Even if you could start the engine without the elec. fuel pump, I wouldn’t recommend flying it.
You have no backup if the mechanical pump fails and gravity fuel feed is not an option in the low wing airplane.
I am not flying until the CB is changed, but the problem was discovered at LFAT so had it failed totally it may have been a whole load of fun 
Luckily I have many spare parts at home
The CB managed roughly 1000 operations over 22 years, so clearly using a CB as a switch is a stupid idea because no switch should fail that fast. Well, it is switching an inductive load, so the problem with burning contacts is the same as the Honeywell autopilot cockup with their red button disconnect switch which disintegrates fast also, due to the autopilot servo clutches being inductive. Both these applications are defective designs; a much more robust switch should be used.
Every TB20 owner should buy this item and carry it. I need to replace the one I am using too… EuroGA bulk buy?
I don’t know if Diruptor sell these parts; most Socata suppliers in France won’t. The Socata P/N is N7173141100. Curiously the paperwork I have says Qty 2! Maybe I bought an extra one for somebody else.
Diruptor 7121fs0568/5 does show up in a few places in the US, $150, and with crazy shipping costs… I have messaged the company in France.
supik wrote:
I wouldn’t recommend flying it.
I was thinking the same, but then you can at least decide about options. If you’re in the middle of nowhere this could buy you a solution to get somewhere to have it fixed.
What would be the operation to get the engine starting ASAP? I assume throttle and mixture full forward.
On the Socata owners website, two members claim the IO540 can be started with throttle pumping (while turning the starter, I presume).
The case I know from my maingenance shop did not succeed, though (and it would have been worth it at a deserted airfield far away)
@Peter : good ideas, I would take one, too ;-)
Add me to the bulk buy if you decide to do that!
Airborne_Again wrote:
IME that how all (Lycoming) fuel injected engines are started.
Yes, also the Senecas I used to fly had this procedure.
ch.ess wrote:
can be started with throttle pumping
I did not think that pumping the throttle would actually pump AVGAS in an injected engine. Someone with insight on that? Because then one could “prime” the engine actually by pumping the throttle before cranking.
Correct. No pumping action in the fuel servo.
But surely not in a carb either.
Peter wrote:
But surely not in a carb either.
Depends if there is an acceleration pump or not. I’ve flown PA28s both with and without an acceleration pump. If the aircraft has one, you can prime it by pumping the throttle, but it is not a recommended procedure.
Airborne_Again wrote:
but it is not a recommended procedure
As is flying with an u/s aux fuel pump. We’re not talking about normal procedures here, more like get-out-of-some-weird-place procedure 
