Alexis wrote:
They can fly whatever they feel like.
They may but they don’t. Drones are not cruise missiles who need a TBO of 2 hours whereafter the whole vehicle goes up in a ball of flames. They want to get their drones back in one piece. One of them costs more than a new SR22… some cost even more than 10 SR22…
They still decide themselves and they don’t have to go through any certification process. That’s all I said. I did not say that they take these decisions easy, but it’s a very different thing to get FAA certification for GA or commercvial aircraft.
Alexis wrote:
it’s a very different thing to get FAA certification for GA or commercvial aircraft.
True and you may recall that I have said that the certification hurdles today are the reason we still live in the 1940ties engine wise.
There is no technical reason for it, it is all protectionism and CYA combined with anti GA sentiments in large parts of that community.
The US Army has a long history of UAV engine problems going back to the Hunter with its twin Guzzi engines. Things have doubtless improved over the years, but Army UAV utilization and the associated reliability is not equivalent to FAA certification.
Silvaire wrote:
The issue there is that Continental does not have rights to the Thielert UAV business, they bought only rights to the commercial business and are ineligible to sell to the UAV business as a result of Chinese ownership. The engines now being supplied for US military UAVs are built by others.
I have it from a good source that the Thielert UAV business is very much alive but it runs through different channels and that Frank Thielert himself is very active and successful in it.
Silvaire wrote:
The US Army has a long history of UAV engine problems going back to the Hunter with its twin Guzzi engines
Yes, one can never know whether the US Army killed the Taliban with a targeted drone stroke or the Moto Guzzi engine failed and the drone fell on his head 
Yes, the Army is receiving Thielert engines some years after the UAV manufacturer funded the Lycoming demo as a risk mitigation, and some years after their pre-existing supply of Thielert engines went away.
Am not sure if I am right as memory is fade. Long time ago I read about a drone operated by the Israeli Air Force that is equipped with a Lycoming diesel, that was a long rang drone. I do remember that at the time I took it as a miss print as I have never heard about such an engine.
With regards to TBO. Lycoming also makes this 4 HP, 2 stroke multifuel engine (works on Diesel/jet as well as gasoline) for a small drone. It has a TBO of 400 H, which is rather amazing for such a small, but rather complex engine. Obviously drones also require a high TBO, and from the video of the EL-005, it’s more important than for a manned aircraft, at least for small drones.
