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Test pilot tales: N614EF

LettersFromFlyoverCountry

Well Known Member
(Cross posted from the blog)





This morning, I took N614EF up for our first trip together and, as she's been for the 11 years we've been married, it wasn't simple. I am, of course, now into the test-pilot stage and I take these things pretty seriously; there's no time to be distracted by deep thoughts of journeys and self-satisfaction -- that's what Sunday was for. There's work to be done.

I can't say it was a particularly enjoyable half hour of work, because I haven't yet accepted the reality that things are going to go wrong and I'm not going to know what to do about them until I learn what to do about them, pretty much like the previous 11 years.

The weather said the winds were 3 knots this morning at Airlake Airport, but like previous times I've arrived, I found different weather conditions -- slightly windier and a little gustier. That's when I realized the AWOS system at Lakeville sucks and they haven't bothered to add a NOTAM or make an announcement to the effect of, "everything we just told you is mostly BS." But it was manageable, so a flying we would go.

The one thing nobody has told me -- maybe the only thing nobody has told me -- is that the plane makes some interesting sounds -- unfamiliar sounds -- on takeoff. Or at least, mine does.

The mag checked showed a drop of about 60 when I shut it down, leaving only the electronic ignition on (Updated correction: This is incorrect. The drop was when I was operating only on the mag). That's more than I've seen drop in the few times I've started the engine, but it's not significantly lower. Still, it was different, just different enough to get in my head.

I could only get 1900 RPM on a static RPM check, lower than the 2150 Tom Berge reported last Sunday, and lower than the 2300 it should be. People have suggested the RPM would go up once the plane was moving so I attempted a takeoff and aborted it fairly quickly. The plane was making noises and, frankly, I couldn't tell if it was engine noises or airframe noises. It could have been backfiring or the engine could have been missing. I seriously don't know; I still don't know. I didn't have anybody standing nearby to tell me.

I removed my headphones to listen but I honestly couldn't tell what I was hearing because, for one thing, I've not been in this position before and I have nothing to compare things to.

I taxied back to the runup area and tried it again and did not detect any particular noises (the RPM hadn't changed). So I took the active runway and took off and, again, found the noise quite distracting, especially considering the fact I had it in my head the plane wasn't developing full power. But it was developing enough power to get airborne and so we did.

On turning downwind, a warning light cane on the engine monitor, showing a fuel pressure of 19 psi. The operating manual for the engine does not list a minimum fuel pressure, and it registered 37 psi on the ground. So I'm assuming the pressure is reduced because the engine is taking a big drink of juice during takeoff that it's not taking when taxiing. But after reaching pattern altitude, I switched tanks anyway.

I started heading for the test area but was fairly glued to some of the numbers I was seeing. I was at about 90 knots, 2,300 feet, and notice the manifold pressure wasn't going higher than 19 (altimeter 29.91, temp 77. FP prop 85 pitch). Cylinder temperatures were all in the green, though the hottest was the #1 cylinder. Curiously, the lowest exhaust gas temperature was also on the #1. I wish I hadn't followed Van's instructions and riveted the #1 cylinder air dam on the baffle.

Keep going? Or return for landing.

I went out five miles and then circled back to join a downwind for landing, which -- considering the winds had now come up -- wasn't that great. Wasn't horrible, it just wasn't up to par for me.

My left brake problems seem to have dissipated but now the right brake seems to be sticking a bit. I'm going to take that apart and clean it and retorque it, as I did the left one.

Back in the hangar, I pulled the top cowling off and noticed a fairly large amount of oil on the bottom cowling "floor." I now engines spew oil, but one problem is -- like the noises -- I have no benchmark to know what's a problem and what's not. Still, this seemed significant to me.



I noticed a little "spray" of oil on the back side of the baffle, just below the oil cooler.



But I couldn't quite find the source. I didn't see anything on the cooler itself to warrant concern, and both connections to it seemed solid. A hint of fuel lube was still around the base of the steel fittings and there was no drips at the connection with the hoses.

I did find a drop on a couple of the bolts at the base of the fuel pump...



I found some oil around what I presume to be drain plugs -- one safetied, the other is a hex nut. But is it coming from here? I don't know.



Looking closer, I can see oil around the sump bolts. By the way, you may find it more helpful to click the image and see the bigger version.



Kind of a dark, oily soot on top of the filtered air box. As long as I was here, I doublechecked to make sure there was no blockage of the filter. There wasn't.



At the front of the engine, you can see a drop of oil near the bracket for the prop oil line (plumbed but not used). Again, it's at the split of the engine case.




(Continued below)
 
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And you can't see it here but there appeared to be a small drip at the hose connection to the fitting for the oil cooler return to the engine (or maybe it's from the engine, I forget).



I also noticed oil on the sump bolts that are used to hold the hangars for the exhaust.

I'm pretty sure we're looking at two separate issues here. The oil situation is, perhaps, a matter of just tightening stuff, unless I'm missing something.

The engine power situation is an entirely different one. Frankly, I've stopped trusting that left magneto. I don't know whether that has anything to do with; I just don't trust it.

I inspected the rest of the engine for any telltale signs and didn't see anything, but then again, I don't really have any knowledge of a systematic way of working my way through analyzing what's going on here.

I do wish I'd hooked up the computer to gather the engine readings for later analysis, but I didn't bring it with me.

It's supposed to be a pretty crappy weekend so flying is probably out of the question, but a crow hop or two is possibly doable. If you've got a good set of ears and a little bit of knowledge about engines, how about standing by and listening from the outside of the plane?
 
Congrats on your first flight with your new bird Bob!

Hey I plan fly to your neck of the woods the end of next week. We will be in the La Crosse and Winona area, leaving hear Thursday and returning on Sunday.

I hope to be able to jump over to your airport home there and see you and Stein and his crew. Let me know if you are going to be around.....
 
Congrats!!!!!!!!!!!!

Congrats on taking the controls for the first time.

Oil----------a little goes a LONG way under the cowl.

Snug up the bolts/nuts you think may be leaking, but do not obsess about it if there is no sign of a reallllly big leak.

The engine will be using oil during the break in time, so dont worry too much about the level going down on the dip stick either-------check with your engine paperwork, there should be information on the acceptable use during the first hours.

From what I saw in your photos, you do not have a problem oil leak----a nuisance one, yes, but not a problem.
 
Hey Bob,
I assume you were throttled back when you were seeing 90 knots and 19", that would make sense. FT on take off you should see Baro" - about 1", MP will follow throttle position.

My FI system reads 24-26 psi, (goes up 1-2 psi with boost pp on) min pressure is 12 psi. It doesn't make sense that you would see 35 psi on the ground and 19 in the air. It shouldn't vary like that. A voltage variation will cause indications to change... and that buss loads can affect voltage on a buss. Any changes in what you had turned on between the time you saw the 35 psi and the 19 psi? A blocked/obstructed fuel tank vent can lower tank pressure resulting in lower output pressure.

Ground static RPM should be at least 2200.. with take off roll around 2400+. 1900 is not right.

Make sure that oil pan strainer plug in the back of the engine pan is in tight. That copper sealing ring is designed as split on one side (facing the pan). Hopefully the plug is tight and the ring is installed facing the correct way.
The RV-8A I'm currently test flying has an Aerosport IO-360 with a small but persistant oil leak which so far I can't find the source of either.

I'm glad you got to fly it, but it certainly sounds like you have some "bugs" to figure out before flying again.
Good luck!!
 
Hey Bob,
I assume you were throttled back when you were seeing 90 knots and 19", that would make sense. FT on take off you should see Baro" - about 1", MP will follow throttle position.

Nope, full throttle.

The situation brings us back to where we were a few weeks ago when we retimed the mag and I was able to get static RPM to 2100 without the throttle fully open. Is it possible torquing down those clamps moved the mag slightly? Eh, maybe. Guess I'll pull it off and start over.
 
Bob, in anything other than an RV you might already be dead. Quit fooling around.....ground that thing until it's fixed.
Those were my thoughts after reading Bob's post also.

When I had my first flight I encountered a problem with my airplane power plant. Without boring anyone with the details I also experienced some power issues on first flight. I ended up talking to one of the guys at VANS after I experienced some problems in the pattern on that first flight. My problems were not exactly like Bob's with low power but my problems prompted my discussion with the Tech guys anyway. I cannot recall the particular fella I was talking with at VANS but he mentioned that my RV could easily lift off at 1700 RPM and maintain a positive rate of climb doing so. That was a very interesting conversation. Definitely NOT something I would ever want to do but still good to know.

Oh, and Dan, pardon the diversion off topic but, your comment kind of reminds me of a certain blog post about a certain blogger who keeps talking about how wonderful it is to fly an expensive twin around the country. Would be interesting to see him try on one of these Experimental RV's just once.
 
Quit fooling around.....ground that thing until it's fixed.

It was six hours ago. The only flight I've had. And now I'm at work and have no plans to fly it again until I can get it diagnosed. I'm not sure why you would characterize this as fooling around. I think I'm approaching things correctly.

This had a test flight the other day with a test pilot. The RPM static was a little low but was not judged to be deficient. I asked about RPM on climbout because people on VAF had told me a month ago that it would increase from a static RPM. But that number was no recorded.

Expect to be jumped on? For what? A few weeks ago people were telling me I was foolish for hiring a test pilot, denying myself the joy of a first flight.

Let's go back over this here, fellas. There was no indication of any problem with either fuel pressure or manifold pressure on Sunday's test flight, nor was there any indication today of a problem until climbout. Engine parameters were quite good.

As for flying again without paying attention to squawks, I've said nothing -- nothing -- about flying this thing again before I get these problems solved.

Look, if you're tempted to pick apart what I've written above, just do me a favor and refrain. What would actually be helpful here, is helping to establish a flow for diagnosing the situation.
 
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Nope, full throttle.

The situation brings us back to where we were a few weeks ago when we retimed the mag..... Is it possible torquing down those clamps moved the mag slightly? Eh, maybe. Guess I'll pull it off and start over.

ABSOLUTELY!! In nuclear power when something changes or goes not as expected, the FIRST thing we did is UNDO what you just did!!

You don't have to pull the mag, unless you did before and got the internal timing messed up.
Mag timing needs to be done by someone who knows EXACTLY what to look at!
You can destroy an engine in a matter of minutes if the timing is wrong in the wrong direction.

19" MP indication and full throttle at 2300 ft in MN?? WOW, something is really wrong.
 
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Fuel Pressure?

Bob,

I nitice you said your fuel pressure was 19psi in the air and 37psi on the ground?? In an earlier video you were giving guidence to your test pilot on the instrumentation in the panel in particular the EIS from GRT. This instrument does not show the decimal point on the fuel pressure display so I suspect your fuel pressure was indeed 1.9psi in the air and 3.7psi on the ground. Lycomings will work with only 0.5 psi flying. I was informed of this on the lycoming forums when I had similar questions about low psi. As for the oil - how much oil is in the engine? My O-360 does not like more than six quarts or it ends up on the inside of the cowling much like you show in the photo's. Hope this helps somewhat.
 
Well, ummm... it was four hours ago. The only flight I've had. And now I'm at work and have no plans to fly it again until I can get it diagnosed. I'm not sure why you would characterize this as fooling around. I think I'm approaching things correctly.

If you'd like to offer some advice on a step-by-step approach to solving this problem, that would actually be useful.

Denial is another symptom that will get you killed Bob. Please don't be angry at those that are trying to keep you, and others contemplating wether they are qualified to do their test flights, alive. Don't fly a sick airplane, period....
Now, if I can help. I would start back at the beginning with your engine. Check fuel flow to insure your system is supplying well above max required. Recheck your mag timing, but I seriously doubt that it is. Check your throttle cable is making it to the stops. All of the simple stuff, check again.
 
Bob,
My O-360 does not like more than six quarts or it ends up on the inside of the cowling much like you show in the photo's. Hope this helps somewhat.

There's more than six quarts. Or was. The question I have is when it blows out...would it blow out around the areas I'm looking at....or does it just get blown around inside the cowling and look like that's where it's coming from?
 
Don't fly a sick airplane, period....
Now, if I can help. I would start back at the beginning with your engine. Check fuel flow to insure your system is supplying well above max required. Recheck your mag timing, but I seriously doubt that it is. Check your throttle cable is making it to the stops. All of the simple stuff, check again.

Again, I've never given any indication I'd accept flying a sick engine so a lot of the advice doesn't really apply. But thanks to all who advised; I appreciate the concern.

I swapped out the long throttle arm for a shorter one a few weeks ago b/c the Van's throttle cable has a slightly shorter range of motion than the throttle arm would allow. The new shorter one (2", I think) allows each to hit the stops.

Checked the mixture cable today, and that's fine as well.

If you look at the test pilot flight on Sunday, I didn't particularly care for the way it started; especially when compared to the way it started on first engine start. But I don't have -- or didn't have -- any numbers via the engine monitor to say there was a problem. But I didn't like it.

I sent a note to Mahlon, but I haven't heard anything back yet. I'm not sure what their transition situation is there at the moment.
 
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Again, I've never given any indication I'd accept flying a sick engine so a lot of the advice doesn't really apply. But thanks to all who advised; I appreciate the concern.

I swapped out the long throttle arm for a shorter one a few weeks ago b/c the Van's throttle cable has a slightly shorter range of motion than the throttle arm would allow. The new shorter one (2", I think) allows each to hit the stops.

Checked the mixture cable today, and that's fine as well.

If you look at the test pilot flight on Sunday, I didn't particularly care for the way it started; especially when compared to the way it started on first engine start. But I don't have -- or didn't have -- any numbers via the engine monitor to say there was a problem. But I didn't like it.

Sorry Bob. I have been following some of your posts but obvioulsy not up to speed on where you where at with things.
Have you checked your fuel flow at the inlet to insure that you are getting enough juice?
 
Hi Bob,
My thought is that the oil "leaks" are probably not important. I would
guess you have your oil filled to the upper limit, and a Lycoming is
almost guaranteed to slowly pump the first quart or more out of the
breather. That oil can end up anywhere on the lower part of the
engine or cowl.

On the other hand, the manifold pressure, fuel pressure, mag drop,
and low power are absolutely grounding items. You will want to check all
of the filters/screens in your fuel system, and probably repeat the
fuel flow test. I also recommend checking the calibration of your
pressure gauges using air pressure and a reference guage.
For your mags (electronic ignition?) check the timing and use
4-cylinder EGT readings to isolate the problem.

Take advantage of the RV people in your area and don't take off
again until everything seems just right. If a problem appears after
lift-off, land immediately and get help. Better to fret about
something that turns out to be minor than to miss-handle a
situation that may become dangerous. With your level of
(in)experience it is difficult to tell the difference.

Oh, and congratulations on your first flight and welcome to the
ranks of successful builder/pilots!
Regards,

- Dan Benua
EAA Tech Counselor
Repeat Offender
 
O or IO?

Indeed, the numbers are different for Carb or FI. If you have a Carb, then I agree about the decimal point display and the spread is reasonable. If you have FI, then the spread is greater than you should expect.

6 Qts for normal level... frankly that's pretty low... I'd never let the oil go that low before a xcountry trip. My experience is the sweet spot as an operating range of 6.5 to 7.5 qts. 8 Qts will tend to blow oil out the breather tube, but it shouldn't end up inside the cowl. Level ususally stabilizes well around 7 Qt.

Since you had that mag off before, maybe your leak is coming from the mag seal? Did you replace the gasket when you pulled the mag?
 
I also recommend checking the calibration of your pressure gauges using air pressure and a reference guage.

Can you give me more information, or a link reference to how this is done?

For your mags (electronic ignition?) check the timing and use4-cylinder EGT readings to isolate the problem.

One mag, one lightspeed. We've tried timing several times and we'll start over and time it again. Can you give me more information on isolating the problems with the EGT readings. I noticed the #1 cylinder was the lowest EGT but the highest CHT. Does that tell me anything?

If a problem appears after lift-off, land immediately and get help.

Thus my confusion about the judgement ratings here. This is what I did. I didn't go off to the test area. I found a problem, I did a 360 to join the downwind, I landed, hangared the plane, and began the process of trying to come up with a plan for solving the problem.

I'm not sure what I was supposed to do differently.
 
Since you had that mag off before, maybe your leak is coming from the mag seal? Did you replace the gasket when you pulled the mag?

There are two gaskets on the assembly. One gasket we didn't remove and the one on the mag itself I didn't change because it had no service time. Should I pull it and toss it?

Sure wish the plane wasn't 35 miles away from home.
 
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"My O-360 does not like more than six quarts "

Very true statement.. I had to run 5 qts in the 0-360 on my Archer. Anything more and it would be everywhere but in the engine. Yes diff plane but same Lyc.
 
Bob,
I don't know you other than on this forum. That goes for most everyone here. However, I consider that irrelevant when it comes to caring about what happens to you guys I interact with on this forum. This really is like family. You are family. DanH is family, Doug is family, all you guys reading this I consider as part of my RV family.

Sooo, given the virtual family dynamics of our involvement with each other, I wish to say this. . . You are posting because you respect the input you receive from those on this forum. You are soliciting their advice on what they think you should do concerning your situation. Now, some have come on here and made statements to the fact that they think you are doing something that is dangerous and perhaps you should step back and examine how you should go about things.

I think it somewhat inappropriate that you become so defensive when these guys are pointing out behaviors that they deem very important to the point that they will talk with you openly about it. Please do not take offense at their concern. Everyone here cares enough about what happens with you to the point that they are willing to "call you out" on something they think you should not be doing. Again, I am saying this because I feel a sense of family while on this forum. Family look out for each other!

I was in a very similar position a couple of years ago. To be honest, I made some decisions that were just flat out wrong during my Phase I period. People on this forum did not call me out on it but others in my personal life during those times did. I am saying this from experience. In a lot of respects I see myself and the manner in which I reacted to their concerns coming out in your responses. Please take a step back and examine your reactions to those who are truly trying to help.

As far as the issues you posted about, I see two you are concerned about. First, the one that you seem to have the most concern, based upon the fact you devoted multiple pictures about and much text describing, deal with oil in your cowling and various locations around your engine. As others have commented, a little bit of oil goes a long way. So, the oil in the pictures you posted does not look abnormal. I would suspect you have a small leak somewhere or perhaps multiple small leaks. Get the torque wrench out and put it on every bolt you can find. One area to look at closely is the oil filler tube seal at the block. This is where I finally found a stubborn oil leak that took me weeks to track down. In my situation the oil was making its way down from that tube fitting to the bottom of the sump. In the process it made its way to many different bolts that I was sure were the cause of the leak only to find over time they were not.

Your second concern deals with your low RPM and MP on your maiden flight. In my opinion, and that of most posting here, this is a much more serious concern. I am not an engine guru so most certainly will refrain from giving advice that most likely will not be helpful and could potentially be harmful to your troubleshooting process. I am sure those like Walt or other engine guys will have much to say about this issue.

I would like to contribute one last thought though. Be patient! And, when I say be patient, I am not only referring to the process of making it through your Phase I period but I am also talking about patience with how you interact with all of those people you surround yourself with during the process, those in person and those you interact with via all the various forums, blogs, etc. you communicate through.

You will iron all of these issues out over time. In fact, I can just about guarantee you will encounter more. I am sure you will deal with them successfully as they come up.

Good luck and have fun!

Live Long and Prosper!
 
One mag, one lightspeed. We've tried timing several times and we'll start over and time it again. Can you give me more information on isolating the problems with the EGT readings. I noticed the #1 cylinder was the lowest EGT but the highest CHT. Does that tell me anything?
Ok, I said I would not clutter things with my comments since I am not an engine guru. However, your setup is the same as mine, one mag and one LightSpeed. Have you examined the spark plug wires feeding the EI to verify they are mapped correctly for each cylinder?

Ok, you can ask me how I know. :eek:
 
engine

The very first thing I would check is the spark plugs. You could have one or more fouled plugs, most likely the lower plugs.
Picture #5 in the original post appears to be a fuel injector. The fuel pump is clearly an "AC style" now Tempest. The injected 360 uses a high pressure fuel pump rated at 25-30 psi.
The low manifold pressure could be from a leak in the manifold pressure line. If you don't have a restictor(#50 drill or smaller) at the engine end of the manifold pressure line and there is a leak, this could cause a loss of power.
Regarding the oil leak, it would be best to retorque all bolts that have been removed to install some type of bracket or clamp. This should be done with a torque wrench.
You could also have a breather issue. There have been numerous other posts on this issue here and on Lycoming forum.
I would leave the mag/electronic ignition until last. The engine seemed to be running fine for the first flight. There is very little chance that this would have changed with brand new components.
 
Pressure, Timing, Judgement

Hi Bob,
Responding to your questions in post #20...

I calibrate gauges by locating a mechanical guage of the
appropriate pressure range and some plumbing fittings, including
a T. Disconnect the guage to be calibrated from the engine,
but leave it connected to the engine monitor. Plumb it all together
with your air compressor so that you can apply air pressure
to both guages simultaneously. Check several points and
if necessary (and possible) adjust the GRT if the readings
are not fairly close.

Timing a mag is a well documented procedure but takes a bit
of experience to learn, especially with an impulse coupler involved.
Find someone to show you how. The Lightspeed with the flywheel
sensor is very difficult to adjust, but not too difficult to check with
a timing light. Lightspeed has directions. I would expect that the
RPM drop will not be completely uniform between a mag and a
Lightspeed (they aren't on my airplanes), but the engine should
run smoothly on either one. You should also be able to lean out
the mixture (during run-up) and see the four EGT's peak within a
relatively narrow range of fuel flow (~0.5 gph).

Regarding judgement, your only mistake was taking off when you
suspected something was not quite right. Next time, have an
experienced guy hanging around so you can consult with him
about funny engine noises or guage readings. There is nothing
illegal about taxi and run-up with two people in the plane.

And don't worry, this is all part of the learning process!

- Dan Benua
 
Gaskets

My general understanding is any gasket once used and taken off should be replaced. They get "crushed" when initially torqued down, which creates the seal, once crushed and reused, they may not seal properly.
 
The mag checked showed a drop of about 60 when I shut it down, leaving only the electronic ignition on. That's more than I've seen drop in the few times I've started the engine, but it's not significantly lower. Still, it was different, just different enough to get in my head.

I could only get 1900 RPM on a static RPM check, lower than the 2150 Tom Berge reported last Sunday, and lower than the 2300 it should be.

Again, I've never given any indication I'd accept flying a sick engine so a lot of the advice doesn't really apply. .

Thus my confusion about the judgement ratings here.

I'm not sure what I was supposed to do differently.

. You are posting because you respect the input you receive from those on this forum. You are soliciting their advice on what they think you should do concerning your situation. Now, some have come on here and made statements to the fact that they think you are doing something that is dangerous and perhaps you should step back and examine how you should go about things.

I think it somewhat inappropriate that you become so defensive when these guys are pointing out behaviors that they deem very important to the point that they will talk with you openly about it. Please do not take offense at their concern.


Good luck and have fun!

Live Long and Prosper!

Nothing else I can add to the above.
 
mag

Bob went thruogh the entire mag/ ei issue, including some help from at least one A&P, and some very detailed support on VAF. Highly unlikely this is an ignition issue other than plugs. The engine ran fine for ground runs and the initial test flight.
No need to rehash the ignition issue until all other possibilitys are eliminated.
 
Your getting a lot of good advice and suggestions. Dan is a friend and very experienced RV dude.

You asked what you could do differently? I was taught from day one, you apply power, first check is are you developing full POWER, if not, abort. It is engrained in me. I do it every flight regardless of what airplane I am flying. I think you got a bit of a bum steer from the forum. Yes, you typically see a bit of an increase in rpm as you roll, but only a bit and it happens pretty quick.
Thank you for posting your experiences. I worry a lot more about those that don't.
 
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I think it somewhat inappropriate that you become so defensive when these guys are pointing out behaviors that they deem very important to the point that they will talk with you openly about it.

I don't have a problem with people pointing out behaviors. I have a problem with the ready-fire-aim reaction when it comes to understanding what the situation was.

As I understand the original allegations. I was intending to take the plane out flying again without solving what may or may not be significant problems. But I never indicated I had any intention of doing so. So I'm not sure how or why I'm expected to confess to a behavior I haven't endorsed and have no intention of committing.

I asked a test pilot to do the initial flight and give me an evaluation and baseline readings. He reported his results which, while the static RPM reading was low, he didn't consider it a deal breaker (a very experienced guy who knows more than most wrote me this afternoon to note that 1900 isn't a deal breaker either). That was the entire idea.

The mag check passed on runup. The fuel pressure check passed on runup . (It also passed when the warning light went off because the Lycoming manual indicates -2 as the minimum. The EI was humming. The CHTs and EGTs were in the green, very much so.

My initial rejection of a takeoff was because of the noise and I couldn't tell what they were or even where they were coming from. I still don't know what they were because, as I wrote, I don't have a baseline. I'm also not at my home airport. Another long-time RVer wrote to me this afternoon that the first time you hear the noises of your RV at full power is pretty, well, interesting. I did not hear the noises in the runup area, only on the runway when accelerating.

I returned to the runup area and reran all the checks and they were satisfactory.

I took off. I had no problem climbing at an estimated best rate of climb (although not having done the tests yet, I don't know what the best rate of climb is. I noticed two problems -- or what I thought were problems 300 feet above pattern altitude and returned to land. I did not depart the pattern knowing there was a possible problem and I returned to the pattern as soon as I could return to pattern level. I had no intention of joining the pattern by descending in to it.

I still had to reduce speed -- and it took some time, this is a fixed-pitch propeller afterall -- so that I could safely deploy flaps in the pattern.

I monitored all engine parameters during this process. CHT and EGT did not appear to be a problem and the engine monitor did not "alarm" during this time. There was nothing to indicate the engine would not produce power to keep me aloft, but if it had quit, I had emergency fields identified below me.

If folks are aghast at any of this, there's not really much I can do about it. More likely, I think people have decided to start preaching before they know the full story of the situation. If people have a problem with my behavior and wish to make this thread about it, I would respectfully request that you (a) gain enough knowledge to render a judgement on a specific behavior and (b) cite a specific behavior.

But I would still much rather have an assist in solving the problems that have the plane on the ground.

My next plan is to get one of those visual RPM things, slap it on there and compare the readings. Or just take it out and find a mercury vapor lamp somewhere.
 
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r/m

The wider the range between stall and top speed, the more unsuited the fixed pitch prop is for the airplane. Best rate of climb can occur at speeds far above the speeds that would be normal with a constant speed prop. I have flown the Sensenich RV prop on a 160 hp Glasair. I don't remember any specific numbers, just that the static r/m was low. I would expect a difference of perhaps 200 r/m between static and 100 m/h indicated. The disparity on the metal sensenich seems to be a bit more than on a wood or wood composite fixed pitch.
 
You did not read me criticizing you for having a test pilot. If you were not qualified to do it then you made a wise decision.

If you do not have the interior fuselage covered with material that dampens noise/vibration, the noise during a take-off roll can be ear-opening.
 
I wish your very experienced guys would elaborate to us modestly experienced guys why not developing full POWER (said rpm not quite accurate) isn't a deal breaker on takeoff. Certainly goes against my training. I am willing to learn though if your mystery experts will chime in.
 
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You did not read me criticizing you for having a test pilot. If you were not qualified to do it then you made a wise decision.

Let's just say I was not *as* qualified as Tom Berge. I'm not sure how many people are. The main problem is that my home field is built right up to the fence, there's a hill at one end, and the Mississippi River on the other side of that.

It doesn't allow first flights for a good reason; there's no place to go, so you want someone in that plane who is absolutely the best for the job, and can evaluate performance.

A lot of people, by the way, take off and then land at the same field, ready to cite "I had high engine temps" as a reason. Berge doesn't do that. He's by the book. He orbited the field until the engine proved to him it was capable of extending, and then he left.

I trust him implicitly. He's simply among the best there is.
 
There are two things that can be depended on when speaking to a group of pilots. First, at least one of them is going to lecture you on something you are doing that they would not. The second thing you can absolutely depend on is that if you dont do it their way, and admit you were reckless and ignorant prior to the education they just provided...you are going to die and likely take a bus load of children and puppies with you.

You were in the plane...you made the call...you survived and I'm ok with that. Now, if the lecturing can settle down a bit, someone will probably come by and help you troubleshoot the mechanical issues. Maybe.

Come on gents, give the guy a break. **** pilots....

:)
 
static r/m

An airplane with a fixed pitch prop almost never develops rated r/m on a static run. The exception would be a VERY low speed airplane with a VERY low pitch prop. For example a STOL airplane capable of flying at 25 m/h with a top speed of 60.
An example in the other extreme is the F1 Racers. Typically less than 2500 r/m static. R/m as high as 4500 for racing.
The Continental 0 200 in the Cessna 150 is rated at 2700 or 2750
, I never could remember the exact number. The typical tired Cessna 150 will probably static around 2100-2200.
 
Bob,

You made a good call to land and ask for help. Mag drop limit according to Lycoming is 175 rpm (50 rpm between two mags, but you have only one), minimum fuel pressure at fuel injector is 12 psi. So those are not the concern. Even the oil leak as it is is not a major problem. Not developing enough power is THE major concern. Hope you can find an expert locally to help you identifying the problem. Noise, may or may not be a problem neither since you really don't have a baseline to make the judgement. Only an experienced RV pilot can tell you whether the noise is normal.

Best wishes on finding someone to help you sort out the problem so you can go back to fly again.
 
I am not aware of ever doing a full power runup. I do get around 2250 RPM at liftoff (O-360/Catto three blade fixed pitch prop) at 7000-9000' density altitude.
 
There's more than six quarts. Or was. The question I have is when it blows out...would it blow out around the areas I'm looking at....or does it just get blown around inside the cowling and look like that's where it's coming from?

Bob...

Where does the oil breather exit?

And, yes, if it exits inside the cowl it can blow around (but, while that can happen, probably should not be assumed).

Dan
 
My general understanding is any gasket once used and taken off should be replaced. They get "crushed" when initially torqued down, which creates the seal, once crushed and reused, they may not seal properly.

The crush washers are one time washers. They get turned a set number of degrees (usually 90 or 135) and are not torqued.

Dan
 
Bob...

A couple more thoughts -

Could the noise be the higher power setting being so noisy to "break squelch?" Happens all the time in mine.

On the oil - why don't you check the drainback tubes to be sure they are tight. These are the small tubes that attach to the cylinder heads and eventually transition to a small hose to reenter the crankcase. You'll see the clamps - they could be loose. Another thought - if you hung the exhaust as per Vetterman's instructions, did the sump attach bolts get torqued back to spec? Bottom line - you'll want to chase this down, but frankly, I don't see a lot of oil here.

On the MAP - you should check the line. It can get loaded up with fuel and that can cause issues with the readings. Also, at idle, the line can be under so much vacuum from the manifold that it gets squeezed (actually sucked) shut. Same thing if you suck a soda straw with the open end plugged. If that's happening, it will stay at that erroneous reading until you open up the throttle and relieve the manifold vacuum. To the extent that your ignition system needs manifold pressure, it's going to look a little funny from time to time.

On the RPM - need to verify the gauge and find the problem. If you've lost confidence in the magneto - hire a A&P to rebuild it (peace of mind).

Lastly, the fuel pressure. Sounds really odd - probably best to get an independent gauge on it and see what's really going on.

Dan
 
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An airplane with a fixed pitch prop almost never develops rated r/m on a static run. The exception would be a VERY low speed airplane with a VERY low pitch prop. For example a STOL airplane capable of flying at 25 m/h with a top speed of 60.
An example in the other extreme is the F1 Racers. Typically less than 2500 r/m static. R/m as high as 4500 for racing.
The Continental 0 200 in the Cessna 150 is rated at 2700 or 2750
, I never could remember the exact number. The typical tired Cessna 150 will probably static around 2100-2200.

Yes. I should have chosen better wording as full rpm did not mean static in my context. Full power is.
1900/19 seems very low but Bob is trying to determine what is normal and right.
Bob - I deleted some if my statements about judgment. You did the best you could considering the information at hand. My apologies. And yes, colorv, type a's abound, let's get Bob back in the air with confidence.
 
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You wrote that you were at 2300 feet, wide open throttle, with a baro setting of 29.91".

Assuming your field is at 1000 feet, the local barometric pressure (using the rule of thumb of 1" per 1000 feet) would be about 28.9". You were 1300 feet above that, so say about 27.5". At wide open throttle you could expect to see maybe a 1" drop due to intake losses (or possibly less since your engine wasn't turning very fast), so that makes 26.5". Yet you only saw 19".

Seems to me that for some reason your engine/intake system is restricted, or manifold pressure is reading incorrectly.
 
Bob...

Could the noise be the higher power setting being so noisy to "break squelch?" Happens all the time in mine.

No, it wasn't squelch. It was a pulsating noise. I'll do some crow hops or fast taxis this weekend and see if I can nail it down. (Anybody in Minnesota want to ride with me?)

Good call on the drainback tubes. I checked those almost immediately as a hangarmate had a leak there with those clamps. But it was tight and pretty.

Re: MP line. Which line? The one forward of the firewall, or the plastic tubing on the backside (which I have teed, with one feeding the GRT manifold pressure unit and one line feeding the lightspeed.
 
Re: MP line. Which line? The one forward of the firewall, or the plastic tubing on the backside (which I have teed, with one feeding the GRT manifold pressure unit and one line feeding the lightspeed.

Actually anywhere in the whole line. Fuel can be drawn into the line and often seeks the lowest spot. That leaves an opportunity for fuel to get into places it doesn't belong and you should have a generous loop in the line to allow for accumulation so it doesn't migrate to the instrumentation. It's kind of hard to say since I haven't seen the plumbing here. But, it's worth checking - disconnect from the instrumentation and the cylinder and blow out the lines.

Dan
 
Hey Bob,

First off Congratulations man! No matter what the future holds, you've accomplished something truly amazing. Beer will forever taste just a little better. ;)

Here are the results from my static ground test. The only thing way off was the fuel pressure as I had the Dynon on the wrong setting. On the correct setting it typically reads 25 or 26 psi and 28 or 29 with the boost pump on. My static RPM made it to around 2150 WOT. I0-360B1B, fixed 85 Sensenich just like yours.

RPM.jpg


ManPress.jpg


OandF.jpg
 
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What would actually be helpful here, is helping to establish a flow for diagnosing the situation.

All right. Consider the nature of manifold pressure. The USA standard gauge simply indicates the actual air pressure in the intake tract. Any reading less than ambient reflects pressure drop due to an intake tract restriction. The pilot-adjustable intake restriction is the throttle plate. It provides a very large restriction in order to idle the engine and a very small restriction in order to allow full power. All other sources of restriction are parasitic, details like the air filter and intake tract shape. The total loss due to the open throttle plate and all parasitic sources don't add up to much in a good design. A 2" pressure loss is a lot.

Per your narrative, you had a manifold pressure of 19" with the throttle plate wide open. At pattern altitude you would have been about 2000 MSL, so ambient pressure would have been roughly 27.8". Your first task is to find the intake restriction causing that 9" pressure loss....or more precisely, the 7 to 8 inches in excess of normal parasitic pressure loss

Before launching the search, do a simple gauge check. What does it read with the engine not running? If the reading roughly agrees with ambient pressure (altimeter setting minus pressure loss for altitude) the gauge is fine.

Given a good gauge, the throttle plate is not in fact wide open, or there is something blocking the intake tract. Confirm throttle position by inspecting the butterfly, not the external lever. Examine the tract starting at the cowl opening and working inward. If necessary remove the fuel injection servo and inspect for trash inside the engine plenum.

When you find the source of the MP pressure loss we'll move along to the next problem (fuel pressure drop), then the next (the oil leak).
_____

Postscript...I see Lars had the same thoughts. And note Jeff's MP at runup, about 28.5".
 
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Testing

Bob,
Boom3's post stimulates another suggestion. Before taking things
apart and looking for problems, take the plane out and tie it down
to a post or car. Start the engine, and after warming up, slowly
advance the throttle from idle to full power. As you do this,
record throttle position, MP, RPM, fuel flow, and fuel pressure
at enough data points to make a graph.

The numbers you get will not correspond exactly to what you will
see in flight; the RPM will be a lot lower at high power and the MP
slightly lower due to lack of ram air pressure. But these data should be
sufficient to determine if there is any problem with your MP guage,
or obstruction to your intake system & fuel system. You should see
MP < 10" at idle and in the high 20's" at full throttle. The fuel flow
may go into the high teens at full power, and the fuel pressure should
not drop substantially. Try this with the boost pump both on and off.

I don't know if your engine monitor can record this data for you,
but you will avoid a lot of work and anxiety if you spend the effort
to collect more quantitative data before hunting for problems that
may not exist.
- Dan Benua
 
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