All revved up with nowhere to go – firing up for an engine run.

Published on 22nd May 2020 at 14:24

It’s a good day at the Qantas Jet Base when it’s time to switch on a Boeing 747 and take the engines for a spin.

Qantas and Jetstar have 220 aircraft grounded at various airports around Australia and overseas due to the drastic reduction in domestic and international flying due to the COVID-19 pandemic.

Even when grounded, there’s a lot of work that needs to done to keep our aircraft ready for when flying resumes.

The aircraft have a number of storage safe-keeping requirements such as cockpit window shades to protect the equipment from sun, covers over the flight instrument sensors on the fuselage and regular wheel rotations to avoid flat spots on the tyres.

Then there’s what we need to do to keep the engines primed for take-off.

Qantas’ Head of Line Maintenance John Walker says every aircraft needs to have an “engine wakeup” and for our Boeing 747s it’s required every seven days.

“Because the majority of our fleet is grounded, it’s a bit like having a classic car parked in the garage, one that you’re only allowed to fire up once a week,” Walker says.

“Doing an engine run is definitely the highlight of the week for our engineers who genuinely care for each tail and love seeing and hearing the familiar roar of the engines as they come to life, not to mention catch the unmistakable waft of jet fuel in the air. Anyone in aviation will tell you it gets in your blood.”

Engineers will jump onboard and head to the cockpit. They’ll then run some safety checks, turn on the aircraft batteries before the Auxiliary Power Unit (APU) is switched on.

A tug is hooked up to the aircraft, which is then towed to the engine run bays on the Jet Base.

This is a special circular area surrounded by a blast fence which is placed behind the engines. The fence is curve shaped and deflects the hot (and very powerful) air up into the atmosphere. It also helps absorb the noise.

A team of engineers stand at a safe distance in front of the aircraft engines to visibly monitor them as the flight deck engineer turns them on one at a time and runs them simultaneously for 15 minutes to remove moisture from the engines and pneumatic systems – in effect “clearing out the cobwebs”.

While the engines have their own built in fire extinguishers, the engineers have a portable ground extinguisher on hand as an extra precaution.

Each of the jumbo engines consumes up to 600 kilos of fuel per hour at idle and at full take off power (which is not used during the engine run for obvious reasons!) generates up to 60,000 pounds of thrust.  A380 engines have a little more oomph with a maximum take-off thrust of 72,000 pounds per engine.