Post by Tom/CalClassic on Jan 13, 2009 19:31:50 GMT -5
bellcobraiv
Johan,
I will try to not get too technical with my answers, so if we just go through your current questions;
CHT; Cylinder Head Temperature. The cylinder heads used on the engines that powered the propliners were forged aluminum. The factory determined a temperature based on engineering data that the cylinder head should not exceed in order to insure a long life without mechanical or structural failure. In addition usually the master rod cylinders were monitored, as these carried the primary thrust load for the engine, for each row. A high indication on a master rod related CHT could indicate potential Master rod bearing problems.
METO; Maximum Except Take Off. This is a maximum continuous operational power setting for engine operations. Once again determined by engineering and testing at the factory. You don’t want to live your life flying around at METO power, If we had to SIM the cost of overhaul and maintenance to get flying hours we would all better understand the concept.
BMEP; Brake Mean Effective Pressure. This is the pressure during the power stroke of a reciprocating engine measured in pounds per square inch. It is used as an indicator of power output by the FE, he could adjust the mixtures to achieve a rise in BMEP and find best power using that information.
BSFC; Brake Specific Fuel Consumption. Since we are in the neighborhood lets hit the other indicator of performance. This is the pounds of fuel burned per hour for each brake horsepower the engines develops.
Brake Horsepower; The total actual Horsepower delivered to the crankshaft, This was originally measured on a prony brake and eventually was measured in test cell and by engine mounted internal Tourquemeters.
MAP; Manifold Absolute Pressure. AH! Now here is something that Americans have forced upon the world The Brits use BOOST Pressure and others use ATMOSPHERES.
MAP is defined as the absolute pressure of the air inside the induction system. On a non supercharged engine this can be below atmospheric, as well as on a supercharged engine that is not producing boost at lower power levels.
British Boost pressure gauges read in PSI and can be converted by adding 14.7 for the standard atmosphere at sea level and multiplying by 2.04. The reverse of the equation works for the opposite conversion. (Divide MAP by 2.04 and subtract 14.7).
Manifold pressure and RPM are settings that are found through testing and engineering that provide the best settings for the engine/airframe combination. For both economy of fuel, and economy of parts. As an example Charlie Thompson was a major representative for Curtiss Wright. He once told me that he was called onto the carpet by Eddie Rickenbacker for engine failures. There were about ten or so Eastern Airlines executives around the table, and Captain Eddie lit into Charlie for the engine problems they were having, after this Rickenbacker said he wanted the responsible person or persons found and identified. Charlie responded, OK sir, You are responsible, You changed Eastern’s climb procedure and your running the engines too hot, too long. You are saving fuel but burning up engines. At this point Mr. Rickenbacker said prove it, a Constellation was made available and the two of them got on board and an air crew took off. Mr. Thompson and Mr. Rickenbacker watched the gauges on the flight engineer panel during climb out following Eastern’s Climb Procedure. Then they cooled the airplane, landed took off again and watched the gauges following the Curtiss Wright/Lockheed procedure, Yes Fuel flow was up, but so was airspeed, torque, and CHT and Oil Out temperatures were down. The airplane was landed. Lunch was served and the policy was immediately changed.
That last story should indicate that even though you are flying a sim procedures were outlined based on real life testing, so some times the why is that is the procedure.
You said ”Like a A-Z manual, explaining in lay man terms what some gauges show, what not to do (you can give full throttle in the DC3 in FS9 for many days on a row without harming the engines, on the ground with the parking brakes on, some fool needs to make us a DLL what prevents this) and why we do some engine settings.. reading notes doesnt tell me anything, only to SET pitch to something, and MAP to something?”
I hope I was able to give some back to the forum I have already taken from. If I can answer any more specifics ask I’ll answer if I know.
BTW, I also wish that an accurate damage model existed for operating engines out of their envelope.
BCIV
Johan,
I will try to not get too technical with my answers, so if we just go through your current questions;
CHT; Cylinder Head Temperature. The cylinder heads used on the engines that powered the propliners were forged aluminum. The factory determined a temperature based on engineering data that the cylinder head should not exceed in order to insure a long life without mechanical or structural failure. In addition usually the master rod cylinders were monitored, as these carried the primary thrust load for the engine, for each row. A high indication on a master rod related CHT could indicate potential Master rod bearing problems.
METO; Maximum Except Take Off. This is a maximum continuous operational power setting for engine operations. Once again determined by engineering and testing at the factory. You don’t want to live your life flying around at METO power, If we had to SIM the cost of overhaul and maintenance to get flying hours we would all better understand the concept.
BMEP; Brake Mean Effective Pressure. This is the pressure during the power stroke of a reciprocating engine measured in pounds per square inch. It is used as an indicator of power output by the FE, he could adjust the mixtures to achieve a rise in BMEP and find best power using that information.
BSFC; Brake Specific Fuel Consumption. Since we are in the neighborhood lets hit the other indicator of performance. This is the pounds of fuel burned per hour for each brake horsepower the engines develops.
Brake Horsepower; The total actual Horsepower delivered to the crankshaft, This was originally measured on a prony brake and eventually was measured in test cell and by engine mounted internal Tourquemeters.
MAP; Manifold Absolute Pressure. AH! Now here is something that Americans have forced upon the world The Brits use BOOST Pressure and others use ATMOSPHERES.
MAP is defined as the absolute pressure of the air inside the induction system. On a non supercharged engine this can be below atmospheric, as well as on a supercharged engine that is not producing boost at lower power levels.
British Boost pressure gauges read in PSI and can be converted by adding 14.7 for the standard atmosphere at sea level and multiplying by 2.04. The reverse of the equation works for the opposite conversion. (Divide MAP by 2.04 and subtract 14.7).
Manifold pressure and RPM are settings that are found through testing and engineering that provide the best settings for the engine/airframe combination. For both economy of fuel, and economy of parts. As an example Charlie Thompson was a major representative for Curtiss Wright. He once told me that he was called onto the carpet by Eddie Rickenbacker for engine failures. There were about ten or so Eastern Airlines executives around the table, and Captain Eddie lit into Charlie for the engine problems they were having, after this Rickenbacker said he wanted the responsible person or persons found and identified. Charlie responded, OK sir, You are responsible, You changed Eastern’s climb procedure and your running the engines too hot, too long. You are saving fuel but burning up engines. At this point Mr. Rickenbacker said prove it, a Constellation was made available and the two of them got on board and an air crew took off. Mr. Thompson and Mr. Rickenbacker watched the gauges on the flight engineer panel during climb out following Eastern’s Climb Procedure. Then they cooled the airplane, landed took off again and watched the gauges following the Curtiss Wright/Lockheed procedure, Yes Fuel flow was up, but so was airspeed, torque, and CHT and Oil Out temperatures were down. The airplane was landed. Lunch was served and the policy was immediately changed.
That last story should indicate that even though you are flying a sim procedures were outlined based on real life testing, so some times the why is that is the procedure.
You said ”Like a A-Z manual, explaining in lay man terms what some gauges show, what not to do (you can give full throttle in the DC3 in FS9 for many days on a row without harming the engines, on the ground with the parking brakes on, some fool needs to make us a DLL what prevents this) and why we do some engine settings.. reading notes doesnt tell me anything, only to SET pitch to something, and MAP to something?”
I hope I was able to give some back to the forum I have already taken from. If I can answer any more specifics ask I’ll answer if I know.
BTW, I also wish that an accurate damage model existed for operating engines out of their envelope.
BCIV