the "not worthy of it's own thread" thread

WDD said:
Carbs in cars didn’t have to deal with drastic changes in altitude as much as planes.
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I wonder how they dealt with the race up Pikes Peak (14,000 MSL).
 
Partly guessing here, my engineering area is electrical not mechanical and I'm not a mechanic - cars didn't have mixture controls, at least none that I remember, I think for two reasons. Lack of major altitude change was probably one, but I think they compensated for that. The other is that normal cars never drove around at 75+% power, and so they didn't need the full rich full power cooling thing we do on take off or lean for cruise. They were balanced to provide a fairly lean mixture under normal driving conditions.

The other thing, though, is that cars used to have manual chokes, and then automatic chokes. Manual chokes were awesome, in that you could always get an engine rich to start and warm up a little. The first automatic chokes tried to do the same thing, but many of them were terrible. The most often stated advantage I've heard, and experienced, about the switch from carbs to fuel injection in cars was that they would reliably start in cold weather. That's not the fuel injection, though, that's really the computer. When I first flew a mechanical fuel injection airplane, I was surprised at what a PITA they were, even dangerous if you don't know what you're doing, compared to a carb.

Oh yeah...and the first plane I learned in had no mixture control at all. A lot of J3's don't. They fly just fine. I have no idea why, except maybe that they're not flying all that high.

Personally, I'd like to have a plane with a mechanical carb, and a two position mixture, like a choke. "Full rich" for takeoff and starting, and "normal" for everything else. Because I'm lazy, and I believe the carb should be able to mix itself.
 
Baked Potato said:
Obviously cars don't drive at tens of thousands of feet, but wouldn't they need a different fuel/air ratio in Los Angeles than they would in, say, Denver?
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A box stock carb would run too rich. The auto companies offered a high altitude kit for people who lived at higher altitudes. Then in the late 70s they started putting O2 sensors and mixture control on the carb for improved emissions (Think lipstick on a pig) that would do some compensation for altitude.
 
Bringing back old memories. With the car carbs, if you flooded the engine you’d push the accelerator all the way to the floor the activate a by pass in the carb to clear the engine.

In the early days of FI for cars, starting in cold weather could be a problem. Engine would turn slow with the thick oil, injectors would flood the engine. Solution was simple. Put in larger amp batteries to spin the engine fast enough to not flood.
 
WDD said:
Bringing back old memories. With the car carbs, if you flooded the engine you’d push the accelerator all the way to the floor the activate a by pass in the carb to clear the engine.
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It wasn’t a bypass, just a function of physics. At low cranking rpm with the throttle plate wide open there wasn’t enough of a Venturi effect to pull gasoline out of the carb bowl and thru the jets.
 
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WDD said:
Bringing back old memories. With the car carbs, if you flooded the engine you’d push the accelerator all the way to the floor the activate a by pass in the carb to clear the engine.

In the early days of FI for cars, starting in cold weather could be a problem. Engine would turn slow with the thick oil, injectors would flood the engine. Solution was simple. Put in larger amp batteries to spin the engine fast enough to not flood.
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Your fuel injection has a cutout at wide open throttle during crank - but not much needed now days.

Bill said:
It wasn’t a bypass, just a function of physics. At low cranking rpm with the throttle plate wide open there wasn’t enough of a Venturi effect to pull gasoline out of the carb bowl and thru the jets.
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The choke was above the throttle plate and generated most of the vacuum to suckerize fuel out. Going to wide open throttle opened the choke at the same time through a de-choke linkage.

You also wanted to "set the choke" before cranking by pressing the throttle pedal down once and releasing - that allowed the choke to close fully and the throttle plate to open up to the "high cam" (fast idle) position. Not everyone knew that. But, after years of cold start evaluations, emission tests, and carburetor tuning, that got to be such an ingrained habit that I would find myself "setting the choke" years after carburetors went away.
 
Capt. Geoffrey Thorpe said:
The choke was above the throttle plate and generated most of the vacuum to suckerize fuel out. Going to wide open throttle opened the choke at the same time through a de-choke linkage.

You also wanted to "set the choke" before cranking by pressing the throttle pedal down once and releasing - that allowed the choke to close fully and the throttle plate to open up to the "high cam" (fast idle) position. Not everyone knew that. But, after years of cold start evaluations, emission tests, and carburetor tuning, that got to be such an ingrained habit that I would find myself "setting the choke" years after carburetors went away.
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In the Skycatcher, I had to stroke the throttle to prime the engine via the accelerator pump since the one I flew did not have the optional primer. Does your "set the choke" procedure accomplish the same thing? Was one press of the throttle enough? The 162 needed a couple of strokes.
 
asicer said:
In the Skycatcher, I had to stroke the throttle to prime the engine via the accelerator pump since the one I flew did not have the optional primer. Does your "set the choke" procedure accomplish the same thing? Was one press of the throttle enough? The 162 needed a couple of strokes.
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Whole different mechanism. The set the choke thing primarily allowed all of the mechanical bits and pieces to assume the cold start position - literally choking off the flow of air into the carburetor - some fuel would have been pumped via yea olde accelerator pump, but that was secondary.
Then there are the Bing carbs on Rotax or BMW or...
 
After 73 days, she’s back in the hangar……

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Well, here it is again. We (at least most of us) made the time switch.

I was smart this year. I started switching my clock ahead 2 minutes a day for the last 30 days...
 
Zeldman said:
Well, here it is again. We (at least most of us) made the time switch.

I was smart this year. I started switching my clock ahead 2 minutes a day for the last 30 days...
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Good idea. On the flip side, my watch loses at least 15 seconds a day, so I just won't adjust it this year and, by November 5, it will be right back to standard time.
 
asicer said:
Looks like I won't be refreshing my night currency for a while. :(
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I had a habit of getting night current in July. Made for a late night (but was still very enjoyable)
 
Bob Noel said:
I had a habit of getting night current in July. Made for a late night (but was still very enjoyable)
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Uffda. At solstice in my town, “night” for passenger currency is 23:55-04:55. I don’t want to get current and I really don’t want to need to be current between those hours.
 
I must be ''unique''.

It is easier for me to make the switch moving forward one hour than the other way around. I seem to be able to fall asleep quicker and easier than when the time falls back. On that night I have trouble falling asleep and seem to have a restless sleep for the next week or two.
 
Can someone help me understand the difference between crabbing and side slipping? I'm not sure watching the Sporty's ground school video helped me understand the difference, and this site says that "you simply turn the aircraft, by using ailerons, into the wind" for a crab technique. But how is that different than a side slip (low wing) technique, where you're using ailerons into the wind as well?
 
Crab is putting nose into the wind to compensate for a cross wind. The wind pushes you enough to compensate for your nose pointing left or right from your direction of travel.

Side slipping is cross controlling not for a cross wind but to slow down and loose altitude. You cross control to put the side of your plane against the wind to slow you down and drop altitude.
 
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WDD said:
Side slipping is cross controlling not for a cross wind but to slow down and loose altitude. You cross control to put the side of your plane against the wind to slow you down and drop altitude.
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The sporty's videos call that a forward slip though. They say there are two methods for landing in a crosswind (side slip and crab) and a separate portion in the video explaining how to compensate for too much speed on final, which called for the forward slip.
 
Forward slip sounds good. I’ve not yet flown backwards slipping LOL.

If you crab you have to un crab right before touchdown so you land with wheels straight. Which at the last moment could be tricky.

You can slip by wing low into cross wind and cross rudder enough to keep you lined up / wheels lined up for landing. You land on the low wing wheel first, then the other main. Some say it’s easier than crabbing and the last moment un crabbing.
 
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WDD said:
Forward slip sounds good. I’ve not yet flown backwards slipping.
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Yeah, they're kind of confusing and some of the Q&A on the topic seemed a bit ambiguous. But I have come to expect that - there was one on a different subject where none of the answers were correct, and the reply I got from Sporty's was just that they represent the questions I'll get on the knowledge test.
 
From the all knowing Google:

Side Slips are used for slipping sideways through the air during a crosswind landing. A sideslip is defined to be a slip where the fuselage is parallel to the line of travel.

Forward Slips are used to lose altitude quickly and take you forward towards the runway. A forward slip is defined to be a slip where the fuselage is not parallel to the line of travel.

That is the fuselage is pointed off to one side of the line of travel.

For X wind landing it is side slipping vs Crab.
 
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Yeah, that's what I don't understand. The difference between side slips and crabs. For both you're using aileron into the wind, correct?
 
Crab - wings level, nose into the cross wind.

Side slip - wing low into the wind, keep plane parallel to runway by applying opposite rudder.
 
Crab, as was pointed out is wings levelish flying a heading that doesn't line up with the runway so your ground track does. (nose not aligned with runway) One needs to kick it straight before touching down unless you are flying an Ercoupe. Ball is centered.
Side slip - wing low but nose aligned with the runway so you are looking straight forward to see the runway (That's why it's called a side slip - you are looking forward). You can land on yea olde upwind wheel first Doesn't work in an Ercoupe. Not "ball centered" coordinated.
Forward slip - wing low but nose not aligned with the runway so you look to the side. (Called a forward slip because the runway is off to one side.) Usually to waste excess energy and get your butt on the ground. Need to kick it straight before touching down. Also not an Ercoupe thing but common on aircraft that don't have those flappy things. If you won't put the rudder pedal right to the floor then you don't have balls.
 
I see. How do you aileron into the wind and also keep wings level?
 
Baked Potato said:
I see. How do you aileron into the wind and also keep wings level?
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In a crab you will use the aileron to turn the plane to a heading that will give you the track you want. once you are on the right heading you will level the wing (aileron neutral) and maintain the track. In a slip, you will use the aileron to maintain heading and opposite rudder to keep you aligned with the runway. so, in a crab you will be flying wings level and ball centered. In a slip you will be banked into the wind and because you are using the rudder to maintain alignment with the runway, the ball will not be centered.
 
Baked Potato said:
I see. How do you aileron into the wind and also keep wings level?
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Alpha Mike spot on.

Summary - crab wing level. Do not aileron into the wind. Me, I just use the rudder to set the crab. To maintain the crab of course just use the rudder.
 
Baked Potato said:
Yeah, they're kind of confusing and some of the Q&A on the topic seemed a bit ambiguous. But I have come to expect that - there was one on a different subject where none of the answers were correct, and the reply I got from Sporty's was just that they represent the questions I'll get on the knowledge test.
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Is it possible that the ambiguity relates to when you lower a wing into the wind with ailerons? If you fly a slip all the way down your final approach, you will be centered on the runway, moving straight down the runway, and nose pointed straight down the runway the whole time. If you fly a crab during your final approach, you will be centered on the runway and moving straight down the runway, but your nose will be pointed into the wind. You will need to transition the plane to also point straight down the runway at some point before you touchdown, otherwise you will side-load the landing gear, which some planes tolerate better than others with results ranging from ground loops to breaking a main gear leg off the plane. You will need to use both ailerons and rudder to make that transition. And it is possible that this transition is what the Sporty's course was talking about.
 
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