Please educate me: where does this photo show any signs of a “burned valve”?
boscomantico wrote:
Please educate me: where does this photo show any signs of a “burned valve”?
Good question. I did not comment on that because I do not see any obvious sign either and hoped someone might comment on it. That’s also why I wrote “burned” (in quotation marks) at least the first time.
I never got a chance to talk to the mechanic, or see the “failed” cylinder myself, so I do not know how the diagnostic was made. A compression test? The valve looks pretty good to me but the mechanic reportedly claimed it felt rounded to the touch instead of flat.
Here is the “Anatomy of valve failure”. The pattern on the valve is not perfectly round – look at the 9 O’clock position. Is that an early sign of valve failure?
Thanks for your post, 351windsor.
Do make a good point about having to operate the school rules, too.
I kid you not his face turned white and said in no uncertain terms that I am not to lean on the ground as it will cause the cylinders to melt.
That however is standard in GA maintenance knowledge of engine operation.
@Aviathor
“As a matter of fact the cylinder which was replaced was the coolest cylinder in terms of EGT but the hottest in terms of CHT.”
Would you mind posting the CHT data?
Did someone check the spark plugs ?
Here’s the CHT data
Two minutes after takeoff (at 00:15:00) I pulled the propeller pitch back to 2400 RPM so you can see the temperatures coming down. At that point I am still full rich. The FF drops from 17,5 GPH to 16,2 GPH as a consequence of the RPM reduction.
Rwy20 wrote:
Given that he is a) in Europe and b) an instructor, I am not the least bit surprised. I have yet to meet a flight instructor in Europe who is enlightened about operating a piston engine.
You are welcome to visit me any time and discuss this in person. But only because I don’t read aviation blogs and magazines and therefore have not come across some of the poular gurus yet does not mean that I don’t know my thing about engines (all kinds of). I’m just tired of this kind of discussion on the internet.
There are no doubt different “cultures” around Europe.
Here in the UK most of the PPL scene is barely hanging on, with nearly all instructors (certainly in my time) just passing through on the way to airline jobs. On top of that you have the directives handed down from the school owner. For example I was never taught to even touch the red lever. Some things in flying are just not a priority when you are trying to push a broad-spectrum intake through the 45hr PPL in something like the average of 60hrs, while trying to stop too many from dropping out because they have reached 60hrs and haven’t yet done the QXC flight… Most will drop out as soon as they get the PPL but that is not “your” problem – so long as you have enough self fly hire business coming from various directions.
However based on what I hear, the UK is hardly unique.
There are clearly exceptions but not commonly encountered IME.
Peter wrote:
However based on what I hear, the UK is hardly unique.
Certainly not.
Peter wrote:
…with nearly all instructors (certainly in my time) just passing through on the way to airline jobs.
I think in our FTO we have a very good mix of old and young, private and commercial and professional and freelance instructors. Myself I am something like “middle generation”, as some of my own instructors (now in their late 70ies to early 80ies!) are still actively instructing, as well as some of the young instructors waiting for their airline chance are my former students. Just calling them/us “European instructors” does not do us justice and I actually take some degree of offense (to be honest!) by being placed second to those wonderful know-it-all supergurus from the Greatest Nation on Earth.
Peter wrote:
On top of that you have the directives handed down from the school owner.
We do have these directives as well. Our FTO has it’s own maintenace (or CAMO as it is called these days) and the engineers (or mechanics, as the now politically uncorrect term would be) tell the owner that a lot of damage is done by over-leaning and running the engines too hot. Therefore we are not supposed to lean anywhere near peak and I can perfectly well understand our management. However this does not prevent me from demonstrating an interested student (most of them aren’t because they will never fly a piston aircraft ever again after passing their ATPL skill test) how to properly lean an aspirated piston engine. I know how to do that because I have owned two of them – mounted on one aeroplane – for a decade.
Same as pilots, there all sorts of instructors. But there are three HUGELY different “flavours”
One is instructors who have little experience flying anything than the C152 / C172 / PA28 / whatever after they got their licence, and have done a bit of “hour building” before getting their instructor ratings.
The second is experienced AIRLINE pilots
An the third is experienced LIGHT AIRCRAFT pilots.
All of them can be excellent instructors, and the last two can overlap, but only the third category knows anything beyond the theory on large piston engine management.
what_next wrote:
Just calling them/us “European instructors” does not do us justice and I actually take some degree of offense (to be honest!) by being placed second to those wonderful know-it-all supergurus from the Greatest Nation on Earth.
I was hoping that you wouldn’t take it personally, but I can see how it is easy to do (especially on an Internet forum). So I apologize for making this comment in this personal context. To me it was just an opportunity to make a point that has been buggering me for a long time, having received my share of derisive comments from European instructors and mechanics when you try to talk about engine operation with them. Compared to this, it is really refreshing to do a checkout in the US, where the first thing they tell you after starting the engine is to lean it.
So again, I don’t know anything about your instructing and I didn’t want to imply that it was in any way substandard or lacking knowledge about engine operation procedures. Not do I think that the majority of the blame should lie with any of the said instructors, as has been pointed out it is the whole ecosystem in which they operate which leads to this situation where they are told not to teach how to use the red lever at all.
This just happened again last weekend in a French club where for checking out on a C182, the clear announcement was: Don’t lean at all below FL080. If I’m told that by the owner, I surely respect it, especially when renting wet. Even though it hurts my pilot pride a bit.
