Human Factors in Aviation
AvParts supply parts to airline maintenance departments. They run a fleet of vehicles which their staff use to deliver parts. The vehicle maintenance manager has raised concerns that the delivery staff have not been completing the weekly servicing that they are required to do on their vehicles. You have been asked to carry out a task analysis of the weekly servicing task so that a checklist can be produced, and training can be designed.
You have interviewed one of the mechanics and found out the following information about the task:
- The task involves a set of engine checks which include checking the oil and screenwash levels and topping them up if required and checking the tire pressures and inflating them to the required pressure as necessary.
- Often tasks get omitted if people have not collected all the required materials before doing the checks (oil and screen wash). These are held in the garage stores.
- Rags, a tire pressure gauge and the tire pump are kept in the vehicle.
- To carry out the engine checks the bonnet must be opened first and closed afterwards. The screen wash check is simple visual check of the level in the reservoirs. If the screenwash is not at maximum is must be refilled. To do this, the screenwash filler cap is removed. Screenwash is then added whilst monitoring the screenwash level. The screenwash filler cap is then replaced. The oil level check requires the removal of and cleaning of the dipstick. The dipstick is then replaced and removed again and the level checked. After replacing the dipstick, the oil level is topped up if the oil level is too low (below halfway between the minimum and maximum level markings on the dipstick. The oil filler cap is first removed. The amount of oil required is estimated, based on the level of the oil on the dipstick. The required amount of oil added and then the filler cap is replaced.
- Each of the four vehicle tyres must be checked. This involves removing the valve cap, checking the pressure with the tire pressure gauge, and inflating the tyre if it is below the required pressure. The required pressure is shown on a label on the edge of the driver’s door. The tire is inflated using a pump as shown in Figure 1. The pump is foot operated and has a pressure gauge so that he tire pressure can be monitored as it is inflated. Finally, the valve cap should be re-fitted.
Figure 1: Foot operated tire pump with pressure gauge