Author Topic: General Aviation Pilots Can Appreciate This - Modelers too!!! (Read 6968 times)

Robert Zambelli · « **on:** April 29, 2009, 08:37:21 AM »

THIS can ruin your day.

And you thought it was bad to burn out a glow plug

Two weeks ago, I was flying my Piper PA 28 up to Pennsylvania to help a friend who had just undergone surgery.
It was a beautiful VFR day and was with flight following at 2,500 feet. Suddenly I heard a VERY loud noise and the plane began shaking violently.

Just like in the movies, I called "MAYDAY", informed ATC that I had a failing engine and I needed vectors to the closest airport. Fortunately, a 90 degree right turn pointed me at an airport 10.4 miles away. The power was way down but I landed safely. Even with a 20 knot tailwind, I landed downwind since it sounded like the engine was ready to let go and I did not want to risk a pattern procedure.
Turning the prop by hand, we found two cylinders with no compression.
We removed #2 cylinder and found what is shown in the pictures - Besides trashed head, plug and piston, the exhaust valve was GONE!!! Not a trace of it anywhere.
Expecting similar carnage, we didn't bother removing cylinder #1.
Most puzzling in that this particular engine, a Lycoming O-320 did not have all that much time on it, around 1,300 hours. Furthermore, it is considered to be one of the most reliable aviation powerplants ever built. Oh well, just my luck!

I've decided that instead of a rebuild that I will go with a zero-time engine from Lycoming.
Bob Z.

Chad Hill · « **Reply #1 on:** April 29, 2009, 08:43:38 AM »

Nice job keeping your cool in such a high pucker-power event.--Chad Hill

Bruce Feaver · « **Reply #2 on:** April 29, 2009, 08:52:25 AM »

Awsome job on your emergency Bob, well handled. I had a student doing circuits in the pattern one night in a C-150 and this very thing happended to him. The engine went to 1500 rpm and stabilzed, at that rpm in the middle of the downwind, he made the approach and landed safely. The Valve Face went 90 degreed and punched a hole in the piston and that dropped the compression in that cylinder to zero. The engine continued to run on three jugs. Investigation revealed that other students had been over leaning the engine on cross contry trips to deal with "low gas" issues and over time this became a weak point for the exhaust valve and it failed. The valve face was discovered in the lower parts of the engine. So good job in handling your event, I give you a "Good Show" for your efforts at keeping safe.

Bruce Feaver
Military Instructor Pilot
Grob 120A

john e. holliday · « **Reply #3 on:** April 29, 2009, 09:08:33 AM »

Great to hear you made it down safe and sound. Do you ever practice for situations like this when you are just flying for pleasure? DOC Holliday

Bill Heher · « **Reply #4 on:** April 29, 2009, 11:52:51 AM »

Downwind straight to the runway probably looked pretty good when you are holding your breath and trying to keep the prop turning through sheer mental willpower!

Isn't it amazing how an aluminum piston can beat a hardened valve head into small enough pieces to let it all blow out the exhaust?

At least the jugs stayed on and you don't have to spend extra money to get the cowling repaired, not to mention having the seat cleaned.

Good job and congratulations on passing the " Stress Test" with flying colors!

FLOYD CARTER · « **Reply #5 on:** April 29, 2009, 12:44:02 PM »

Wow! A sick engine can certainly increase the pucker factor. About 1980, or so, my Focke-Wulf 44J was being flown to Oshkosh (by my partner). Somewhere over the Rockies, the engine got sick. After landing, he found one of the valve pushrods was missing! This is a 7 cylinder radial Siemens 150 hp engine. I don't understand how it could get loose, but fortunately, a substitute was quickly found and installed. The plane finally made it to Oshkosh for the fly-in.

floyd

Tom Niebuhr · « **Reply #6 on:** April 29, 2009, 02:22:20 PM »

Good job Bob.

Since it is very expensive no matter what, the Zero time engine is also a good investment

Pinecone · « **Reply #7 on:** April 29, 2009, 03:14:47 PM »

OUCH.

Good job though.

Worst I had, was a stuck exhaust valve in C-172. Of course, this happened at about 100 feet of altitude, off a shortish runway, near gross. And nowhere nice out front to set it down. But 3 cylinders provided enough power to hold altitude and fly a very close in pattern, but on final, it cleared up. And since field had NO services (First Flight)....

So a nice spiral climb until enough altitude to glide to the next field, and staying within gliding distance of a field, hopped back home.

Figured it was lead buildup from 100LL in a 80/87 engine.

Steve Fitton · « **Reply #8 on:** April 29, 2009, 03:20:22 PM »

Well done Bob! Glad you made it down in one piece and the plane is fixable. That makes a great (albeit expensive) "there I was" story.

As an aside, the piston in my brother's XR-75 motorbike looked like that after he couldn't find a carb screw while tinkering on it. We did find what was left of the screw after the engine quit...

Clancy Arnold · « **Reply #9 on:** April 29, 2009, 04:32:16 PM »

Engine failure is never a nice day.

I used to own an Ariel Square Four motorcycle. The engine has 2 counter rotating crankshafts! I donot think it would take very long to find a "missing screw" in this engine.

There is a flywheel in the center of each crankshaft and the flywheels overlap.
Clancy

Dick Fowler · « **Reply #10 on:** April 29, 2009, 05:28:13 PM »

Good job but it helps that the good Lord was in the right seat... he must have something really good that he wants you to do... maybe at Brodaks?

roger gebhart · « **Reply #11 on:** April 29, 2009, 06:20:31 PM »

Nothing like that "I knew it all along" feeling when the wheels touch. Can't cover up the racket from the knees knockin' though. Good job Bob. rog

Ironbomb · « **Reply #12 on:** April 29, 2009, 07:05:29 PM »

Robert, glad you turned the emergency into an uneventful incident. How long have you been flying? Any thoughts as to what let go? keeper break? Hope you have many more happy landings. Greg

Robert McHam · « **Reply #13 on:** April 29, 2009, 07:19:22 PM »

Back in the '80s Our work had a new Ford Courier truck, made by Mazda but with the Ford 2,3L popular with Ford at the time. Less than a thousand miles it had on it when i was driving it, made the left turn to get on the interstate on ramp. I just hit second gear in the turn and all of a sudden the engine sounded like it was coming apart!
I only heard the noise for a few seconds at most but I could not believe how loud it was. I can almost imagine whay your noise was like but I cannot compare the rest as I was not 'at altitude' and having to stay calm while I looked for a soft place to land.

Turns out that one of the carburetor studs had backed itself out and fell into the intake only to find its way to the top of # 1 piston. There it did a dance of death. Company got a new engine out of it but truck was down for over a week. Boss was unhappy that whole week!

Robert

bob branch · « **Reply #14 on:** April 29, 2009, 08:07:17 PM »

Once again the truth comes out. Flight training is the best training available anywhere. Most of us pilots just keep getting higher ratings cause the teaching is so good. The Most gifted teachers I have ever had were flight instructors. The training is so good when an emergency comes up you are ingrained to do it so right it usually works out. My worst was an engine failure at 600 ft on takeoff over downtown Detroit. But same as Bob's deal, the training takes over and you do the right stuff. Good work Bob.

Oh yea, you don't start shaking doesn't start til you are on the ground. That's why emergency landings always look so good on TV.

bob branch

Jim Pollock · « **Reply #15 on:** April 29, 2009, 09:42:59 PM »

Ty,

Back when I was young and stupid.....well just plain stupid I guess, I used to have dogfights with ducks using 150's.
I guess I'm glad that I didn't catch any.........ugh!

Jim Pollock

Garf · « **Reply #16 on:** April 29, 2009, 10:12:02 PM »

I rebuilt a Corvair engine that looked like that inside. It had swallowed a valve seat.

Mike Scholtes · « **Reply #17 on:** April 29, 2009, 10:49:15 PM »

Well the answer to this inflight emergency seems obvious to me: Just glide until you come to the Hudson River!

Seriously, as a long time ragwing flyer I can imagine what went through your mind when the engine let go. As we say, in an emergency you default to the level of your training. You must have had some good instructors along the way. And you can pat yourself on the back for keeping a level head. At least you had a plane you could put down on a golf course or country road, depending on the terrain.

Small plane pilots are taught to always be scanning the terrain ahead and around you for a possible emergency landiing site; it becomes second nature eventually. Luckily our boy did not have to test his off-field landing skills.

Chris McMillin · « **Reply #18 on:** April 30, 2009, 12:54:25 AM »

Had a valve drop the poppet end off on a Pratt&Whitney R-985 near Portland one day cruising IFR in the Twin Beech in and out of the clouds flying down to SoCal. It started shaking, I richened it up, it kept shaking so I shut it down and declared an emergency.
Broke out of the clouds nice and high on vectors to Portland Intl, landed and called the boss at Paine Field to send a cylinder with a mechanic.
Next morning we put on a cylinder, ran it up, and off we went. It ran about another 1000 hours!
Chris...

Bill Heher · « **Reply #19 on:** April 30, 2009, 09:01:04 AM »

Gotta love that P&W toughness!

Charlie Pate · « **Reply #20 on:** May 05, 2009, 11:26:06 AM »

this is /was a fairly common problem in air cooled auto motive engines.
The oh so durable VW bettle engine , proved not so durable, when
installed in the hatch back.
problem: oil breakdown due to usual factors (not enough; too long between
changes; improper grade.
Oil temp went up ;air temp from oil cooler was increased and blown
over the left front cylinder by the cooling fan, resulting in increased cyl
head temp and valve in guide seazure.
Then, here came the piston.

The pontiac (I am told ) Fiero , though water cooled, due to low oil capacity
in the crancase, as well as the usual oil abuse listed above, resulted in
connecting rod failures and a in some cases a rod in the gas tank .
In this case it was known to really become a FIREO.

Then sometimes things just break.
A fellow I new years ago,had a new johnson 35 .He carefully broke it in and had it
on a stunt plane he was using to teach his wife to fly.
It was on the ground running a fast four cycle as his wife was walking out
to the handle; the engine came to a sudden stop!
Problem , a broken con rod.

Darrell Mims · « **Reply #21 on:** May 07, 2009, 12:33:38 PM »

Somewhere at home I have a picture of a Cylinder with the aluminum head stripped off .Since the piston was riding up and down in the cyl. we just had a miss. On aircraft engines the Alum. head is screwed on to a steel cyl. There were some models that had a problem of this happening ,and I think they were Lycoming engines .

Dick Fowler · « **Reply #22 on:** May 07, 2009, 01:12:10 PM »

Quote from: Mike Scholtes on April 29, 2009, 10:49:15 PM

Small plane pilots are taught to always be scanning the terrain ahead and around you for a possible emergency landiing site; it becomes second nature eventually. Luckily our boy did not have to test his off-field landing skills.

Very true. I live in rural Ohio so there are lots of places to choose from most of the time. However, my flight instructor liked to make me fly into Burke Lakefront Airport right in downtown Cleveland. As we would start getting into the heavily populated suburbs of Cleveland, my pucker factor would go up by a magnitude of ten. Isn't any way that I or people on the ground were going to get away with out serious problems in a forced landing in that situation. Give me cornfields any time.

John Stiles · « **Reply #23 on:** May 07, 2009, 01:41:19 PM »

That valve had to have detonated, and pieces migrated into the other cylinder....I don,t believe that an aluminum piston could shatter a valve. On a low hours engine...shouldn't have happened at normal operating RPMs. But a valve with a factory flaw might do that....maybe you'd like to go to a different engine.....how about a Mitsubishi

taildragger-j3 · « **Reply #24 on:** May 07, 2009, 03:30:42 PM »

Lost the exhaust valve in #4 cylinder in an O-320 in a C-172. Managed to glide to about 100 yards short of the end of the runway and landed in a cotton field. Everything would have been OK except for the irrigation ditch at the end of the rows. Flipped over on it's back with the tail almost on the threshold. Not a good day!!

john e. holliday · « **Reply #25 on:** May 07, 2009, 03:58:36 PM »

Years ago there was a single engine craft that landed on I-35 in the medial strip. Had enough room from one over pass to the next that he plenty of room. He stated he was lucky that there were no culverts in the medial strip. By the way, once the problem was fixed the highway patrol stopped traffic on southbound lanes so he could take off. DOC Holliday

John Stiles · « **Reply #26 on:** May 07, 2009, 04:27:34 PM »

Most pilots would do well to train on the short landing....like vietnam era pilots did for the c-130s. Very short landings[and takeoffs can be achieved with the proper technique!

Chris McMillin · « **Reply #27 on:** May 07, 2009, 04:44:06 PM »

Off airport landings are not ideal, but highways are often sites of successful ones.

A P-51 Pilot had an engine failure in the 80's and landed on a divided highway with enough energy to roll off and park in a truck stop. I had a picture of it sitting in it's parking space with traffic cones around it, maybe I can find it. Once the problem was rectified, the highway was blocked and the Mustang flown off the highway to depart, cool.

Best Mustang street departure I have ever heard of, now that I've highjacked this thread completely, was the Planes of Fame's N5441V taking off out of the city of Buena Park departing the now closed "Cars of Stars/Planes of Fame" facility on a four lane city street, awesome.

That reminds me of Lyle Shelton gear-down ferrying a Mustang for a restorer and having the fuel selector valve handle break off in between tanks while over Lome Linda, Ca. It quit cold. He glided it OK into a field (there were still fields in SoCal in the 80's), but I think they put it on a low-boy for the rest of the trip from Compton to Chino. Good thinking.

Chris...

Darrell Mims · « **Reply #28 on:** May 08, 2009, 06:39:28 AM »

Quote from: John Stiles on May 07, 2009, 01:41:19 PM

That valve had to have detonated, and pieces migrated into the other cylinder....I don,t believe that an aluminum piston could shatter a valve. On a low hours engine...shouldn't have happened at normal operating RPMs. But a valve with a factory flaw might do that....maybe you'd like to go to a different engine.....how about a Mitsubishi

OH yes !!! the piston will bend the valve and break it off, then it rools around in the cylinder making a smooth top piston into a knerled blob of metal and has busted thru in some cases

John Stiles · « **Reply #29 on:** May 08, 2009, 07:08:17 AM »

Quote from: Darrell Mims on May 08, 2009, 06:39:28 AM

OH yes !!! the piston will bend the valve and break it off, then it rools around in the cylinder making a smooth top piston into a knerled blob of metal and has busted thru in some cases

Oh, don't get me wrong...I've seen that, even found a brass screw imbedded in a piston that never made a single complaint. I found it when I decided to rebuild the motor. I'm thinking.....shattered valve....! The way I understood it, the motor was pretty low hours....why or what would make the piston strike a valve under normal operating conditions? Maybe the plane aspirated something foreign and broke the valve stem....but I'd expect to see the valve imbedded or even driven through the piston.....but the picture doesn't show that. And where did the valve head go?

Wayne Collier · « **Reply #30 on:** May 08, 2009, 07:22:00 AM »

Just a guess, but looking at the picture, I suspect that the valve head may be partly hammered into the piston. Smaller bits may have gone out the tailpipe. It was the exhaust valve. With the port now open, anything small enough was likely blown on out.

Back in the early 80s I went with a buddy of mine to a machine shop in Arlington, TX to get a 350 short block reworked for his Camaro. The machine shop had a display case of failed parts that they thought were unusual or impressive enough to put on display. There were several bits of "engine history" to see. I was especially amazed at a connecting rod that was bent almost double.

RC Storick · « **Reply #31 on:** May 08, 2009, 08:00:32 AM »

Quote from: Charlie Pate on May 05, 2009, 11:26:06 AM

this is /was a fairly common problem in air cooled auto motive engines.
The oh so durable VW bettle engine , proved not so durable, when
installed in the hatch back.
problem: oil breakdown due to usual factors (not enough; too long between
changes; improper grade.
Oil temp went up ;air temp from oil cooler was increased and blown
over the left front cylinder by the cooling fan, resulting in increased cyl
head temp and valve in guide seazure.
Then, here came the piston.

The pontiac (I am told ) Fiero , though water cooled, due to low oil capacity
in the crancase, as well as the usual oil abuse listed above, resulted in
connecting rod failures and a in some cases a rod in the gas tank .
In this case it was known to really become a FIREO.

Then sometimes things just break.
A fellow I new years ago,had a new johnson 35 .He carefully broke it in and had it
on a stunt plane he was using to teach his wife to fly.
It was on the ground running a fast four cycle as his wife was walking out
to the handle; the engine came to a sudden stop!
Problem , a broken con rod.

What we see on Harley's is the valve stem gets worn and oil starts seeping down on the exhaust valve and leaves a deposit. It hardens and holds the valve open. Then the position hits it and the same thing happens. I would say this is what happened to this engine. Not a uncommon occurrence in air cooled 4 stroke engines.

After examining this picture this is what exactly happend to this engine. But good job getting it on the ground.

Robert Zambelli · « **Reply #32 on:** May 11, 2009, 06:24:36 AM »

Hello all and thanks for the interesting comments, complements and advice.
Yes, when something like that occurs, the pilot training kicks in, no matter how far in the past.
My instructor always stressed that no matter what, "FLY THE AIRPLANE". Once everything is in place, checklist applied, search for a landing spot (in case the engine let go before I made the airport), it just becomes a waiting situation. Even though I had the field in sight, I had no idea how long the powereplant would hang on so I just continually looked form airport to ground, just in case. If I had to go "off airport", it may not have been all that bad since it was fairly flat all around. But still -------------------------------.

Robert S: What you said makes a lot of sense in that the residual from oil burn-off can eliminate all guide-to-stem clearance and lock things up. The Lycoming design is called a parallel setup in that should there be a piston/valve impact, it would be square on, slamming the valve shut and supposedly not breaking it. Also, aviation oil is low ash dispersant which should minimize carbon deposition from burn off.
Regarding lead build up on the stems, I have an autofuel STC and I use a lot of low-lead automotive fuel. When I check the plugs, they're like new.

Who knows? In any case, the main issue now is preparing my wallet for the shock!!!

Thanks again to all who responded,

Bob Z.

RC Storick · « **Reply #33 on:** May 11, 2009, 07:33:34 AM »

Well how I know for sure this is what happened because its always the exhaust valve that does it. If it sticks open far enough it does not matter how square it hits the piston. Not sure how many RPM you were turning at the time but lets say 2000 (could be more or less RPM with same results) , so the piston hit the valve 33 times in one second. That can do a lot of damage in a second.

This engine is obviously a interference fit engine. Bad design in my book for a aircraft engine. A interference fit engine is any engine that the valve train in its open position will contact the piston at TDC (top dead center). Most high performance engines are designed this way. The Japanese wised up and redesigned their car engines so when a cam belt broke it didn't wipe out the whole engine.

Robert Zambelli · « **Reply #34 on:** May 11, 2009, 09:19:52 AM »

Hi, Robert - good call BUT----------------------------------
I think it may be a clearance engine. The C/R is only 6.5:1.
It was turning 2,450 RPM
There is a good chance that the valve just plain broke without any contact.
Secondly, when a valve stem has enough buildup to hang it open it usually gets jammed into the guide. In my case,, it was completely gone.

I did have a situation in a car when a valve adjusting broke at the locking nut. It screwed in, crashed the valve but the valve only bent.

Bob Z.

RC Storick · « **Reply #35 on:** May 11, 2009, 09:29:05 AM »

Could the valve guide be gone because of carbon build up causing it to brake off and get shot out the exhaust pipe? Probably so. But one thing is for sure its broke!

EddyR · « **Reply #36 on:** May 11, 2009, 09:41:43 AM »

Back 10 years a friend and I had rented a C172 about 10 times at Clearwater Executive Airpark. We liked this one plane so we rented it instead of some others they had. It went in for a motor rebuild and a new pilot took two friends for a ride after the rebuild. She was over Clearwater beach at 500ft when the motor stopped. She put the plane down in the soft sand in a short distance with people all around.The clear part of the beach is not very long.I went and looked at the scene and it is amazing she didn't flip over as she went over three maintenance ditches and just cleared a long dock.We had called and were going to rent the plane but were told it was rented.She also landed 90 degrees to the wind.There were three fatal crashes at Clearwater Ex when I lived there and they were all shortlandings.The motor failed because the long bolts that hold the head to the block were defective and stretched.
Ed

John Stiles · « **Reply #37 on:** May 11, 2009, 10:18:45 AM »

I still believe the engine aspirated some foreign object....maybe a loos nut or screw from the carb....it does happen, I've seen it in a 2 cyl. Popping John[john deere]!

Phil Bare · « **Reply #38 on:** May 11, 2009, 10:25:47 AM »

Robert, a safty precaution that I learned years ago is to run a can of marvel mystery oil in each tank if you are using auto gas, the low lead content of auto gas will not keep the lube level of the valve stems up where it needs to be.
The 320 also had an upgrade on the exahaust velve stems from 7/16 to 1/2 and it was done for the very reason that put you on the ground.
Always add top lube if you are running auto gas. I have used MMO in 0235, 0320, 0360, and 0540 lycomings for many years and have had good results with it.

billbyles · « **Reply #39 on:** May 11, 2009, 03:04:13 PM »

Quote from: Phil Bare on May 11, 2009, 10:25:47 AM

Robert, a safty precaution that I learned years ago is to run a can of marvel mystery oil in each tank if you are using auto gas, the low lead content of auto gas will not keep the lube level of the valve stems up where it needs to be.
The 320 also had an upgrade on the exahaust velve stems from 7/16 to 1/2 and it was done for the very reason that put you on the ground.
Always add top lube if you are running auto gas. I have used MMO in 0235, 0320, 0360, and 0540 lycomings for many years and have had good results with it.

While Marvel Mystery Oil will no doubt work just fine, you might want to see if it is included in the Auto Gas STC and approved for aviation use as stated. Something working just fine and being FAA approved are two different things. Not having FAA approval for something like this is not a trivial thing.

Robert Zambelli · « **Reply #40 on:** May 11, 2009, 06:21:37 PM »

I installed the autofuel STC in 1991 and have run autofuel almost exclusively. I also add about 8 ounce of MMO to a full tank of fuel.

Bob Z.

Dennis Adamisin · « **Reply #41 on:** May 11, 2009, 07:20:28 PM »

I dunno Z-man. I think I liked it better when you only blew-up Surpass 40's.

Sheesz this is a scarry story - glad you kept your wits an got it down OK

Phil Bare · « **Reply #42 on:** May 11, 2009, 08:10:08 PM »

Quote from: Robert Zambelli on May 11, 2009, 06:21:37 PM

I installed the autofuel STC in 1991 and have run autofuel almost exclusively. I also add about 8 ounce of MMO to a full tank of fuel.

Bob Z.

Had your engine been converted to the 1/2 inch valves?

Jim Pollock · « **Reply #43 on:** May 11, 2009, 08:56:36 PM »

Well, lets see now...Once again I used to chase ducks for fun in a Cessna 150.

Another time flying the return flight on a charter to San Diego my oil cooler in a Cessna 206 broke itself in half and drained all the oil over the side of the fuselage. Of course I didn't notice until the cylinder head temperature started rising while over the Lake Hughes VOR which is on the crest of the tehatchapee (sp of course) mountains north of LA. I took it down the north slope with about 1/3 throttle using the old flying motto "half of something is much better than all of nothing"; I managed to land the plane in a little town near Apple Valley? I guess it's been so long ago I can't remember much, but I did call for a backup plane to pick me up. That was in Feb 69 and a lot of ground fog in the central valley diverted me from Modesto to Oakdale to land, and boy we just barely made it in too!

Whew!

Jim Pollock

Pinecone · « **Reply #44 on:** May 12, 2009, 09:45:32 AM »

We used to run MMO in 80 octane engines fueled with 100LL to prevent valve sticking. None when we switched to auto fuel. But the engine did get some 100LL every so often, so not truely unleaded.

An interference engine may run without valve damage with the valve partially open. The interference can be only at full valve lift. But a valve stuck due to sticking in the guide can be stuck wide open. Crap on the valve seat will not hold the valve wide enough open for most engines to make piston - valve contact.

But some engines can have valve - piston contact from floating the valve due to too high of RPM. The Ford Escort engine used in my race car can, and has, done this.

Ted Fancher · « **Reply #45 on:** May 12, 2009, 06:01:10 PM »

Bob,

I'm just curious if you filed a NASA/ASRS report on the incident?

Ted Fancher

chuck merkel · « **Reply #46 on:** May 13, 2009, 09:29:40 PM »

Bob, Glad to hear that you were able to land safely. Although I haven't piloted an airplane in 30 years you are absolutely right about the training kicking in during an emergency. I was my Dad's second private pilot student and got my license right out of high school. While I enjoyed flying it simply became too expensive for a college student and flying is one of those things that you have to do frequently enough to maintain proficiency. I still use some of what I learned from flying today - clipped to the visor of my truck is a pre-tow checklist for my boat. I hope that your plane is repaired and that you are back in the air soon.

Chuck Merkel

Norm Faith Jr. · « **Reply #47 on:** May 13, 2009, 11:36:24 PM »

Absolutely, positively, without a doubt...AUTO FUEL...regardless of an STC, (both of my planes have one) should not be used as a regular diet for our aircraft engines. Say what you think, think about what you say. I will not warrant any engine that I overhaul, or any cylinder that I replace if the customer runs it on auto fuel. BTW: Most engine builders, Continental or Lycoming (the last time I checked) will not warrant an engine that is run on auto fuel. Gibson Aviation, Tulsa, who does all of my cylinder repairs/overhauls, will not warrant them for auto fuel. Most of all it makes a plane "stink." I can get within 10 feet of a plane drinking A/F and smell it. Most of the fuel leaks my shop deals with is A/F. 90% of the stuck valves, sucked valves, galled cylinders and valve guides and cracked heads...I've dealt with...A/F. I do know that some pilots, especially Cherokee drivers, will run A/F in one wing and AV in the other, using the AV for take offs, climbs and landings, while cruising on A/F. Most of this is not just my opinion, but the culmination of years of "hands on, been there; done that," experience. (side note) In 1996 I bought a new Craftsman Lawn Tractor which I used as an airplane tug (for the smaller aircraft) up to six days a week and cut the grass around our hangar. I ran it from day-one on AV-gas. I Replaced one gear box, several spark plugs, a bunch of tires and filters, then in 2004, I replace it with a new tractor, retiring the old one to the house for lawn work. I filled it up with A/F after running out the tank of AV. The third time I used it to cut my lawn...it sucked a valve and broke the rod simultaneously...Coincidence??? Must of been a cultural shock.

Norm
A/P I/A PPSEL
FBO Operator
(CDH)

FLOYD CARTER · « **Reply #48 on:** May 14, 2009, 02:00:02 PM »

Dumbest thing I ever did was when I took off at Taft, CA in my C-140. Engine quit cold as I was about 10 ft off the ground. Panic! Fortunately, I glanced at the fuel selector lever and it was OFF. Just enough fuel in the carb to take off. I saved it just before touching down again. Lucky for me I was alone, or else I would have had to explain my lack of smarts!

Floyd