Ultralights

While studying the new pipistrel panthera, I noted NO lower air exit, none, it's completely flat under there.. Where it does exit is quite a brilliant method, something I was certain would have been tried in older aircraft (read all up until last year) Again, a solution only newer technology and data made possible.

mcgrath50

Mick,

I don't know who you are or where you operate but I hope one day I come across you resume in hand! Thanks for not being stuck in the 'bad old days'. I know there are many operators like you but there are also too many who don't believe in the science and don't think outside the old box.

Jaba et al.,

Keep up the good work of educating! Hopefully you keep running courses in Oz as I am saving to make it to one ASAP.

Ethel the Aardvark

Just read this from RAM aircraft co website in the USA.

RAM is aware that some aircraft engines are designed and have FAA approved procedures to operate at lean-of-peak settings, and RAM knows that there are advocates for LOP operations whenever balanced fuel nozzles are installed. RAM supports the installation of balanced or matched fuel flow nozzles, but does not, in fact cannot, condone or approve their use to operate an engine at an unapproved mixture setting. RAM’s position is that LOP is not suitable for all airplanes, engines, or pilots. A major engine manufacturer has made a point that it only takes a brief episode of mis-management to bring about deep internal damage, and they point out that pilots don’t always realize when it happens, since their engine continues to operate. They suggested that lean-of-peak can be akin to operating on the edge, and that doing so requires pilots to be very precise, have good instrumentation, and watch their engine mixture and throttle full time. RAM agrees.
RAM reminds pilots that mis-management at LOP settings can cause both dynamic stresses and thermal stresses that hammer main and rod bearings, burn pistons, burn valves, and cause cumulative exhaust system damage. RAM encourages pilots wishing RAM would recommend other than (ROP) rich-of-peak to research the numerous White Papers and Engine Manufacturer’s Publications addressing the advocacy issue of LOP vs. ROP. RAM reminds it’s customers and friends in General Aviation that mixture management of a turbocharged Cessna 414A at FL230 is more demanding than the mixture management required of a normally aspirated Cessna 210 at 9,500 feet. Again, RAM cannot recommend LOP operation for any aircraft piston engine not authorized to do so by its manufacturer or an appropriate FAA approved flight manual supplement (AFMS).

Seems to be a much more balanced argument.
Maybe the thread title should be changed again to " Everthing you wanted to know about engine management in the experimental category but was too afraid to ask".

gerry111

I recently had the absolute pleasure of taking my 84 year old Dad for about a two and a half hours GA flight, for the first time. The aircraft was a 1967 V35 Bonanza and my Captain was operating the Bo's IO520 LOP!

Perhaps doubly risky, yr right, as those V tails sure can be killers...

Thanks again, Creampuff!

jdeakin

RAM builds fine engines, and does fine work.

But RAM remains the lone holdout on LOP operations, solely because of one man there, the owner, who has blocked all attempts to educate him, to show him data. Like "yr right," he simply refuses to listen. He has softened his stance a bit, he used to say "Warranty is void if operated LOP." Then it was "Warranty may be void, if operated LOP." Maybe he's dropped that language. To our knowledge he has never actually denied warranty because of LOP operation - perhaps because he's never recognized it!

"The Concert Pianist does not ask the fellow who tunes the piano for advice on how to play the piano." (Stuart Spindel)

The rest of the crew mostly admits it's a nutty policy, but he is very authoritarian.

LeadSled

Folks,
I could not have said it better myself, Mr. John Deakin has very succinctly summarized CASA as an organisation. In my view, CASA's (and ATSB) technical competence has deteriorated since the era of the Whyalla accident.

yr right,
If you have any doubts about the accuracy of the above comments, I suggest you look at the last two ICAO audits of CASA, and their public results, or the results of the last two FAA audits. In polite language, they do tend to confirm Mr. Deakin's views.

I note you have still not answered very specific questions posed at post#315, as a result of your accusation. This being the case, I think we can safely assume no such regulations exist, despite your claims to the contrary.

The difference, legally, between you doing a Type course for an endorsement on your license being "CASA Approved" and the course under discussion here, is the latter does not result in any CASA action.

Obviously, you believe that "CASA Approved" is a bit like sprinkling holy water on the course, making the contents sacrosanct.. Some time ago, I attended part of a CASA Airworthiness Delegates Initial and Refresher, for both CASA AWIs and industry delegates. Some aspects of the course were staggeringly legally incorrect, particularly pertaining to the requirements of various airworthiness (C.of A.) categories.

How many aeroplanes have I "put" on the Australian register, I guess over the years I have been involved in a dozen or more. A fact that is totally irrelevant to this discussion.

As to the LAME being "the last line of defense", you speak in jest, surely.

I have lost count of the number of aircraft, over the years, I have knocked back, as a result of defects found after the aeroplane has been presented to me for service, with an MR signed by a LAME.
When I sign a CAR 233 certificate, or otherwise accept an aeroplane for service, I am signing for far more that just the LAME's opinion of serviceability of the aircraft.

yr right, if you doubt this, just read CAR 233.

The LAME as the "last line of defense" --- I think not.

With reference to CAR 138, and a POH/FCOM/whatever name used, and the reference to the C-207, I would suggest that the application of CAR 138 is limited by the definitions of the contents of a POH, as detailed in the TCDS, and FAA advisory material on the subject, plus GAMA guidelines, for GAMA members.

If the restriction on LOP is in the airworthiness limitations, you have two choices:
(1) Comply, or;
(2) Negotiate a variation with the Type Certificate Holder, if this is successful, this will carry FAA (if it is a US built aircraft) approval of the variation.

In my view, given the legal mechanism for issuing a Certificate of Airworthiness in Australia (since 1998), CAR 138 cannot impose a greater limitation than presented in the original POH, just by the fact that something is printed in the POH. However, if CASA so chooses, it has other regulatory provisions to impose changes to a POH, usually in my experience, to the detriment of safe operation of the aircraft. And further, in my opinion, many such CASA directions are beyond power, in that CASA have no power to amend the certification status on an aircraft not originally certified in Australia.

Finally, I must say that, despite the length of this thread, I still have not decided whether yr right's "contributions" are for real, or just a bleeding long windup.

Tootle pip!!

PS: In the UK, in the 1960s, we were operating IO-540 for over 3000h TBO, low rpm, high boost and LOP. Never had a cylinder failure, only scheduled maintenance, with close trend monitoring, all to an approved program.

Aussie Bob

I have been suspecting the same for some time. No one is that beligerant surely?

No Hoper

Reference cylinder longevity on aero piston engines:
Fit new cylinders on overhaul instead of the second or third life life ones go a long way to stopping problems.
Finally Cockney Steve admits he knows very little about aviation maintenance.
Reference Yr Rights contribution, consider the diverse and thought provoking information provided by the stalwarts of our industry and whether that would have been forthcoming without him

Ultralights

Even if Yr right is trolling, or widing up, it still has bought out the big names in aviation which has lead to some very interesting and enlightening conversation, and generally been an educational thread when you pick out the wheat from the chaff.

Aussie Bob

But: Should you get these brand new cylinders and disassemble the valves to check correct seating before use? Will the supplied piston have the ring gap correctly set?

If you throw them on directly from the factory without checks will they be as reliable as carefully reconditioned items?

Serious questions!

Referencing yr right contribution: It has been one of the best parts of this thread, regardless of what it is, i agree.

yr right

Im certainly not trolling I dealing with real facts as I see them. To the point that the RAM statement has said what ive been saying. There a lot of backing down on certain points from the other side changing there figure's etc.
Classic is the whallya accident, if the engine was placed in high it would not have failed, its that simple


The myth that if you run LOP your engine with be better etc make o/h etc is just that, An engine run ROP will do the same. Its the driver that determines engine life and how he/she treats the engine over its life.


They bring up oh big radials where doing it, Yep they where. But you cant compare a large radial to a light weight lyc or tcm they just arnt built the same . Just look at the head radial free as in the breeze and the other two compact on top of each other. Then look at the valve stem large big and sodium filled to dissipate the heat into the guild the other two well what do you think, next the seat Radial most had rotating seats once again for heat removal and so the seat was not always in the same spot. The other two well. So if your going to compare apples compare them to apples and not to something else.


Im not in these other peoples league as to design etc but neither am I saying I am. What ive said and been consistent with is what I see on the hangar floor.


Now Jaba ask your wife would she approve any operation that flew outside the POH. I can answer that for you if you like.


Now as for CASA and the ASTB they are a joke you don't have to tell me that. But to run a course with no accreditation or endorsement's and say well this is it we done the data just believe us and all is well.
Like ive said fuel is cheap planes arnt falling out if the skies, if you feel the need to change and the POH says you can do it, but also don't go and cry to your maintenance org and expect pitty tell them what you done and im sure they will show you the results.


Cheers

yr right

Gerry 111 yer well V tail bonnzas have a horrible rep and gee if the where so good I guess beech would still be making them but they don't rrrr well you not a Dr are you by any chance.
Cheers

Aussie Bob

Thanks yr right, and I am reading all you have to say, perhaps your opinion on my questions above?

Thanks AB

43Inches

With regard the Whyalla accident;

The ATSB surmised that the left engine failed due bearing failure, which in turn the crankshaft failed. The ATSB tried to pin this on LOP operation when in fact their own report states the majority of Whyalla pilots were leaning to 50F ROP, with occasional leaning LOP as part of an experiment. Even if the accident day the pilot leaned 50F LOP the bearing had failed 50 operational hours previously and was doomed to fail that flight. The engine oil temperature had been trending high and even exceeded 245 prior to the accident day, this was hinting at something going wrong. It apparently was fixed a day or two before the accident.

The exact reason for the right engine failure is still unknown but the best guess was that the pilot pushed the power up with the RPM and mixture still set for cruise, this in turn resulted in severe detonation and cylinder melting. We do not know what method of leaning he used, it is still and forever will be speculation.

The other Chieftains in the fleet were checked and no faults found other than trend data maintenance associated with high temperature operation. Was this due to a few hours operating LOP or the majority hour operating 50F ROP. I know of two other Chieftains (of the 15 or so) that suffered crankshaft failure, neither of these were operated LOP and failed in almost identical fashion to the MZK.

The ATSB acknowledged that leaning in the climb may result in mild detonation, this would not have led to bearing/crankshaft failure or piston melting considering the climb power setting they were using. However Whyalla had an initial climb procedure to lean with power settings 38-40" higher than the recommended POH procedure.

yr right

and if anyone can tell me why im trolling or a wind up please let me know and also give us your qualification's and what makes you such an expert on the operation and maintenance of an aircraft engine.


Also ill just add here about px diff. Have a look at a top fuel engine letting go at full noise at over 300 mph and how the flame moves forward and into the driver, once again extreme but dose point out the power of low and high px diff.


Cheers and off to do some more science.

Oracle1

Lycoming has sodium filled valves, just did a pot on an IO-550 Continental and the exhaust valve is allowed to rotate for even wear and hot spots. Both Lycoming and continental have relatively large guides to transfer heat out of the valve. Also the seat doesn't rotate the valve rotates, if the seat rotated it would pop out and snap the valve.


Please address the questions everyone are asking you yr wrong.

yr right

Yes most shops pull down and check valves and seats. Ring gaps are always checked before assembly. The only time I don't do it is if the cly come from an o/h shop and I'm in the field I have them the assy done for me in the work shop
Cheers

Walter Atkinson

Yr Right's explanation of how air moves under a cowl is on par with the explanation I got from my 13 yr. old daughter when I asked her the same question last night.

It is over-simplified, incomplete and, uh, wrong. It is, however, also on par (and incomplete) with what I was taught in A&P (LAME) school many years ago. It's that darned, ole, pesky data again.

We put a 36-probe CHT monitor in a Bonanza. We put dozens of tufts of yarn under the cowl and around the cowl openings. We then put a video camera under the cowl so we could WATCH what happened in real time as we flew. So far, we know of no other researchers, including OEMs who have done this.

Here's what happened (for free, data and knowledge you cannot get ANYWHERE else--at any price):

(BTW, what happens is NOT what we were taught happens, which is to some degree is "logical." Logic be damned when DATA is involved.)

1) the air comes in the far, outer edges of the cowl opening.
2) It travels along the outer edges of the cowl (in some case, outboard of the rocker covers)
3) the moving air mass on both sides of the cowl hits the rear backplate…
4) whereupon it makes a 90˚ turn toward the middle and meets over the spine of the engine.
5) This combination air mass then moves FORWARD across the spine of the engine and out behind the spinner and moves over the windscreen.
6) the tufts of yarn around the cowl opening are standing straight OUT----TOWARD the propeller!

THAT's why you get oil on the windscreen when you have an upper deck oil leak.

A relatively small amount of the turbulent air finds it's way down through the fins and out the lower cowl openings. Increasing the upper/lower deltaP helps a LITTLE.

What helps a LOT, is to alter the incoming airflow so that it does not go out of the front of the cowl. What helps even more is to alter the metal baffling to encourage more air where it's needed and less where it's not needed. Most cylinders are not evenly cooled around their circumference. We spent over a decade figuring out how to make the cylinders ROUND thru even cooling. That's why we have six CHT sensors on each cylinder.

I have been told that we know more about air-cooling, baffling, and air flow under a cowl than anyone on the planet. Based on my conversations with OEMs, that may be true.

I know this will rub poor, ole Yr Right the wrong way since he's probably convinced that the OEMs know more than I do, but I have the DATA--they don't.

After explaining this to my 13 yr. old and showing her the video, she said, "That's really cool. I bet not many people know that, huh?"

Walter Atkinson

So, we are to believe that radials are somehow different than flat engines?

They are both spark-fired, gasoline, piston engines with aluminum heads, steel barrels, pistons with rings, cranks that run on bearings made of the same material and have many more similarities than differences. They both reach peak EGT at the same F:A ratio. They both use the same aluminum alloy.

AND, when Little Johnny Deakin flies his Bearcat straight up, it's a horizontally opposed engine!

Now, tell me again, just what are the differences?

Oh, there is one main difference… the detonation margin on the radials is narrower. Detonation can be initiated in a big radial by the pilot's mis-use of the RPM lever. It's essentially impossible to cause detonation in a NA, conforming TCM or Lycoming being operated on conforming fuel. How do I know that? We've been testing this in the most advanced engine test facility in the world…. for over 15 years.

Walter Atkinson

While the notion that a valve rotates is a commonly accepted notion, it is not supported by the engine monitor data of a leaking exhaust valve. Neither is it supported by borescope observation. Honestly, whether or not it rotates cannot be proven or disproven. It can be proven that the notion that it rotates at a given frequency is definitely misguided.