flying a parabola in a carbureted plane

SixPapaCharlie

SixPapaCharlie

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I had a tremendously rewarding flight yesterday.
Co-worker, 62 years of age, knows I fly because I am a pilot and so I tell everyone when I meet them (usually before I tell them my name).

Anyway. He has never been in a plane smaller than a big one. He is Scottish (looks and sounds like that actor) Says "I flew across the pond" a lot.

I call him yesterday and say "Hey I am flying myself to breakfast, wanna join me?"
He said (read this bit in a Scottish accent) "Awe Crikey Yeah! I got nothin goin on today. I'd love to have a go at it."


I am going to digress a bit. So he has a lot of crazy expressions. My favorite is when he is talking about computing instead of saying how you or I would say "You click enter and launch it" he says frequently "If you want to print the label, you just queue it up, hit the tit and you're off."

He said it once in a large meeting and I looked at my CEO deadpan and in my best normal non Scottish accent, said "Apparently we're gonna have to hit the tit in order to make this program work boss. We've definitely not been doing that."

But I digress.

So I fly to pick him up and he is like a kid in a candy store, filming, taking pictures, asking questions. I have never had a more enthusiastic passenger. He really reminded me of me when I was his age.

It was probably one of the most rewarding flights I have had since several others.
I ask his permission to show him some maneuvers and he I think agrees. I really can't understand any of his expressions. What does it mean in Scottish "No please no"?

We do a steep turn and he is loving it.

Then! I say "Hey, I can make you float a bit. Are you up for it?"
Then another crazy Scottish saying "God please Bryan, make it stop. I can't take it anymore".
Which I think means "Go for it". Who knows?

I fly the parabola and as I am pitching down, the engine gets pizzed! (not Scottish Pizzed meaning "drunk") It starts losing power. I pushed the yoke down harder to show the engine whose boss and it upped its game. Now the engine was really phoning it in. I pushed harder one more time to call its bluff and the engine wasn't having any of it. It was very lethargic. Obviously carb ice.

So I pulled back and leveled off and the carb ice must have melted at that point because the engine began running perfectly again. I have done this maneuver many times in carbureted and fuel injected planes and never had it create carb ice like this.

The engine has always run smoothly through the maneuver.
Is there any danger in doing this (up and down bit) in a carbureted plane?
Like could it actually kill the engine?

Thanks in advance for reading all of that and responding with thoughtful answers.
 
That kind of carb ice typically goes away the moment you get back to positive G. Not a big deal. It just gets quiet for a moment and the event has a surprising resemblance to the carb ice you get when you run a tank dry.

You may also notice that your oil pressure may appear to go to zero - this is due to the lesser known pump ice - more like Slurpee ice than Scotch and Soda ice. Again, not a big deal.
 
I have no idea about the carb but I think you should write a Scottish-English dictionary. Or module for google translate.

And fly like a boss!
John
 
It might kill the engine but it won't really be dead. Call it zombie engine.
 
The story is even better when I use Robin Williams' voice when he does the bit on how some drunk Scottsmen created golf.

Also when I use Michael Myers and his BFB voice.
 
Yeah ive had students kill engines nosing over too hard in stalls. It usually fires right back up...usually.
 
You're fine, worse case it leans out at a lower power setting and re catches, no biggie.

Good on ya for showing a Scott a good time
 
Silly wabbit . . . you gotta do it inverted - ice hates back pressure.
 
SixPapaCharlie said:
I fly the parabola and as I am pitching down, the engine gets pizzed! (not Scottish Pizzed meaning "drunk") It starts losing power. I pushed the yoke down harder to show the engine whose boss and it upped its game. Now the engine was really phoning it in. I pushed harder one more time to call its bluff and the engine wasn't having any of it. It was very lethargic. Obviously carb ice.

So I pulled back and leveled off and the carb ice must have melted at that point because the engine began running perfectly again. I have done this maneuver many times in carbureted and fuel injected planes and never had it create carb ice like this.
Click to expand...

[I wimped out on my original reply to avoid the ban hammer]

You sure it was carb ice? I think our fuel systems are designed for 6 or 6.5 pounds per gallon. Maybe the extra gravity made the fuel heavier so it wouldn’t leave the carburetor bowl? Just be damned glad you didn’t fly into a gravity well.
 
The carb ice dispenser is clogging up from lack of use. During the pre-flight passenger briefing emphasize they have to put more ice in their Scotch while airborne for safety reasons.
 
rtk11 said:
[I wimped out on my original reply to avoid the ban hammer]

You sure it was carb ice? I think our fuel systems are designed for 6 or 6.5 pounds per gallon. Maybe the extra gravity made the fuel heavier so it wouldn’t leave the carburetor bowl? Just be damned glad you didn’t fly into a gravity well.
Click to expand...

I think you are close. But the fuel got lighter, not heavier, it might have just barely been floating into the carb. Which of course is why it formed ice, it was in an area of lower pressure. Everyone knows that when you rapidly move from high pressure to lower pressure, things freeze. And being ballistic pretty much seals the deal. ;)

Bryan, you are a steely eyed missile man.
 
My little Sonerai does not like to do rolls to the right. Aileron rolls to the left are fine. But, rolling to the right causes the engine to stumble immediately. Since the prop is a pretty skinny 52 inches, and I don’t have a starter, I haven’t pushed the issue. But I’m pretty sure it’s because the way the carb is mounted, the main jet experiences negative G when rolling right. I’m also pretty sure a barrel roll done correctly wouldn’t cause this.
 
Old friend of mine would do aerobatics in a Stearman, loved how it would cut out then roar back to life.
 
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