ctfarmer

I had a similar intermittent problem. Dynon are very good with their service which i could not fault. You will almost certainly lose all the settings in the unit which is a bit of a pain to reset to the same as you had.

Thanks Corey Replaced regulator and good to go. Apparently they mostly fail producing no output rather than too much.

Hi to all. I have been a long time away but great to be back with a passion. I haven't been able to find much info on this problem. Flying today i noticed voltage climbing as high as 18V and seemed to more or less climb lineraly from ~12.5V to ~18 depending on engine revs. I connected a meter across the battery and verified the Dynon values. Removing the plug from the regulator and with batt master and gen push button switches on, both B and G terminals had full battery voltage of 12.7V on them. Turning off the battery master and gen switches, voltage initially read 12.7V but gradually reduced from 12.7 to zero presumably as the capacitor discharged. All good to my mind. Ground between body of regulator and battery negative was fine. Any thoughs? Regulator replacement time?

SL-40 failed internally with over voltage to part of the circuit. Not reparable. Installed a new Icom A220 radio. Looks to be, on the surface, far better made and engineered. However, for the entire duration of my first flight, i had what appeared to be a squelch problem - could not be set to overcome noise. Turned out to be a 12V to USB socket adapter i had running my Ipad plugged in in close proximity to the radio. Easy fix once i found the cause and it is a much nicer unit to operate. As well, looking at its design and manufacture, the cast aluminium chassis for example and general feel of knobs, i have far greater expectation it will be more robust electronically.

Interesting. So if you start off with more in the right tank resulting from it sitting low on the RHS and proceed with what you think is a coordinated flight, going by your ball, you are potentially pushing even more fuel to the right tank. And from memory, it was your LH tank that drained first prior to your forced landing. Very interesting. Based on that, i am going to check my ball accuracy as per Tom's method.

Another point Roger has made, so often, over time. "Fuel goes in the direction of the ball" That needs to be understood from a base perspective. Why does the ball move at all? Because you are uncoordinated - you are either slipping or skidding. The resultant gravity and g-forces on the aircraft are not acting through the center of gravity. Which is also to say, the resultant lift forces are not in line with the resultant of gravity and g forces. The ball is simply a pendulum in your aircraft. So if the ball (assuming it is accurate) is centered, in a CT with symmetrical twin tanks, your fuel balance in each tank will automatically trend towards equalization. Therefore, any existing fuel unbalance in tanks will, in that condition, level themselves in time from the hydro-static pressure differences in the tank. Same as sitting on a flat and level surface. Fuel is the same medium, in a sense, as the ball. Same forces on the pendulum. So, fundamentally, if the ball moves one way, similarly will the fuel. The magnitude of the force pushing the ball is also relevant. If the ball is way off center, the same greater forces are applied to the fuel so it will transfer faster. If you find the need to transfer fuel, do as Roger's says but understand why and and it will be an automatic deduction for eternity.

I think this point needs to be reiterated over and over. The fuel pickup and the fuel sight tubes are both located on the inside of each tank. There is an important concept to understand here. If you have fuel showing in any one or both sight tubes, unless you are flying inverted, you must have fuel to the engine. If you have fuel in one sight tube, you can be sure there is fuel to the engine. This however is not a good condition to find yourself as, any increase in your un-coordinated state, can, very quickly, un-port or uncover the fuel pickup in the tank that was showing fuel leading, possibly quite quickly, to fuel starvation. So the condition of fuel starvation in this manner is as follows - you are flying for a period uncoordinated; all fuel in one tank transfers to the other; you continue to fly uncoordinated; all fuel remaining in the other tank, having an outward force component from uncoordinated flight, pushes outward until there is no fuel covering the fuel port. This condition also pushes fuel away from the sight tube, so, in this steady state condition, both tanks will show no fuel in either sight tube. There is fuel in one tank but you cant see it. Summarizing this condition - # you have no fuel in one tank (and obviously no fuel in that sight tube) # you have fuel in the other but it is moved outward uncovering the fuel delivery port (and you have no fuel in this sight tube either as it is moved to the outside of the tank). Under such steady state conditions, if only for a very short period, you will quickly use up fuel in the delivery lines and float bowl and fuel starvation is likely. The more fuel in the tank, the more uncoordinated you can be without starvation occurring in this manner. Bottom line - fly coordinated and the problem is no more. Fly with more fuel and the likelihood of fuel starvation resulting from un-coordinated flight lessens.

Grounds were all fine. Was able to borrow the same radio from another aircraft. No problem with it in my cradle. Opened mine and it smelled slightly of burnt electronics. One cap is clearly cooked. Very odd.

I have a Garmin SL40 and has just experienced the following problem. During a flight, the Tx stopped working but the panel still displayed the dual frequencies. Prior to this issue the unit was working normally. I terminated the flight and started to troubleshoot on the ground. The following symptoms are evident. · Turn the power on using the circuit breaker or avionics switch and the dual frequencies display for about 1-3 seconds then fade or flash quickly away to nothing. · During the 3 seconds, the Tx appears to work until the unit goes off. · Once off as above, the unit has no working functions. · With power on the unit, using the units on/off control knob and nothing shows - the unit doesn’t turn on at all. · the head phones plugged in or unplugged, have no affect on the operation as above. I have measured 12+VDC on pin 1 on the RS232 connector on the cassette mounting plate. I have negligible resistance to the ground/earth on Pin 9 (power earth) back to the busbar located on the passenger side firewall in the cabin. I have not checked the resistance from there to the battery negative terminal but did tighten up the bolts. Everything else works fine connected to that ground busbar and will check further tomorrow. I suspect a ground or power issue but on the basis of the tests i have done, everything looks fine. I will set up a 3-4 amp load and load test from pin 1 to pin 9 measuring voltage at the same time. Anyone got any thoughts.

In relation to flutter, there does appear to be good reason that its occurrence is related to TAS and not IAS. I understand Vne is normally stated as IAS and normally has a margin to account for such variances. Flutter is not typically caused by excessive forces (ie high IAS) but the synchronizing of often small forces over the air frame to coincide with natural frequencies. In which case your TAS is the relevant measure which produces the effect. Therefore, in a case such as yours Andy, it might be reasonable to expect that this problem will present itself at lower IAS at higher DA. Ie constant TAS.