Maintaining the aircraft
From the bolts to the rotorblades, every single component on each of the charity's three aircraft is closely monitored and must be repaired or replaced when it comes to the end of its allotted lifespan.
The rigorous maintenance schedule is one of the most significant expenditures of the charity and one which people often don't consider. In this sense, the aircraft is not seen as one object but as a sophisticated collection of inter-dependent parts.
From the moment it is fitted, each component has a set lifespan based on how long it can be safely operated. This lifespan is set by the manufacturer and is measured in calendar age, its number of flying hours and the number of cycles it has completed. These thresholds can be triggered at different times, depending on how busy the aircraft has been or the type and location of incidents it has attended. A component must be repaired or replaced when the first threshold is reached, regardless of the status of the other measurements. Each part has its own certification, right down to the bolts that keep the rotors attached.
Often, the cycle is the first of the measurements triggered. A cycle begins when the aircraft takes off and completes when it lands.
Our Pride of Cumbria aircraft faces more maintenance bills than the other two aircraft because of the nature of its work. Mountain rescue missions, fairly common in the Lake District, often involve multiple cycles. For instance:
Cycle one: The aircraft takes off from Langwathby and lands on scene. The patient is found to have fallen into a ravine and is inaccessible by the aircrew trauma team. A Mountain Rescue Team has been called out but is half a mile down the fell.
Cycle two: The aircraft flies the half mile to pick up members of the Mountain Rescue Team. It then ferries them back to the site of the incident. The patient is recovered and treated on scene.
Cycle three: The patient is flown to hospital for further treatment.
Cycle four: After handing over the patient to awaiting medical staff at the hospital, the aircraft flies back to base.
An existing component may still be in full working order at the time it must be replaced, but the whole process is absolutely necessary if the charity is to adhere to the rigorous safety standards set by the manufacturers and overseen by the Civil Aviation Authority. These regulations were established to protect the people who fly on the aircraft: the patient and the crew looking after them.
The maintenance schedule outlines each of the the components and how long they have before they are due to be replaced. This is devised and managed by aviation services experts Multiflight, based at Leeds Bradford International Airport, which also provides GNAAS' pilots as part of a service agreement.