Thermawing

Alternator failure may be a risk, but falling out of the sky because of nonexistent deicing may be a bigger risk. Depends on individual risk assessment.
So what’s the actual status of thermawing – not available, avaible only for Cessna, or available and STCable for other aircraft ?

Cobalt wrote:

I also seem to remember that the voltage used for the Thermawing system is higher – 80 Volt or thereabouts – probably to keep the currents lower than if using 28V.

Correct.

Correct, but this makes no difference to the Thermawing system.

The control box is powered from the avionics bus (which is powered in turn from both main buses via diodes, no cross-tie required), but the power for the Thermawing system it controls is taken from a dedicated third alternator.

I also seem to remember that the voltage used for the Thermawing system is higher – 80 Volt or thereabouts – probably to keep the currents lower than if using 28V.

The Columbia/Corvalis has a cross-tie so you need both alternators to fail to be out of luck.

TKS will always run from the aircraft battery, if the alternator fails.

Thermawing will stop working the instant that its dedicated alternator fails.

Correct. ALTERNATE is a direct link between MAIN PUMP 2 and the RH BUS.

Where did you get that ? I have NEVER seen a dedicated back-up battery for the TKS system.

DA42 but you’re right it’s not dedicated battery. Switching ALTERNATE at TKS panel connects pump to RH bus – I believe in case of alternator failure it will be supplied from battery. Correct me if I’m wrong.

Cobalt wrote:

So between a reputational problem with its launch aircraft, conservative pilots and Cessna, it didn’t make it,

Cobalt nailed it.

Emir wrote:

Unlike that TKS has backup battery for the pumps even in MEP aircrafts.

Where did you get that ? I have NEVER seen a dedicated back-up battery for the TKS system.

From what I can recollect when the Columbias were first to be equipped with Thermawing, and then later went to TKS:

• when the aircraft was sold, the Thermawing wasn’t ready / available, so Columbia agreed to fit it later (it was included in the price of that aircraft)
• later, a Thermawing equipped Columbia caught fire. While this was ultimately traced back to a botched installation (the lighting protection mesh wasn’t cut back sufficiently, leading to a short circuit), this incident damaged the reputation and held things back further while this was being investigated
• Columbia Aircraft then offered TKS as an alternative, at the same price, and many owners went for that
• when Cessna took them over, they dropped Thermawing, but honoured the Columbia TKS installation

So between a reputational problem with its launch aircraft, conservative pilots and Cessna, it didn’t make it,