Catapult/Arrestor Operations (FSXA)

From FSDeveloper Wiki

The FSX Acceleration pack introduces native functionality to simulate aircraft operations for a large flat-decked aircraft carrier.

The catapult launch system is designed to simulate a modern catapult assisted takeoff.
IRL it consists of a track built into the flight deck, below which is a large piston or shuttle that is attached through the track to the nose gear of the aircraft.

The landing system is designed to simulate systems to aid the recovery of an aircraft.
IRL it consists of a series of cables strung across the landing area which the aircraft hooks on to.

The FSX Acceleration pack includes a preconfigured functioning aircraft carrier model, plus a carrier enabled F/A-18 aircraft.

Includes info missing from the published SDK.

Contents 1 Configuring 1.1 Prerequisite 2 Configuring (FSXA) 2.1 fsx.CFG 3 Configuring (Aircraft) 3.1 Catapult Assist (Aircraft) 3.1.1 aircraft.cfg - launch-bar 3.1.2 Model - launch-bar 3.2 Arrestor Cables (Aircraft) 3.2.1 aircraft.cfg - Tailhook 3.2.2 Model - Tailhook 4 Configuring (Vessel) 4.1 Takeoff Components 4.1.1 Catapult Assist (Vessel) 4.2 Landing Components 4.2.1 Runway (Vessel) 4.2.2 Arrestor Cables (Vessel) 4.2.3 Optical Landing System (OLS) (Vessel) 5 Operating 5.1 Takeoff 5.2 Landing 6 Related 6.1 Internal 6.2 External

[edit] Configuring

To enable the Catapult/Arrestor operations functionality, two seperate key aspects must be configured/functioning -

• Aircraft - The launch-bar, (for the catapult), and tailhook, (for the arrestor-cables), located on the aircraft.
• Vessel - The runway, catapult, and arrestor-cables, for the carrier you'll takeoff from, and recover to.

[edit] Prerequisite

The FSX Acceleration key-mapping must also be functioning correctly.
Please see [Key Mapping (FSXA)]

[edit] Configuring (FSXA)

[edit] fsx.CFG

In the [Realism] section.
Add/edit to enable -

• CatapultForceLimiter=1 - Only fighter type aircraft can be catapulted.
• CatapultForceLimiter=0 - Enables the catapult systems to generate the required force for any type of aircraft.

TODO - Find/add info how FSX discriminates between fighter and non-fighter aircraft.

[edit] Configuring (Aircraft)

[edit] Catapult Assist (Aircraft)

To launch an aircraft, a launch bar is lowered to engage the catapult system.

Add a launch bar to an aircraft, by either -

• defining a [launch_assistance] entry in the aircraft configuration file.
• setting the attachpt_Launch_Bar_Pivot and attachpt_Launch_Bar_Lug attach points in the model,

An entry in the configuration file will override the model's attach points, if they exist.

[edit] aircraft.cfg - launch-bar

Works for any aircraft.

Add a section titled [launch_assistance]
with the following parameters and values -
launch_bar_pivot = Launch bar pivot point, relative to datum reference point.
launch_bar_lug = Launch bar lug point, relative to datum reference point.

Example - Boeing F/A-18

[launch_assistance]
launch_bar_pivot = 5.0, 0.0, -1.0
launch_bar_lug = 5.0, 0.0, -4.5

Marker States - A tool to aid positioning, see download at bottom of page:

Lamont Clarke's wiki - Adapting FSX aircrafts to acceleration carriers

[edit] Model - launch-bar

Requires the model's source code.

TODO - Add/edit/split instructions for implementation.

[edit] Arrestor Cables (Aircraft)

To trap an aircraft, a tailhook is lowered to catch an arrestor cable.

Add a tailhook to an aircraft, by either -

• defining a [tailhook] entry in the aircraft configuration file.
• setting the attachpt_tailhook_pivot and attachpt_tailhook_hook attach points in the model.

An entry in the configuration file will override the attach points, if they exist.

[edit] aircraft.cfg - Tailhook

Works for any aircraft.

Add a section titled [tailhook]
with the following parameters and values -
tailhook_length = Length of tailhook in feet.
tailhook_position = Tailhook pivot point, relative to datum reference point.

Example - Boeing F/A-18

[tailhook]
tailhook_length = 4.5
tailhook_position = -49.0, 0, -2.5

Marker States - A tool to aid positioning, see download at bottom of page:

Lamont Clarke's wiki - Adapting FSX aircrafts to acceleration carriers

[edit] Model - Tailhook

Requires the model's source code.

TODO - Add/edit/split instructions for implementation.

[edit] Configuring (Vessel)

To specify that a ship has one or more catapults, runway, and arrestor cables,
the appropriate Attach Points need to be added to the vessel model.

These features can only be implemented by editing the model's source code.

Important
This article is specifically refering to Attach Point Names, and not refering to the model's Animation Tags.
Unfortunately the Animation Tags label name's spelling and capitalization, plus the index numbering is inconsistent, (e.g. for blast shield, catapults, steam).

Note
The attach points for carrier operations are not included in the list of options in the attach point tool.
These need to be manually entered as an empty attach point.

The actual code used can be checked in Object Properties/User Defined to ensure there have been no syntax errors.
See [1] for further details.

For pre-existing models, you'd have to use addon systems,
e.g.

Barendregt's - FS2004 Carrier Operation Package V2.0

Barendregt's - FSX Carrier Operation Package V3.0.

[edit] Takeoff Components

[edit] Catapult Assist (Vessel)

A maximum of four operational catapults and blast shields is supported.

For each catapult required, add an -

• attachpt_catapult_start_n
• attachpt_catapult_end_n
• attachpt_blast_shield_n

Where n is the index# between 1 and 4 identifying the catapult and matching blast shield.

The start position is the point where the aircraft should connect its launch bar.
Developers have reported - Distance from the model's origin to start position must not exceed 65 metres.

The blast shield point should be the center hinge of the shield.

[edit] Landing Components

[edit] Runway (Vessel)

The area where an aircraft lands.
A carrier can only have one runway.

Add the following -

• attachpt_runway_start
• attachpt_runway_end
• attachpt_runway_edge

The attachpt_runway_edge point defines the half-width of the runway,
and should be to starboard of attachpt_runway_start.

This will activate the 'Meatball' glideslope indicator on the left hand side of the defined area.
It is not required for a working carrier if the US style 'Meatball' is inappropriate.

[edit] Arrestor Cables (Vessel)

A maximum of four operational arrestor cables is supported.

For each arrestor cable required, add a pair of -

• attachpt_cable_n_1
• attachpt_cable_n_2

Where n is the index# between 1 and 4 identifying the arrestor cable.

[edit] Optical Landing System (OLS) (Vessel)

The OLS indicates the glidepath information to pilots in the terminal phase of landing on an aircraft carrier.

The OLS is automatically placed on the left hand side of the area defined as the runway (see above).
It is not possible to configure the OLS for anything other than the default glideslope, or to alter the style and configuration of the lights.

[edit] Operating

TODO - Add/edit/split instructions for testing & operating.

[edit] Takeoff

Use one of the KEY_TOGGLE_LAUNCH_BAR_SWITCH or KEY_SET_LAUNCHBAR_SWITCH key events to drop the launch bar from the nose of the aircraft.

This is an animated feature of the F-18, and the launch bar should be visible.

The aircraft should be moved into position on the catapult, and then one of the KEY_TAKEOFF_ASSIST_ARM_SET or KEY_TAKEOFF_ASSIST_ARM_TOGGLE key events should be used to attach the launch bar to the bogie of the catapult, (not modeled/animated).

• If the aircraft is not in the correct location, the connection will not be made.
• If all goes well, the connection will be made, and the blast shield will be raised.

The KEY_TAKEOFF_ASSIST_FIRE event key is used to fire the catapult. The user cannot control the position of the aircraft until the aircraft clears the deck.

If for any reason the assist arm is unset, again using the KEY_TAKEOFF_ASSIST_ARM_SET or KEY_TAKEOFF_ASSIST_ARM_TOGGLE key events, then the blast shield will also be retracted.

The aircraft can then be moved away from the catapult.

[edit] Landing

Use one of the KEY_SET_TAIL_HOOK_HANDLE or KEY_TOGGLE_TAIL_HOOK_HANDLE key events, or the TAILHOOK POSITION simulation variable, to set the tail hook in position.

Land on the appropriate spot on the carrier.

There are typically four arrestor cables.

• If the aircraft does not land with excessive speed, it will be brought to a halt and pulled back a short distance.
• If it does land with excessive speed the cables will not prevent the aircraft going off the deck.
• Cable breaks are not simulated.

The aircraft can be parked on deck, perhaps using the KEY_TOGGLE_WING_FOLD or KEY_SET_WING_FOLD key events to fold the wings.

[edit] Related

[edit] Internal

[edit] External

Credits -

• Paul Lange's blog - Launch Bars and Carriers (No longer available).
• Lamont Clarke's wiki - Adapting FSX aircrafts to acceleration carriers