G3 vibration case study.

Question: Why would I want vibration analysis on an engine monitor?

Larry installed an Insight G3 color graphic engine monitor in his Trinidad Socata TB20 last year.

Larry says:

"I had used the Excel vibration graphing tool on Insight’s website to print out the vibration analysis data from my G3 over a couple of flights for a baseline benchmark.

After flying the G3 for 8 months I also had a new 3 bladed prop installed on my Trinidad Socata TB20 with a Lycoming IO 540.

After 90 hours I noticed grease, and had to have the prop pulled and resealed. I was told that the reseal would be covered under warranty but that I did not need the prop balanced again.

It felt rougher to me, however, so I printed out another vibration analysis which confirmed more vibration after the re-seal than before".

To: Insight
Subject: Balance

Hi Dan,
I am having my prop rebalanced this morning and will send you a new "after balance" chart as well as a couple more "before re-balance" charts later today. The shop tells me when they balance, they are correcting the vibration in the vertical axis only. I told them the Insight sensor measures in all 3 axis. Do you know if it is the X, Y or Z axis that correlates to the vertical that they are correcting?
Larry


To Larry

The Vertical axis is the Z Axis on our sensor. The Left-Right lateral axis is Y.
Because the prop spins in a plane defined by YZ, prop imbalance will contribute equally to Y and Z. X is Fore-Aft, and in theory would be relatively unaffected. Note that this definition depends on your sensor being mounted in the same orientation as the pictorial airplane on the sensor itself. If you've mounted it in some other orientation, you will have to translate it accordingly.

We look forward to examining the vibration spectrums.

Dan

Vibration data of new balanced prop (showing some imbalance)

Vibration data of prop after repair. (vibration noticeably worse)

Vibration data of rebalanced prop (a lot smoother as you can see; better than new)

Hi Dan,

The prop balance was completed and it definitely feels much smoother. We went from .8 IPS to .05 IPS. I have attached another "before" graph (I believe I had sent you a couple previously) which was taken today prior to the prop balance. The data was done at 2500 feet at 65% power at 100 ROP. The "after" graph was also taken today after the prop balance under the exact same conditions.....2500 feet, 65% power and 100 ROP. The graph improvement for the Z average is pretty dramatic as you can see.

I owe this "warranty" prop balance to the evidence supplied by my G3 prior to and after the prop reseal.
Larry

Conclusion:

A new balance was approved under warranty.

Answer: A G3 color graphic engine monitor is one of the few things you can put in your aircraft that will actually pay for itself.

More on this story to come.

G3 Pilot Feedback

I recently upgraded my Baron B55 from a GEM 1200 to two new Insight G3 2.25" instruments. These color engine gauges take engine management to a new level at a very affordable cost. The upgrade used my existing probes and wiring for the EGT and CHT sensors and reduced the time and cost of the installation dramatically. I can now see the temperature of every EGT and CHT simultaneously in addition to the color coded bar charts on a crystal clear LCD screen. The lean boxes that show the current EGT variance from peak EGT make the leaning process very simple and easy to monitor throughout the flight. On top of that I get backup instruments for all other key engine data to provide redundancy to my unreliable legacy engine gauges. The Insight G3 instruments make flying my plane even more fun and safer than ever.

Joe Lechman

1976 Baron B-55

"During my first flight with the G3, I very quickly learned the value of the probe diagnostic functionality. It turned out that this flight was also the first flight with 6 new cylinders on my Cessna P210 so it was intended to be a 2 hour, high power break-in flight On the ground, during run-up, all my EGTs and CHTs looked normal. However, 15 minutes into the flight, the #3 EGT began to show odd and fluctuating temperatures. I was flying with my mechanic and we both believed that we had a probe issue but decided to head back to the airport and land just in case it was something in the new cylinder. Given our newness to the G3, neither of us thought to look at the probe diagnostics page until we were actually on final. Once it dawned on us that the G3 could tell us if we had a probe failure or not, a quick glance at the probe diagnostic page showed the #3 EGT probe at around 90 ohms resistance, an obvious failure. The G3 made it very easy to spot as the data for that probe was displayed in red. Now that we were confident that we had a probe issue and not a cylinder issue, we continued the flight, saving a complete cool-down cycle on the new top end as well as the time to un-cowl and diagnose the #3 EGT probe.

Interestingly, back on the ground after the flight, the #3 EGT probe again showed 5 ohms. Clearly this probe was only malfunctioning at high temperatures, making it very difficult to diagnose on the ground. Insight has really touted this feature and I have now had the real-world experience to understand exactly why.  Great job, Insight!"

All the best,

Jim Baum

N5447A