:45.
scifi is offline  
Old 18th Oct 2018, 10:31
  #14 (permalink)  
 
Join Date: Aug 2005
Location: EDLB
Posts: 172
With 30min VFR or 45min IFR reserve it will become an interesting calculation. Possible, Yes but economic?
EDLB is offline  
Old 18th Oct 2018, 12:02
  #15 (permalink)  
 
Join Date: Jul 2016
Location: Broughton, UK
Posts: 67
Just another snag.... How many airfields have the right PLUG...?
scifi is offline  
Old 18th Oct 2018, 12:37
  #16 (permalink)  
Moderator
 
Join Date: Aug 2006
Location: Ontario, Canada
Age: 58
Posts: 4,203
I was hired to investigate the design and design compliance of a proposed STC modification of a 172 from Lycoming engine to electric motor. Though achievable, the major commercial obstacle was the loss of use of the aircraft while the batteries were recharged - fly it for 45 minutes, and it then sits for many hours recharging. Not good utility, though it seems like this operation has a better than normal opportunity.

For commercial operation, the modification will have to be STC approved (to maintain a C of A). A challenge is that the present basis of certification of the aircraft (and for STC) contains a lot of design standards which would exclude electric motors as powerplants. This should and will change, though a lot of regulatory changes will be needed, and those don't happen quickly.

Electric planes will become practical for some roles, but in the mean time, some battery advancement is still needed. We'll get there on day, and everyone who is trying, is helping.
Pilot DAR is offline  
Old 18th Oct 2018, 12:43
  #17 (permalink)  
 
Join Date: Jan 2008
Location: Blighty (Nth. Downs)
Age: 72
Posts: 2,052
Originally Posted by msbbarratt View Post
The noise doesn't come from the engines, their cores are far too small to make that din.
Yes. Unless they employed very clever technology, the props on the electric one would be nearly as noisy. Would they be constant-speed and fully-feathering, or would either of those features be unnecessary?

Unless the aircraft could continue to do the leg to Kirkwall, which seems unlikely with current battery technology, Loganair must be contemplating creating records for lowest average aircraft utilisation per day.

"Hello Madam, welcome to Papa Westray. I hope you enjoyed your noisy flight from Kirkwall. If you wish to continue your journey, please gather your personal items together and accompany me to our quiet, environmentally-friendly, Whispering Dwarf aircraft for the short hop to Westray...."
Chris Scott is offline  
Old 18th Oct 2018, 13:10
  #18 (permalink)  
 
Join Date: Jan 2008
Location: Reading, UK
Posts: 10,653
Originally Posted by Pilot DAR View Post
Though achievable, the major commercial obstacle was the loss of use of the aircraft while the batteries were recharged - fly it for 45 minutes, and it then sits for many hours recharging.
One way around that would be a quick-change battery module so that they don't have to be recharged in situ.
DaveReidUK is offline  
Old 18th Oct 2018, 13:17
  #19 (permalink)  
 
Join Date: Jul 2010
Location: Asia
Posts: 523
Possibly some energy could be returned to the batteries by windmilling propellors on the descent in the same way electric vehicles can recharge their batteries by using the motor as a brake.

Electric cars can recharge to around 80% very quickly, it's the last few percent which takes time to trickle in.
krismiler is offline  
Old 18th Oct 2018, 13:22
  #20 (permalink)  
 
Join Date: May 2005
Location: Denmark
Posts: 185
Regarding this type, this is one of the funniest posts I've read in here: Britten Norman Islander
Gargleblaster is offline  

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.