Anyone that has tailhook and time in an OV-10 by their name has my respect (and anyone with F4 time by their name has my undying envy, too...).
In December we had a thread on a similiar topic, regarding resetting circuit breakers. I used a couple of examples there that I was recently searching for...I found the thread, and rather than cut and paste, here's the link (I think the examples are relevant):
http://forums.flightinfo.com/showthread.php?t=90405
Way2broke, you probably won't find the cause for that fuse being opened. Fuses commonly get zapped with close to their rated amperage, and don't open...but can be weakened (just as the filament in your basic lightbulb eventually burns out, but in a slightly different way). Sometimes they just go. Especially if it's one of the automotive filament type inline fuses. What you may have is an indication of another problem developing, however.
The battery master relay is a simple device; it's got four terminals; one in and one out that's big...that's the battery power going to the aircraft, and a little terminal in and out. One of those little terminals goes to the battery master relay, and the other goes through the battery master switch. A switch problem, or a problem at the battery master relay could have caused a spike that popped the fuse. Sometimes a little corrosion on the relay itself that sets a path to ground or shorts the relay just a little can indicate an impending failure in the relay, or even the master switch. Other possibilities exist too, such as shorts in the wire (including internal shorts). A little time spend with a multimeter can wring that out, if the problems aren't so intermittant that they hide themselves.
Carrying spare fuses is a good idea.
Don't feel bad about not knowing about the fuse. I had something similiar happen to me in a medium turboprop (with a similiar setup, believe it or not). I had nearly a thousand hours in type when it happened, and when I called it in to the mx department, they knew exactly what it was. I felt kinda dumb for asking...but I didn't know. Last week I was introduced to three circuit breakers under my seat that I didn't know existed...and I've been in this airplane for over a thousand hours too. Right under the seat. If it was a dog it would have wet on my leg. Again.
My all time bonehead incident involved an engine I'd hung on a Sabreliner, after replacing a number of turbine inlet guide vanes. Once it was on, I tried spooling it up on the battery, and found I could only get a few percent. It made no sense. Nothing about trying to start it made any sense. I spent hours and hours troubleshooting it, alternating between my own efforts, and those of two well known hands with that type, long distance by phone, for the better part of the day. The Chief Pilot got involved, and tried runs. He was at a loss. Late in the day as the sun was setting, and had long since set on the gentlemen on the far coast who was patiently helping, came his question.
"I don't want to insult you, so don't take this the wrong way, but we've tried everything I can possibly imagine. Is there any chance, and again, don't take this the wrong way, that the T-handle is pulled?"
That's roughly akin to asking the patient if he remembered to take the spoon out of his coffee cup to explain his sore eye. Not only had I been in that cockpit several dozen times during the day, but so had the chief pilot. Of course we'd checked it. It's on the checklist...that's why they call it a checklist, isn't it?
"Do me a favor. Just humor me. Just go up in that cockpit and give it rap, just make sure it's in for me. Will you do that?"
"Yes, sir." So I did. I checked, and...DOH!!!!!!!!!!!!!!!
(Starters don't start and electricity doesn't flow and things don't work so well when the device is pulled that opens the electrical circuits, arms the fire bottle, cuts off the hydraulic, bleed air, and fuel...)
Live and learn. She started right up after that. I thanked him and never had the guts to call him again.
In December we had a thread on a similiar topic, regarding resetting circuit breakers. I used a couple of examples there that I was recently searching for...I found the thread, and rather than cut and paste, here's the link (I think the examples are relevant):
http://forums.flightinfo.com/showthread.php?t=90405
Way2broke, you probably won't find the cause for that fuse being opened. Fuses commonly get zapped with close to their rated amperage, and don't open...but can be weakened (just as the filament in your basic lightbulb eventually burns out, but in a slightly different way). Sometimes they just go. Especially if it's one of the automotive filament type inline fuses. What you may have is an indication of another problem developing, however.
The battery master relay is a simple device; it's got four terminals; one in and one out that's big...that's the battery power going to the aircraft, and a little terminal in and out. One of those little terminals goes to the battery master relay, and the other goes through the battery master switch. A switch problem, or a problem at the battery master relay could have caused a spike that popped the fuse. Sometimes a little corrosion on the relay itself that sets a path to ground or shorts the relay just a little can indicate an impending failure in the relay, or even the master switch. Other possibilities exist too, such as shorts in the wire (including internal shorts). A little time spend with a multimeter can wring that out, if the problems aren't so intermittant that they hide themselves.
Carrying spare fuses is a good idea.
Don't feel bad about not knowing about the fuse. I had something similiar happen to me in a medium turboprop (with a similiar setup, believe it or not). I had nearly a thousand hours in type when it happened, and when I called it in to the mx department, they knew exactly what it was. I felt kinda dumb for asking...but I didn't know. Last week I was introduced to three circuit breakers under my seat that I didn't know existed...and I've been in this airplane for over a thousand hours too. Right under the seat. If it was a dog it would have wet on my leg. Again.
My all time bonehead incident involved an engine I'd hung on a Sabreliner, after replacing a number of turbine inlet guide vanes. Once it was on, I tried spooling it up on the battery, and found I could only get a few percent. It made no sense. Nothing about trying to start it made any sense. I spent hours and hours troubleshooting it, alternating between my own efforts, and those of two well known hands with that type, long distance by phone, for the better part of the day. The Chief Pilot got involved, and tried runs. He was at a loss. Late in the day as the sun was setting, and had long since set on the gentlemen on the far coast who was patiently helping, came his question.
"I don't want to insult you, so don't take this the wrong way, but we've tried everything I can possibly imagine. Is there any chance, and again, don't take this the wrong way, that the T-handle is pulled?"
That's roughly akin to asking the patient if he remembered to take the spoon out of his coffee cup to explain his sore eye. Not only had I been in that cockpit several dozen times during the day, but so had the chief pilot. Of course we'd checked it. It's on the checklist...that's why they call it a checklist, isn't it?
"Do me a favor. Just humor me. Just go up in that cockpit and give it rap, just make sure it's in for me. Will you do that?"
"Yes, sir." So I did. I checked, and...DOH!!!!!!!!!!!!!!!
(Starters don't start and electricity doesn't flow and things don't work so well when the device is pulled that opens the electrical circuits, arms the fire bottle, cuts off the hydraulic, bleed air, and fuel...)
Live and learn. She started right up after that. I thanked him and never had the guts to call him again.
