XLSX tabs are linked together with key fields. A strong convention is that
such a key is labelled as <remote-tabname>::<remote-field>. More details are provided in Understanding sheets cross references.
A summary of those relationships are shown Figure Fig. 33.
Fig. 33 LOPA tabs relationships (click to enlarge)¶
This sheet is used to define the different seats / monuments installed on the cabin LOPA.
Each line corresponds to one seat or cabin monument. This sheet centralises key information and properties of each seat / cabin monument.
The following figure shows an example of standard seat definition in the sheet “item_info”:
The following figure shows an example of non standard seat definition in the sheet “item_info”. In this example a seat with a surrounding furniture is captured in the “item_info” sheet.
Fig. 35 Example of non standard seat info (seat + furniture)¶
ITEM_INFO-type
type: string | enum: ['Seat','Other']
Define the type of cabin item.
“Seat” should be entered in this field for standard seat installation.
For any other cabin monuments defined the type “Other” should be specified.
ITEM_INFO-label
type: string
Define the cabin seat / monument label
The label specified in this field is used to refer to the cabin seat / monument.
Typical label for standard seat is “Sxy” with “xy” being the seat ID shown on the cabin LOPA.
Specify the number of passenger of the corresponding seat
This field is only mandatory for standard seat.
ITEM_INFO-part_number
type: string,null
Specify the cabin seat / monument part number
This field is complementary to the associated cabin seat / monument label.
ITEM_INFO-designation
type: string,null
Specify the cabin seat / monument designation
This field allow a complete description of the corresponding cabin seat / monument.
For instance, “BEA W DBL seat RH - Last row” could be used to describe a double seat.
Specify the seat mass used for the interface load calculation
This field is an optional field as it is not used by the FTools in the current version.
This mass will be used in a future FTools version to check the correspondance between the seat IFL and its mass.
This field is a mandatory field for standard seat as it is used for the seat running load justification (seat individual weight and seat row weight).
The Maximum Installed Seat Weight is the maximum allowable weight for the seat with all components and includes all
equipment the seat installer may add to the seat, such as emergency equipment or literature pocket contents. This weight is equal
to the minimum total tested seat weight of all static/dynamic tests used for substantiation of the subject seat P/Ns. However, this
weight must be verified against seat track interface loads and other aircraft/structural limitations.
ITEM_INFO-item_loads::label
type: string
Define the IFL associated to the cabin seat / monument
Specify if the associated Interface Load should be made symmetric for the seat / monument
If the IFL is directly applicable to the seat / monument the field should be “0”.
If the IFL should be made symmetric for the relevant seat / monument the field should be “1”.
Warning
The option as_symmetry can only be applied on seat / monument sharing the same source of IFL and the same interface point geometry. This option will symmetrize both load and geometry.
For Boeing B777 the aircraft coordinate system is defined 92.5in forward of the fuselage nose.
Example 1: Interface points defined in local coordinate system¶
The interface points of the double seat shown on Fig. 36 can be defined as shown in the following table:
Fig. 39 Interface points defined in local coordinate system¶
Note
‘z’ coordinate doesn’t need to be entered as it is assumed that all items are installed on seat tracks, hence ‘z’ is set to the default FE model location.
Example 2: Interface points defined in AC coordinate system¶
In some cases it is more convenient to define the item interface points location in the aircraft coordinate system.
For instance in the FWD section when the Business Class seat is installed on canted seat tracks, the interface points are provided in the aicraft coordinate system.
In the seat manufacturer IFL report the interface points are located in STA, BL.
Fig. 41 Interface points location in AC coordinate system¶
In the Sheet “item_geom”, the Seat 1A and 1C interface points can be specified as shown in the following table.
Fig. 42 Interface points defined in AC coordinate system¶
Warning
Interface point X coordinate specified in global coordinate should not be mixed with aircraft station STA.
For instance, an interface point located at STA909 on a Boeing B777-300 should be converted to X=909+210=1’119in
Tip
Interface points location can be entered in local or global coordinate system as long as it remains consistent per item. A good practice is to used the same interface point ID as the one defined in the IFL report. It will ease the Interface Load entering in Sheet “item_loads”
Note
The interface points ID entered in this sheet correspond to the IFL ID and not the LOPA ID from the seat manufacturer report.
The same point ID will be used in the Sheet “item_loads”” to specify the interface load.
The sheet is used to define the installation of cabin item as specified on the LOPA.
The item installation is restricted to seat tracks.
Fig. 43 illustrates the data filling of sheet “item_asm” for a standard seat installation.
Fig. 43 Example of Item assembly specification for standard seat installation¶
Fig. 44 illustrates the data filling of sheet “item_asm” for a non standard seat installation (Business class seat with surrounding furniture).
Fig. 44 Example of Item assembly specification for non standard seat installation¶
Note
In the example of Fig. 44, Seat 1A and Furniture 1A reference points are located on FWD canted seat track (BL-104.16 and BL-69.38 respectively).
However, in sheet “item_asm”, rail_tag is entered as LBL108 and LBL74. Internally, FTools performs an automatic positioning with rail_tag and x_loc definition.
Warning
when the seat / cabin item is installed with some interface points on both canted and straight seat track, selection of the “reference point” is very important as it can lead to different location.
(see Fig. 45)
The following figure illustrates the seat / cabin assembly process in FWD transition area. As shown on Fig. 45 the selection of different reference point leads to two different cabin item installation.
Fig. 45 Assembly of cabin item in transition area¶
This capability to select the orientation of the installed item (along canted part of seat track or along straight seat track) is usefull in some peculiar cases. For instance in this transition zone, a seat can be installed along the line of flight or along the canted seat track.
Define seat track by ‘rail_tag’ where the item reference point is located
The list of available ‘rail_tag’ depends on the aircraft type and floor structure configuration “fsconf”.
Note
On standard B777 the following ‘rail_tag’ are available: ‘LBL108’, ‘LBL74’, ‘LBL33’, ‘LBL11’, ‘RBL11’, ‘RBL33’, ‘RBL74’ and ‘RBL108’
ITEM_ASM-x_loc
type: number | dimensionality: length
Specify the X location of the cabin item (seat or other monument) reference point
Warning
The ‘x_loc’ is defined in the AC coordinate system and it shouldn’t be mixed with aircraft station (see example of Fig. 43 for STA to x_loc conversion)
ITEM_ASM-item_geom::point_id
type: integer
Specify the ID of the item interface point
This ID is a cross reference to a point ID specified in Sheet “item_geom”
The rail_to_item_axis_angle field is used simutaneously with item_axis field.
When item_axis is provided, the placement of the relevant item will be rotated around the item reference point by the angle specified in this field. The angle is provided in degrees.
The following figure shows an example of the same bulkhead with different orientations.
The angle is defined as the the angle between the rail X axis (+X axis in a regular section) and the two points vector described in item_axis. In Fig. 47 the bulkhead located at X=600in and X=700in have the same reference point and same specified angle. The difference is the item_axis specification. For the one located at X=600, the vector goes from poit 1 to point 2, whereas this is reversed for the latter, hence the difference in the placement. A detailed picture is shown in Fig. 46.
Specify the span used for the definition of item repetitions installation
This field should be used in combination with field “repeat_pitch” or “repeat_nb” to specify multiple installation of one cabin item (seat or monument).
(see Fig. 49 for repeat parameters definition and Fig. 50 for example)
Specify the pitch used for the repetition of the item installation
This field “repeat_pitch” can be used with the field “repeat_nb” or “repeat_span” to specify multiple installation of one cabin item (seat or monument).
(see Fig. 49 for repeat parameters definition and Fig. 50 for example)
ITEM_ASM-repeat_nb
minimum: 1 | type: integer,null
Specify the number of repetitions used for the item installation
This field should be used in combination of a specified “pitch” or a “span”
Theoretical explanation of repeat function in FTools
Fig. 49 presents a schematic view of how the FTools repeat function is built with the three parameters (repeat_pitch, repeat_nb and repeat_span).
A combination of two of the three parameters is enough to define an item repetition.
Fig. 49 Illustration of the three repeat parameters.¶
Example of item installation repetition definition
Fig. 50 illustrates three possible ways of entering the installation of four seats S25 on the outboard left side.
Fig. 50 Example of same seat repetition written in three different ways¶
This sheet is used to define the installation load cases corresponding to the IFL specified in Sheet “item_loads”
It creates an association between load case ID and its label. This sheet can be also used to define combined load cases.
Fig. 51 and Fig. 52 illustrates two possible load cases definition.
Fig. 51 Example of load cases definition (Standard seats with different POC)¶
Fig. 52 Example of load cases definition (Business class seats with different positioning)¶
Note
In the example of Fig. 52 combined load cases are entered in two different ways. For load case ID 7 to 12, the FTools linear load case combination is used, whereas for load case ID 15 to 20, 23 to 28, 31 to 36 the interface loads are directly provided in Sheet “item_loads”
LCIDS-id
type: integer
Define the load case ID and should be a unique integer.
This ID is used by the FTools to refere to a single load case. This ID is associated to a set of Interface load defined in Sheet “item_loads”
LCIDS-configuration
type: string
Specify the load case configuration
Standard seat
For standard seats, Interface Loads are provided with all seats in Taxi, Take Off and Landing (TTOL) position but with different Passenger Occupancy Combination (POC).
Those different seating combination can be specified through this configuration field. For instance, a 9g FWD load case can be associated with a “full occupancy” or “partial occupancy” configuration.
In Fig. 51, configuration “POC ID1” corresponds to all seats fully occupied; configuration “POC ID2” corresponds to all seats partially occupied outboad and configuration “POC ID3” corresponds to all seats partially occupied inboard.
Non standard seat
Non standard seat, like Business class seat, can have Interface Load generated at different seat position: “TTOL, Tracking, Relax, Bed, etc…”. Those positions are recorded in this configuration field.
Standard and non standard seat
For a cabin LOPA mixing standard and non standard seat, the configuration field should be used to describe the associated configuration of all seats. For instance it can be “TTOL - Fully occupied”.
LCIDS-label
type: string
Specify the load case label in a text format.
For instance a typical ‘label’ can be ‘9g FWD’.
LCIDS-lcids_acc::id
type: integer,null
Specify the ID of a corresponding acceleration
This field is a cross reference to an ID of an acceleration defined in Sheet “lcids_acc”
When the cabin item (seat or monument) Interface Load (IFL) is generated by a linear combination of two elementary load cases it is possible to use the FTools load case combination facility in order to define this load case. It prevents an additional Interface Load definition in Sheet “item_loads”.
Fig. 54 provides an example of load case linear combination definition. For instance, ID 201 defines a linear combination of load case ID 105 and ID 102 with a combination factor k=0.4=1.6/4 and k=0.2419=1.5/6.2 respectively. In this example, load case acceleration factors are those specified in Fig. 53.
ID 201 = (1.6/4) x 4 ay + (1.5/6.2) x -6.2 az = 1.6 ay -1.5 az = 1.6g RHS + 1.5g DOWN
The sheet is made to specify the loading applied on interface points.
The interface load entered in this sheet are loading applied on the floor structure by the cabin.
IFL are defined in aircraft coordinate system by default. This may be adjusted by using axis field.
Warning
In canted section, interface load provided in seat track coordinate system must either:
be converted to aircraft coordinate system for entry in this sheet.
Specify an ID of a load case defined in Sheet “lcids” and corresponding to the IFL entered in the line
ITEM_LOADS-item_geom::point_id
type: integer | default: _pad_
Specify the ID of the interface points defined in the Sheet “item_geom”
Normally all the interface points of an item should be listed once for a given load case.
If one interface point is omitted no loading will be considered applied on it.
This field is a cross reference to the field ‘point_id’ of the Sheet “item_geom”.
This sheet is used to provide document reference regarding the IFL entered in the Sheet “item_loads”
Reference document with revision should be used to ensure a correct traceability of Interface Load.
The list of document(s) entered in this sheet will be presented in the Structural Substantiation Report (SSR).
Here is an example of IFL reference document definition:
Enter label to make cross link to reference document
The label entered here should be a short keyword to create a cross reference between the document full description and the IFL entered in the Sheet “item_loads”.
This sheet can be used to override default seat load allowable
By default, FTools automatically associate the most relevant seat load allowable to each seat based on seating configuration, seat pitch, tapered section and seat track used by the seat installation.
Thanks to this sheet, FTools user have the possibility to override this load allowable association by a new one.
Fig. 60 illustrates the modification of default standard seat allowable thanks to Sheet “std_alw”.
Fig. 60 Example of standard seat load allowable modification¶
STD_ALW-rowid
type: integer | minimum: 0
Specify the row ID of the seat(s) impacted by the modification of load allowable
Specify the transverse location of the seat(s) impacted by the load allowable modification
By default, all seats in the row specified are impacted by the modification. This is equivalent to write ‘l,c,r’ in this field.
‘l’ stands for ‘left’, ‘c’ for center and ‘r’ for right.
If only the outboard left seat is impacted by the load allowable modification, ‘l’ should be entered in this field.
STD_ALW-std_alwid
type: integer | minimum: 1 | maximum: 16
Define the ID of seat allowable replacing the default allowable provided by FTools.
For Boeing B777 aircraft the list of IDs are presented in the following table.
Fig. 61 Boeing B777 standard seat load allowable ID¶
