Baron BE55 Hobbs Power?

Anybody's guess. If you have access to the maintenance manual, AND the hobbs in there is still the factory OEM install, you MIGHT be able to figure it out. I say MIGHT because in the case of our Navajo, it just shows a pressure switch in the schematic. No mention of what pressure it is (oil? if so, which motor?). Unfortunately, many older aircraft have had the Hobbs circuit modified or never had a hobbs in the first place, so the install is aftermarket and often the only way to figure out what powers it is to trace wires. Different variations I've seen: Battery master, Avionics bus, oil pressure (straight from the battery), oil pressure (off the main bus), pitot pressure, gear up and in the wells...
 
Roger said:
Anybody's guess. If you have access to the maintenance manual, AND the hobbs in there is still the factory OEM install, you MIGHT be able to figure it out. I say MIGHT because in the case of our Navajo, it just shows a pressure switch in the schematic. No mention of what pressure it is (oil? if so, which motor?). Unfortunately, many older aircraft have had the Hobbs circuit modified or never had a hobbs in the first place, so the install is aftermarket and often the only way to figure out what powers it is to trace wires. Different variations I've seen: Battery master, Avionics bus, oil pressure (straight from the battery), oil pressure (off the main bus), pitot pressure, gear up and in the wells...
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That is kind of what I was guessing, I will keep snooping around though. Thanks!
 
On the BE58's, and in theory, the BE55's should be the same, it is connected to the gear. I have flown three BE58's. On two of them it is connected to the gear up switch. Meaning the gear only runs when the gear is retracted. This was great for training, since we would only put about .6 on the airplane for an hours worth of approaches. The third BE58 that I flew had the gear connected to the squat switch (Weight on Wheels), so that the Hobbs started the second you left the ground.
 
skydisaster said:
On the BE58's, and in theory, the BE55's should be the same, it is connected to the gear. I have flown three BE58's. On two of them it is connected to the gear up switch. Meaning the gear only runs when the gear is retracted. This was great for training, since we would only put about .6 on the airplane for an hours worth of approaches. The third BE58 that I flew had the gear connected to the squat switch (Weight on Wheels), so that the Hobbs started the second you left the ground.
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I am kind of hoping that it will be one of those two actually. I am going to get my MEI in one next month and was just wondering if I was going to get to pay for $100 worth of taxi-time each flight or not.
 
In our BE95-55s, it is the Tach meter that is hooked up to the gear squat switch. This is because they don't want to use taxi time in maintenance time lines (100 hours, oil changes, overhaul, etc.) As far as the Hobbs meter goes, I have always wondered this...I know it starts the second we turn on the right engine and runs until shutdown of the right engine, so im curious as to what runs it. I think a ligitamate guess would be oil pressure off the right engine.
 
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