lax888
Posts: 224
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Why No 3x4x2 Seating Instead Of 3x3x3?

Tue Feb 08, 2011 2:02 pm

Hi everyone

I was wondering why planes with 9 seats across don't use the 3x4x2 arrangement? I remember SR/LX used to have it on their MD11 and if I am not mistaken NH has it now on their B773ER. However I would think that this is an attractive way to arrange the cabin since you can avoid the row with 5 seats and still can allow couples to fly together.

Thoughts? comments?
 
nws2002
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RE: Why No 3x4x2 Seating Instead Of 3x3x3?

Tue Feb 08, 2011 7:49 pm

IFE boxes can generally control three seats. So the 3-3-3 configuration requriers 3 boxes per row, and the 2-5-2 and 3-4-2 would require 4 boxes per row.
 
Viscount724
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RE: Why No 3x4x2 Seating Instead Of 3x3x3?

Tue Feb 08, 2011 11:16 pm

Quoting LAX888 (Thread starter):
I remember SR/LX used to have it on their MD11

KL MD-11s were 2-4-3 until they switched to 3-3-3 a couple of years ago when they installed new seats and PTVs. Swissair was 3-4-2 on MD-11s (with the 3-seat unit on the left side, while on KL the 3 seat unit was on the right side).

Egyptair's 777-200ERs were 3-4-2 when delivered. Not sure whether that's been changed since. I belive MS is the only carrier with 3-4-2 on 777s.

747s were 3-4-2 for the first few years of service until demand started to pick up and they switched to 3-4-3.
 
maddogjt8d
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RE: Why No 3x4x2 Seating Instead Of 3x3x3?

Wed Feb 09, 2011 1:21 am

A little over a decade ago, I flew on a Tradewinds L-1011 pax charter from JFK-CUN-JFK and one of their L-1011s (N75AA if I remember correctly) had a 3-4-2 layout and I remember thinking it was odd since one of their other L-1011s I flew was 2-5-2. So I guess my answer is that I've seen it done, but not in scheduled carrier ops.
 
AJ
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RE: Why No 3x4x2 Seating Instead Of 3x3x3?

Wed Feb 09, 2011 8:08 am

Quoting Viscount724 (Reply 2):
Egyptair's 777-200ERs were 3-4-2 when delivered. Not sure whether that's been changed since. I belive MS is the only carrier with 3-4-2 on 777s.

Still 3-4-2: http://www.egyptair.com/English/Pages/FleetDetails.aspx?Aircraft=11
Their -300ERs have 3-3-3: http://www.egyptair.com/English/Pages/FleetDetails.aspx?Aircraft=12
 
lipzoan
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RE: Why No 3x4x2 Seating Instead Of 3x3x3?

Sat Feb 12, 2011 5:48 pm

first i think made more easier for cabin crew to manage passenger needs,then 3-3-3 get easier to keep weight balanced along longitudinal axe
 
deltamartin
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RE: Why No 3x4x2 Seating Instead Of 3x3x3?

Sat Feb 12, 2011 6:56 pm

Quoting Viscount724 (Reply 2):
KL MD-11s were 2-4-3 until they switched to 3-3-3 a couple of years ago when they installed new seats and PTVs. Swissair was 3-4-2 on MD-11s (with the 3-seat unit on the left side, while on KL the 3 seat unit was on the right side).

And AY's had 3-4-3 if im not mistaken.
 
bohica
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RE: Why No 3x4x2 Seating Instead Of 3x3x3?

Sat Feb 12, 2011 7:06 pm

The problem with a 3-4-2 configuration is that an airline has to buy a set of 2 seats, a set of 3 seats, and a set of 4 seats for each row. Multiply that times the number of rows in the airplane and it gets very expensive. I'm not even considering IFE boxes, overhead panels, spares, etc. It is much cheaper for an airline to have everything standardized with a 3-3-3 configuration where they only need to buy sets of 3 seats.
 
Viscount724
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RE: Why No 3x4x2 Seating Instead Of 3x3x3?

Sat Feb 12, 2011 11:27 pm

Quoting deltamartin (Reply 6):
Quoting Viscount724 (Reply 2):
KL MD-11s were 2-4-3 until they switched to 3-3-3 a couple of years ago when they installed new seats and PTVs. Swissair was 3-4-2 on MD-11s (with the 3-seat unit on the left side, while on KL the 3 seat unit was on the right side).

And AY's had 3-4-3 if im not mistaken.

As I recall, at one time AY had a few MD-11s in high-density 3-4-3 layout in the entire cabin for use on charter-type routes. When they were retired they were 9-abreast (forget whether it was 3-4-2 or 2-4-3) in the forward Y class cabin and 10-abreast (3-4-3) in the rear cabin. Always seemed strange to have such a big difference in product on the same aircraft in the same class of service.
 
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Starlionblue
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RE: Why No 3x4x2 Seating Instead Of 3x3x3?

Sun Feb 13, 2011 3:02 am

LIPZOAN,reply=5]first i think made more easier for cabin crew to manage passenger needs,then 3-3-3 get easier to keep weight balanced along longitudinal axe[/quote]

The balance thing is a non-issue. Look at all the DC-9 and MD-80s flying around with asymmetrical seating. It's a small amount of weight a very small distance from the centerline. Well within design limits.
"There are no stupid questions, but there are a lot of inquisitive idiots."
 
Tod
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RE: Why No 3x4x2 Seating Instead Of 3x3x3?

Tue Feb 22, 2011 4:29 pm

Quoting bohica (Reply 7):
The problem with a 3-4-2 configuration is that an airline has to buy a set of 2 seats, a set of 3 seats, and a set of 4 seats for each row. Multiply that times the number of rows in the airplane and it gets very expensive. I'm not even considering IFE boxes, overhead panels, spares, etc. It is much cheaper for an airline to have everything standardized with a 3-3-3 configuration where they only need to buy sets of 3 seats.

L/H and R/H seat assemblies are already usually different part numbers.

Outboard PSU can be standardized with both sides configured for three.
 
Max Q
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RE: Why No 3x4x2 Seating Instead Of 3x3x3?

Sun Mar 06, 2011 6:52 am

Quoting Starlionblue (Reply 9):
The balance thing is a non-issue. Look at all the DC-9 and MD-80s flying around with asymmetrical seating. It's a small amount of weight a very small distance from the centerline. Well within design limits.

Think about it. The seat arrangement is not actually assymetric at all. On the DC9/ MD80 the Aisle is what is offset. The aisle seat on the three side is on the centreline with the two seats either side 'balancing' the Aircraft
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doug_or
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RE: Why No 3x4x2 Seating Instead Of 3x3x3?

Sun Mar 06, 2011 6:22 pm

Quoting Max Q (Reply 11):
The aisle seat on the three side is on the centreline with the two seats either side 'balancing' the Aircraft

If the aisle seat is on the centerline, then one side would have mean one side had 2 seats and the the other had two seats and an aisle. Since both sides are the same size and and all seats are the same width, this is impossible.
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