Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

Electrical output of airliners?

Tech Log The very best in practical technical discussion on the web

Electrical output of airliners?

Old 24th Sep 2013, 09:32
  #21 (permalink)  
Thread Starter
 
Join Date: Mar 2011
Location: London
Age: 39
Posts: 38
I think recline is critical if you want to sleep

here's the recline angle my design is aiming to achieve within a 33 inch pitch

mommus is offline  
Old 24th Sep 2013, 09:35
  #22 (permalink)  
Thread Starter
 
Join Date: Mar 2011
Location: London
Age: 39
Posts: 38
it sounds then like available electrical power will be less of an issue with 4-engined aircraft, since twinjets carry more than half the passengers.
mommus is offline  
Old 24th Sep 2013, 15:18
  #23 (permalink)  
 
Join Date: Jun 2009
Location: Australia
Posts: 64
There is already a business class seat that moves almost in the same way (however goes further in some ways). I've tried everything to miss them because I don't like it, sliding down them is not nice, however for economy it would be an improvement. Maybe don't make the middle part move too sloped.

Also you could use something that causes resistance instead of a motor if I'm thinking on the same lines.
Phalanger is offline  
Old 24th Sep 2013, 18:52
  #24 (permalink)  
 
Join Date: May 2008
Location: Scotland
Age: 75
Posts: 452
Any maintenance engineer that had to work with electrically actuated seats regards them as a device of the devil - most types I have worked with have been grossly under engineered.
bcgallacher is offline  
Old 24th Sep 2013, 22:30
  #25 (permalink)  
Thread Starter
 
Join Date: Mar 2011
Location: London
Age: 39
Posts: 38
bcgallacher - thanks for the info, can I PM you to ask you a few questions?

Phalanger - yeah I've seen a business class seat that is technically flat but not horizontal. the passenger is kind of tilted like they're undergoing a sea burial.

I've tried to keep the passenger's thighs horizontal or slightly raised to stop them sliding down.

Last edited by mommus; 24th Sep 2013 at 22:31.
mommus is offline  
Old 25th Sep 2013, 17:28
  #26 (permalink)  
 
Join Date: Jan 2012
Location: USA
Posts: 39
msbbaratt

I've flown with CX, and I'm afraid to say they're awful. Long haul London to Heathrow was pretty intolerable. All things considered I'd far rather have a seat that reclines. I've been avoiding CX ever since at all costs.
London all the way to Heathrow? Yep, intolerable.
CallmeJB is offline  
Old 25th Sep 2013, 18:06
  #27 (permalink)  
 
Join Date: Sep 2013
Location: USA
Posts: 41
HDRW - thanks for the reply

I'm glad you wrote that, because my design is aimed at preventing exactly the problem you describe.

As a passenger, you have a constant space that remains the same irrespective of the actions of the passenger in front of you, in fact, you will not be able to tell whether the seat in front is reclined or not.
There is no such magic.

Be gone charlatan!
Altcrznav is offline  
Old 25th Sep 2013, 22:01
  #28 (permalink)  
Thread Starter
 
Join Date: Mar 2011
Location: London
Age: 39
Posts: 38
There is no such magic.

Be gone charlatan!
I guess you'll just have to wait and see if you're proven right.
mommus is offline  
Old 26th Sep 2013, 08:33
  #29 (permalink)  
 
Join Date: May 2008
Location: Scotland
Age: 75
Posts: 452
Mommus - PM me if you wish
bcgallacher is offline  
Old 26th Sep 2013, 10:57
  #30 (permalink)  
 
Join Date: Feb 2002
Location: UK
Age: 54
Posts: 2,679
787 has 4 x 150 KVA (two per engine).
Correction: 4 x 250KvA (two per engine) plus two on the APU.
TURIN is offline  
Old 27th Sep 2013, 12:41
  #31 (permalink)  
 
Join Date: Nov 1999
Location: UK
Posts: 1,195
Good luck Mommus, the world needs innovation. Don't be put off by the idiots on here.

I recently flew as pax on some seats which reclined to near horizontal, and did so by moving the seat squab forward, and a foot rest upwards. These were very comfortable and one could actually sleep rather than cat-nap/doze.

However, there were only 18 such seats in an area that can fit 51 normal business seats. If such fully reclining seats were fitted any closer to each other, outboard occupants would not be able to get past the inboard occupants to the aisles if the latter's seat was in full recline? As it was, one had to carefully step over the other persons legs.

Last edited by Uplinker; 27th Sep 2013 at 12:42.
Uplinker is offline  
Old 27th Sep 2013, 14:58
  #32 (permalink)  
Thread Starter
 
Join Date: Mar 2011
Location: London
Age: 39
Posts: 38
Uplinker - thanks for the feedback. In terms of being able to get past people from a window seat (or similar) I have had to accept that you'll need to ask the people beside you to unrecline their seats and get up. With the density of seating required for 33 inch seat pitch, there really is no way around that.

I've found that even on United Economy Plus you still need to ask people to move if you want to get out, and you spend far more time in your seat that you do getting in and out of it, so I figure that is one of the insurmountable issues with economy class.

I'm just about to start buying components for a prototype, so fingers crossed it will work as a concept.
mommus is offline  
Old 1st Oct 2013, 04:26
  #33 (permalink)  
 
Join Date: Feb 2004
Location: Australia
Posts: 1,300
I'm intrigued by the single motor concept. Most designers seem to have gone for multiple motors. Is this only for independent control over various chair elements or might it also be that wiring and multiple (micro) motors are lighter than heavy connecting mechanical mechanisms?

That aside, wouldn't the key to comfort be the relative position between the feet and the body (heart)? Some designers have even put seat pocket-like pouches in the seat in front in which you can put your feet (to raise the height of your feet). As a plus six-footer, I've tried various methods to get comfortable in Economy, including putting my feet on the seat (bum) cushion and wrapping a suitcase type strap around my legs to stop my feet slipping off.

From a Line Maintenance perspective:

Accessibililty to motors, microprocessors and the like is a key issue for us. Why do manufacturers force engineers to pull apart the entire seat, just to access the important stuff? Instead of simple hinged panels with one or two dzus fasteners, we get RSI removing dozens of long phillips screws (or having to get out our spanners and socket wrenches). Also note that getting under the seat for access to electrics, often involves sliding our bodies between two rows of seats with our legs in the aisles (which, during turnarounds, are routinely kicked, tripped over or bashed with carts and vacuum cleaners). It's bad enough in Business and First where the pitch is larger. Lifting a seat cushion and going in from the top is much easier.

In the race for lighter construction (to compensate for the weight of electrics), the chair often ends up either being made of exotic, expensive materials, or razor sharp sheet metal which cuts your hands to shreds when you try to work on the chair. The flimsiness of armrests often results in the liberation of arm padding and end caps. By the way, if you do make moveable armrests, please ensure that there is room in the hinge channel to feed seat recline & IFE controller wiring AND the connector plugs.

Whatever you do, please try make the armrests hinged, so you can at least, if the flight is relatively empty, stretch out over 3 or 4 seats.

I can so understand why one commentator's airline removed the electric seats. Electric seats have been around for decades and they still aren't getting any more reliable. It's gotten so bad, our airline has had to form dedicated teams to work on the seats. That is really not good for the airline's bottom line. imho, motorised Economy seats are just going to magnify this problem.
NSEU is offline  
Old 14th Oct 2013, 14:51
  #34 (permalink)  
Thread Starter
 
Join Date: Mar 2011
Location: London
Age: 39
Posts: 38
NSEU - thanks for the reply. There's some very interesting and helpful stuff there.

With respect to the number of motors and complexity - I only propose to use one motor per seat, so if you want to recline, you will also have to accept the leg cushion coming out too (and another important dynamic change that I can't mention at present). This might seem stingy, but it allows the mechanism to be infinitely more simple and the whole structure to be lighter.

I believe the great increase in comfort over standard economy seats will offset the limited control over body position (in comparison to a business type seat)

With respect to access for maintenance - I had considered using a quick-release subframe carrying the motor and main mechanicals that can just be swapped out with another, but that would increase the weight quite a bit, and also be cumbersome, especially servicing a window seat on a 3 abreast layout.

Access to the motor and associated parts would be by removing the seat bottom, as you suggest. Since the lifejacket is contained within the leg rest/foot rest this is easier to achieve.
mommus is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


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.