GMAS - This reply is to address some of your concerns relative to the Engine Gauge Cluster for 2362S
Weight and balance issues - I did not account for the oil pressure lines I removed or the terminal lugs I cut off the end of the old wiring. The Pigtails were included in the weight of the new gauge cluster. I soldered the pigtails to the existing aircraft wiring and added a couple of wires for the oil pressure gauges. I also put heat shrink over the soldered connections. I think those small differences in weight are negligable.
I agree with you. The old Bordon tube oil pressure gauges sure have an advantage when the entire electrical system goes south. I have had that happen, but it was a shutdown choice when a fuel quantity indicator decided to turn into smoke. This version also has an advantage in that there is no longer risk of an oil leak causing problems in the cabin. I don't see any difference in the response time of the Bordon tubes versus the electric guage. Could be a wash... I'd say a matter of choice. Adding the electrics here does add another opportunity for failure.
Item number 6 - I have been instructing a friend in a 71 (I think) Skymaster. I was surprised to note that he did not have an ammeter. There were only idiot lights for the electrical system. I am much more satisfied with the meters. I would think it would be up to the aircraft owner to determine whether he (or she) wanted to do multiple meters or keep just one meter and the rotary switch.
As you noted, this system will only be useful on older aircraft. The newer ones do, in fact, have a totally different fuel quantity system. Unfortunately, this gauge system does not improve the accuracy over the original system. It just gets rid of the smoke when the gauge decides to go South - no matter which way you are flying.
I think this cluster really only opens some options for solving some problems. In my case, I could have gotten a four gauge cluster and just replaced the fuel gauges. I just didn't want to have to hang them some place else on the panel. Also, I can replace individual guages now and don't have to pull the whole panel to get a single gauge repaired. You can even operate the airplane with some of them removed --so long as you placard the removal.
As for items 19 and 20... Boy! Is this ever an area of ambiguity! This strictly has to be worded in such a manner as to please the person who will approve the change.
I expected to do a technical write-up and go with that, but the truth of the matter is the FEDs desire wording that tends to indicate that all applicable sections of AC43 and FARs are covered. There really isn't much interest in the "how it work's" department.
And, YES, you caught me. I am not an A&P, I'm one of those rare A only's. And I only got that to protect my airplane from so many mechanics to which maintenance is just a daily routine. I make some mistakes, but, so far, I haven't done things so dumb as to hang a propeller with the blades on backwards or install an induction air cable in such a manner as to infringe on the ability to return the landing gear handle to the down position. And most of the time, I don't break somthing else while fixing the original problem. I'm doing this for self protection.
I do appreciate your comments and will consider them when I try to make my next change to the Skymaster. The cowl flaps on this model use the 17 foot long cable to drive the satisfy the position switches when the flaps have reached the chosen position. My shop was able to attach this to the rear firewall by clamping it about three inches below the hardened end of the cable. Guess what happened the first time the cable decided to be a little stiff. Yep, it bent the cable severely enought to render it useless. $250 worth of cable and $1000 worth of labor - SHOT. Anyway, the next job is to replace that assembly with the newer arrangment such as found in the 71 model. I currently have Mr. Nieser looking for parts for me.
I'm sure it will be interesting to get the Form 337 wording just right - again.
Jim