Crane (DEREK) Construction

The Crane is used for the removal and refitting of the Gearbox. It is relatively light weight and portable so that it can be transported in the backseats of the helicopter. To assemble the crane no tools are needed to save on weight, instead everything is pinned and screwed in place. The task takes about half an hour to construct and inspect with an experienced five-man team of engineers.

1. With two engineers standing on the helicopter lift the first section of the crane shown below using two people to lift.

2. Maneuver the base of this section onto the thread shown below.

3. Tighten this by hand until the section is secure but still maneuverable.

4. Spread the legs of this section out to the two locking points which are shown below.

5. Align the cranes legs over these locking points and then force the pin through the hole in the locking point and the legs as shown below.

When pushing the pin through the engineer should feel a click and the pin should be protruding by this much (shown below)

6. Inform team working on tail rotor that the crane is being installed and to under no circumstances move the tail rotor as it is directly attached to the gearbox.

7. Now securely tighten the first part of the crane so that the screw is tight thus preventing movement.

8. Using two engineers lift the second section of the crane up to the two engineers on the helicopter. At this point it is vital to have a supervisor looking out for any potential hazards.

9. Move the second section of the crane into position above the first section of the crane and slowly lower it into place.

10. Whilst one engineer holds the second section of the crane on the first the second engineer places the locking pin through the two components (s/he should also feel a clicking sensation once the pin is secure).

11. Using the Clip on the pulley system lock the pulley onto the arm of the crane (this is done before the next stage as it is easier to access when the crane is in this state – also prevents pulley from knocking the side of the aircraft and potentially causing damage).

Once attached it should look like this.

12. Whilst one engineer pulls on the arm of the crane the second engineer will align the plates and force another pin through the sections to lock them in place.

Note the pin is located through the top hole, the second hole at the bottom of the plate is used for the removal of the engine as the crane is designed to remove both the engine and the gearbox.

13. Fit the gearbox lifting plate to the bottom of the crane (notice how the securing point is aligned away from the center – this is to cancel out the shape of the gearbox which skews the center of gravity).

14. This plate is then attached to the top of the gearbox by the three holes in the gearbox lifting plate. The finished crane should look as below.

15. The last process of constructing the crane is to inspect it once the assembly process is finished to check it is safe for operation. Check all the pins are securely locked in place and that no damage has been caused to the crane during assembly.

Crane Removal

The removal of the crane is the reverse of the construction. It is important to apply the same safety precautions as well as take additional care not to be hasty on removal.

Crane Health & Safety

The health and safety for constructing using and removing the crane come under the general COSHH, PPE and Engineering Management section. However, the construction process of the cane involves working at height necessary safety precautions must be taken.

Whilst working at heights it is important that the crane is sturdy and secure and can take the load/weight of the gearbox required to be removed. This will ensure the equipment for working at height does not collapse and cause any injury to anyone or further damage to the aircraft. To prevent this possibility, the cranes designs make sure that the staging is made to fit to the shape of the helicopter thus increasing the structures sturdiness. An example if this design is the image below which shows a secure connection between the crane and the helicopter which allows movement but prohibits the crane from falling off the aircraft.

Alike when working safely a height, it is important to wear Personal Protective Equipment and be trained to carry out lifting operations; this is required under the Lifting Operations and Lifting Equipment Regulations. Hardhats are usually mandatory to wear in case the lifted object falls and to protect against head knocks. This also gets the job done safely and efficiently with a reduced risk of accidents as the trained personnel will know what they are doing. As well as this, it is advised to have easy sight and access from all participants of the work and good verbal and visual communication (such as practiced hand signals etc.) to aid this and reduce risks of accidents and damage further. On top of this during lifting of the crane there must be a supervisor, someone who is not involved in any task but watches from a distance to see the whole process and to pick up on potential dangers. Lifting equipment and cranes must also be serviceable (fit to use) and be able to take the load of aircraft components/sections. Additionally, the equipment should be checked and approved by health and safety authorities that it is the right equipment for the job. There should also be sufficient space for the equipment to move freely, with clear ground space to avoid any ‘near misses’ to crashing into other aircraft and objects. Strewn objects and tools can also create a tripping hazard and risk of accident in regards to placing the lifted object down and in the case of an accident/dropping the component/engine/section of aircraft.