One of the very best talks and easy to comprehend discussion on turbocharging (Normalizing) an aircraft engine. Ive been involved with turbocharging development since the early days.

Good stuff. I am not one to tell anything to Mike Bush but I do have a couple comments. As someone who has extensive experience with turbo applications I will say that the “cool down” procedure isn’t really to allow the turbo to spin down. It actually spins down very quickly. That’s why it is important to not be “ham fisted” and yank on the throttles. The primary purpose for allowing a cool down period is to allow for cooling of the turbine section while providing continuous oil flow to the bearings. The turbine is extremely hot during flight as it is producing boost. If you do not have a decent amount of time to allow this cooling and shut down engines quickly, it can heat soak the turbo including the bearings. This could over time damage the bearings due to coking of the oil. So a few minutes of idle or low speed taxi prior to shut down is a good thing. Also, it is fair to mention that direct drive or mechanical driven supercharger systems also require power to operate thus placing an extra load on the engine. This can produce more engine heat and reduces efficiency.

The six minute idle period suggested in POH's is not about letting the turbo shaft slow down..........the shaft will slow down within thirty seconds after you reduce power to idle..........the six minute idle period is to let the turbo shed the heat in the Center section where the oil and bearings are located.......the Center section is connected to the compressor and turbine sections which are hot from operation.........if you shut the engine off quickly , the Center section gets cooked by the heat that has not had time to dissipate ..........the intake air and lower exhaust temp and air flow through the turbo will cool the unit fairly quickly if left to idle.........but it must have time to complete the heat removal..........even the lube oil helps remove heat from the center section...........if the cooling down period is shortened , the excess heat will coke or carbonize the lube oil in the shaft bearings and over time will wear them out or cause the bearings to drag or completely seize up..........lube oil will coke relatively quick when exposed to heat left behind after a hasty shutdown...........unless people see the turbine section glowing orange under load , they do not realize how much heat is being absorbed by the turbo from the exhaust flow through it.........if you do not give the turbo time to dissipate that heat and you shut off the engine too quickly after landing , the turbo cooks in its own juices and damage is inevitable..........the idle period is not about letting the turbo wind down in rpm...........it is about cooling it off..

Hello! I have a channel of Turbocharged and modified cars, in my case, i own a GM Chevette Stock engine with 1 bar of max pressure @ stock 1.6l engine. Im searching for sources to create a video tryin to explain "The history of Turbo Chargers". I knew that this development began into locomotives and aircraft. This video explain me so much about it. Thnak you, and apologize me for my poor english.

"I would never... consider purchasing a non-turbocharged aircraft", I couldn't agree more.

Loved my V35-TC.

At 12:23 I think he got the eastbound and westbound backwards.

Very much enjoyed that. Answered so many questions for me. I was in a syndicate for a turbo arrow with a TSIO 360. Although there a problems with this engine, with thorough knowledge and understanding, it is a great performing engine. Not great with ham-fisted pilots.

My ears perked up when Mike mentioned aftermarket intercoolers. Years ago some clients I occasionally gave flight reviews and IPC’s to upgraded their Piper Turbo Lance (one of those T-tail versions). Once I discovered that I checked the Chapter 9 revision to the POH and discovered the manufacturer HAD a power conversion chart. I cautioned them to follow it but they said they were just going to run it off the original performance charts. It came back to bite them. I don’t know how much time they put on that engine before it died but die it did on an IFR XC (oil on the windshield and a frozen engine) that resulted in a total loss of the airplane and serious injuries to the pilot.

I'm waiting for info on turbo normalization.

I’m not sure he fully understands why you wait to shut down your engine with a turbo charger. The turbo charger spools down almost immediately when you cut the throttle to idle. My understanding, especially coming from the trucking world and agricultural world is a turbocharger runs extremely hot and not only does the oil lubricate, but it also cools the center section which is literally touching the exhaust. So while running hard, that center section is extremely hot and the oil is cooling it while it’s running so a four minute idle Cools down the casting so that when you shut the engine off, you don’t have burnt oil that can eventually plug the supply to the bearings.

Going back to the airlines running DC-6's and DC-7's, the DC-7's were retired before the DC-6's. Why would anybody retire a newer model before the older model, you may ask? The DC-7's used a turbo-compound engine. That meant that there was a reduction gear to connect the turbo to the prop shaft to extract more horsepower from the exhaust gas. Think about the reduction ratio required to go from turbo rpm to prop rpm. The system was very tricky to maintain and poorly understood by the industry. Gears are heavy and introduce eccentric loads that are not present with a more common turbo. Turbo-compound engines were late to the party and never fully arrived. So, if the airlines couldn't live with turbos, how was general aviation supposed to make that magic happen? The naming conventions got a little sloppy, turbo-compound is a whole different animal from the turbos that we are familiar with.

Mike, Was the comment about headwinds going against you to the E and with you going west backwards?

To fly at the altitudes optimal for a turbocharged aircraft, you will need oxygen or pressurization. Could you comment on the added cost of maintainance of these systems and the increase in insurance rates for these vs the normal aspirated aircraft. It seems that with these factored in, the cost differential goes up consideralbly. Thanks.

Turbo normalized is generally cooled down by landing due to no demand on the system. Under 6000' on let down the system is idleing so to speak.

At the 12:20 mark in the video he mentions flying west bound and east bound and the headwind/tailwind scenario.. Having lived and flown most of my flying career in Colorado and Arizona flying to and from CA and east to TX(from AZ), I've found the west northwest bound flights have HEADWINDS while east southeast bound has the tailwinds which is opposite of what he says. Has he said it backwards here or do many others find east bound headwinds and west bound tailwinds?

Other than 2 motors to maintain and the higher training / proficiency burden (which I think one should do in a single as well) is there any additionrreason for why not a twin ? just lower Mx ?

buy a diamond,, problem solved :))