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Topic: Boeing To Make Door Modification On 737 MAX
Username: 817Dreamliiner
Posted 2013-05-27 07:35:59 and read 26326 times.

Read this from an Article on Aspire Aviation:

Quote:
It is on course to reach the firm configuration in mid-2013. Intriguingly, Aspire Aviation can exclusively reveal that Boeing is looking to feature a door modification on the 737 MAX 8 which will add around 9 seats to the aircraft’s capacity of seating 162 passengers in a 2-class configuration. The door modification is likely to be a standard feature across all MAX variants, Aspire Aviation‘s sources at Chicago-based Boeing say.

As a result, 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, is unlikely to match the A321neo’s high-capacity 236-seat option enabled by the addition of an overwing exit, deactivation of door 2 and a push back in the location of door 3, as well as adopting the SpaceFlex aft-cabin configuration. Airbus claims this high-capacity configuration will reduce seat-mile costs by 5% alone.

The door modification, the same sources say, will enable the 737 MAX 8 to meet its 13% fuel burn per seat reduction target while increasing its payload/range performance with a “negligible” impact on the aircraft’s manufacturer’s empty weight (MEW).

Its interesting, but what Im failing to understand is what kind of modification to the door will allow them to add 9 more seats unto the aircraft? Or does the article mean to say door configuration??

Source: http://www.aspireaviation.com/2013/0...s-all-fronts/#.UaNg7TUFb6U.twitter

[Edited 2013-05-27 07:40:11]

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: PHX787
Posted 2013-05-27 07:45:32 and read 26266 times.

Quoting 817Dreamliiner (Thread starter):
Its interesting, but what Im failing to understand is what kind of modification to the door will allow them to add 9 more seats unto the aircraft? Or does the article mean to say door configuration??

Depending on where they position the door, and the shape of the fuselage, that's what determines how many more seats they can squeeze in. Are they completely redesigning the fuselage cross-section with the MAX?

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: travelavnut
Posted 2013-05-27 07:46:13 and read 26238 times.

Quoting 817Dreamliiner (Thread starter):
but what I failing to understand is what kind of modification to the door will allow them to add 9 more seats unto the aircraft?



That would be 1,5 rows worth of seats.

I am also having a hard time visualizing that...  

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Stitch
Posted 2013-05-27 07:59:52 and read 26074 times.

Maybe they are increasing the door size?

The 737 family currently uses Type I doors at the front and back per aviation-safety.net and per FAA FAR 25.807, each door is certified for 45 passengers per exit.

The Type C door, which is the same height but wider (minimum of 30 inches vs. the 24 inches of the Type I), is certified for 55 passengers per exit.

So if Boeing replaced Door 1L with a Type C door, that would increase the Evacuation Limit by 10 people. And since it is the same height as a Type I door, just wider, clearance should not be an issue.

[Edited 2013-05-27 08:00:48]

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: N821NW
Posted 2013-05-27 08:06:41 and read 25963 times.

Quoting Stitch (Reply 3):
Maybe they are increasing the door size?

Could you tell me how having a BIGGER would make MORE passengers fit? I have a hard time understanding that one...

And if they decide to shrink the door then we will have issues if there is a need for a emergency evacuation, considering how obese American's (and to a lesser extent Canadian's) are getting I can already visualize people getting stuck in the door and having to be pushed by other passengers...heck just imagine Rob Ford trying to get out of a current Boeing B737NG over-wing exit.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: N62NA
Posted 2013-05-27 08:15:40 and read 25850 times.

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...

Yeah, I'm a bit confused about this as well!

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: catdaddy63
Posted 2013-05-27 08:17:26 and read 25840 times.

WN has commented in the past that the entryway to the aircraft is a boarding bottleneck. Making the L1 door wider, thus enlarging the pathway might be something they pressed for.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Stitch
Posted 2013-05-27 08:24:41 and read 25741 times.

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...
Quoting N821NW (Reply 4):
Yeah, I'm a bit confused about this as well!

Larger doors allow a higher evacuation limit. 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.

The 737-900 had the same EL as the 737-800 because it had the same number and type of exits. So even though it had more cabin floor area than a 737-800, they could not use it. The 737-900ER added two additional exit doors which raised the EL and allowed that extra space to be utilized to seat more passengers.

And Airbus is also considering modifying the location of exit doors, as well as adding additional exit doors, to the A321-200neo to raise the EL from the current 220 to 236.

All that being said, neither the 737-800 nor the 737-8 are at their ELs in a two-class configuration...

So maybe they are pushing Door 2L / Door 2R farther back to extend the cabin floor length which would allow an additional row to be added without as deep a cut in seat pitch (plus removing / moving a toilet to free up a half row)?

[Edited 2013-05-27 09:22:55]

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: clydenairways
Posted 2013-05-27 08:27:34 and read 25709 times.

So a 739 MAX with a maximum of 226 seats. It will be interesting to see this door modification that will enable this. It's hard to visualize this without more details.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Stitch
Posted 2013-05-27 08:29:02 and read 25675 times.

Quoting clydenairways (Reply 8):
It will be interesting to see this door modification that will enable this. It's hard to visualize this without more details.

Think of the current 737NG door, just six inches wider.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: clydenairways
Posted 2013-05-27 08:33:51 and read 25630 times.

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

Ok. But where do the additional seats go then? Take another toilet/galley out?

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Stitch
Posted 2013-05-27 08:40:51 and read 25533 times.

Quoting clydenairways (Reply 10):
Ok. But where do the additional seats go then? Take another toilet/galley out?

As we are talking 1.5 rows, I would expect that it would be a combination of removing a toilet, tightening the seat pitch and using slimmer seat backs.

In a Boeing OEM configuration, the 737-800 is 160 in two classes (12F at 36 inch pitch and 148Y at 32 inch pitch). To get to 162, I am assuming the MAX will have six seats in the Overwing Exit Row as opposed to the 4 in the 737-800.

So remove the toilet and tighten the seat pitch, that would give 12F and 159Y for 171 total.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: N821NW
Posted 2013-05-27 08:46:50 and read 25444 times.

Sorry but I really can't see Boeing making a bigger door...

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: 817Dreamliiner
Posted 2013-05-27 08:58:12 and read 25324 times.

Quoting Stitch (Reply 9):
Quoting Stitch (Reply 11):

Interesting, never actually thought of it that way.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: rj777
Posted 2013-05-27 09:02:54 and read 25306 times.

Are there any current airplanes that use type C doors?

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: speedygonzales
Posted 2013-05-27 09:03:15 and read 25272 times.

I'm guessing moving the front doors forward and/or the rear doors backwards, and possibly adopting the flat rear bulkhead from the 900ER on all models.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: garpd
Posted 2013-05-27 09:04:51 and read 25242 times.

Perhaps they are increasing the size of the R1 and R2 doors? Both of which are smaller than their L1 ans L2 counterparts if I am not mistaken

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: scarebus03
Posted 2013-05-27 09:15:04 and read 25106 times.

so the B707-300 fuselage is going back into production  

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Stitch
Posted 2013-05-27 09:15:06 and read 25101 times.

Quoting rj777 (Reply 14):
Are there any current airplanes that use type C doors?

The A321 uses them per A321 Type C Exit / Door 2L (by Ditzyboy Jun 7 2009 in Tech Ops)

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: 817Dreamliiner
Posted 2013-05-27 09:21:25 and read 24932 times.

Quoting speedygonzales (Reply 15):
I'm guessing moving the front doors forward and/or the rear doors backwards

Im not sure if the doors can be moved any further than they already are:


View Large View Medium
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Photo © Christopher Melaisi

Quoting speedygonzales (Reply 15):
and possibly adopting the flat rear bulkhead from the 900ER on all models.

Isnt this being done already or am I mistaken?

Quoting garpd (Reply 16):
Perhaps they are increasing the size of the R1 and R2 doors? Both of which are smaller than their L1 ans L2 counterparts if I am not mistaken

Are they? I always thought they were the same size?  

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Stitch
Posted 2013-05-27 09:25:01 and read 24821 times.

Quoting garpd (Reply 16):
Perhaps they are increasing the size of the R1 and R2 doors? Both of which are smaller than their L1 ans L2 counterparts if I am not mistaken.
Quoting 817Dreamliiner (Reply 19):
Are they? I always thought they were the same size?    

Per the ACAP, the Type I doors used on 1L and 2L measure 0.86m x 1.83m while those used for 1R and 2R measure 0.76m x 1.65m.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: N821NW
Posted 2013-05-27 09:25:08 and read 24817 times.

Quoting 817Dreamliiner (Reply 19):
Are they? I always thought they were the same size?

From what I know almost all R doors on Boeing planes are smaller then the L doors.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: 817Dreamliiner
Posted 2013-05-27 09:29:05 and read 24711 times.

Quoting Stitch (Reply 20):
Per the ACAP, the Type I doors used on 1L and 2L measure 0.86m x 1.83m while those used for 1R and 2R measure 0.76m x 1.65m.
Quoting N821NW (Reply 21):
From what I know almost all R doors on Boeing planes are smaller then the L doors.

Hmmm, well, you learn something new everyday  

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: by738
Posted 2013-05-27 09:44:44 and read 24311 times.

Interesting on current 738 the front LH and rear LH are also different sizes (inches)
1 Main Fwd LH 1 Type I 864W x 1829H (34 x 72),
2 Main Aft LH 1 Type I 762W x 1829H (30 x 72),
3 Service (Fwd, RH, Aft, RH) 1+1 Type I 762W x 1651H (30 x 65 - both)
4 Overwing/Emergency left 2 Type III 508W x 914H (20 x 36)
5 Overwing/Emergency right 2 Type III 508W x 914H (20 x 36)

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: garpd
Posted 2013-05-27 09:47:24 and read 24263 times.

Quoting scarebus03 (Reply 17):
so the B707-300 fuselage is going back into production

If it ain't broken, don't fix it.  

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: ODwyerPW
Posted 2013-05-27 09:50:21 and read 25371 times.

I'm wondering what this does for the 737-7Max max single class capacity? Are we finally looking at a true 149pax -7 with decent seat pitch (WN config)?

Was door reconfiguration a factor in WN becoming a launch customer for the -7?

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Leo467
Posted 2013-05-27 09:57:09 and read 25075 times.

Interesting idea. I can clearly see that the exit door is a limiting factor with a new generation of seats which have slimmer cushions and save a couple of inches in valuable floor space. So the 8 Max is aiming towards the famous 199 Pax configuration always wanted by Ryanair???

On a side note - can anybody explain why a 737-800 has an Exit Limit of 189 Pax and a A320 of 180 Pax, but the A320 has larger doors (at least on the right hand side of the aircraft, but I would assume this does not matter?!).

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Blueshamu330s
Posted 2013-05-27 10:14:05 and read 25266 times.

Adding extra seats to achieve CASM guarantees; how old school.

There was I expecting high tech, ground breaking innovations and new propulsion technology...  

Rgds

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: HiFlyerAS
Posted 2013-05-27 10:20:37 and read 25059 times.

Quoting Stitch (Reply 11):
To get to 162, I am assuming the MAX will have six seats in the Overwing Exit Row as opposed to the 4 in the 737-800.

I think you're thinking of the 737-700. The -800 has a full six abreast at the overwings.

Quoting 817Dreamliiner (Reply 19):
Im not sure if the doors can be moved any further than they already are:

Agreed. Moving the front doors forward would encroach on an already tight flight deck and electrical panels built into the wall. With the tapering of the aft fuselage, the rear doors can't really be moved much further back than they already are. They're already quite 'stubby'...low height clearance as it is.

I thing this might all come down to a wider main cabin door L1 to allow for faster egress in an evacuation, thus allowing the limit to be raised slightly. But it also means airlines will have to reduce seat pitch to 29-30" which they might be hesitant to do without the fear of alienating customers.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: SSTeve
Posted 2013-05-27 10:47:48 and read 24351 times.

Quoting Blueshamu330s (Reply 27):
Adding extra seats to achieve CASM guarantees; how old school.

There was I expecting high tech, ground breaking innovations and new propulsion technology...

They shouldn't do it because it's not cool enough?

Incidentally, one of the technology features requested by flight attendants is a door that's easier to open, because the existing door is grandfathered in. They may not be changing the door that matters, though... that's not clear to me, and of course it's all just informed speculation at this point.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Stitch
Posted 2013-05-27 11:03:21 and read 23999 times.

Quoting Stitch (Reply 11):
To get to 162, I am assuming the MAX will have six seats in the Overwing Exit Row as opposed to the 4 in the 737-800.
Quoting HiFlyerAS (Reply 28):
I think you're thinking of the 737-700. The -800 has a full six abreast at the overwings.

While that is true for most, if not all, airline operators of the type, Section 2.4.13 of the Boeing 737 Family ACAP shows a row of 6 seats at the forward overwing exit and a row of 4 seats in the aft overwing exit for a Mixed Class configuration of First Class and Economy Class seating.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: 1337Delta764
Posted 2013-05-27 11:10:45 and read 23813 times.

Since Boeing is modifying the doors, why not add a slide raft option? The 737NG is the only current Boeing or Airbus aircraft that does not offer them (they are at least optional on the A32x).

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: HiFlyerAS
Posted 2013-05-27 11:50:14 and read 22938 times.

Quoting Stitch (Reply 30):
While that is true for most, if not all, airline operators of the type, Section 2.4.13 of the Boeing 737 Family ACAP shows a row of 6 seats at the forward overwing exit and a row of 4 seats in the aft overwing exit for a Mixed Class configuration of First Class and Economy Class seating.

You're probably right...it's likely carrier-option. If there is more legroom they can have six seats but with a tighter space they need to leave out the window seat and can only have two seats per side instead of three.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: BA777
Posted 2013-05-27 12:30:49 and read 22115 times.

So Ryanair could get the capacity up to 198...?

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: speedygonzales
Posted 2013-05-27 12:40:54 and read 21843 times.

Quoting 817Dreamliiner (Reply 19):
Quoting speedygonzales (Reply 15):
I'm guessing moving the front doors forward and/or the rear doors backwards

Im not sure if the doors can be moved any further than they already are:

It will be tight, but we're only talking 1m or so for 9 more seats.

The Aspire Aviation article doesn't have much details, but the reason I'm leaning towards moving the doors is that they mention incrasing the standard two class capacity from 162 to 171, which points to lengthening the cabin, not increasing the 189 seat exit limit. If it could be achieved by using slimmer seats or rearranging the cabin layout, there's no need to change the doors or wait for the MAX. The max limit is only mentioned for the -9, but it's not clear if the 226 number came from Boeing, or if Aspire got it themselves by adding 9 to 215.

Anyway, whatever the door modification ends up being, the need to change the doors to increase capacity is IMO an admission by Boeing that the NEO has a solid lead on the MAX.

Quoting 817Dreamliiner (Reply 19):

Quoting speedygonzales (Reply 15):
and possibly adopting the flat rear bulkhead from the 900ER on all models.

Isnt this being done already or am I mistaken?

Boeing's ACAPS document only show the flat bulkhead on the drawings of the 900ER, but they might have changed it for the 700 and 800 without updating the documentation,

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Viscount724
Posted 2013-05-27 15:01:31 and read 19482 times.

Quoting Stitch (Reply 30):
Quoting Stitch (Reply 11):
To get to 162, I am assuming the MAX will have six seats in the Overwing Exit Row as opposed to the 4 in the 737-800.
Quoting HiFlyerAS (Reply 28):
I think you're thinking of the 737-700. The -800 has a full six abreast at the overwings.

While that is true for most, if not all, airline operators of the type, Section 2.4.13 of the Boeing 737 Family ACAP shows a row of 6 seats at the forward overwing exit and a row of 4 seats in the aft overwing exit for a Mixed Class configuration of First Class and Economy Class seating.

KLM 737-700/800/900s all have 3-3 seating at the overwing exits (with a few inches more seat pitch).

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: DocLightning
Posted 2013-05-27 15:06:34 and read 19374 times.

Quoting PHX787 (Reply 1):
Are they completely redesigning the fuselage cross-section with the MAX?

A complete redesign of the cross-section would be too much of a deviation to be still considered a 737 for regulatory purposes. They would have to certify it as an entirely new type and come up with all the procedures for pilots to ensure a common type rating and etc. etc. etc. The cross-section cannot change.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Viscount724
Posted 2013-05-27 15:12:39 and read 19300 times.

Quoting DocLightning (Reply 36):
Quoting PHX787 (Reply 1):
Are they completely redesigning the fuselage cross-section with the MAX?

A complete redesign of the cross-section would be too much of a deviation to be still considered a 737 for regulatory purposes. They would have to certify it as an entirely new type and come up with all the procedures for pilots to ensure a common type rating and etc. etc. etc. The cross-section cannot change.

If not mistaken the 757 and 767 have a common pilot type rating but they certainly don't have the same cross-section.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: garpd
Posted 2013-05-27 15:18:25 and read 19165 times.

Quoting Blueshamu330s (Reply 27):
Adding extra seats to achieve CASM guarantees; how old school.

There was I expecting high tech, ground breaking innovations and new propulsion technology...

Rgds

Your sarcasm aside, there is nothing wrong with eeking out more efficiencies from an established design. If a relatively minor change to the doors allows for more seats in the same fuselage, it wouldn't make sense not to take advantage of that.

Perhaps this just goes to show how well the 707/737 fuselage was designed, that even after 50 years it's still as adaptable and efficient as it was when the first ones rolled of the production line.

Few fuselages have stayed in production over so many models for so long.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: lightsaber
Posted 2013-05-27 16:18:55 and read 18341 times.

Quoting 817Dreamliiner (Reply 19):
Quoting speedygonzales (Reply 15):
and possibly adopting the flat rear bulkhead from the 900ER on all models.

Isnt this being done already or am I mistaken?

Is it? I would think the MAX would standardize on the 900ER bulkhead, but that is a detail I do not know...

What is the answer?

Quoting speedygonzales (Reply 34):
but the reason I'm leaning towards moving the doors is that they mention incrasing the standard two class capacity from 162 to 171, which points to lengthening the cabin, not increasing the 189 seat exit limit.

Interesting find. Although 3 of those seats would be from the bulkhead move...

Lightsaber

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: jetmarc
Posted 2013-05-27 16:44:39 and read 17948 times.

What I don't understand is how does a wider door make a difference?? Unless being wider allows for a dual lane escape slide. Can somebody explain to me... is it because people can apparently move through it faster as if easier to round the corner? The MD80 had a max seating of 172 even with that little dinky R1 service door/hatch! I too wonder if its more about configuration than modification. Perhaps they'll make the 737MAX more like the A321 and ditch the OWWEs for 900ER style hatches forward and aft of the wings.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: etops1
Posted 2013-05-27 17:16:02 and read 17517 times.

Can they please change the slide arming mechanism on the door ? That girt bar has got to go .

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: fpetrutiu
Posted 2013-05-27 17:18:10 and read 17476 times.

Quoting BA777 (Reply 33):
So Ryanair could get the capacity up to 198...?

thank God it's not up to RyanAir... Then we'll see a 550 pax 737...

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: 0NEWAIR0
Posted 2013-05-27 18:34:57 and read 16343 times.

Quoting fpetrutiu (Reply 42):
Then we'll see a 550 pax 737...

...All standing and holding on to overhead hand straps that will retract if their coin slots aren't continuously fed.   

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: mffoda
Posted 2013-05-27 19:49:06 and read 15353 times.

Quoting fpetrutiu (Reply 42):
Quoting BA777 (Reply 33):
So Ryanair could get the capacity up to 198...?

thank God it's not up to RyanAir... Then we'll see a 550 pax 737...

On the other hand.... It definitely throws a wrench into the per seat cost argument when the OEM's used different numbers in their ads... Particularity, since Boeing using 162 seats in their assumptions for the 737-8 and Airbus used 157 seats in their assumptions... When comparing to the 150 seat A320neo's... I wonder how the new numbers add up with 171 seats for the 737-8??

Maybe ferpe can give us some insight...  

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: planemaker
Posted 2013-05-27 21:05:34 and read 14516 times.

Quoting mffoda (Reply 44):
On the other hand.... It definitely throws a wrench into the per seat cost argument when the OEM's used different numbers in their ads... Particularity, since Boeing using 162 seats in their assumptions for the 737-8 and Airbus used 157 seats in their assumptions... When comparing to the 150 seat A320neo's... I wonder how the new numbers add up with 171 seats for the 737-8??

It is a bit of joke, really, this game they play... not only seat numbers but distance as well - whatever makes them look better. However, other than on sites like this, the "propaganda" is pretty pointless since airlines run the true numbers through their own network and in their own configurations. Furthermore, the COC & CASM is only part of the purchasing decision.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Stitch
Posted 2013-05-27 21:32:48 and read 14247 times.

Quoting planemaker (Reply 45):
It is a bit of joke, really, this game they play... not only seat numbers but distance as well - whatever makes them look better.

Both OEMs partake of this game - Airbus is playing with door distances, number of doors, seat pitch and seat design to fit 236 seats into an A321-200neo.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: goosebayguy
Posted 2013-05-27 22:36:10 and read 13554 times.

Its a fair point that many people these days are slightly larger. I'm wondering when it was decided that 45 or 55 people could evacuate these doors and if people's increased girths these days actually reduces the number able to evacuate. Anyone know what year these rules were introduced?

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: ggflyboy
Posted 2013-05-27 22:40:54 and read 13555 times.

Quoting Stitch (Reply 3):
The Type C door, which is the same height but wider (minimum of 30 inches vs. the 24 inches of the Type I), is certified for 55 passengers per exit.

I think this is the real joke. 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, especially if the modification is only made to 1L. 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... Airbus had one entire side blocked for the A380 certification.

And another thought... 1L is located close to the low-density first class area, so this modification would not proportionally help the extra 9 people stuffed into the back.

Maybe this is cynical comment, but in an accident the 73 tends to break apart somewhere just forward (or aft) of the wing box anyway, so it might make this a moot point... lots of people just get out through the split. Think Turkish, Lion Air, etc.

Btw, somewhat unrelated: took a ride in my first 757-300 today--- second row from the back. Just like sitting in the back of the bus! Felt like I was one with the rudder. Anyway, this might be informing my opinion here on seating density and exit configuration.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: SSTeve
Posted 2013-05-27 22:45:55 and read 13482 times.

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

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...)

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: will
Posted 2013-05-27 23:15:18 and read 13209 times.

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...........

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: ggflyboy
Posted 2013-05-27 23:15:52 and read 13225 times.

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.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: r2rho
Posted 2013-05-28 01:06:18 and read 12173 times.

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...

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: debonair
Posted 2013-05-28 01:53:45 and read 11749 times.

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)?

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: garpd
Posted 2013-05-28 02:07:28 and read 11649 times.

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.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: yeelep
Posted 2013-05-28 04:09:17 and read 10664 times.

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

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: nclmedic
Posted 2013-05-28 04:37:50 and read 10340 times.

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.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Aviaponcho
Posted 2013-05-28 05:22:30 and read 9865 times.

Seems old news for me

http://atwonline.com/aircraft-amp-en...econfigures-737ng-extra-space-2014

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: JAAlbert
Posted 2013-05-28 06:51:29 and read 8856 times.

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.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: mffoda
Posted 2013-05-28 06:51:57 and read 8862 times.

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?

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Aviaponcho
Posted 2013-05-28 07:13:38 and read 8638 times.

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...).

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Aviaponcho
Posted 2013-05-29 05:39:10 and read 7204 times.

We should know more today i think !

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: ODwyerPW
Posted 2013-05-29 08:47:12 and read 6937 times.

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]

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Aviaponcho
Posted 2013-05-29 08:57:49 and read 6879 times.

Flat bulkhead comes with a 400 lb penalty

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: ODwyerPW
Posted 2013-05-29 09:08:02 and read 6851 times.

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.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: bikerthai
Posted 2013-05-30 06:08:40 and read 6186 times.

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

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: ODwyerPW
Posted 2013-05-30 11:30:47 and read 5889 times.

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?

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: queb
Posted 2013-05-30 14:42:27 and read 5680 times.

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

https://vine.co/v/bYDvzwQUmZl

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: ODwyerPW
Posted 2013-05-30 14:58:19 and read 5608 times.

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.

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: lightsaber
Posted 2013-05-30 22:56:13 and read 5179 times.

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

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

Lightsaber

Topic: RE: Boeing To Make Door Modification On 737 MAX
Username: Aviaponcho
Posted 2013-05-31 00:33:59 and read 5055 times.

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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