Months of work on an ex-military BO105

In this video Mattylp attempts the first engine start of his ex-German military BO105 helicopter, which has been sitting for more than a decade. He and his dad have spent months replacing parts, fixing problems and putting the helicopter back together. Inside the cockpit he has civilianised the aircraft and reduced seven gauges to two. Because the helicopter is in the experimental exhibition category, he can fit a modern lithium iron phosphate battery that is not yet type certificated for standard category aircraft. Older turbine helicopters like this one normally use nickel cadmium batteries. The new battery weighs 12.4 pounds against 53 pounds for the original, while giving more power to the starter, so the helicopter loses around 40 pounds. He also wires in a charger so a phone or tablet can be charged in flight, something these old helicopters did not have.

Ground handling wheels and four rotor blades

The next job is to move the helicopter on new, bright orange ground handling wheels, which are large because the BO105 is so heavy. Until now it had only come off the trailer and the lift. Then the four main rotor blades go on one by one, turning the rotor head each time to fit the next blade. He says he has only ever fitted blades to a two-bladed helicopter before, and that a mistake could mean $25,000 to $100,000 worth of damaged blades. The first blades are harder than expected, but by the fourth they have the process down, with help from his dad and Matt at the airport.

First start in ten years and chasing leaks

For the test runs many panels stay off so his dad can watch the engines from outside, while everything else is closed and nothing is loose. The helicopter is fuelled for the first time in about ten years, and the oil is checked in both tanks, the gearbox and the tail rotor. He starts engine number two first and says it is the most nervous he has ever been during an engine start, even though he has started plenty of turbine helicopters. Both engines run, but there are a couple of small leaks and smoke from the right engine. On the Sunday they return to bring the engines from idle up to 100 percent and check temperatures and pressures, which he calls mandatory for a helicopter that has not flown in a long time. They trace the leak to an oil line that feeds a bearing near the hot turbine wheel and was cross-threaded. After fixing the threads they start the engines a second time, and he calls it a huge success, with a few leaks expected on a helicopter that has been sitting this long. He also praises the German mechanics who maintained the aircraft to a very high standard.