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First few flights questions

D

dweyant

Well Known Member
I now have four flights and about three hours on my RV-14A.

She is going to be a great airplane, already flies really well, and I am quite impressed with the smoothness of the IO-390 engine.

Couple questions for the group.

Oil Pleasure. At anything other than idle the oil pressure is firmly in the green (72 psi), but at low idle it is dropping barely into the red range (48 psi). Do I need to increase the idle pressure?

Also, I have not been able to find a manifold pressure range for the instrument. What is everyone using for green/yellow/red.

Thanks,

-Dan
 
Here's mine, same engine, end of flight. SavvyAnalysis if you have never used it, good way to view data.
 

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I don't think most people have color warning ranges on their MAP. Like OAT, it's just a reading.
 
For a non-turbocharged engine there are no M.P. limits. Many folks will "green arc" their MP gauge to avoid low MP settings during descent. I have seen 17" commonly marked at the bottom of the MP green arc.
 
Here is my set up. I put all green for the MP, thought it looked better with color. Also put my oil Temp & pressure yellow arc more conservative than Lycoming numbers. I put the yellow arc very close to my normal operating limits. That way I will see a potential problem sooner.



IMG_9514.JPG
 
I’d suggest that for first flight, you want to remove potential distractions - that means inhibiting any alarm that isn’t absolutely critical for safe flight. To me, that pretty much meano oil pressure - and if you’re fuel injected, maybe fuel pressure if you set it as low as you can for the engine to still run (maybe 13 psi or so). I have done to many first flights where the owner had set limits for CHT (and even EGT, the absolute value of which measn nothing….) to protect very low limits, and I had nothing but alarms and flashing lights going off as I went around the pattern. Keep an eye on things, yes - but you have better things to do on a first fight than hear bells & tones, respond to try and cancel flashing messages, and worry about if the wings are about to fall off.

Paul
 
Ironflight said:
I’d suggest that for first flight, you want to remove potential distractions - that means inhibiting any alarm that isn’t absolutely critical for safe flight. To me, that pretty much meano oil pressure - and if you’re fuel injected, maybe fuel pressure if you set it as low as you can for the engine to still run (maybe 13 psi or so). I have done to many first flights where the owner had set limits for CHT (and even EGT, the absolute value of which measn nothing….) to protect very low limits, and I had nothing but alarms and flashing lights going off as I went around the pattern. Keep an eye on things, yes - but you have better things to do on a first fight than hear bells & tones, respond to try and cancel flashing messages, and worry about if the wings are about to fall off.

Paul
Click to expand...

This is great advice. For my first flight, I had my CHT alarm set too low and my stall warner (Van's metal tongue style, not yet adjusted) was also set up to honk and flash at me, and so my panel was lighting up and dinging like a casino during my first flight. Not exactly a distraction-free first flight. If I were to do it again, I'd have turned these off or at least made them non-alerting annunciations.
 
The numbers in post #6 apply to all direct drive non turbo Lycomings starting with the 0 235. Some of the numbers are not original numbers for a particular model but revisions from the factory. The 115 # for a cold start is one example.
If you adjust to oil pressure to the high end of the green arc for cruise the idle oil pressure should be well above 25# even with hot oil.
 
Ironflight said:
I’d suggest that for first flight, you want to remove potential distractions - that means inhibiting any alarm that isn’t absolutely critical for safe flight. To me, that pretty much meano oil pressure - and if you’re fuel injected, maybe fuel pressure if you set it as low as you can for the engine to still run (maybe 13 psi or so). I have done to many first flights where the owner had set limits for CHT (and even EGT, the absolute value of which measn nothing….) to protect very low limits, and I had nothing but alarms and flashing lights going off as I went around the pattern. Keep an eye on things, yes - but you have better things to do on a first fight than hear bells & tones, respond to try and cancel flashing messages, and worry about if the wings are about to fall off.

Paul
Click to expand...
Yep,

This was my 12th first flight. Always minimal/no alarms, worry about flying the airplane, the rest can come later.

Got the answer I was looking for (thank you) on the minimum idle Oil PSI.

-Dan
 
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