Ask Paul: What’s causing intermittent roughness?

Q: I am an European-based A&P with a customer who is experiencing intermittent roughness and loss of rpm (200) typically close to the top of climb on a long climb out. The roughness goes away once it is throttled back, and it does not occur all the time. The snag can’t be produced on the ground. The aircraft is just off annual check and had the 1,000 hours mag inspection carried out, apart from various other visual inspections, plus the routine other items.

I’ve thought about the possibility of a sticky valve, an issue in the carb venturi or some issue with the mags, but thought if it were any of these that the issue would be there all the time?

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Ask Paul: The Cherokee Rattle

Q: I just bought a 1974 300-hp Cherokee Six. It has about 1,200 hours to run, has great oil pressure, good compressions, hardly uses oil, no metal in the filter, but during the run-up at 2,000 rpm, the engine makes quite a deep knock.

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What oil should I use?

The two most common questions that I still get are: 1. What oil should I use in my aircraft engine? And 2. Are different brands and grades of oils compatible?

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A Q&A with Lycoming’s top man

After Oshkosh, I sent an email to Michael Kraft, Lycoming’s senior vice president and general manager. Due to this busy travel schedule, he was just able to get his answers to me. To honor his request, I agreed to run this in a Q&A format.

Q: Is Lycoming working on or considering development of a diesel cycle piston aircraft engine?

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Continental extends TBOs up to 400 hours

Continental Motors has increased TBO up to 400 hours on Gold Standard Factory produced engines.

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Ask Paul: Why are my #3 cylinder CHTs so high?

Q: Recently — 50 hours ago — I had a Lycoming O-360-A4A overhauled with new ECi Titan steel cylinders installed. The #3 cylinder has had high-ish CHTs from the beginning. [Read more...]

Blue skies ahead for Cessna’s diesel 182

One of the interesting technical stories from this summer’s AirVenture in Oshkosh was that Cessna has completed certification and introduced into the market a diesel cycle 182 aircraft, known as the Turbo Skylane JT-A.

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Storing your airplane for the winter

Are you ready for winter? Is your plane? AVweb recently published a primer on the importance of preparing your plane for winter. It’s complete with detailed instructions for Lycoming and Continental engines. Check it out here.

Ask Paul: What are these aluminum specks?

Q: I lost the left mag on my O-540. When I took it apart, I found four aluminum specks in the top oil screen. I pulled the rear housing off and found the aluminum gear still in the engine. I sent it off for repairs to Tulsa, where they installed a new oil pump, shaft, gears and housing, as well as a new fuel pump and dry vaccum, and two rebuilt mags. I ran it for 1.5 hours, then pulled the screen and found a few specks again, but not as many as the first. Any ideas?

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More tips on breaking in your engine

In the past few months, my friend Paul McBride has written several very interesting and informative articles on “breaking in” an aircraft engine, including “How to break-in your engine”. I recommend that you read them when or if you have a new or rebuilt engine to install on your aircraft. [Read more...]