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dzsoki

dzsoki

Member Since 30 Aug 2013
Offline Last Active Nov 25 2017 06:49 PM

Revision of cabin configurations in AE

26 December 2013 - 03:24 PM

Currently in AE we have a Max Seats parameter to describe the seating capacity of an aircraft.

This Max Seats parameter equals the maximum certified evacuation seat number of an aircraft. (FAA exit limit)

This FAA exit limit not suitable to describe the cabin size and the possible cabin configurations of an aircraft, becuse this FAA exit limit does not always match the cabin capacity of an aircraft.

Max seats = cabin capacity = exit limits

 

Please check the following example for the Airbus A340 series aircrafts:

Airbus factory datas: http://www.airbus.co...aft/a340family/

 

A340-200

Max seats in AE: 420

Cabin lenght: 46,06 m

Cabin width: 5,28 m

 

A340-300

Max seats in AE: 440

Cabin lenght: 50,35 m

Cabin width: 5,28 m

 

A340-500 (this aircraft intended for ultra long range flights)

Max seats in AE: 375

Cabin lenght: 53,56 m

Cabin width: 5,28 m

 

A340-600

Max seats in AE: 475

Cabin lenght: 60,98 m

Cabin width: 5,28 m

 

An Airbus A340-500 cabin is bigger than a A340-200 by more than 6 meters, in the reality if I configure

- 20F 60C 274Y (354) for both aircraft I will have more space in the A340-500.

Currently in AE I can configure only the following cabin config for A340-500, which has larger cabin than the A340-200:

- 20F 60C 229Y (309)

 

Using FAA exit limits to determine the actual seating capacity of an aircraft can be misleading in some cases. For bigger planes the max passengers certification process depends on the manufacturers strategy, let's see a simple example. We have two planes Airbus_1, and Boeing_1ER, both plane have the same cabin size, both designed for ultra long range flights.

 

Strategy of Airbus_1: This aircraft intended for long range usage so I certify it with 400 pieces of 32" pitch seat, nobody will use it with configurations above this.
Strategy of Boeing_1ER: I certify this aircraft with more 440 pieces of 30" seats, because I will have other aircrafts with comparable cabin size, and I will use this certification to take out this process for other shorter range aircrafts as well, with similar cabin size (we save money, if we go for the maximum amount of seats and test just once).
 
In AE this would mean that we can configure the following cabin layouts for two aircrafts, with exactly the same cabin size:
Airbus_1: 30F 60C 229Y (319)
Boeing_1ER: 30F 60C 269Y (359)
 
In the reality we can configure Airbus_1 to 30F 60C 269Y (359) the same capacity, exactly the same seat pitch, like the Boeing without any problem, but we took the FAA exit limit, as if it would describe the actual cabin size, which is not right and this caused errors in our calculations.
 
For bigger planes the manufacturers own seat map drawing, comparing cabin sizes, comparing actual seat plans with seat pitch data, will give you much more punctuality than FAA exit limits alone.
 
For the above mentioned example, I think two parameters should be used to describe the seating capacity of an aircraft in AE:
1, maximum allowed passengers (FAA exit limit)
2, cabin size (actual cabin size in seats)
 
Airbus_1:
maximum allowed passengers: 400
cabin size: 440
 
Boeing_1ER:
maximum allowed passengers: 440
cabin size: 440
 
-first parameter determines the maximum allowed seats for the aircraft.
-second parameter determines the maximum cabin size which can be used for seating
-at default the two parameters should be equal for all aircrafts, so it won't cause any problems in AE, only aircrafts where differences exist between the cabin size and max. allowed passengers could be fine tuned easily
 
To summarize, FAA exit limits have much better punctuality for smaller aircrafts, as most of the time they really reflects the maximum capacity and the actual cabin size of the aircraft.
At bigger planes the max. seating capacity depends on the actual cabin size, and the certification strategy of the manufacturer, which sometimes can be really misleading.
 
Possible cabin configurations accordingly for this example:
 
Airbus_1:
- 30F 60C 269Y (359)
- 400Y (400)
- 440Y (440)
 
Boeing_1ER:
-30F 60C 269Y (359)
-440Y (440)
 
Example cabin configuration solutions for the A340 series:
 
-Airbus A340-200:
maximum allowed passengers: 420
cabin size: 420
 
-Airbus A340-300:
maximum allowed passengers: 440
cabin size: 440
 
-Airbus A340-500:
maximum allowed passengers: 375 (ultra long range aircraft, this is why it certified so low)
cabin size: 468 (from the cabin width & lenght compared to A340-300)
 
-Airbus A340-600:
maximum allowed passengers: 475
cabin size: 520
 
-Boeing 777-300ER:
maximum allowed passengers: 550
cabin size: 550
I quoted 777-300ER here because it's a good example for the max seats certification strategy. If we take the FAA exit limits data, as cabin size this will tell us that the 777-300ER has a 46,6% bigger cabin than a A340-500. But that's not real. We get realistic cabin size ratios if we use the cabin size parameters.
 
Some Boeing aircraft examples, where these new parameters can be also used:
 
-Boeing 737-600:
maximum allowed passengers: 149
cabin size: 140
(this 149 seat number phisically won't fit into the aircraft, exit limit is higher than the actual capacity, because the exit limit is determined by the emergency exit door configuration, which matches 737-700)
 
Boeing 737-900 and 737-900ER: two aircraft with exactly the same cabin size.
 
"Boeing later introduced the 737-900, the longest and most powerful variant to date. Alaska Airlines launched the 737-900 in 1997 and accepted delivery on May 15, 2001. Because the -900 retained the same number of exits as the -800, seating capacity was limited to 189 in a single-class layout."
 
Boeing 737-900
maximum allowed passengers: 189
cabin size: 220
 
Boeing 737-900ER
maximum allowed passengers: 220
cabin size: 220
 
the maximum allowed configuration currently in AE:
16F 0C 149Y 
because the FAA exit limits not matches with the cabin size for this aircraft, we have calculation errors and cannot even configure a real world cabin configuration here.
The same applies for the Airbus A340 500/600 series. 
 

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