C205 engine failure POV jumper dumper

[Colonel]

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[url=http://www.ntsb.gov/_layouts/ntsb.aviat ... 071&akey=1]http://www.ntsb.gov/_layouts/ntsb.aviat ... 071&akey=1[/url]


[quote][font=verdana] The engine was shipped to the manufacturer's facility for further examination. After an initial inspection, the engine was prepared for a run in the test cell. Once installed, the engine started on the first attempt without hesitation. The engine speed was brought to 1,000 rpm to warm up the engine to normal operating temperatures. The engine was run at 1,200 rpm for five minutes to stabilize. The engine throttle was advanced to 1,600 rpm, 2,100 rpm, and 2,450 rpm and held for five minutes at each rpm setting to stabilize. [b]The engine throttle was then advanced to the full open position and the engine began to "stumble" and lose power.[/b][/font]

Investigators then began troubleshooting the fuel system. Subsequent engine runs would result in the engine only being capable of attaining 1,800 rpm. Further troubleshooting revealed [b]both number 2 cylinder intake valve springs were broken.[/b] Visible rust was observed on the surfaces of the springs. The broken valve springs were replaced and the engine was run again. [b]After replacing the valve springs, the engine was capable of operating normally at full power.[/b] The engine throttle was rapidly advanced from idle to full throttle six times, where it performed normally without any hesitation, stumbling or interruption in power. No further anomalies noted that would have prevented normal operation or production of rated horsepower.

[b]The fractured inner and outer intake valve springs from the number 2 cylinder were subsequently examined by investigators. [u]Both springs showed fatigue fractures originating from rust pits on the surfaces.[/u][/b]

A review of the engine maintenance logbooks revealed that a 100 hour/annual inspection was completed on October 14, 2014, at 7,857.8 hours tachometer time. About 13 hours of operating time had accrued since the last inspection of October 14. About 1,501 hours had accumulated on the engine since its last major overhaul.

According to the engine manufacturer's operating manual, under the 100-hour inspection procedures, it states, "Remove valve rocker covers, and inspect visible parts of the valve mechanism for breakage and lack of lubrication. All parts should be covered with oil."[/quote]

I keep making noise about the dangers of internal
engine corrosion, and no one gives a shit.  Here's
the inside of a valve cover of a supposedly legal
and airworthy aircraft that I flew for a customer:


[img width=375 height=500][/img]

[ScudRunner-d95]

I flew a C205 and we could have taken those IO-470 engines well beyond TBO, albeit it wasn't the power on power off like the jumper dumpers do. We had great maintenance professionals and never skimped on anything (other than the interior), as my boss use to put it "sure we could save a few bucks, but whats a crash and lawsuit going to costs?". 

I might be wrong but isn't the 470 the same block as the 520 but with smaller jugs?