And what country can preserve its liberties if their rulers are not warned from time to time that their people preserve the spirit of resistance? Let them take arms. The remedy is to set them right as to facts, pardon and pacify them. What signify a few lives lost in a century or two? The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants.
What if the prop fails? What if it eats a valve, a rocker arm breaks or worse, the crank breaks? What if....so many things can go wrong. Which is why I'll stay over here on land.
Let me help you with your concerns. :-) Turboprop, so no valves, no rocker arms, no crank. Of course other things could go wrong, but a purely rotary machine has some advantages.
That is a Pratt & Whitney PT6 engine, the work horse of aviation in the 600hp to 1000hp range. Super-Dependable and have been in production since 1966. There is no valve train or crankshaft in a gas turbine engine and the Hartzell propeller is just as reliable. Unlike automotive engines, aircraft engines are removed before failure and have mandatory inspection and overhaul intervals. On a PT6 every 150 or 200hrs all the filters will be inspected or changed and the engine externally examined and the mechanics will also perform power assurance checks, measuring ambient temperature, field altitude, fuel flow, prop rpm, gas generator rpm, torque, ITT (Inter Turbine Temperature) and comparing the readings to the graphs in the manual. Any parameter that is out of range will lead to further investigation to discover and rectify the cause.
Every 400hrs a borescope inspection is performed with a fiber-optic scope. Aviation and nuclear reactor technicians were using borescopes long before Dr.s started using them for colonoscopies. The scope is used to examine the combustion chamber for cracking, buckling and loss of the ceramic coating.
At 1800hrs an HSI (Hot Section Inspection) is performed. The engine is split open in order to expose the combustion chamber, the guide vanes and the compressor turbine wheel, which are the hottest parts in the engine. In addition, the pilot checks the engine performance every takeoff (trust me on this, every pilot in the world wants a healthy engine and will report the slightest discrepancy in the logbook). In addition there are mandatory Life Limits on most of the rotating parts in a turbine engine. At my job that I retired from there was a PT6 with over 22,000hrs time in service and several with over 15,000hrs. If you drove a car at an average speed of 60mph for 22,000hrs it would travel 1,320,000 miles.
The CF-34, the civilianized engine from the A10 Warthog, has one in-flight shutdown every 13,000,000 hours. A Rolls-Royce engine on an Iceland Air 757 went over 40,000hrs on-wing, it was only removed to change time expired internal components.
What if the prop fails? What if it eats a valve, a rocker arm breaks or worse, the crank breaks? What if....so many things can go wrong. Which is why I'll stay over here on land.
ReplyDeleteTough way to live a life imo... but we each have our live to live as we see fit. Best of luck to you Mr Anonymous.
DeleteThat's a turbine.
DeleteAnyway, the 'what ifs' are why so much of flight training, basic to recurrent, is emergency procedures.
Let me help you with your concerns. :-) Turboprop, so no valves, no rocker arms, no crank. Of course other things could go wrong, but a purely rotary machine has some advantages.
ReplyDeleteThat is a Pratt & Whitney PT6 engine, the work horse of aviation in the 600hp to 1000hp range. Super-Dependable and have been in production since 1966. There is no valve train or crankshaft in a gas turbine engine and the Hartzell propeller is just as reliable. Unlike automotive engines, aircraft engines are removed before failure and have mandatory inspection and overhaul intervals. On a PT6 every 150 or 200hrs all the filters will be inspected or changed and the engine externally examined and the mechanics will also perform power assurance checks, measuring ambient temperature, field altitude, fuel flow, prop rpm, gas generator rpm, torque, ITT (Inter Turbine Temperature) and comparing the readings to the graphs in the manual. Any parameter that is out of range will lead to further investigation to discover and rectify the cause.
ReplyDeleteEvery 400hrs a borescope inspection is performed with a fiber-optic scope. Aviation and nuclear reactor technicians were using borescopes long before Dr.s started using them for colonoscopies. The scope is used to examine the combustion chamber for cracking, buckling and loss of the ceramic coating.
At 1800hrs an HSI (Hot Section Inspection) is performed. The engine is split open in order to expose the combustion chamber, the guide vanes and the compressor turbine wheel, which are the hottest parts in the engine. In addition, the pilot checks the engine performance every takeoff (trust me on this, every pilot in the world wants a healthy engine and will report the slightest discrepancy in the logbook).
In addition there are mandatory Life Limits on most of the rotating parts in a turbine engine. At my job that I retired from there was a PT6 with over 22,000hrs time in service and several with over 15,000hrs. If you drove a car at an average speed of 60mph for 22,000hrs it would travel 1,320,000 miles.
The CF-34, the civilianized engine from the A10 Warthog, has one in-flight shutdown every 13,000,000 hours. A Rolls-Royce engine on an Iceland Air 757 went over 40,000hrs on-wing, it was only removed to change time expired internal components.
Plus there is a spare engine on the other side.
Al_in_Ottawa
Before cars, BMW started off making airplane engines. Their logo is the stroboscopic image of a propeller.
ReplyDelete