MMS&TF Piston Engine Seminar By Chad Menne / Malibu Aerospace Teledyne Continental Motors “Gold Motor” Textron Lycoming “Grey Motor”

Who am I and why are we here? Chad Menne Malibu Aerospace Over 7,000 hours of PA46 time Corporate flight experience Aircraft management Flight test experience Engineering – Research & Development FAA Certification Tests Maintenance / Production Flight Tests

Today’s Topics Both Lycoming & Continental Engines How do we operate these engines? Why do we operate them that way? What are we missing? What is my mechanic missing? What are common problems?

Let’s talk engines Reliability “Piston engines are comprised of a thousand parts flying in all different directions, looking for a way out.”

Let’s talk engines Reliability “Piston engines are comprised of a thousand parts flying in all different directions, looking for a way out.” 98 out of 1385 total accidents were due to powerplant failures (7%), representing 21.4Million flight hours (Nall report 2007). That is one accident every 218,367 flight hours caused by engine failures,(turbine & piston). 11 of them resulted in fatalities (0.8%), which equals ONE fatal accident every 1.95Million flight hours due to engine failure. The TOTAL fatal accident rate is 1 per 84,920 flight hours for ALL types of accidents in ALL types of planes.

Let’s talk engines Reliability “Piston engines are comprised of a thousand parts flying in all different directions, looking for a way out.” 98 out of 1385 total accidents were due to powerplant failures (7%), representing 21.4Million flight hours (Nall report 2007). That is one accident every 218,367 flight hours caused by engine failures,(turbine & piston). 11 of them resulted in fatalities (0.8%), which equals ONE fatal accident every 1.95Million flight hours due to engine failure. The TOTAL fatal accident rate is 1 per 84,920 flight hours for ALL types of accidents in ALL types of planes. The piston PA46 fleet averages about 150,000 hours/year That means we should see one accident every 1.5 years and one fatal accident every 13 years due to engine failure (piston & turbine) Some sources claim a piston engine fails every 3,200 flight hours. Pratt & Whitney claims a PT6 failure every 333,000 flight hours by comparison

Common Problems Both Malibu & Mirage Exhaust! Magnetos Turbochargers Turbo transitions, slip joints, gaskets, clamps Magnetos Cam wear, moisture/corrosion, points, dist. block Turbochargers Don’t expect them to go to TBO Cam & lifter corrosion and wear Excess moisture, fuel dilution, shearing & thermal breakdown of the oil

Malibu specific problems Exhaust valves Most common cause from high power & high CHT & exhaust temps Starter drive adapters Lightweight Iskra starters can cause premature wear Air conditioner driveshaft seals can leak Cylinder & ring wear First to be blamed & rarely the cause Bearing end play Check for proper end play during pre-flight and DO NOT fly without end play! Borescope for detailed inspection before condemning a cylinder Be sure to use TCM master orifice tool for daily calibration during a compression check

Mirage specific problems Exhaust valve guide wear (high oil consumption and rough running) Broken oil control rings Poor break-in results (high oil consumption) Lycoming does not allow mineral oil Cracked oil sump at turbo support studs Cracked internal oil baffle Be sure to check suction screen for rivets Fuel servo problems Unable to get proper ground mixture or full power fuel flow Can cause surging in cruise Fuel line AD 2008-14-07 every 100 hours (cracking due to improper securing of lines)

Believe it, or not! Lifter Main bearing

Crankcase bearing journal

Crankshaft Bearing Wear

Oil Sample - Good

Oil Sample - Bad

Most Common Sources of Wear Metal Elements in Oil Iron Cylinders, rotating shafts, valve train and any steel part sharing the oil. Copper Brass or bronze parts, bushings, bearings, oil coolers, sacrificial coatings. Nickel Valve guides, trace element in steel, some cylinder types. Chromium Rings, cylinders, a trace element in steel. Silver Sacrificial coatings, a trace element in some types of bearings, bearing cage plating Magnesium Engine casings, additives Aluminum Pistons, piston pin plugs, bearing overlay, casings. Lead Primarily leaded gas blow-by, traces from bearings Silicon Abrasive dirt from intake air, silicone sealers and gaskets, sample contamination. Tin Bearings, bronze parts (with copper), anti-wear coatings. Molybdenum Traces of anti-wear coatings, some cylinder types, and bearings.

Exhaust Woes Leaky Gasket Colorful clues

Mirage Turbo Transition Heavy, Cast Inconel Erosion & Blistering

Malibu Turbo Transition .065” Stainless Steel Check at EVERY Oil Change!

Tailpipe Trouble Corrosion has its way Heat Muff - Uncovered

V-Band Clamps

Exhaust Clamps Malibu & Old-Style Mirage Clamps Crack from over-tightening

Exhaust Clamp Engagement The right way The WRONG way

Sump Cracks (Turbo Mounts)

Turbochargers

Common Turbo Problems Compressor damage Bearing failure Seal failure Scavenge pump failure Scavenge hose failure Wastegate failure or sticking

Turbochargers Bearings Compressor Damage

Engine Cooling

Things that you can do Vent oil cap after shutdown (minimize corrosion) Watch EGTs and trend data (ignition and fuel injection anomalies) In-flight mag checks (look for hot or cold EGTs) Oil samples (watch for iron, nickel, almuminum) Watch for peak TIT drift (up or down) Drift up is usually ignition or low compression Drift down is usually a probe going bad

The best pilots can juggle The best way to prolong your engine’s life and improve safety is to know how to balance parameters Trade one temp for another Engine limits are not intended to provide longest life, but are instead proven to be acceptable for short durations Add fuel only as necessary to achieve a good balance during climb Less fuel means more power! (power means heat)

Which is worse??? 360° CHT – 1650° TIT 400° CHT – 1580°TIT

Which is worse??? 360° CHT – 1650° TIT 400° CHT – 1580°TIT The TIT is an exhaust gas temp, the CHT affects the engine’s ability to dissipate heat A cooler CHT can transfer more heat away from a valve 400° CHT – 1580°TIT Less differential from valve to seat and guides removes less heat from valve Localized oil temps will be hotter at valve guides

Operations How hot is too hot??? Lean of Peak, no free lunch CHT or EGT/TIT, not both (valve wear) High TIT equals more exhaust wear Lean of Peak, no free lunch Lose speed (less power at same power setting) Wear exhaust (higher EGTs, more oxidation) Not as smooth (slight roughness or surging) Cooler CHTs (helps offset the higher EGTs and cool valves)

LOP Cost Comparison Continental Lycoming 20% fuel savings ($28,000 over 2000 hours) 1500 hrs x 21GPH x $4.50/gal - 20% 2% speed loss ($9,000 additional aircraft cost over 2000 hours) 1500 hrs x 200kts - 2% / 196kts x $300/hr Increased exhaust wear costs ($3000 over 2000 hours) Lycoming 25% fuel savings ($35,000 over 2000 hours) 1500 hrs x 21GPH x $4.50/gal -25% 10% speed loss ($50,000 additional cost over 2000 hours) 1500 hrs x 200kts - 10% / 180kts x $300/hr Increased exhaust wear costs ($10,000 over 2000 hours)

Ignition timing and combustion speed How to change your ignition timing??? Engine speed Higher RPM = less advance (less time to burn) 2500 RPM = 1 Revolution every .024 seconds Lower RPM = more advance (more time to burn) 2300 RPM = 1 Revolution every .026 seconds or 9% more time Mixture ratio ROP Leaner mixture = more advance (burns faster – sharper power pulse) Richer mixture = less advance (burns slower – softer power pulse) Mixture ratio LOP Richer mixture = more advance (burns faster – sharper power pulse) Leaner mixture = less advance (burns slower – softer power pulse)

Affects of RPM on “Combustion timing” Lower RPM Higher RPM TDC Peak Pressure Intake Compression Combustion Exhaust Earlier Peak Pressure, More Time to Burn, More Cooling Time per Cycle, Less HP, Cooler EGT, Cooler CHT TDC Peak Pressure Intake Compression Combustion Exhaust Later Peak Pressure, Less Time to Burn, Less Cooling Time per Cycle, More HP, Hotter EGT, Hotter CHT

Affects of mixture on “combustion timing” TDC Peak Pressure Affects of mixture on “combustion timing” ROP Combustion LOP Combustion TDC Peak Pressure Intake Compression Combustion Exhaust Faster Combustion, Sharper Pulse, Cooler EGT, Hotter CHT TDC Peak Pressure Intake Compression Combustion Exhaust Slower Combustion, Lower Pressure, Hotter EGT, Cooler CHT

Leaning Techniques No wonder you’re confused! Rich of peak, lean to peak, lean of peak TIT peak method, a.k.a.“the factory method” Fuel flow method JPI lean find “Lean L” method JPI lean find “Lean R” method “The big pull”

What’s My Horsepower??? Continental Lycoming LOP, FF x 15 = HP ROP, FF x 13.25 = HP (Can vary a lot) Lycoming LOP, FF x 14 = HP ROP, FF x 12 = HP (Can vary a lot)

E-mail me, cwmenne@malibuaerospace.com Thank you! Questions Comments E-mail me, cwmenne@malibuaerospace.com Fly Safe!