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What went wrong with your 1st flight?

Randy

Well Known Member
I am about to fly my airframe with a completely new firewall forward package and most of the wiring has been highly modified / simplified from what I had with my Subaru experimentation days.

The airframe is well proven, always flew nice and straight, has about 400 hrs on it.

What are the most common problem areas to inspect for prior to taking her up with the new power plant up front?

Heat from exhaust?
Inadequate cooling?
Anything come loose?

I am just looking for pointers on things that others have experienced that I might be able to learn from and perhaps avoid having the same experience.

Randall in Sedona
RV7A, IO-375 low compression and WW RV200.

Data: 8432 R oil cooler (RV10 mounting scheme) is on the firewall with 4" scat feeding it, has a butterfly valve on cable to control oil temps I hope.

Dual Pmags and EICommander, planning to break in with max advance of 26 degrees.

EZ Cool cowl flaps to let some extra air out, planning to leave them open during break in, thinking I will need to.

Pre oiled cylinders, purged fuel system and verified good flow from boost pump.
 
Two of us had the same issue on first flight.....radio squelch. That PAR100 is not intuitive. Know your equipment.
 
Funny you mention the PAR 100, that was the only minor thing that went wrong on my first flight. When you toggle frequencies with the PAR 100, you have to be very careful to not change the frequency, just a very slight twist when you depress the tuning knob, and you will have a new unexpected frequency up on the left. Well, not being experienced with the radio, I pulled up the wrong frequency and didn't realize it, and could not figure out why my ground crew would not talk to me. No big deal, all first flights should be so uneventful.
 
Yeah, with all the pieces of equipment in my plane, the PAR100 is the only one I dislike.
 
plug on top of gascolator

Verify the plug on top of the gascolator is tightened. I found weeping after the 3rd flight. It wasn't tight.
 
Probably the most common problems are non-problems, that is, false alarms. dont set your limits very tight - if at all (I only set oil pressure to alarm on a first flight, and if the engine is running fine, don't overreact to annunciations.
 
Hello from Alaska, Randy!
Again, thank you very much for your help on my 7 a couple of months ago.

As to your question...
I have made several first flights in RVs for others. All with Lycomings.

That said, I have also maidened the same Glastar twice...once with a Subaru and once with a Lycoming. The Subaru seemed to have built-in problems relatively often and the performance wasn't as advertised. The Lyc is still churning along over a year and a half later with ZERO problems.

Just check the line items others have posted and you will probably notice an increase of confidence in your power plant right off the bat.

Bob
 
Idle speed

Check your idle speed, short final isn't a great place to discover it's set too low. A high and tight pattern isn't a bad thing either:)
 
Like Paul mentioned, I had false positives. Alert threshold were set too low. It took me awhile to get them set correctly, specifically EGTs. The alert would go off while short final and idle throttle. I just had to bump it up a bit more to solve that issue.

The major issue was a mechanical fuel pump that failed on a new engine. I probably wouldn't have noticed it, except that I missed turning on the electric boost pump before takeoff. Fortunately, I drilled on the emergency procedures thoroughly before flight, so I caught it pretty quick and it was a none issue getting back on the ground.

The other lesson learned was that the chase pilot got concerned on why I wasn't talking to anyone and kept asking if everything was ok. My first priority was to address the issue, but I probably could have been a little quicker letting him know I had an issue.
 
For me, it was skyrocketing CHT's on climbout. My flight was at high altitude so leaning for best power on takeoff translated to the CHT's taking off on me (in hindsight, maybe should've just gone full rich). Probably not an issue if your airport is under 5000 ft, just keep an eye on it. Bottom line, for me it wasnt flying the airplane, it was monitoring all of the engine instruments (and talking to tower) that caught me off guard a little. Mostly just rookie mistakes, but worth noting. Have fun!

Oh...and what Bill said, he was my hangar mate at the time and flew a week before me...and warned me about the PAR100EX squelch/volume control, which was big. Always nice to have someone go first.
 
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Semi loose wire on oil pressure sending unit. On 3rd flight, oil pressure was intermittent and was fluctuating between 25 and 70 PSIG. turned out to be a loose connection. I also put lock-tite on the retaining nut for both fuel and oil senders.
 
As above, I have done a fair number of first flights... and ensure owners disable all audio warnings / alarms and as I put it "screaming women shouting push as I get airborne" :eek:

Suggest do one "aborted takeoff" to also discover any emerging issues, consider them on the taxi back before 1st takeoff.

Keep 1st flight short - say 10-15mins, pull cowls and look over closely...

Aim of 1st few flights is a safe flying VFR aircraft. Leave the technical / avionic / fine tuning / limits for a while...

Just a few thoughts ;)
 
I conducted the first flight of my -4 a few years ago, after 15 years of building, which included a complete rebuild of the engine, mags, carb all done by myself, so virtually 100% of the plane was un-tested. I took all the advice I could get from others, as well as the concerns of engine break-in ect. I had a briefed ground crew, as well as a good friend with a Maule orbiting near by for in flight observation. Took my trusty handheld as a back-up in the event I needed it. Run-up was good, took off ,climbed to about 5K and flew for 1.1 hrs... everything was "in the green" and acted the way it was supposed to. I had a list of things in my plan, slow flight to check stability,trim,ect. Flap operations (electric) ,high speed runs, fuel selector functions, and all the other usual requirements. I ran the engine as per break in process, and did some fast laps around the airport . The biggest surprise was how fast an hour had gone by, and it was time to land! One suggestion I would think about is a video camera to capture the panel, and then you can go back real time and see what all your stuff is doing and make notes later, rather than trying to jot it down or remember it.
 
I had the AOA and pitot lines swapped. No airspeed indication in flight, but I got one on the ground (taildragger). Not exactly a big deal, and easily corrected before the 2nd flight.
 
I had an erratic oil temp reading....... temp was going from 70 to over 250 and back to 70 again in just a second or two..... not physically possible, CHT and EGTs were all in range, so we continued the flight.

Turns out it was a bad ground on the temp transmitter.
Other than that, everything else worked surprisingly well.
 
Airspeed

Despite all the information to the contrary, you can GENTLY blow into the pitot while someone watches the airspeed. This will at least verify that the pitot static is connected properly. Handheld GPS for backup if the airspeed doesn't work properly.
 
Hi Randy,
First flight after Subby-Lycoming switch went well except the flap motor failed with flaps at about 10.
The Barrett 0360 ran like it should with no issues whatever.
Same can be said for the Barrett Superior 0360 on the 8.
All I can say beyond that is check everything twice, push the throttle up, let it rip and enjoy it. :)
 
My Dynon screen went black. Had backup airspeed, but no backup engine instruments. Ended up not being a big deal, but was a bit disconcerting when I had had grown accustomed to flying by power settings.
 
Despite all the information to the contrary, you can GENTLY blow into the pitot while someone watches the airspeed. This will at least verify that the pitot static is connected properly. Handheld GPS for backup if the airspeed doesn't work properly.

A gentler approach. Take a ballon blow it up lightly and put it over the pitot tube. Should hold pressure and show the same airspeed on all your instruments if you have more then one that is... .
 
RV-10 - RPM and CHTs and Landing Lights

Dynon RPM multiplier was set wrong- indicating ~1500 RPM at full throttle, and the dams in front of #1&2 cylinders caused high CHTs on those cyl. --- not big deal -- easily corrected --- Landing light breaker was too small and opened when I tried the lights.
 
1st flight

Climbed rocket-like to 3000 feet then leveled out at 75 to 85% power. Never got even up to 300? CHT on the front two cylinders. Had lots of warnings about fuel although I had plenty. Still working on that. Return to land because of low temperatures. There were no other problems except a drafty cockpit, heavy left wing and a nervous pilot. 1st ldg a greaser. What a ride!
 
note to authors emphasis on GENTLY

Despite all the information to the contrary, you can GENTLY blow into the pitot while someone watches the airspeed. This will at least verify that the pitot static is connected properly. Handheld GPS for backup if the airspeed doesn't work properly.

I failed my first airspeed indicator by blowing on it to see if it worked. It did, one time. Lesson learned.
 
Probably the most common problems are non-problems, that is, false alarms. dont set your limits very tight - if at all (I only set oil pressure to alarm on a first flight, and if the engine is running fine, don't overreact to annunciations.

As above, I have done a fair number of first flights... and ensure owners disable all audio warnings / alarms and as I put it "screaming women shouting push as I get airborne" :eek:
...
I often tell people to turn off all the alarms. You will be busy looking at Oil temp, oil pressure, and CHT's for most of the first few flights. So no need to have them screaming at you.

For me, it wasn't my first flight but the second one that go me. All was 100% perfect with the first flight but on that second one, one of my ignitions lost its timing mark, a problem that was fixed long ago. CHT's climbing into the 500's will get your attention pretty darn quick.

Also, later in my phase 1 test period I had four engine stoppages on four different flights. It turned out to be an un-insulated fuel line that ran between the gascolator and fuel flow meter. The problem only showed up during slow flight; high power + low airspeed = high temps in the engine compartment. Once I insulated that line, the problem went away.

Be careful and good luck! With your past experience with the Subaru engines, this will be fairly routine.
 
Be sure to DOUBLE check important stuff

Some I have witnessed:

Clogged fuel injector, caused cold cylinder at 1000'

Loss of alternator - not connected properly if at all

Throttle linkage coming loose in the climb - ask yourself how you would handle that one!

If at all possible find someone experienced in formation to be your chase/safety pilot. I have done this a few times as the chase and had one on my 1st flight. Not a formation takeoff, I let guys takeoff as if I where not there, once there is no immediate need for them to return to the airport I takeoff and join up, they fly there jet as they wish, I will get myself on the wing. First thing is a leak and rigging check then enjoy watching another RV pilot get the grin.

The chase can be a valuable asset and can take the load off you if you have an issue you need to handle. A chase can give you confidence in your airspeed readout, if you match them within a few knots you can trust yours more fully when you come back to land. More important if yours goes out as in blank EFIS the chase can fly on your wing and be a verbal airspeed indicator, been there done that one.

Most of all chair fly the first flight and what if all you can, you might even loose some sleep a few nights but it will make you double check things.

Good Luck
 
Oil Door

Not on the first flight but on my first flight the oil door came open. It is a longer story. I thought I had it fixed, but I didn't. I just slowed down a bit and headed home.

I have the hidden push button latch and I guess the door bows up some in flight and it can come unlatched. I have since made an aluminum door. So far so good. If you have any doubts put some duct tape on the door for first flight and remember fly the plane, the door will be fine. :)
 
By gently I mean just enough to get a reading of 80-100 on a 250/300 mph airspeed. never had a problem doing this.

Yes, just use a little caution. I did this to ground-check both the EFIS and steam gauge, up to about 70 kts, and found a very good correlation between the two. I held the tubing about 3-4 inches from my mouth and started really slow.

This thread is great reading. Will turn off alarms for first flight. :)
 
One other suggestion that works well prior to your first flight.

Have someone take you up in their plane, it doesn't matter if it is not an RV, and fly your first flight profile. While this is going on, look outside for possible places to land, towers, and other obstacles. Also fly the profile on Google Earth so you know where you are going and where you can go, if things turn bad. Trying to find a suitable landing sight after the engine stops making noise, may not be possible.
 
1. No airspeed indication - IFR cert shop swapped my AOA and Pitot
2. Oil temp skyrocketed - wrong setting in my Skyview
3. Failed ADHRS - Full pitch up and 90 degree bank indication.
4. Near the end of my flight a VERY loud banging sound resulting in a "Pan, Pan, Pan"- wing to body fairing seal flopping.
 
First Flight Issues

1) Canopy rear skirt buzzing (actually howling) when greater than 120 knots. Sounded like the airplane was coming apart until I slowed down and it quit. Started again when I sped up. Note to self, don't go fast until you get this sorted out! (A little padding fixed that 560 hours ago).

2) Oil pressure over 100 PSIG at high power. Did not do this during the ground runs on the engine I overhauled. Hard to keep your eye off of the red warning light! It was a major distraction. A couple of turns on the adjustable relief valve took care of this when back on the ground.
 
Nothing!

I paid attention to everyone's advise, triple checked everything.
And I was perhaps lucky too.
But on my first flight, absolutely nothing was amiss.

Sigh. Grin.

320 hrs later, same story.
 
OPs update on first flight, this got a little long...

Well I took her up today for three flights totaling a little under 2 hrs flight time. To recap, this is a first flight with this new IO-375 engine but the airframe has about 400 hrs of Subaru time on it, RV7A. So firewall forward is all new in addition to a major rewiring job, new panel etc. Running dual Pmags and EICommander. For initial flights I modified one of the extra timing curves for a max advance of 26 degrees, pretty much making them into good magnetos:).. In flight I was seeing 28 degrees advance for some reason but this did not seem to cause any problems at all.

On first attempt to start I flooded it bad and learned that the old PC680 is not up to the task of turning the engine over with the spark plugs in:) I put in my back up battery and it seems to be in better shape, at least I got it started. I will have to get a fresh battery coming. Both of the batteries I had laying around have seen lots of duty on the Sube installs.

I did an offset departure as planned, climbing right up into the down wind to make it much easier to get back to the runway if needed, wasn't needed.

The only squaks were an Inop. Angle of attack indicator that was cured once I found that the soldered connection at the switch had broken off from a little too much abuse and re positioning. (I love my AOA and don't like being without it) it is the Advance Avionics Sport model. I am happy to hear Betty saying" angle angle push push" as I take off and land:)

The other one was a too low idle speed. Gave the throttle stop a half turn in between flights, problem solved.

I am very happy with how well everything is working. I instrumented to measure differential pressure between the top of the engine and behind the engine. I use aquarium stones on the ends of cheap tubing and a 0" -15" water column Magnehelic pressure gauge. High side centered at the engine lift thingy, the low side behind the engine in what I assume is a fairly dead air zone.

At around 160 knots, 4,500', OAT around 50F I always see more then 10" differential. If I open my EZ cool cowl flaps it goes up above 13". Very happy with those results. I put extra effort into sealing up the leaks. I would love to hear what others have measured!

It has been my experience that radiators, intercoolers, and oil coolers work well at around 6 or 7 inches differential, so seeing over 10" and low CHTs during break in has me smiling.

CHTs are not an issue at all. Cyl 1 293, 2 301, 3 316, 4 310, all in F.
They pretty much kept that spread and did not very much as long as I kept the mixture full rich. The air dams are still at full height. Maybe I need to add some aluminum tape also to even things out. Glad I did not cut them down ahead of time like I was tempted to do.

The engine was sucking up over 16 GPH at 25 square. Just following the break in instructions that came with the engine, which basically amounts to fly it like you stole it! As I accelerate out on the runway and go to full rich I can hear the engine note go down a notch and I suspect I will see even better performance once I can start leaning it a bit. I am taking off from 4500'. The instructions from Aerosport and other reading says to leave it full rich as long as the engine is running clean. It is not missing or anything but I know I am way rich of best power mixture.

My oil cooler, the legendary 8432R, is really working great. It is on the firewall with a modified RV10 mount and 4" scat feeding it, also have cable operated 4" valve. I could close the valve and watch the oil temps climb up to 220F or so, then just crack the valve open and pretty much put the oil temp anywhere I want it. I kept it close to 200F so far.

On the last flight of the day I began to notice some vibration that I suspected was the pilots side muffler making contact with the cowl. Clint at Vetterman already made a change to my Trombone system, but I obviously need a little more clearance. For now, I ground away the honeycomb where the contact marks were and laid some reinforcement glass layers there, giving it a bit more clearance. Hopefully that will allow more flying and getting the engine broken in, but I may have to send the header back to Clint for another modification. Have to check to see if the engine is settling in the mounts any but it appears that the spinner is nicely fitting to the cowl like I set it up.

Overall I am a happy camper and certainly look forward to more flights tomorrow, maybe even get past my 5 hour phase 1 period after a truly major alteration..

Thanks again for all the ideas of things to look for on first flights. I probably should have checked my idle speed more carefully on the ground before first flight but it did not create any problems.

Randall in Sedona
RV smile is on again after a full time four month full time effort on the engine install.
 
Great news Randall!

I'm not sure why the P-mags went to 28* and will run some tests on my next flight. Which should happen when it stops snowing here in South Carolina.
 
Not on the first flight but on my first flight the oil door came open. It is a longer story. I thought I had it fixed, but I didn't. I just slowed down a bit and headed home.

I have the hidden push button latch and I guess the door bows up some in flight and it can come unlatched. I have since made an aluminum door. So far so good. If you have any doubts put some duct tape on the door for first flight and remember fly the plane, the door will be fine. :)

Same here on my (and the) first flight. I continued without any adverse affects, but it screwed up all the first flight pictures - oh well, it was super-minor in the grand scheme of things. No other squawks.
 
I instrumented to measure differential pressure between the top of the engine and behind the engine. I use aquarium stones on the ends of cheap tubing and a 0" -15" water column Magnehelic pressure gauge. High side centered at the engine lift thingy, the low side behind the engine in what I assume is a fairly dead air zone.

At around 160 knots, 4,500', OAT around 50F I always see more then 10" differential. If I open my EZ cool cowl flaps it goes up above 13". Very happy with those results. I put extra effort into sealing up the leaks. I would love to hear what others have measured!

Nice work Randy.

10" and 13" appear to valid numbers for a stock cowl and stock cowl with additional exit area. I don't have a data set for a -6 cowl, but if you'll contact me offline I'll be happy to outline a plan to get it ;)

RV-8 cowls with well-sealed baffles had differentials between 9" to 10" at 160~165 knots.

Opening your cowl flaps reduces lower plenum pressure, thus increasing the differential.

CHTs are not an issue at all. Cyl 1 293, 2 301, 3 316, 4 310, all in F. They pretty much kept that spread and did not very much as long as I kept the mixture full rich.

You're a candidate for a shrinking exit and some additional speed.
 
How to Check/Calibrate your ASI

If you really want to test your airspeed/pitot system, see the article below. It is very easy, accurate and cost very little.

I didn?t check my airspeed prior to first flight but I have since. I was concerned about my RV-9 stalling at 54 MPH (Van says 44 MPH). I found my airspeed off 9 MPH at slow speeds and 3 MPH at cruse speeds. Once again Van is right on the numbers.

http://www.rst-engr.com/rst/articles/KP89JUL.pdf
 
thank you for the summary and congratulations. What are your thoughts on alternative engines? Do you regret having spent time and effort and $$ on the subaru?

I wish you many hrs of reliable and safe operation.
 
Well it is hard to say that I regret what I did with the Subarus, other than all the flying time I missed out on. That and I never felt right about asking my wife to come along with me a good part of the time as I was always testing something.

But in reality it was a great learning experience. If not for the dangers involved I would love to have kept up the effort and succeeded, but those darned emergency landings get to you after a while...

Randall
 
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