The reason for not running your engine under high loads at low RPM is because of the oil film. A fixed pitch propeller has the RPM directly tied to the load. But if you run it under high load at low RPM, the oil film is not being replaced very quickly and you must use a much thicker oil. This significantly reduces the efficiency because it increases the amount of drag on the engine. Also, thicker oils are a lot harder to lubricate all the components during the startup and in cold weather, and is more susceptible to thermal shock. This is why they recommend not running under high loads at low RPM. Medium loads at low RPM is fine though. Just don't push it to the extreme.
FYI, The Klapmeir brothers, Alan and Dale, are from DeKalb, Illinois, not Wisconsin. I know this because I grew up with them. Dale was in my DeKalb High School graduating class of 1979. Alan was a few years older. I'm enjoying your class, BTW.
I thought maneuvering speed was a minimum, not a maximum. Isn't maneuvering speed the minimum velocity required to safely make a maneuver from straight and level flight? I'm just confused as a student as I have received contradicting information from other credible sources. Thank-you for all of the wealth of knowledge you provide!
There is a maximum and a minimum safe maneuvering speed. The lower speed maneuvering speed limit is due to stalls, AKA the break in airflow over the wing, preventing you from creating lift. Maximum maneuver quoted airspeed for most planes is more of a structural limitation.. a 172 going over 160 knots is subject to structural failure. and pulling a hard turn at 150 knots, you very well are risking flight surfaces or entire lifting bodies AKA wing. in some extremely fast planes, they may have a never exceed speed, around 500 MPH because of compressability. as airflow gets closer to supersonic, lots of weird things happen such as inverted control input, or no reaction to input at all. the closer you get to MACH 1, you start to see an actual shift where the center of lift of the airplane is located.
V(sub letter)A specifically is the speed at which an airplane will stall before exceeding its maximum load limit. Basically, this is the speed at which the airplane will stall before it breaks apart. There are different manuevering speeds as you described, but the aren't identified as V(sub letter)A: Take V(sub letter)O for example
@@bran5605 Thank you very much, that clears up alot of confusion about the term maneuvering speed. I was confused because there are also maximum safe speeds, especially for rotary wing aircraft due to retreating blade stall for example, notated as Vne (Velocity never exceed.)
Honestly curious on how many fully glass cockpit schools or rental planes this guy thinks there are. From how he talks every plane is brand new with glass cockpits.
Take a trip around any airport and you'll see glass cockpits are becoming the norm. It doesn't have to be a G1000. Dual G5s and a nav/gps navigator is the same effect.
Glass cockpits can be had for as low as $6,000 now, which is actually about the same price as a full set of steam gauges. As components fail people are replacing with glass cockpits. Even 1950s airplanes can have a glass cockpit steam gauge put in for like 250 bucks.
It was a joke about how the numbers that they use for the default are based off of the average temperature in 1960 even though the temperature is higher now.
Leave it to a virtue signaling intellectual not to be able to make it through a technical presentation on flight without making a reference to climate change.
This was a reference not to climate change, but to lead in the atmosphere. Unfortunately, led from airplane fuel is one of the most significant sources, and aviation has a measurable impact on the amount of birth defects and cancer rates. Additionally, breathing lead is considered worse than drinking it, and we already eliminated lead from our water in 1960. Unfortunately airplanes have not caught up yet. It wasn't virtue signaling about climate change, it was virtue signaling about the very real effects of breathing lead and even the FAA recommends not to breathe it. In fact, pilots or people who frequent airports, have over 10 times the amount of blood lead levels and that corresponds to about six points lower IQ on average.
Also, it's not really virtue signaling when it's a legitimate and very real concern. It has a measurable impact on aviation and therefore it is actually relevant. Unfortunately, If you don't Believe in science, why the fuck are you watching any college lectures? If you don't believe in climate change then you don't believe in science, then why are you even trying to watch this?
The reason for not running your engine under high loads at low RPM is because of the oil film. A fixed pitch propeller has the RPM directly tied to the load. But if you run it under high load at low RPM, the oil film is not being replaced very quickly and you must use a much thicker oil. This significantly reduces the efficiency because it increases the amount of drag on the engine. Also, thicker oils are a lot harder to lubricate all the components during the startup and in cold weather, and is more susceptible to thermal shock. This is why they recommend not running under high loads at low RPM. Medium loads at low RPM is fine though. Just don't push it to the extreme.
FYI, The Klapmeir brothers, Alan and Dale, are from DeKalb, Illinois, not Wisconsin. I know this because I grew up with them. Dale was in my DeKalb High School graduating class of 1979. Alan was a few years older. I'm enjoying your class, BTW.
I thought maneuvering speed was a minimum, not a maximum. Isn't maneuvering speed the minimum velocity required to safely make a maneuver from straight and level flight? I'm just confused as a student as I have received contradicting information from other credible sources. Thank-you for all of the wealth of knowledge you provide!
There is a maximum and a minimum safe maneuvering speed. The lower speed maneuvering speed limit is due to stalls, AKA the break in airflow over the wing, preventing you from creating lift. Maximum maneuver quoted airspeed for most planes is more of a structural limitation.. a 172 going over 160 knots is subject to structural failure. and pulling a hard turn at 150 knots, you very well are risking flight surfaces or entire lifting bodies AKA wing. in some extremely fast planes, they may have a never exceed speed, around 500 MPH because of compressability. as airflow gets closer to supersonic, lots of weird things happen such as inverted control input, or no reaction to input at all. the closer you get to MACH 1, you start to see an actual shift where the center of lift of the airplane is located.
V(sub letter)A specifically is the speed at which an airplane will stall before exceeding its maximum load limit. Basically, this is the speed at which the airplane will stall before it breaks apart. There are different manuevering speeds as you described, but the aren't identified as V(sub letter)A: Take V(sub letter)O for example
Steven Hanaway interesting! Thanks for your insight on this
@@bran5605 Thank you very much, that clears up alot of confusion about the term maneuvering speed. I was confused because there are also maximum safe speeds, especially for rotary wing aircraft due to retreating blade stall for example, notated as Vne (Velocity never exceed.)
Honestly curious on how many fully glass cockpit schools or rental planes this guy thinks there are. From how he talks every plane is brand new with glass cockpits.
Take a trip around any airport and you'll see glass cockpits are becoming the norm. It doesn't have to be a G1000. Dual G5s and a nav/gps navigator is the same effect.
Glass cockpits can be had for as low as $6,000 now, which is actually about the same price as a full set of steam gauges. As components fail people are replacing with glass cockpits. Even 1950s airplanes can have a glass cockpit steam gauge put in for like 250 bucks.
These are awesome!!! Better than the books
Pizza?
this is a very good presentation! thank you
Made me hungry for pizza
Ummm, see this is what people hate about professors; he complains @29:00 about burning fossil fuels, but flies his planes,,,the hypocrisy is thick
small trainers are rather efficient which is what most general aviation centers around
That was a joke about how great the standard atmosphere used to be! (I certainly don't claim to be saving the planet!)
It was a joke about how the numbers that they use for the default are based off of the average temperature in 1960 even though the temperature is higher now.
Leave it to a virtue signaling intellectual not to be able to make it through a technical presentation on flight without making a reference to climate change.
This was a reference not to climate change, but to lead in the atmosphere. Unfortunately, led from airplane fuel is one of the most significant sources, and aviation has a measurable impact on the amount of birth defects and cancer rates. Additionally, breathing lead is considered worse than drinking it, and we already eliminated lead from our water in 1960. Unfortunately airplanes have not caught up yet.
It wasn't virtue signaling about climate change, it was virtue signaling about the very real effects of breathing lead and even the FAA recommends not to breathe it. In fact, pilots or people who frequent airports, have over 10 times the amount of blood lead levels and that corresponds to about six points lower IQ on average.
Also, it's not really virtue signaling when it's a legitimate and very real concern. It has a measurable impact on aviation and therefore it is actually relevant. Unfortunately, If you don't Believe in science, why the fuck are you watching any college lectures? If you don't believe in climate change then you don't believe in science, then why are you even trying to watch this?