S

Stan Bahrns

Active Member
Getting ready to test run engine & wondering if it is ok to run the engine at full throttle without the wings as I have see on a lancair or something similar that had the main gear collapse in that situation. Has anyone done this or have any suggestions.
Thanks, Stan
RV7-A QB
Aluthern Ill
 
As I understand it, it's not recommended to run the engine at all without the wings on. The wings do a lot to damp out the power pulses of the engine, and without them, there have been reports of people damaging the tail skins. I did it with the rotary engine, but wouldn't think of doing it with the Lycoming.

Cheers,
Rusty
 
I ran my RV6 with no wings to full throttle and didnt die or damage anything. Your results may vary. Im very glad I did this at home cause it gave me lots of stuff to work on.

I did not do this with my 8 cause the big engine scared me :eek:

2ndrunup7.JPG
 
It sure is tempting to start the engine in the driveway, just to see the reaction from the neighbors. They keep asking me if I'm going to take off from the street. :eek:

Think I'll wait for both events until I get to the airport and get the wings on permanently.
 
Substantial damage could occur to the Fuselage from the engine kicking or possibly back firing. It is not designed to take this kind of load without the wings on. They give it a much longer moment and also take that kicking load off the landing gear. I too have been tempted but I'm so close to moving it to the Airport it would be silly not to wait till it looks like a plane. I wouldn't recommend it.

Dan- wheres that video? I'd like to see it, others may too. This board is all about learning from others.

-Jeff
 
RV_7A said:
Dan- wheres that video? I'd like to see it, others may too. This board is all about learning from others.

-Jeff
Click to expand...
It's on the VAF board somewhere. I did a search for it, but haven't found it yet...
 
It looks like the gear just retracted. Does anyone know if this was actually related to the engine run, other than that the brakes were used?
 
Its pretty clear it blew the left wood wheel chock out and the AC got to moving forward while sliding the right wheel chock forward and then it stuck. He obviously had the brakes locked and the momentum just folded the leg back. It could happen to any of us if we took that route.

Im not sure having the wings on woulda helped this crazy scenario but it sure makes you think about securing your plane with something other than the brakes and wheel chocks.

-Jeff
 
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A friend of mine constructed the aircraft and installed the Walter turbine. Apparently a breaker left open by an avionics tech the day before was forgotten by the cockpit crew. This caused the downlock to disengage and the retract sequence to start. Very expensive. The prop was destroyed, engine had to go back to Walter and the right stab was broken off. The aircraft rotated/ walked around on the prop quite a distance hence the scattering cameraman. Aircraft is all repaired now and they hope to have it flying this summer.
 
I think the lesson learned is...TAKE EVERY PRECAUTION. Whether it's checking the breakers or just limiting variables to the absolute minimum, wouldn't you all agree that there's too much at stake to take known risks that can be avoided?
 
Wha's the hurry

I'm not sure what you are gaining by wanting to run the engine without the wings that can't wait till the wings are on.

As has been noted, the wings provide a dampening force and stability. In the event the engine runs rough, backfires etc.. you are possibly going to spend more time repairing the damage created than it would have taken to put the wings on.

Unless there is pressing reason, wait. JMHO.
 
fixed gear rv

FIRST, I WIL RUN MINE WITH THE WINGS ON. but i doubt the fixed gear would fold up like the turbine plane did. it only tried to retract as commanded inadvertantly. i do think the potential is there to do some airframe damage. why risk it?
 
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Preserved Engines....

Lots of good thoughts here - one I haven't seen mentioned is that if your engine has been preserved for storage, one you run it, you now have to either re-preserve it, or you face the issue of an engine that won't be run for a while . It probably took me two or three months from the time I COULD have run my engine in the driveway until the time that I DID run it at the airport - now that might or might not be significant, but since my builder had done a great job of preserving the engine for storage, I saw no reason to undo this until I was pretty much ready to fly.

Paul
 
Paul has a good point

This is why I didn't run my engine until after I got my FAA inspection. I checked before the inspection and was told that it was not necessary to run
the engine before inspection.

I only did a couple of gound runs (to set the idle and prop speed). I didn't do any taxi testing. This was to save the engine from gound heat (brand new engine and I wanted to break is in right).

My first flight was at an airport with a 5000 ft runway. So I knew that if the take roll had a problem I could easly abort and land.

Kent
 
Fear, Uncertainty, and Doubt

When I started building seven years ago we all used the George Orndorff videos to help with the building process. They were exceptional, I still have my set for the 8 all the way through systems install and engine start up of his RV6A. He did his first start without wings so.... I did as well.

I fired up my O-360 without the benefit of tail or wings. I tied my tail cone to a small tree which I subsequently blew most of the leaves off of. The net was I found several small fuel leaks which I fixed and I discovered that my brand new lycoming engine ran like a champ. After several years of flying that same 8A, and doing acro, I can say that it suffered no apparent damage from the experience.

Why did I do it? What did I gain? After starting that engine, I was jazzed. I put all my effort to getting that plane to the airport and in the air. It suddenly went from a pile of parts delivered by the UPS guy to a real aircraft. Thanks to Vans utter lack of support for anything firewall forward ( this has changed a bit since I constructed mine as it was before Van's FWF kit ) it was a huge validation for both me and my wife at the time that this expensive toy would soon fly.

Is there risk? Yes. Is it a BIG RISK? Not from my experience but your mileage may very.

Will I do it again on my 9A.... ask me in two months :D

- Jim
 
I did too! No harm done

When building my -6 I also ran the engine quite a few time with the wings off... and it worked out well for me. No after effects or damage of any kind was apperent..except to my hearing! Its hard to imagine that the wings do anything but possibly dampen some of the torque...from the engine.
Maybe we can submitt this to Mythbusters..
Will running an airplane engine without the wings mounted cause it to fly apart?
 
RickS said:
Maybe we can submitt this to Mythbusters..
Will running an airplane engine without the wings mounted cause it to fly apart?
Click to expand...
I can see it now... "Ok Adam, let's take the worst case scenario. We'll strap a jet engine to an RV-4 and position it in a 20 knot crosswind..."
 
I know a guy

who built a Pulsar...Came to first engine start, no wings and relied on little wood chocks.

Pulled it from the hangar and positioned it 90 degrees to the door...In the next door hangar was my friend Wayne who was finishing up his Walter turbine Glassair 2+2.

The story goes, the little Rotax caught, and the throttle was WIDE OPEN...It jumped the chocks, turned left and careered into the side of the glassair, kocking off the jacks, bending the gear etc etc.

Now Wayne is in a wheelchair, thank heaven he was not not in the wrong place!!!!

If you don't fix the wings for crying out loud at least get a length of rope and a vehicle to tie it to.

Frank
 
Ok, that does it! 9 silly anecdotes, to 3 "I did it and nothing bad happened".
What in the world does a turbine retract operated by a retard have to do with idling a Lycoming????

I have been agonizing over this question for the last 3 weeks, and having read all this I'm going to do it for sure! I have a 400 hr since new engine that hasn't run in 18 months, and I think a good ground run would be good for it! Not to mention the great shot of motivation it would give me!

I have a 4 cylinder engine analyzer, so I can't get it too hot, and I just can't believe there will be any airframe damage....... provided I tie it down properly!

Video to follow!
 
Sorry to burst your bubble John, but a "good" ground never does an engine good. The only run that does an engine good is to fly it and get it up to normal operating temperature. You just can't get up to this point on the ground. If you can't fly it, it's better left alone.
 
The wings act as 2 giant levers which prevent the torque from the engine spinning the fuse. I know an ultralight that did the same thing as that Lancair.
 
Mel said:
Sorry to burst your bubble John, but a "good" ground never does an engine good. The only run that does an engine good is to fly it and get it up to normal operating temperature. You just can't get up to this point on the ground. If you can't fly it, it's better left alone.
Click to expand...

Well Mel, I hate to burst your bubble, but I am going to run the engine anyway! I would love to get this engine up to operating temperature, but I probably won't for the next 12-18 months, and I already see evidence of corrosion in one of the bores. I know the cam and lifters will show the same.

I have electric preheat on the pan, which I know wil evaporate most moisture before and after the start. Watch for the video!
 
gpiney said:
The wings act as 2 giant levers which prevent the torque from the engine spinning the fuse. I know an ultralight that did the same thing as that Lancair.
Click to expand...

Did you by chance read the three testimonials that indicated no problems running without the wings???? GIANT LEVERS??????
 
John,
I certainly didn't mean to insult you. You can do whatever you like. It's your engine. I was simply advising as a A&P mechanic of over 30 years that running an aircraft engine on the ground is never a good thing unless you have a test cell and a proper test club. You will never get the oil up to temp thereby introducing condensate to the interior of the engine.
 
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I too Mel, am an A&P of over 30 years, and I KNOW that any oil is better than no oil. Besides, those old wives tales pre-date the use of electric pre-heaters. You should try one. Only 160 BUCKS.

A test club is only necessary for high-power, extended operation, and my airplane is as well instrumented as any test cell. These engines suffer mightily from extended storage. Mine was never preserved because it was a pulloff from a hangar collapse. I am choosing the lesser of two evils.
 
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I, too, have been running my engine to help keep the internals properly lubed. I've been running it without the prop installed (Eggenfellner H6), which gives me the opportunity to walk around it to check for any leaks or such without worrying about the prop. I can run it for about 10 minutes before the oil and coolant temps get up to normal operating temperature. With a high volume electric fan blowing accross the radiators, I can run it indefinately without it overheating.
As long as one takes precautions to ensure that the plane is securely tied down and no one is likely to be hurt by the prop, I see no reason not to run an engine on a partially completed airplane.
 
I noticed that Kahuna was runing his engine without the wings AND without the tail feathers.

IIRC, (and since I am in the old geezer category, I sometimes do not remember correctly) the RV that twisted the fuselage was running the engine without the wings but with the empenage on. The prevailing wisdom at that time seemed to be that the tail feathers caused the twist in the fuse because they were so far back and would not dampen the torsional pressures from the engine without the wings on.

Has anyone out there run the engine without the wings and WITH the tail feathers on? If so it would kill this theory.

If I decided to run the engine before first flight, I would be sure to start it without any flying surfaces. (Wings or tail feathers) and tie it down securely.


Just my thoughts.

Wes Hays
Winters, TX
N844WB 740+ hrs
RV-7A - Finishing Wings
 
I having been thinking about this from the perspective of the tail dragger RV-7.

When I look at the engine mount and landing gear, it appears to me that the landing gear would transmit any torsional force directly to the ground, without transfering much, if any load to the fuselage.

On my airplane the gear is directly integrated with the engine mount "birdcage", and it is integrated well ahead of the firewall.

Any thoughts? I guess I know a number of builders around here who put the tailfeathers on and started the engine. Many actually taxied around without the wings.
 
Wes Hays said:
I noticed that Kahuna was runing his engine without the wings AND without the tail feathers.
Click to expand...

Id be hard pressed to identify how the tail feathers would have an effect on fuse twist. I also do not recommend this procedure. I was young and dumb back then and would never have done it without my best friend and trusty IA A&P buddy Scott there with me making sure I did not do anything stupid, which I can almost guarantee I would have had he not been there. While I lived to tell about it, that is not a reason to do it. Any number of things could have gone wrong that could have led to disasterous results.

You can bet I did not run the Super 8 without the wings. Yikes! I did turn the engine over till I got oil pressure in my shop several times to lubricate. Also used the moisture plugs which I cycled (by nuking em) several times. I believe there are safer ways to lube and remove moisture. I also accidently turned the engine over in the shop while messing with stick grip wiring and the starter hung, shooting those moisture plugs and pellets all over the place. Scared the bejeses out of me and the family that was 2 floors up listening to to all my racket. I was burried in the cockpit messin with relays. What a dope! :eek: Was like Pearl Harbor in my basement. Good grief I can do stupid things.

Best,
 
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Kahuna said:
I also accidently turned the engine over in the shop while messing with stick grip wiring and the starter hung, shooting those moisture plugs and pellets all over the place. Scared the bejeses out of me and the family that was 2 floors up listening to to all my racket. I was burried in the cockpit messin with relays. What a dope! :eek: Was like Pearl Harbor in my basement. Good grief I can do stupid things.
Click to expand...
This is why that big fat cable going to the starter is in place but not connected, and it won't be until I get to the airport. I could only imagine what would happen if that thing came to life in my basement. OUCH!
 
I wouldn't want to take on the burden...

Being that John is an A&P, he must understand the burden of starting his engine at this time. But for anyone else reading this tread, please understand if you want you engine to last us must run it on a regular basis. This means starting and bring up the oil temp at least three time per month. This should take 20 to 30 minutes of flight conditions. So make sure that you can commit to the time and cost and have the correct condition to do this on the ground if you are not flying yet.
With 12-18 month to go on the project, this could be costly in lost building time as well as taking away from the money for the project.
I understand the desire to hear my project make motor sounds as soon as possible, but I would recommend others to spend the money and time inside a flying airplane (rented if needed).
In Johns cast he is rightly concerned about corrosion. If anyone else finds themselves in a similar situation, I would suggest that you get the engine pickled. If done correctly the engine will be Ok for years and it can be picked for not to much money. It is also very quick to get a picked engine ready for flight.

John please understand that I am not trying to change your mind or am I saying that your have made the wrong decision for you. I only want to pass on my views to other that may be thinking about starting their engine early.

Kent
 
Run and engine lube

Slightly off topic.... I have a pickled engine from Lycon and am still months from flying. Plan to install prop and may have to turn the crank a little to position prop for spacing in our garage. For Mel and others with some experience do I need to do anything to protect it from corrosion if the engine is just turned a little? The garage is slightly heated and stays above 40F. I have Vans heater and could put this on to keep engine core warm - is this a worthwhile thing? For whatever it's worth Vans recommends you not run the engine without wings in place and also suggests tying the plane down - seems a good idea. Bill
 
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Bill,
The problem with turning the engine is that the rings wipe the preservative oil from the cylinders. If you have to do this I would turn it so that 2 pistons are at bottom of stroke, spray preservative oil into those cylinders. Then turn it back 'til the pistons are at 1/2 travel and spray those 2 cylinders. Then leave it alone.
If your shop stays above 40F with low humidity, you shouldn't have a problem.
972-784-7544
 
kentb said:
Being that John is an A&P, he must understand the burden of starting his engine at this time. But for anyone else reading this tread, please understand if you want you engine to last us must run it on a regular basis. This means starting and bring up the oil temp at least three time per month. This should take 20 to 30 minutes of flight conditions. So make sure that you can commit to the time and cost and have the correct condition to do this on the ground if you are not flying yet.
With 12-18 month to go on the project, this could be costly in lost building time as well as taking away from the money for the project.
I understand the desire to hear my project make motor sounds as soon as possible, but I would recommend others to spend the money and time inside a flying airplane (rented if needed).
In Johns cast he is rightly concerned about corrosion. If anyone else finds themselves in a similar situation, I would suggest that you get the engine pickled. If done correctly the engine will be Ok for years and it can be picked for not to much money. It is also very quick to get a picked engine ready for flight.

John please understand that I am not trying to change your mind or am I saying that your have made the wrong decision for you. I only want to pass on my views to other that may be thinking about starting their engine early.

Kent
Click to expand...

Alot of airplanes don't fly 3 times a month, so I'm not sure how important that number is. My engine hasn't seen action for 18-20 months.......that's 60 times your "3 times monthly" regimine. What about that time spent without oil on the cam and lifters and cylinder bores?

The electric preheat evaporates any moisture in the crankcase. If we've seen 3 people say there is no structural damage from running, what is all this debate?
 
What will be will be...

Why don't we just let Yukon John do his thing? After all... it's his engine and if he wants to run it... well who cares... ;-) This thread is not going anywhere. Tie the plane down and start it up. Show us the video... Hello...
 
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Mel said:
Bill,
The problem with turning the engine is that the rings wipe the preservative oil from the cylinders. If you have to do this I would turn it so that 2 pistons are at bottom of stroke, spray preservative oil into those cylinders. Then turn it back 'til the pistons are at 1/2 travel and spray those 2 cylinders. Then leave it alone.
If your shop stays above 40F with low humidity, you shouldn't have a problem.
972-784-7544
Click to expand...
Mel: Thanks for your prompt response. I'll do it! Bill
 
Running the motor w/o wings is one thing - taxi test w/o wings!

DOH! Don't you think an engine run-up (garage/yard or whatever) should include anchoring the airframe to something sturdy enough that you can't "cruise around"?
 
How about no wings, no tail and no prop.

I would like to push the plane out of the garage to fire it up to idle only and check for leaks and see if all the electrical is working rather than deal with these things at the airport. The wings and tail are not on and without the prop on how risky can it be?
 
Yukon said:
Did you by chance read the three testimonials that indicated no problems running without the wings???? GIANT LEVERS??????
Click to expand...
I think levers is appropriate terminology. A lever is a tool used to impart a moment over a distance. Wings do this. They will add mass moment of interia to the plane, acting to stabilize it. Will it make the difference between standing upright and flopping over? At some moderate power setting, probably not.

If you're seeing corrosion in the cylinders, why not spray in some preservative oil to coat the cylinder walls?? That's a no-brainer to me.

If it were me, I'd lash the plane down laterally.
 
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Fallalloveryou said:
I would like to push the plane out of the garage to fire it up to idle only and check for leaks and see if all the electrical is working rather than deal with these things at the airport. The wings and tail are not on and without the prop on how risky can it be?
Click to expand...

That's all I'm going to do too, when I get back into town. The perceived risk varies from "you'll snap your longerons" to "you'll damage your engine by not flying it".

Because there are three guys right here in this thread that have done it with no ill consequences, I think you and I can too! But.......

0) Double check all fuel and oil lines, prop bolt torque.
1) tie down the tail, chock the wheels, so she doesn't get away.
2) preheat if you have one, to evaporate any moisture, before and after
3) no more than 1000 rpm (+-)
4) no longer than a few minutes of run without a cowling and baffles.
5) Monitor CHT - Let it cool between a couple of runs, if you like.
6) Have a fire extinguisher handy

Have fun!
 
Fallalloveryou said:
I would like to push the plane out of the garage to fire it up to idle only and...
Click to expand...
Best laid plans of mice and accidentally reversed throttle linkages...

Jeez, I don't get this. Seems almost like "get-there-itis" as it applies to first engine runs. And it indicates a willingness to cut corners imho. What corners will you cut in your test flying?

I mean...the POSSIBILITY exists for things NOT to go perfectly as planned. Why not at least stack the deck in your favor as much as you possibly can?
 
dan said:
Best laid plans of mice and accidentally reversed throttle linkages...

Jeez, I don't get this. Seems almost like "get-there-itis" as it applies to first engine runs. And it indicates a willingness to cut corners imho. What corners will you cut in your test flying?

I mean...the POSSIBILITY exists for things NOT to go perfectly as planned. Why not at least stack the deck in your favor as much as you possibly can?
Click to expand...

Dan,

With all the risky behaviors you endorse, while airborne, I find it hard to believe you would take a stand aginst this.

So tell us, Dan, how would one go about hooking up a push-pull cable backwards on a sump mounted Lycoming carb? And with a the firewall forward kit that most people are working with from Van's???? And for the
sake of arguement, how would the wings being attached mitigate this risk?

What in the world does a ground run have to do with a test flight program? If anything, our airplanes will be that much more flight-ready when the time comes. Who doesn't do a ground run anyway prior to first flight? I intend to do many.
 
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Low Pass said:
I think levers is appropriate terminology. A lever is a tool used to impart a moment over a distance. Wings do this. They will add mass moment of interia to the plane, acting to stabilize it. Will it make the difference between standing upright and flopping over? At some moderate power setting, probably not.

If you're seeing corrosion in the cylinders, why not spray in some preservative oil to coat the cylinder walls?? That's a no-brainer to me.

If it were me, I'd lash the plane down laterally.
Click to expand...

Bryan,

Because the cam and lifters rust as quickly as the cylinders, and there is no way to spray them.
 
Yukon said:
With all the risky behaviors you endorse, while airborne, I find it hard to believe you would take a stand aginst this.
Click to expand...
Conservatism of convenience, right? :rolleyes: Seems like we're both party to that hypocrisy here and there.

For this engine start thing, it's just that I've heard too many stories that somewhere in there said "and as soon as the engine caught it revved up to max RPM." I haven't seen it in person, but it has happened, right?

It's not likely to happen to you (John) since I guess you're a seasoned A&P. And I mean that sincerely. But when people get eager/excited they do dumb things sometimes.
 
A tad more fuel for the fire....

I'm no structural engineer but I do know that metal remembers...

Say for example that you do an at home ground run with a partially completed airframe, and all seems well with the run. Nothing broke loose, no leaks noted, no apparent damage to the fuse....

There have been many documented cases of inflight structural failure of aircraft (mostly older warbirds) that regularly did aerobatics. It's like wiggling a piece of aluminum back and forth. Eventually it will crack and break in two.
Who's to say that there isn't the beginning of subtle metal fatigue because of a ground run.

Who the heck knows? Not me, that's for sure! I'm sure I will probably play it safe here.
 
I have a suggestion..

If you have a Lycoming engine (flying or building) you need to read the Lycoming Key Reprints. You will find it here:

http://www.lycoming.textron.com/main.jsp?bodyPage=/support/publications/keyReprints/index.html

Quoting from the Key Reprints: Under (Frequency of Flight)

"Flying as often as possible to bring the engine temperatures up to their normal operating levels will help to eliminate moisture. A ground run of the engine only is not considered satisfactory. Frequent flights are needed."

Under (The Unfortunate Choice)

"Any engine that is not used frequently should be preserved."

Under (Low-Time Engine May Not Mean Quality and Value)

"If an engine is to be out of service for longer than 30 days, it should be preserved as specified in Textron Lycoming Service Letter No. L180."



Please read the entire reprints. If your engine is a Lycoming, you should know this information.

What I get out of reading the Lycoming information:

1. If your engine is currently preserved (new or overhauled) don't run it until you are close to your first flight.

2. If your engine is used (not preserved), you either need to start running on a regular basis, or preserve it until you are close to your first flight.

Dont' cut your engine life short by "get-there-itis" as Dan says. Considering all the time spent on your project and the patience required to get it done, have a little more Patience's and wait on engine start-up. The problems found during the first run that will need to be corrected will not take long.

By the way the key reprints also have good information about the steps needed to do the first run.

Kent

Kent
 
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