Reduced power setting on take off

[Joe Gremlin]

Wow, really?

How would one know that you were joking? I didn't see any of these :joke:in your post. So how exactly would anyone know you were only kidding? How exactly would a 50 hour private pilot who might be reading the forum know you were joking?

 

[seaav8tor]

Light piston engines have an enrichment feature built in when the throttle is full forward. This is to add extra fuel so that in worst case conditions, hot engine, hot air, sea level, the detonation margin is increased and extra fuel helps to keep CHTs lower than they would be otherwise. You bypass this feature if you takeoff with less than full power. Is this a big deal? In many cases no but I would not do it without an engine monitor that monitors all CHTs.

 

[TFaudree_ERAU]

Light piston engines have an enrichment feature built in when the throttle is full forward. This is to add extra fuel so that in worst case conditions, hot engine, hot air, sea level, the detonation margin is increased and extra fuel helps to keep CHTs lower than they would be otherwise. You bypass this feature if you takeoff with less than full power. Is this a big deal? In many cases no but I would not do it without an engine monitor that monitors all CHTs.

Carbureted, fuel injected, or both?

 

[seaav8tor]

both

 

[TXTBOOK]

How would one know that you were joking? I didn't see any of these :joke:in your post. So how exactly would anyone know you were only kidding? How exactly would a 50 hour private pilot who might be reading the forum know you were joking?

Because your learn the difference between a car engine and an airplane engine pre-solo and this guy has "flight instructor" in his profile.

 

[Joe Gremlin]

Because your learn the difference between a car engine and an airplane engine pre-solo and this guy has "flight instructor" in his profile.

So that means I should assume just because someone has CFI after their name, they clearly understand the basics of how aircraft engines work? There was a time when I used to believe that. But I've flown with far too many buffoons that had a CFI ticket and absolutely no idea what happens on the other side of the firewall to make such an assumption any more.

 

[TXTBOOK]

You're right. My comments about assuming he knows what he's doing when he tells a joke should not stretch to your opinions on people and their ability. I apologize for attempting to apply my thought process to your ability to judge people.

I'm a 60 hour student pilot and I "got" the "joke".

Mooooooooving on.

 

[Bumblebee]

I often say to myself that if there are two ways to take something, take it in the best way. I didn't get the "joke" either, but had I had time to respond before we got a little crusty with one another I was thinking, "Oh he got me...LOL" OK that would have been funny, if I had had just a little more SA...

I do understand JG's concern that someone may not have the background to understand that it was a joke and not an accurate way to look at the difference between auto engines and aircraft engines, and he did explain the difference nicely.

and you know what, now we had a joke and some learning all at once!

we take off at 2500 SHP per engine when we could be producing 3250 SHP at 105,000 lbs even on hot days... (that's still 10,000 SHP) and sometimes we use ALL the runway, but we passed our refusal speed 3000 feet behind us. It seems that sometimes we bring up the gear so we don't get a flat on the barbed wire

 

[tgrayson]

OK that would have been funny, if I had had just a little more SA...

If it was a joke, and I'm not sure that it was, then it's an example of Poe's Law. There are many flight instructors and highly experienced pilots who use the same reasoning, so if a 60 hour student didn't take it seriously, then it's more likely due to his lack of experience.

Regardless of whether it was a joke or not, many readers aren't likely to interpret it that way, so if the view goes unchallenged, they walk away thinking there is merit to the idea.

 

[Old Pete]

Is Poe's Law an example of Poe's Law. After reading that explanation I'm not sure if Poe's Law is a real "Law" or just a parody of other "Laws".

 

[TXTBOOK]

If it was a joke, and I'm not sure that it was, then it's an example of Poe's Law. There are many flight instructors and highly experienced pilots who use the same reasoning, so if a 60 hour student didn't take it seriously, then it's more likely due to his lack of experience.

Regardless of whether it was a joke or not, many readers aren't likely to interpret it that way, so if the view goes unchallenged, they walk away thinking there is merit to the idea.

I took it as a joke because the information he posted was, IMO, obviously false.

Similar to the post I made in the prop-syncing thread where I claimed to "sync" the single prop on a C172 during the take-off roll.

No big deal.

 

[tgrayson]

Is Poe's Law an example of Poe's Law. After reading that explanation I'm not sure if Poe's Law is a real "Law" or just a parody of other "Laws".

I don't know what you mean by "real law", but it's a very commonly cited observation in internet discussion groups after a bizarre post. There is no conceivable idea too stupid to be sincerely believed by at least one member of society.

 

[Bumblebee]

I don't know what you mean by "real law", but it's a very commonly cited observation in internet discussion groups after a bizarre post. There is no conceivable idea too stupid to be sincerely believed by at least one member of society.

I knew that the info was inaccurate, but I had heard this discussed before in a room a long time ago, and even asked one of my mentors, who owns a Flight School and is an A&P and is an amazing mechanic. He said run 'em at full power they're made for it. It was only then that it was clarified for me.

I could understand why someone might think this way, so believing this statement is not really too far afield for some of our less experienced members. There will be no confusion here now.

 

[Old Pete]

I don't know what you mean by "real law", but it's a very commonly cited observation in internet discussion groups after a bizarre post. There is no conceivable idea too stupid to be sincerely believed by at least one member of society.

Unlike Murphy's law, and many other truisms or adages, I have never heard of it before. Sounds as if some guy on the internet named "Poe" said something and eponymously named it "Poe's Law". Not sure whether its supposed to be profound or parody.

 

[Bumblebee]

http://www.urbandictionary.com/define.php?term=Poe's+Law

pretty cool, I had never heard of it before either...

 

[CoffeeIcePapers]

If it was a joke, and I'm not sure that it was, then it's an example of Poe's Law. There are many flight instructors and highly experienced pilots who use the same reasoning, so if a 60 hour student didn't take it seriously, then it's more likely due to his lack of experience.

Regardless of whether it was a joke or not, many readers aren't likely to interpret it that way, so if the view goes unchallenged, they walk away thinking there is merit to the idea.

When the OP begins the thread with:

I figured with all the flame bait floating around, i would throw my own into the mix...

You can't really expect any useful discussion to happen. If an instructor can't be bothered crack open the POH/AFM and read the normal operations for the aircraft he is teaching in, obviously, said instructor shouldn't be instructing. Same with a 60 hour private pilot or pre solo student.

 

[tgrayson]

You can't really expect any useful discussion to happen. If an instructor can't be bothered crack open the POH/AFM and read the normal operations for the aircraft he is teaching in, obviously, said instructor shouldn't be instructing. Same with a 60 hour private pilot or pre solo student.

I agree with the sentiment, but when you have probably half the instructors in the country teaching no oversquare power settings, can you really say these people shouldn't be instructing? I think there is some interesting psychology that occurs here and I'm sure it's not limited to aviation. But it seems that when someone gives you a rule which is more restrictive than one you have from authority, you tend to give it some credibility, unless the authority directly contradicts it.

While very few instructors are teaching partial power takeoffs, almost all of them advocate a power reduction immediately after takeoff in aircraft with a constant speed prop, and the only source of this technique is from flight instructors. Once someone gets it into his mind he should do this, the lack of a specific recommendation for the technique in the POH is not sufficient to eliminate the habit, at least for most people.

My own view is that a great many pilots would benefit from throwing away what they were taught about flying a particular airplane and start from scratch using the POH.

 

[Bumblebee]

When the OP begins the thread with:



You can't really expect any useful discussion to happen.

Actually, if it's not in the Lav, I fully expect useful discussion to happen. I read this thread when there was only one or two responses, and considered closing it since he stated it was flame bait. On second thought, I realized that was a funny and off handed way to start a discussion.

I have used these forums over the years for hangar talk, paricularly when I was sequestered at home doing my college studies. It is helpful to be sure that people understand when misinformation is a joke, especially when the delivery is particularly obtuse as was the "joke" in question.

 

[ppragman]

I agree with the sentiment, but when you have probably half the instructors in the country teaching no oversquare power settings, can you really say these people shouldn't be instructing? I think there is some interesting psychology that occurs here and I'm sure it's not limited to aviation. But it seems that when someone gives you a rule which is more restrictive than one you have from authority, you tend to give it some credibility, unless the authority directly contradicts it.

While very few instructors are teaching partial power takeoffs, almost all of them advocate a power reduction immediately after takeoff in aircraft with a constant speed prop, and the only source of this technique is from flight instructors. Once someone gets it into his mind he should do this, the lack of a specific recommendation for the technique in the POH is not sufficient to eliminate the habit, at least for most people.

My own view is that a great many pilots would benefit from throwing away what they were taught about flying a particular airplane and start from scratch using the POH.

I don't do anything because my "CFI told me to," that's a path to failure if I ever heard one. Most CFIs in my experience are lower time guys with very little practical outside the training environment experience, as a result, unless they've been around the block once or twice, or have CFI'd for long enough to have to do a FIRC, I don't really take what they say as "authority." The 15,000hr pilot who's been flying for the last 25 years and is also a mechanic? He's much more of an authority than the 22 year old kid like me trying to impart knowledge.

The POH won't help you either in many many small piston singles. Why? Because the POH was written 40 years ago, then minimally updated to keep up with the changing legal ramifications of manufacturing airplanes. I pull the power back after takeoff for multiple reasons in a HP airplane. One 2500RPM is less work for the engine than 2700RPM, two, airplanes are loud and there's no sense in rattling the windows for 10 minutes after departure, and three if I don't need the power to accomplish what I'm intending on accomplishing, why spend all the extra fuel to torque that engine extra hard? It doesn't make sense. The moral? Think for yourself. Following the POH or the CFI mindlessly does you no good what-so-ever.

 

[tgrayson]

Think for yourself. Following the POH or the CFI mindlessly does you no good what-so-ever.

And yet you duplicated their technique exactly, with no evidence in favor of it, so I suspect this "25 squared" mantra has indeed influenced you. The only thing unambiguously true is that lower RPM will result in lower noise.