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PDX88
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Why no 2L boarding door option on aircraft with tail mounted engines?

Sat Nov 02, 2019 8:16 pm

It would’ve been interesting to see an option for a 2L boarding door on the MD80/90 or 717. There is plenty of room on the fuselage for an additional door with an no obstruction for a jet bridge and would help speed up boarding times and provide an enhanced first class experience. Weight and passenger seating capacity would’ve been limiting factors but was this ever considered for part of the designs?
 
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hOMSaR
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sat Nov 02, 2019 8:22 pm

There’s no need for an extra door, so why would they add one?
I was raised by a cup of coffee.
 
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longhauler
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sat Nov 02, 2019 8:34 pm

Just because I stopped arguing, doesn't mean I think you are right. It just means I gave up!
 
DarthLobster
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sat Nov 02, 2019 8:35 pm

In most cases (especially the DC-9 family), the wings are pretty far aft, which would interfere with jetway placement.
 
cschleic
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sat Nov 02, 2019 8:37 pm

longhauler wrote:


Tridents and IL-62s as well.
 
KlimaBXsst
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sat Nov 02, 2019 8:42 pm

Nice post. That is sure one way to get people on and off more quickly.

Aesthetically the A 340 got it right!
 
Antarius
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sat Nov 02, 2019 8:45 pm

PDX88 wrote:
It would’ve been interesting to see an option for a 2L boarding door on the MD80/90 or 717. There is plenty of room on the fuselage for an additional door with an no obstruction for a jet bridge and would help speed up boarding times and provide an enhanced first class experience. Weight and passenger seating capacity would’ve been limiting factors but was this ever considered for part of the designs?


None of those aircraft are big enough to need a second jetway. The added weight, cost etc. Would not provide adequate return.
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northstardc4m
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sat Nov 02, 2019 10:56 pm

I could swear I've seen a picture of an IL-62 with on 2 jetways... but I cannot find it now...

Anyways both the IL-62 and Tu-154 have the type of L-2 doors that can provide dual boarding... lots of pictures with dual stairs for either one but none on dual jetways.
Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety.
 
Prost
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sun Nov 03, 2019 12:30 am

The 727 and MD-80 had integrated stairs in the tail cone, isn’t that enough?
 
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lightsaber
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sun Nov 03, 2019 1:56 am

KlimaBXsst wrote:
Nice post. That is sure one way to get people on and off more quickly.


Loving that photo


As mentioned, MD-80/DC-9/727 would tail load.

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MIflyer12
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sun Nov 03, 2019 1:57 am

Prost wrote:
The 727 and MD-80 had integrated stairs in the tail cone, isn’t that enough?


My last tail stairs loading/deplane was to a China Northern MD-90 -- that probably made its way into the Delta fleet.
 
USAirKid
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sun Nov 03, 2019 2:08 am

Do the MD80/90/717 have enough capacity to make the time and effort of docking and removing an extra jetbridge worth the time?

I've not closely analyzed the ramp operations, but I'd doubt the speed of passengers boarding would be enough of a limiting factor...
 
N766UA
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sun Nov 03, 2019 2:21 am

Because 99% of jetways are single bridges, and the F class cabin in these jets is so relatively small there’s no benefit to boarding/deplaning through just an L2 door. It’s a pointless addition of a significant amount of weight.
 
Karlsands
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sun Nov 03, 2019 2:55 am

[url][/url]
DarthLobster wrote:
In most cases (especially the DC-9 family), the wings are pretty far aft, which would interfere with jetway placement.

That would actually allow more room up front for jetways etc .
 
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admanager
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sun Nov 03, 2019 4:16 am

MIflyer12 wrote:
Prost wrote:
The 727 and MD-80 had integrated stairs in the tail cone, isn’t that enough?


My last tail stairs loading/deplane was to a China Northern MD-90 -- that probably made its way into the Delta fleet.


The last tail stair boarding I can remember was a Martin 404 at MIA going to Key West. My wife of about 18 hours at that point knew she was married to an airline geek. 36 years later she has learned to accept this curious behavior from her son and husband.
 
rbavfan
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sun Nov 03, 2019 4:31 am

DarthLobster wrote:
In most cases (especially the DC-9 family), the wings are pretty far aft, which would interfere with jetway placement.


He is talking about an L2 door fwd of the wing on the MD series, not aft of it. That location means the wing would not affect it.
 
Viper911
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sun Nov 03, 2019 4:56 am

cschleic wrote:
longhauler wrote:


Tridents and IL-62s as well.


Add the TU-154 to the list as well. Having flown the 154 quite often in the 90s i remember that only once we boarded via 1L, rest of the time it was 2L.

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airtrantpa
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sun Nov 03, 2019 5:41 am

Wouldn’t the extra boarding door offset the weight to the port side? Wouldn’t that affect the symmetry of the fuselage? I always thought thought a boarding door was always exact opposite each other the counter weight the other.
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Prost
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sun Nov 03, 2019 7:35 am

Well currently the 1 right galley doors on several planes aren’t the same size as door one right, and aircraft aren’t completely symmetrical.
 
32andBelow
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Sun Nov 03, 2019 7:54 am

It’s a 100 seat airplane. Your going to rip out 6 seats so 94 people can board slightly faster?
 
PDX88
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 6:13 am

airtrantpa wrote:
Wouldn’t the extra boarding door offset the weight to the port side? Wouldn’t that affect the symmetry of the fuselage? I always thought thought a boarding door was always exact opposite each other the counter weight the other.


No more than 2-3 seating screws up the longitudinal weight and balance.

32andBelow wrote:
It’s a 100 seat airplane. Your going to rip out 6 seats so 94 people can board slightly faster?


The 717 seats 120.

But aside from the 717, the MD90 seats 158 which could’ve been useful. Airlines have been trying many different tactics to decrease turn times, the hypothetical was if there was an option for the aircraft to be delivered with an optional 2L door in front of the wing today, which would only eliminate 2 seats if the 2 side was on the left, if airlines would’ve gone for it.
 
32andBelow
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 6:36 am

PDX88 wrote:
airtrantpa wrote:
Wouldn’t the extra boarding door offset the weight to the port side? Wouldn’t that affect the symmetry of the fuselage? I always thought thought a boarding door was always exact opposite each other the counter weight the other.


No more than 2-3 seating screws up the longitudinal weight and balance.

32andBelow wrote:
It’s a 100 seat airplane. Your going to rip out 6 seats so 94 people can board slightly faster?


The 717 seats 120.

But aside from the 717, the MD90 seats 158 which could’ve been useful. Airlines have been trying many different tactics to decrease turn times, the hypothetical was if there was an option for the aircraft to be delivered with an optional 2L door in front of the wing today, which would only eliminate 2 seats if the 2 side was on the left, if airlines would’ve gone for it.

The fastest way to board is through 2 sets of air stairs but airlines aren’t willing to do it.
 
Some1Somewhere
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 6:47 am

Plenty of airlines will board 737s or A320s from both the front and rear in good weather.
 
Max Q
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 7:38 am

airtrantpa wrote:
Wouldn’t the extra boarding door offset the weight to the port side? Wouldn’t that affect the symmetry of the fuselage? I always thought thought a boarding door was always exact opposite each other the counter weight the other.



It’s not an issue, plenty of aircraft have exterior doors that don’t match up on both sides or smaller doors on one side than the opposite


Interestingly aircraft that have vertically opening passenger doors (L1011, DC10, 767)
stagger these doors to allow space for them to slide up tracks into the overhead opposite each other
The best contribution to safety is a competent Pilot.


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ACDC8
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 7:48 am

YVR had 2 bridges for WS's 737s some years back, didn't last long. They do ground board their Q400s with both doors at times, as does AS, at least at YLW. Pretty sure that aligning two jetways onto a short haul airliner eats up any time saved in boarding 100-150 people.
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Someone83
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 8:28 am

PDX88 wrote:
It would’ve been interesting to see an option for a 2L boarding door on the MD80/90 or 717. There is plenty of room on the fuselage for an additional door with an no obstruction for a jet bridge and would help speed up boarding times and provide an enhanced first class experience. Weight and passenger seating capacity would’ve been limiting factors but was this ever considered for part of the designs?


The door is rather small and also it is rather tight between the wings and engines. And also these aircraft and a door and stairs through the tail cone. Been boarding/de-boarding through that numerous times on SAS MD-80 fleet

Some1Somewhere wrote:
Plenty of airlines will board 737s or A320s from both the front and rear in good weather.


That is how its done here in Norway, but usually independent the weather ;) On airports with skybridge, that goes to door 1, and than a stair us used on door 2. At airports withough skybridges, stairs are used on both door 1 and 2. This way both SAS and Norwegian can do fast turn arounds with 737-800s, usually scheduled in 30 minutes or less
 
oldannyboy
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 12:24 pm

727-100 had one.
 
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hOMSaR
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 1:07 pm

Think about it this way, if 2L boarding for faster turn times was so important, why did Airbus eliminate 2L on their latest iteration of the A321?

On a plane that’s even smaller, such as the DC-9/MD-80/90 series, that door adds unnecessary weight (mentioned earlier) and takes up space that could be used by seats. This reduces flexibility of the configuration.

When the DC-9 was designed, boarding times weren’t exactly a limiting factor. The “enhanced first class experience” during boarding is always going to be a secondary factor and would never actually drive airline fleet decisions.

What are design factors are decreasing weight and increasing cabin layout flexibility, which is why you’re seeing designs with fewer doors and/or doors plugged, where possible.

oldannyboy wrote:
727-100 had one.


The 727-100 had a 2R door, but as far as I can tell, it did not have a 2L.
I was raised by a cup of coffee.
 
RDUDDJI
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 1:35 pm

hOMSaR wrote:
There’s no need for an extra door, so why would they add one?


This, and more doors = less seats.
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COSPN
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 2:19 pm

The quickest is stairs forward and aft .. but in the USA we have the ADA law so must always use a jetway “if available” or can be sued under the Americans with disabilities act
 
birdbrainz
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 2:34 pm

DC-10/MD-11/L1011 also have 2L loading.
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johns624
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 2:43 pm

PDX88 wrote:
provide an enhanced first class experience.
How so? So they wouldn't have to look at the great, unwashed masses as they filed their way back to steerage?
 
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hOMSaR
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 2:44 pm

COSPN wrote:
The quickest is stairs forward and aft .. but in the USA we have the ADA law so must always use a jetway “if available” or can be sued under the Americans with disabilities act


ADA does not apply to airlines. Though there is an Air Carriers Accessibility Act (ACAA), which is similar.
I was raised by a cup of coffee.
 
KlimaBXsst
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 5:49 pm

birdbrainz wrote:
DC-10/MD-11/L1011 also have 2L loading.


True, location of the number 2 boarding door on the L1011 Tristar was superior though in my opinion
Aesthetically the A 340 got it right!
 
32andBelow
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 9:56 pm

COSPN wrote:
The quickest is stairs forward and aft .. but in the USA we have the ADA law so must always use a jetway “if available” or can be sued under the Americans with disabilities act

Alaska would board the rollers with a modified catering truck when they had the combi.
 
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smithbs
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 10:24 pm

ACDC8 wrote:
YVR had 2 bridges for WS's 737s some years back, didn't last long. They do ground board their Q400s with both doors at times, as does AS, at least at YLW. Pretty sure that aligning two jetways onto a short haul airliner eats up any time saved in boarding 100-150 people.


Same at YYJ - I was through there some weekends ago and watched Q400s from three different airlines (AS, WS & AC). All of them used stairs fore and aft. I then flew the AS Q400 to SEA, where only the front stair was used. I was earlier on a Q400 at BOI - also loading front and aft.

I just find it ironic that outstations like BOI and YYJ can find it worth their while to work multiple air stairs on their RJs, but mainline hubs like SEA can't be bothered with multi-door loadings of 737, A320 and up. It also makes me all the more skeptical of the MoM/NMA/whatever concepts from Boeing that propose using two aisles to speed boarding and therefore cut turn times. Who is really shaving turn times that close? You could load multiple doors on an A/C if you really want to. But few seem to care.
 
BTV290
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 10:49 pm

Several issues here... Think of the 757--it has a 2L door, but you can't attach two jet bridges to it at most standard-configuration gates. the doors are too close together. I will say, it's nice to have that 2L for boarding, though, as it allows the FAs to take care of first class service without obstructing the flow of pax on board. That would be the only benefit I could see to adding a 2L door to these smaller aircraft--but like someone else mentioned, their premium cabins are so small, it really doesn't make that much difference.
Regarding the A321s, most of the models with a 2L door can't have a jet bridge on that door anyway, due to the engine being too close. The proximity sensors on the bridge go off, and you only have about five inches of wiggle room until the bridge slide is in the cowling.

Lastly, tail mountain aircraft sit very low to the ground. As it is, most 717/M90/M80 types have to park fairly far out on the lead in line, because the jetbridge needs to be able to extend out pretty far, in order to accommodate how low it has to sink to reach the aircraft. On most jet bridges I've driven, meeting a T-tail takes the bridge right to the end of its maximum extend length. If you were to try to put a door beyond that, and then use it for boarding--airports would have to literally rip off their jet bridges and put about ten feet of extender hallway on, in order to make it work.

Bottom line: not worth the pay off.
 
stefanJ
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Mon Nov 04, 2019 11:19 pm

BTV290 wrote:
Several issues here... Think of the 757--it has a 2L door, but you can't attach two jet bridges to it at most standard-configuration gates. the doors are too close together. I will say, it's nice to have that 2L for boarding, though, as it allows the FAs to take care of first class service without obstructing the flow of pax on board. That would be the only benefit I could see to adding a 2L door to these smaller aircraft--but like someone else mentioned, their premium cabins are so small, it really doesn't make that much difference.
Regarding the A321s, most of the models with a 2L door can't have a jet bridge on that door anyway, due to the engine being too close. The proximity sensors on the bridge go off, and you only have about five inches of wiggle room until the bridge slide is in the cowling.

Lastly, tail mountain aircraft sit very low to the ground. As it is, most 717/M90/M80 types have to park fairly far out on the lead in line, because the jetbridge needs to be able to extend out pretty far, in order to accommodate how low it has to sink to reach the aircraft. On most jet bridges I've driven, meeting a T-tail takes the bridge right to the end of its maximum extend length. If you were to try to put a door beyond that, and then use it for boarding--airports would have to literally rip off their jet bridges and put about ten feet of extender hallway on, in order to make it work.

Bottom line: not worth the pay off.



Not to nitpick however ... In regards to A321, all models with a 2L door CAN have a jet bridge, however due to the proximity of the engine most operators avoid it. LH however used to (still does?) do it at FRA and MUC - have boarded through 2L numerous times from a jet bridge at these airports.
 
Max Q
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Tue Nov 05, 2019 5:58 am

hOMSaR wrote:
Think about it this way, if 2L boarding for faster turn times was so important, why did Airbus eliminate 2L on their latest iteration of the A321?

On a plane that’s even smaller, such as the DC-9/MD-80/90 series, that door adds unnecessary weight (mentioned earlier) and takes up space that could be used by seats. This reduces flexibility of the configuration.

When the DC-9 was designed, boarding times weren’t exactly a limiting factor. The “enhanced first class experience” during boarding is always going to be a secondary factor and would never actually drive airline fleet decisions.

What are design factors are decreasing weight and increasing cabin layout flexibility, which is why you’re seeing designs with fewer doors and/or doors plugged, where possible.

oldannyboy wrote:
727-100 had one.


The 727-100 had a 2R door, but as far as I can tell, it did not have a 2L.



Correct, that door was specifically to allow servicing of the mid galley on the 721
The best contribution to safety is a competent Pilot.


GGg
 
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deltacto
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Re: Why no 2L boarding door option on aircraft with tail mounted engines?

Tue Nov 05, 2019 9:37 am

oldannyboy wrote:
727-100 had one.


Yes! Dan Air installed an extra exit door on both sides of the 727-46's they bought from JAL

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