In reading online articles and posts, some old timers seemed to suggest the information from the monitor may be distracting to a pilot. I found once again, the wrinkles contain good experience and wisdom...for me, the data revealed a world of mechanical ignorant furled assumptions. Over the last 6 months, my time has been spent learning to fly my Grumman Cheetah without over stressing the engine, flying high density in a HC O-320 with a tight cowl.
The experience from the first 6 months (30 hours) on the new monitor were eye popping. My #3 calendar on high DA days is >440 F unless I take proactive action (starting at run up through level off. The back cylinders are normally warmer, no surprise, but #3 gets hot fast and it'll hit 460 without intervention.
Next surprise was shock cooling on a this 160hp engine, I thought I was smooth on the throttle; not the case. Needing to manage over cooling on a AA5A just wasn't an expectation, everything read sets a perception the over cooling issues were reserved for complex (cowl flap configured) platforms.
Then out of left field, it came appearant the LASAR's ennunciator light was not illuminating as it should on Mag check...the run up checklist specifies the light should be "verify off" following mag check...well, it was off, theough 12 hours following annual I ran up and flew with that ennunciator OFF. The problem, it wasn't coming on during the mag check as it should.
I spent several hours upside down under the panel looking for the problem, even ran a comm cable from the LASAR on the firewall inside the cabin to connect a netbook...on an aside, thanks Microsoft for eliminating hyperterm from Win7. This was IT, cable fabrication, USB comm cable driver meets airplane ignition. I learned a bunch about the LASAR ignition as a result, most importantly determined the LASAR was working flawlessly, with exception of the ennunciator (root cause a bad molex crimp), a 30 second fix. My theory, the molex crimp was poorly made and the wire snagged on the EDM700 when it was installed next to the light, the pin's strain relief tab looked as though it'd never been crimped to the insulation. File this under expect collateral damage when adding technology to the panel.
Look close, white wire found disco'd next to the Molex, it's intended for the middle pin on the MOLEX and provides ground return (required for the circuit to work):
The LASAR comm port displays a vt-100 readout of the ignition parameters, this is very cool. I wish I had room on the panel for a terminal display full-time:
While hanging out under the panel, I became more familiar with the avionics wiring and feel more comfortable with it now. I worked in proximity to the pilot headset jack and took the opportunity to use super fine emery cloth on the connections and bent the connections back into shape to provide a tighter mating between plug and jack. This little bit of effort cleaned up my intercom crackling and ATC seems happier to talk to me now.
Since my last post, my plans to MTB all over Colorado this summer were high jacked by a shiny new EDM700, but the time invested in gaining a better understanding of how my pilot techniques affect the integrated systems on my Cheetah, priceless.
Lesson learned:
EDM-700
1. Conventional wisdom and techniques handed down by CFI to student is safety focused...flying without dying; not getting the best life out of a power plant
2. Conventional single cylinder CHT/EGT and analog OIl temp is better than nothing, and that's about it
3. Old timers who warn the data from the monitor may be distracting is valid, in my case alarming, I invested in subtle pilotage techniques to improve temperature management, I've had to fly a little further in front of the airplane to get acceptable results; overall more gentle.
LASAR
1. Add a checklist item to verify the light comes on during mag check
2. The LASAR comm port is really good way to know if the LASAR is really working, really the only way
3. The mechanical TACH is reading 100 RPM lower than the LASAR (reading from the mag directly)...add a Digital TACH to the EDM at annual
Intercom
If you have noise in the system, clean and tighten connections at the jacks, big improvement with $0
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