Learn how an aircraft launch bar connects the nose gear to a carrier catapult, how the holdback works, and why it is not a tailhook.
An aircraft launch bar is a hinged, load-bearing arm on the nose landing gear of a CATOBAR-capable carrier aircraft. For take-off, deck crew seat it in the catapult shuttle; when fired, the shuttle pulls the bar and accelerates the aircraft. It is separate from both the holdback bar and landing hook.
What does the launch bar connect to?
The launch bar engages the moving catapult shuttle in the flight deck’s catapult track. Its mounting transfers the shuttle’s longitudinal force through the reinforced nose landing gear structure and into the airframe.
The bar does not generate thrust or hold the aircraft stationary. It is the mechanical link through which either a steam catapult or an electromagnetic launch system accelerates the aircraft. Our explanation of the complete carrier catapult mechanism covers the shuttle and launch system in more detail.
How is a launch bar used during a carrier take-off?
The launch bar is lowered and connected under the direction of trained flight-deck personnel, using procedures specific to the aircraft and carrier.
- Align the aircraft: The pilot taxis onto the catapult centreline while deck crew guide the nose landing gear towards the shuttle.
- Lower the launch bar: The aircraft’s launch-bar control places the bar in its extended position so it can enter the shuttle fitting.
- Engage the shuttle: The aircraft moves forward until the launch bar is properly seated. The deck crew visually verify the connection.
- Attach the holdback: A separate holdback assembly connects the aircraft to a deck fitting and prevents it moving while slack is removed from the launch system.
- Tension the catapult: The shuttle takes up the load against the holdback. The catapult setting is selected for aircraft mass, configuration, wind and operating conditions; the launch bar itself does not determine this force.
- Launch the aircraft: After engine, control-surface and configuration checks, the catapult fires. The holdback releases or its calibrated release element separates, and the shuttle pulls the aircraft along the deck.
- Disengage: Near the end of the stroke, the aircraft separates from the decelerating shuttle. The launch bar remains on the aircraft and is returned to its stowed position according to that type’s system and procedure.
Is a launch bar the same as a holdback bar or tailhook?
No. The launch bar, holdback assembly and tailhook perform separate jobs at different stages of carrier operations.
| Component | Location | Purpose |
|---|---|---|
| Launch bar | Nose landing gear | Connects the aircraft to the catapult shuttle for take-off |
| Holdback assembly | Usually between the nose-gear structure and a deck fitting on nose-tow aircraft | Restrains the aircraft while the catapult is tensioned, then releases at launch |
| Tailhook | Rear fuselage | Catches an arresting wire during landing |
| Ground tow bar | Landing-gear towing point | Allows a tractor to move the aircraft; it is not part of the catapult launch |
A launch bar is therefore not lowered for landing. The distinction becomes clearer when comparing it with folding-wing and arresting-hook equipment.
Do all carrier aircraft have launch bars?
Only aircraft designed for a compatible nose-tow catapult system need this type of launch bar. Modern CATOBAR aircraft normally have reinforced nose gear and the required shuttle interface, but ski-jump and vertical-launch aircraft do not use a catapult for their normal take-offs.
Some older catapult aircraft used detachable bridles connected to reinforced points on the airframe instead of a nose-gear launch bar. A tailhook alone also does not make an aircraft catapult-compatible; our overview of aircraft engineered for carrier service explains the other structural and operational requirements.
Why might a launch bar fail to engage?
In real carrier operations, an incorrectly aligned aircraft, incomplete shuttle engagement, an unsafe indication or damaged equipment stops the launch sequence. The deck crew disconnect and reposition or inspect the aircraft rather than attempting a launch with a doubtful connection.
In a flight simulator, a visible lowered launch bar does not necessarily mean the catapult is attached. The aircraft must support carrier launch functions, the carrier must have a working catapult zone, and the nose gear must be positioned correctly. FSX users can follow our FSX Acceleration launch-bar and catapult procedure when the model supports it.