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will
Posts: 305
Joined: Sat May 22, 1999 12:31 am

RE: Boeing To Make Door Modification On 737 MAX

Tue May 28, 2013 6:15 am

Hi,

I really can't comment on door size designs and how they effect cabin layout.. But, the current 737 series door design really needs attention and modernization... It's a pig...The current design is mechanically complex, awkward and real monster to rig.. The thought that went into the design of the 777 door is magic.. Easy to use, maintain and extremely reliable.. The 737 series desperately needs this re think, modernization and something along the style and operation of the 777 door....

I welcome it... YAY...

Regards.

Will...........
 
ggflyboy
Posts: 50
Joined: Thu Jan 05, 2012 3:10 am

RE: Boeing To Make Door Modification On 737 MAX

Tue May 28, 2013 6:15 am

Quoting SSTeve (Reply 49):
On the other hand, what makes you think an increase in the width of the door by 25% wouldn't mean an 10% increase in passengers escaping? (In my own opinion, 24" would seem like a bottleneck...)

I'm not opposed in principle to a wider door meaning more people get out - it makes sense on a certain level.

I do think a) that an extra 6 inches is not enough to get two people out at once (not two lanes) and b) the aisle is only 19". So the supply of people coming up to both doors is limited by the flow rate of the aisle. Once the passenger is in the entry vestibule, they then have the option of up to two exits. I'm not counting the cockpit windows...  

I guess my point is, people escaping from the aircraft are typically not encumbered by the door itself (or so I would imagine- maybe not true for some dinky service doors), but actually getting to the door. The plan proposed by Boeing seems to just exacerbate the "getting to the door" problem (by adding more people, decreasing pitch) but has marginal or negligible benefit to the flow rate of people out of the door itself (still one at a time).

As an aside I agree that the current door on the 737 is occasionally a bottleneck during boarding due to the added complexity of luggage and ground staff creating two-way traffic. A slightly wider door might help with boarding. But both of these boarding factors should be absent during an evacuation.
 
r2rho
Posts: 3096
Joined: Tue Feb 27, 2007 10:13 pm

RE: Boeing To Make Door Modification On 737 MAX

Tue May 28, 2013 8:06 am

Quoting Stitch (Reply 7):
So assuming the 737 MAX is not "cabin floor area limited" and the seating capacity is capped by the EL, increasing the door size to raise the evacuation limit would allow more seats to be fitted.

I guess it's a safe assumption, since not being "cabin floor limited" is the main thing that makes this possible IMO - the extra exit limit would allow Boeing to "play" more with the available cabin floor than what is possible today.

Quoting Leo467 (Reply 26):
So the 8 Max is aiming towards the famous 199 Pax configuration always wanted by Ryanair???

   Any extra seat that can be squeezed in will be happily embraced by FR. In fact, I wouldn't be surprised if they provided a good portion of customer feedback for this Mod to Boeing.

Quoting 817Dreamliiner (Thread starter):
the 737 MAX 8 will likely seat 171 passengers while the MAX 7 and MAX 9 will accommodate 135 and 189 passengers in a 2-class configuration, respectively. Though the 737 MAX 9, capable of carrying 215 and 226 passengers in a single-class layout before and after the door modification,

What I'd really like to know - or more specifically, guys like FR or WN would really like to know - what the single-class capacity of the -7 and -8 would be...   

Quoting lightsaber (Reply 39):
I would think the MAX would standardize on the 900ER bulkhead

Makes sense, 3 seats "for free" and more manufacturing commonality, looks like a no-brainer but no official confirmation from Boeing that i'm aware of.

Quoting ggflyboy (Reply 48):
Isn't there also a certification requirement to assume that half the exits might be blocked? What if "half the exits" means that the wider doors are inop? But I guess the OEM gets to choose which exits are blocked when they certify...

The requirement is for all the exits on one side of the aircraft to be blocked. So it's half, but a specific kind of "half".

Quoting ggflyboy (Reply 48):
What bizzarro study proved that increasing the door width by 6 inches means an extra 10 passengers can get out in an emergency?? At this point, there's no hard science and we're just playing games

You may want to ask that question to the FAA and their "bizarre studies" department...
 
debonair
Posts: 4001
Joined: Sat Jan 03, 2004 10:50 pm

RE: Boeing To Make Door Modification On 737 MAX

Tue May 28, 2013 8:53 am

Quoting Stitch (Reply 9):
Think of the current 737NG door, just six inches wider.

Would it be possible to fit sliding doors (like on the Airbus A320)?
 
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garpd
Posts: 2542
Joined: Thu Aug 11, 2005 9:29 am

RE: Boeing To Make Door Modification On 737 MAX

Tue May 28, 2013 9:07 am

Quoting debonair (Reply 53):

Would it be possible to fit sliding doors (like on the Airbus A320)?

Not without expensive recertification and probably a long and expensive re-design period.
It may also cause the fuselage to have to be recertified with all the work that goes into that too.

Can-o-worms. Best left closed for what is merely the latest and probably final variant/derivative of a model.
arpdesign.wordpress.com
 
yeelep
Posts: 766
Joined: Mon Apr 04, 2011 7:53 pm

RE: Boeing To Make Door Modification On 737 MAX

Tue May 28, 2013 11:09 am

The plane is floor space limited, the size of the current doors have no effect on the two-class seating limit. The only way I can see an increase of two class seating is to go with the flat aft bulkhead and move the L2/R2 doors aft.

The wider L1 door argument doesn't hold water, as its already a Type C door. It can't be certified as such because to do so the L2/R1 and L2 doors would also have to be Type C doors. So if that's Boeing's plan, the L1 door would be the least likely to be widened.

http://www.ecfr.gov/cgi-bin/text-idx...14:1.0.1.3.11.4.178.58&idno=14
 
nclmedic
Posts: 169
Joined: Sun Oct 11, 2009 9:25 pm

RE: Boeing To Make Door Modification On 737 MAX

Tue May 28, 2013 11:37 am

Quoting N821NW (Reply 4):
Could you tell me how having a BIGGER would make MORE passengers fit? I have a hard time understanding that one...

Doors are only certified for specific limits in an evacuation - a larger door has a higher potential through-put of passengers in the given 'safe' evacuation time.
 
Aviaponcho
Posts: 836
Joined: Wed Aug 24, 2011 12:13 pm

RE: Boeing To Make Door Modification On 737 MAX

Tue May 28, 2013 12:22 pm

 
JAAlbert
Posts: 1980
Joined: Tue Jan 31, 2006 12:43 pm

RE: Boeing To Make Door Modification On 737 MAX

Tue May 28, 2013 1:51 pm

Quoting ggflyboy (Reply 48):
What bizzarro study proved that increasing the door width by 6 inches means an extra 10 passengers can get out in an emergency??

It seems to me the walk thru space from the galley to the cabin is very tight as it is - even if you increased the door width, unless the aisle is also increased up at the front I don't see how more people are going to get through.
 
mffoda
Posts: 1099
Joined: Thu Apr 15, 2010 4:09 pm

RE: Boeing To Make Door Modification On 737 MAX

Tue May 28, 2013 1:51 pm

Quoting Aviaponcho (Reply 57):
Seems old news for me

http://atwonline.com/aircraft-amp-en...-2014

Old news.... Then how do you explain the other 6 seats that are Not covered in that article?
harder than woodpecker lips...
 
Aviaponcho
Posts: 836
Joined: Wed Aug 24, 2011 12:13 pm

RE: Boeing To Make Door Modification On 737 MAX

Tue May 28, 2013 2:13 pm

Sorry, my analysis is right here http://avia.superforum.fr/t502p460-boeing-737max#37514

+6 seat flat bulkhead and - 1 WC (or +9 seats -2 WC)
+ Swall
+ 7 in

All right ?

That's why I said no news for me
But of course i'm not sure

(But it was important for the recent ryan air order, i'm probably not to far...).
 
Aviaponcho
Posts: 836
Joined: Wed Aug 24, 2011 12:13 pm

RE: Boeing To Make Door Modification On 737 MAX

Wed May 29, 2013 12:39 pm

We should know more today i think !
 
ODwyerPW
Posts: 1624
Joined: Thu Dec 09, 2004 6:30 am

RE: Boeing To Make Door Modification On 737 MAX

Wed May 29, 2013 3:47 pm

Quoting r2rho (Reply 52):
What I'd really like to know - or more specifically, guys like FR or WN would really like to know - what the single-class capacity of the -7 and -8 would be...

Me too. Specifically, I'd like to know what the single pax capacity is of the 7max, 8max and 9max at 31/32" pitch (assumes use of slimline seating).

My questions assume flat rear bulkhead, widened door and slimline seating (which most carriers will adopt, no?).

[Edited 2013-05-29 08:49:59]
learning never stops.
 
Aviaponcho
Posts: 836
Joined: Wed Aug 24, 2011 12:13 pm

RE: Boeing To Make Door Modification On 737 MAX

Wed May 29, 2013 3:57 pm

Flat bulkhead comes with a 400 lb penalty
 
ODwyerPW
Posts: 1624
Joined: Thu Dec 09, 2004 6:30 am

RE: Boeing To Make Door Modification On 737 MAX

Wed May 29, 2013 4:08 pm

Quoting Aviaponcho (Reply 63):

Yes, I'm aware of that. It has been an option on the NG800 and the NG700 ever since it was introduced as standard on the NG900ER. A plane full of slimline seats may compensate for some of that weight increase.

Of course one imagines a wider door carries a weight increase as well. As do bigger engines, taller nose gear and larger split blended wingtips.

It will be interesting when they decide which weight increasing options are worth it, and which are not, to achieve the right balance of CASM, Comfort and Capacity.

Hopefully, by the end of this year we will know all of these details.
learning never stops.
 
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bikerthai
Posts: 3572
Joined: Wed Apr 28, 2010 1:45 pm

RE: Boeing To Make Door Modification On 737 MAX

Thu May 30, 2013 1:08 pm

Quoting by738 (Reply 23):
Interesting on current 738 the front LH and rear LH are also different sizes (inches)

The difference is size between the forward left and right hand side is more important.

As evacuation rule state that you must evacuate the airplane with doors on one side not used because of potential fire on the outside of the aircraft, then the forward evacuation limit is dependent on the smaller 30" service door.

If they make this service door the same size as the entry door, can they fit in a few more passenger as part of the evacuation scheme? This would be the easiest to do because you do not have to adjust any frame spacing.

The next option is to make the aft doors larger. Don't think they would need to re-arrange any frames here either, though making those doors larger would extend the door forward as the aft portion is bound by an existing frame. Extending the door forward would meed re-sizing that lav in front of the door.

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
ODwyerPW
Posts: 1624
Joined: Thu Dec 09, 2004 6:30 am

RE: Boeing To Make Door Modification On 737 MAX

Thu May 30, 2013 6:30 pm

Quoting bikerthai (Reply 65):
The next option is to make the aft doors larger. Don't think they would need to re-arrange any frames here either, though making those doors larger would extend the door forward as the aft portion is bound by an existing frame. Extending the door forward would meed re-sizing that lav in front of the door.

The rear lavs are already pretty small arent' they?
learning never stops.
 
queb
Posts: 1026
Joined: Tue Jun 01, 2010 3:10 am

RE: Boeing To Make Door Modification On 737 MAX

Thu May 30, 2013 9:42 pm

the debate is closed, Boeing confirms no door change on Max 8

https://vine.co/v/bYDvzwQUmZl
 
ODwyerPW
Posts: 1624
Joined: Thu Dec 09, 2004 6:30 am

RE: Boeing To Make Door Modification On 737 MAX

Thu May 30, 2013 9:58 pm

He states 800 and 8Max have similar interior configurations. That closes the argument for the additional 9 seats? No specific mention of the door. Did not hear comments on the 9Max or 7Max.
learning never stops.
 
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lightsaber
Moderator
Posts: 20972
Joined: Wed Jan 19, 2005 10:55 pm

RE: Boeing To Make Door Modification On 737 MAX

Fri May 31, 2013 5:56 am

Quoting Aviaponcho (Reply 63):
Flat bulkhead comes with a 400 lb penalty

So about 130lbm per passenger... That is reasonable and economic.

Lightsaber
I cannot wait to get vaccinated to live again! Warning: I simulated that it takes 50%+ vaccinated to protect the vaccinated and 75%+ vaccinated to protect the vac-hesitant.
 
Aviaponcho
Posts: 836
Joined: Wed Aug 24, 2011 12:13 pm

RE: Boeing To Make Door Modification On 737 MAX

Fri May 31, 2013 7:33 am

Quoting queb (Reply 67):

https://vine.co/v/bYDvzwQUmZl

Bon anniversaire on this board Queb 
That's what I told Daniel Tsang : no door change for a +9 PAX in 2 class layout.

Although there is obviously room for very high density layout in the 28-29i pitch for the -800
Max PAX (exit limit 189) is with 30in pitch and no of the upcoming cabin optimisations.. -> that would require door rework

But ? adding door (or mid cabin complex) will consume space -> reducing effective cabine floor area. And enlarging right doors will also reduce cabin lengh ...

Let's see, it's not that clear

[Edited 2013-05-31 01:14:25]

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