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Off Airport-AGAIN !!
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fiebichpvMay 17, 2016, 1:25am
Off Airport-again

There I was flying along peacefully at 1000 feet AGL on my way to an afternoon Mid-America Antique Group pot-luck fly-in. My contribution to the fly-in was two packages of cookies because that is about all that will fit in my AirBike's aft storage compartment. Sometimes I eat part of my contribution before loading the cargo or else it won't fit. It is a sacrifice I willingly make.

It was 55 degrees, a bit chilly, my AirBike was running nicely, it had plenty of power and I was a happy pilot. I had been flying for about 1-1/2 hours. One becomes complacent under these conditions. Then, like a sucker-punch in the kidneys, anti-aircraft gunfire exploded from the tree line. Flak bursting around me was causing my little WWI fighter to shake. Suddenly the engine lost more than half of its power, made a strange sound like it was strangling and barely responded to throttle inputs. I was going down!

Damn Huns! This time they were west of Wichita in the area where former hangar mates Bill Bailey, Wayne Clevenger, and Steve Ewing now reside. They were supposed to keep this area clear of intruders. I wondered if they were doing their jobs?  In all fairness, they did clear the air, there were no planes in sight, all the commotion came from the below. Maybe their orders did not include destroying ground artillery?

Kansas is mostly "airport." However, in springtime much of it is un-landable because of maturing wheat crops. Landing in a wheat field would flip a plane quicker than Paul Bunyan standing at a pancake griddle on even a bad day. In short order, I selected a harvested corn field allowed to go fallow from last year. Unfortunately the rows ran perpendicular to the wind. However, on the turn around edge of the field was one swath of corn planted perpendicular to the others. It lined up perfectly with the wind direction, I chose that as my landing strip.

Of the five off-airport landings I have made, this was the smoothest. Making that possible was the well-washed and fallow field. Either that or I am getting good at such emergency touchdowns? Humbly, I think I would say it was the latter.

As the plane slowed on the dirt field, I turned it towards a farm house and came to a stop about 100 yards away. I exited the cockpit and checked the damage.  It must be a coincidence because the Hun's certainly are not so accurate that they can hit an engine's spark plug from 300 yards. But they did! It was blown clean out of its hole with such force that all the threads were stripped. This caused a major compression leak!

An elderly widowed farm wife named Delores, came out to investigate. Driving her steam-powered tractor, she hooked-up then pulled my plane close to her house and under a shade tree. She offered me water and encouragement. This also provided some excitement for her because she had never entertained a handsome, real pilot---ever. In addition to my good looks, it must have been the goggles, silk scarf, and leather jacket that impressed her. I may never know.

Using the widow's wireless, I signaled Vi, my base commander, of the predicament. This caused her to go into action. She unbolted a head from my spare 503 Rotax engine and would bring it along with other appropriate tools (like a torque wrench) to me 40 miles distant. While she was doing that, I used my on-board tools (yes, from that little Rotax plastic pouch) and removed the #1 cylinder head.  During this time the farm wife watched intently and with some amazement at what was going on in her front yard.

Meanwhile, her free-range chickens wandered about clucking and pecking at the earth. I was careful not to step where they had been. I don't like chickens. Years ago I vowed not to make a meal of something that ate with its pecker.

My commander's approach was signaled by the rising dust cloud as she zoomed towards me on the gravel road in her trusty WWI rubber-tired wheeled vehicle.

Within an hour of the base commander's arrival, the replacement head was installed and all those wires and pieces of engine were back in place. A couple of pulls on the Armstrong Starter made that little Rotax engine spring to life. Following ten minutes of engine ground run, it was ready for the real test---flight.

Taxiing downwind far enough to have adequate "runway," I turned 180 degrees and did a full engine run-up. All was good! Feet on the rudder pedals, right hand on the stick, left hand on the throttle, and teeth gritted. I was ready for flight as was my AirBike! Pushing the throttle full forward, I quickly was on my take-off run bumping over decaying corn stubble. Soon my little plane was airborne just in front of its own dust cloud. I made a climbing circling turn. Once satisfied the repair was good, I flew a heading for my home airport 45 minutes away. As I flew over my base commander and the farm wife, I let out a stream of smoke for effect. Both women later said they thought that was a neat way to depart. My hope was that they would not think the engine was coming apart.

An hour before sunset my airdrome was in sight and I began the pre-landing check-list. Descending to 600 feet AGL, I entered the downwind pattern after crossing mid-field. Making left traffic, I entered base leg then final. With the throttle retarded, the airspeed dropped and my altitude decreased. The air was noticeably cooler as I neared the ground. Soon I was gliding with an idling engine and touching down on the sod runway. Safely home!

With my plane refueled, and the post-flight completed, I covered it with tarps and secured it in the hangar. After a couple of gentle pats on the cowl, I climbed into my own military vehicle for the drive home. This airdrome is miles from the nearest village wireless transmitter which makes communication impossible until I get closer. I will signal my base commander when I am within range.

Paul D. Fiebich
a.k.a. AirBike Ace
May 16 '16

Note: like all my stories, this one too is based on an actual event. It is mostly true, however, some of the details have been slightly embellished while others are outright lies. It is up to the reader to determine which is which. Good luck!




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Dick RakeMay 17, 2016, 3:24am
Well done Paul for your cool, calm and collected handling of the forced landing and for the forethought to make sure the Base Commander was properly trained in recovery operations.
RicardoMay 17, 2016, 4:51am
Nice story Paul. Great writing and fine pictures as well.
However, next time, please make us believe that it was a gorgeous young widow who help you and also insisted in staying with her overnight... not an elderly widow  
Arthur WithyMay 17, 2016, 12:38pm
Wow ...what a stretch...LOL.... .....I phoned Pauls wife and she said he needed some excitement so he staged ALL the photos for the Media.....god damn...hes good

Great photos...as always..and some of the story COULD be true..????

Glad to know that Paul....ACE ...!!!!...can land anywhere safely and churn out a good yarn

Ohhh his "Family" is sooo used to it...LOL...or should I say ....the...ETLB....


Well Done Paul

cheers Arthur
Bob HoskinsMay 17, 2016, 5:00pm
Hi Paul
Sorry you had an off field, and glad nothing serious, but sure enjoyed the story, You ARE the ACE bud.
Bob
Fly safe and have fun.
RicardoMay 17, 2016, 11:04pm
I wonder how common is this type of failure in a Rotax engine?
flydogMay 18, 2016, 12:21am
Sully Sullenberger is jealous of you Paul!
fiebichpvMay 19, 2016, 12:32am
Tom, thanks for making the request for more information about the "blown out" spark plug. My comment was in the works but not finished, it is now. I am sure others were waiting for more information also.

An item that was not involved:

1. I am using Penzoil mixed with gasoline at a 50:1 ratio. This had nothing to do with the blown-out plug problem.

Some things that were associated with the blown-out plug:

1. This blown-out plug was the same one that was "loose" (was not loose enough to turn using fingers only, but it didn't take much wrench effort to turn it) in the previous engine seizure incident posted on the board

2.All plugs were torqued to the Rotax manufactures specification of 20 ft. pounds (240 inch pounds) following the seizure repair

3.The blown-out plug had the CHT sending ring on it.

4.The Blown-out plug did not have a gasket (more on that later)

5.The blown-out plug did have a light coating of anti-seize paste (more on that later)

Things to consider when trying to determine why this plug blew out.

1.The spark plug threads in the head may have been damaged from the "loose" spark plug during the previous incident, reducing its grip even though torqued to the proper value.

2.Using anti-seize paste may have contributed to over-torqueing the plug because there was less resistance until proper torque value was achieved. I have read from two sources, (both Rotax reps.) one stating to use anti-seize paste and another (in a chart) stating not to use it. Applying conflicting information is always a difficult choice when determining what to do.

3.Again, from Rotax reps., some say to use the spark plug gasket with the CHT sending ring, others say not to use it. More conflicting information.

4.This engine has in excess of 700+ hours, one complete overhaul including crankshaft, two "top" overhauls, and a third "top" overhaul replacing one seized piston and rings.

5.Following Rotax recommendation, the spark plugs are replaced every 25 hours, that means at least 28 regular spark plug changes thus far. This contributes to thread wear.

6.Additionally, the plugs have been removed numerous times to "read" them during those 700+ hours following carburetor adjustments and brand oil changes. Also broken CHT wires at the sending ring caused more plug removal scenarios. More thread wear.


In summary, I believe the blown-out plug was caused by:

1.Previously damage threads

2.Over torqueing due to using anti-seize paste

From now on I will:

1.Not use the anti-seize paste

2.Use the spark plug gasket on the plug with the CHT sending ring (as well as the other plugs)

4.I recommend everyone make the safer choice as I have in the above two statement.

5.I will repair the head using a replacement thread insert (not a Heli-Coil) called Sav-A-Thread and recommend using it any time a "loose" plug is discovered. Failure is inevitable.

As I have previously stated on other posts, this board offers a wealth of experience and well documented procedures that have worked. It is gratifying to see so many responses to these types of situations, however, ultimately each of us must make the decision they feel best suits them and what they believe in.

All of us will be looking forward to the comments others have on this topic and their experiences.

Paul D. Fiebich

stevejahrMay 19, 2016, 1:08am
WRT thread wear and heli coils: my understanding is that heli coil repairs can provide a stronger thread than original.  And given threads in aluminum, a heli coil will upgrade the wear surface of the threads to harder steel thus greatly reducing or eliminating thread wear as a concern.
fiebichpvMay 19, 2016, 3:30am
A Heli-Coil will leak under the engine's compression. The preferred fix is to use the solid type of steel insert per the brand I mentioned (or a similar one). The Sav-A-Thread is called a "Spark Plug Port Repair Kit" and is meant to be used in both steel and aluminum heads. It is manufactured by Stanley.

Paul D. Fiebich
Arthur WithyMay 19, 2016, 8:50am
Hey TTT...Paul has always been Impressive...!!
Sterling SilverMay 20, 2016, 4:46am
For what it's worth, in days of yore, when working on certificated (is that the correct term?) engines, the correct procedure was to use anti-seize compound and torque the plugs. The anti-seize was to be sure one could remove the plugs next time. Spark plugs were the only place that I religiously used anti-seize. Perhaps the guy before me had over-torqued the plugs that were difficult to remove, I can't say. I would stay with the anti-seize, but that's just another conflicting opinion.

When I get conflicting reports on correct procedures I revert to what has worked for 100 years in aircraft, automotive and stationary engines, if I know what that is. (The earlier part of that time period I would have learned from others, by the way. )

The aircraft engines had brass or bronze inserts in the heads that were threaded for the spark plugs. If you are screwing the plugs into aluminum, there might be a different issue with anti-seize compound. I don't think that is the case, I just threw that in to cover a remote possibility of which I might be ignorant.

Enjoyed the story, and maybe I don't know you well enough yet, but I believed that you had lost a plug. Now - the widow, not at all until I saw the picture of the plane under the tree, then I wasn't sure. She was probably named Edgar and had a beard to his, I mean her, belly button, but I enjoy it the way it was.
Bert
fiebichpvMay 20, 2016, 2:41pm
The spark plug had physically backed out of the hole about half an inch. The spark plug retainer spring that holds all the plug caps in place stopped it from exiting the engine completely and hanging from its plug wire. According to the published chart for using anti-seize paste on Rotax engines, the 503 was specifically identified as one not to use the paste on. I do recall that the 912 and 914 Rotax engines were identified as ones on which to use the paste. Unfortunately, I just cannot make sense of the second to last and the last sentence of your recent post. Sorry, but I am just not connecting. What am I missing?

As always we appreciate your comments, you have a vast experience on engines.

Paul
Sterling SilverMay 20, 2016, 3:48pm
Quoted from fiebichpv Unfortunately, I just cannot make sense of the second to last and the last sentence of your recent post. Sorry, but I am just not connecting. What am I missing?

As always we appreciate your comments, you have a vast experience on engines.

Paul


I was meaning to dig you about embellishing your story by claiming that a widow came out to help.   Then when I saw the picture of the plane under the tree I decided maybe there was also a widow.     However, since the author might sometimes "remember bigger than actual", maybe it was just an old farmer who towed the plane.  
I just meant to go along with the others who kid you about maybe adding to your stories. I really don't care if everything in the story was fictional except the plug's coming loose. It's a great way to present what happened, what caused it and what you did to fix it. I appreciate the education.

I would do as you plan concerning the anti-seize. If the Rotax book says not to use it and your previous experience has not indicated a need for it, then I, personally, would not use it. It has been a long time since I flew with a Rotax.

Hope the ground attack on the Huns improves up there so that you have no more adventures of that nature.

Bert
stevejahrMay 20, 2016, 3:53pm
Quoted from fiebichpv A Heli-Coil will leak under the engine's compression. ...


Call me skeptical on that one.  The sparkplug gasket covers leakage in the thread area for both native and heli-coil.

The bigger problem with heli-coil is improper installation: using the wrong coil for the application and thus having either a gap without threads or excess coil hanging out either end.  If extended into the chamber the coil makes a very good glow plug leading to pre-ignition which can lead to detonation.  That is probably enough in aircraft applications to bias towards full thread replacement types of solutions.
beragoobruceMay 21, 2016, 3:24am
Thanks for both the story & the lessons learned from it, Paul. Great post.
aeronutMay 21, 2016, 8:38pm
Thanks for the narrative Paul. Many lessons to be learned from it.
never surrender; never give-up
fxflyrJanuary 9, 2017, 8:47pm
Paul wrote in the main story: Making left traffic, I entered base leg then final. With the throttle retarded, the airspeed dropped and my altitude decreased. The air was noticeably cooler as I neared the ground. Soon I was gliding with an idling engine and touching down on the sod runway. Safely home!

I am sort of new flyer (< than 100 flights behind a 2 stroke Hirth). I have noticed that if I pull the thottle all way back to idle at the end of downwind that my EGT's stay nice and low. I am descending at a fairly sharp angle but maintaining good airspeed. As I enter the short short final I can add a bit-o-throttle and she settles in smoothly. I am interested in you telling me about your "throttle retarded". My reading and actual experience says that partial throttle causes those EGT's to soar into the red zone. BTW I usually run my chain saw either wide open on at idle with a few blips in between just to sound like I know what I am doing.

thanks  Tommy
radfordcJanuary 10, 2017, 5:02pm
You can safely reduce throttle to partial power as long as you don't lower the nose of the plane.  Reduce throttle and raise the nose puts you on the "back side of the power curve".  You increase rate of descent without increasing speed.

However, I'll bet when Paul said "throttle retarded" he meant all the way to idle.
Kaliche KidJanuary 11, 2017, 7:46pm
Quoted from fiebichpv According to the published chart for using anti-seize paste on Rotax engines, the 503 was specifically identified as one not to use the paste on. I do recall that the 912 and 914 Rotax engines were identified as ones on which to use the paste.


Love the lessons learned in your "adventures against the Huns" style. Do you happen to recall if the 447 engine was on that chart as for or against the anti-seize paste?
Abraham
fiebichpvJanuary 12, 2017, 5:58pm
When coming in for that landing, I was already at less than half power while in "the pattern." I kept it at that throttle setting until I was assured of landing because that was all I could get out of the engine. By the time I figured out that the engine wasn't going to come back up and I knew landing was inevitable, it took less than 30 seconds to touchdown. I typically land with some power on to provide additional rudder control, so it is likely that I didn't go to idle until just prior to touchdown. I don't recall looking at the temperature gauges.

the chart identifying use and no use of anti-seize on the Rotax engines was is one of the 2015 Sport Aviation magazines. I don't recall which, but will try to find it and report back.

Delores was indeed the property owner and she did use a 4-wheel vehicle to tow me to her yard and under the tree. However, in reality, the vehicle was a 4-wheeler used to supplement farming activities. This landing did provide a bit of excitement for her and later she stated that it gave her bragging rights during her weekly poker games! When the article was published in Powered Sport Flying magazine, I sent her a copy along with an AirBike business card and several post cards. She sent me a Christmas card stating "Thanks for the memories". we make friends in the strangest places.

This is my favorite off-airport landing and I am happy to share it with you for whatever enjoyment and benefit can be derived.

Paul Fiebich
fiebichpvJanuary 13, 2017, 3:39pm
At last, I found the two articles dealing with use of anti-seize compound on two-stroke Rotax engine threads. Below are two excerpts from two sequential issues in the EAA Experimenter magazine. This information is exclusive of that which is applied to the Rotax Series 9 (four-stroke) engines in which such lubrication is recommended.

The Experimenter magazine is co-joined with Sport Aviation magazine, it is no longer a stand alone magazine.


--------------------------------------------------------------------------------


"EAA Experimenter Magazine Vol 6 #2 February 2016
by Carol & Brian Carpenter

Over-torque of the spark plug can damage the threads in the cylinder head, in turn reducing the ability of the spark plug to transfer heat into the cylinder head. Both Rotax and NGK recommend against the use of an anti-seize compound on the spark plug threads. The anti-seize compound significantly reduces the friction, and over-torquing the spark plug becomes very likely. Also, the anti-seize compound is typically an electrical conductor, which, if it propagates to the electrodes, can short out the spark plug causing ignition failure.

NGK manufactures its spark plugs with a corrosion resistant coating that is designed to be installed into the cylinder head without any thread lubrication, which is the recommended procedure for the Rotax two-stroke engines."

Recommended spark plugs for two-stroke Rotax engines: NKG BR8ES (for plugs up engine installation--clarification by Paul.)
From another source Rotax recommends using the NKG BR8EIX (for plugs down engine installation--clarification by Paul)

Paul's comment: Although not mentioned above, the article also states that the intended purpose of anti-seize compound is to facilitate heat transfer from the spark plug to the cylinder head. However, notwithstanding, some mechanics use anti-seize to reduce the potential for the dissimilar metals of steel and aluminum from "rusting" together in the presence of combustion moisture.


--------------------------------------------------------------------------------

Additionally, the following might be worth noting.

"EAA Experimenter Vol 5 #3 March 2016
by Carol & Brian Carpenter

The Rotax manual is very clear on the subject, 'Attention: Never clean spark plugs with an abrasive cleaner.' We do know that the use of media blasting does help to round off the edges on the electrodes. It is the sharp edges of the electrode that promote a good clean spark.

Cleaning, if at all, should be relegated to the task of spraying with carb cleaner and then blowing them out with an air nozzle. If you have a spark plug condition in need of more than this, you would probably benefit from new spark plugs.


All of the debate about cleaning automotive type spark plugs used in the Rotax engine is really kind of irrelevant. A properly set up, maintained, and operated Rotax engine should never see any problem with spark plug performance in between the required spark plug inspection or change interval.

Only engines that have some significant deficiency require extraordinary spark plug maintenance."

I hope this is useful information and answers Kaliche Kid's anti-seize paste question.

Paul D. Fiebich
radfordcJanuary 13, 2017, 6:51pm
I have used anti-seize lube on Rotax sparkplugs for going on 20 years with no problems.  I do not install plugs with a torque wrench!  Tighten the plugs by hand until they are in the "Goldilocks zone"...not too loose, not too tight.
bigblockz8January 17, 2017, 10:55pm
Quoted from radfordc I have used anti-seize lube on Rotax sparkplugs for going on 20 years with no problems.  I do not install plugs with a torque wrench!  Tighten the plugs by hand until they are in the "Goldilocks zone"...not too loose, not too tight.


We used "German" torque when I was in a flight school shop for most stuff...Gutentight. But for the plugs we did the torque values specified by Lycoming with a torque wrench (believe it or not a lot of A&P's I have worked with don't use or even know the value).

We always used anti seize but when I forgot it once I did notice that the plug seemed to tighten more quickly vs. with it. After breaking a plug that was over torqued (only 90in lbs over...) and had no anti seize it was a PITA to get it out. We dremeled a slot and used a screw driver (an over zealous co-worker used an impact wrench and twisted part of the plug off).
flycanadianguyJanuary 28, 2017, 4:20pm
Great story good read! ๐Ÿ˜€