Speaking at Helitech International 2016, 10 years after his first airshow, Flying Bulls helicopter aerobatic pilot Rainer Wilke gave his perspective on how he and his team have kept an impeccable safety record.
“We are always looked at with eagle eyes; if something goes wrong, many fingers will be pointed at us,” he noted. However, no flight accident or incident has been reported — so maybe helicopter aerobatics and safety are not a contradiction.
For the Salzburg, Austria-based Flying Bulls team, the helicopter project started in 2005. From the beginning, Wilke said it was clear the aircraft had to be a Bo.105. “The Bo.105’s rotor head is oversized — the H145 uses the same, despite its much higher weight,” Wilke said.
As an early rigid (hingeless) rotor design, it has a huge safety margin built in, he explained. For example, he said it is impossible for the rotor to touch the tail boom.
In fact, MBB (which was later merged into Eurocopter, now Airbus Helicopters) engineers had aerobatics in mind when they designed the Bo.105 in the ’70s. As a result, it can perform the same maneuvers as a fixed-wing aircraft — except longer flight upside down. Rolls, loops and backflips are feasible. “Eurocopter supported us from the beginning,” Wilke added.
Limitations are -0.5g and 3.1g in negative and positive accelerations, respectively. Wilke emphasized aerobatics is not necessarily the most demanding flight phase for the airframe. “Autorotation landing are much more demanding for [the] fuselage,” Wilke said.
Another key number is the low time spent in actual aerobatics — between five and 7.5 hours per year.
Nevertheless, frequent airframe checks are required. This translates into a calculated operating cost of €35,000 (approx. US$39,000) per flight hour. Maintenance technicians focus on tail and intermediate gearboxes. Another emphasis is on areas where cracks can develop in normal flight. “We pay extra attention to foreign objects in the cabin,” Wilke added.
The Flying Bulls have two aerobatic pilots. Another two will be trained next year. They will start with fixed-wing aerobatics to become familiar with unusual spatial orientation. Each year, before the season starts, the team rents an airport in Slovenia to rehearse.
Creating a routine requires special attention, as some maneuvers might not form a safe sequence when put together. The usual minimum height is 300 feet.
The Flying Bulls were the first to perform helicopter aerobatics commercially. However, Wilke already had a long experience as a military aerobatic helicopter pilot.
Now, as a civil pilot, the situation is more complex. Depending on the country, a display authorization or an aerobatic license is needed. The ICAS (international council of air show) card is not recognized in Europe.
$39,000 Per flight hour?? Maybe someone misplaced a digit?
39K/hr is probably correct, as component times are lowered, inspection scheduled frequency is increased and special inspections are added