Kingair 200/350 Start up sequence
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I haven't flown a 200 for about 12 years but I'm more current on the 300 series, both 300 and 350. The first thing we have to remember is that this is aviation and there are thousands of, "I was told once," stories.
I always wait for the ITT to stabilize before going to high idle because I was told once that until the ITT is stable the boundary layer of air that separates the fire from the combustion chamber wall is not fully formed.
I have seen historical data that shows the benefit of alternating starts when it comes to the cost of overhauls. The worry about amperage drop comes from the days of smaller gauge wires being used. The wires used now days is thick enough that amperage drop is negligible.
I've never understood the starting in feather unless you were starting both engines using a GPU so the person disconnecting wouldn't get blown away.
As I understand it, going to high idle prevents the engine from bogging down under the increased load. The start on newer models is still just using the battery until higher n1 it's just that the generator control unit (GCU) is taking care of taking the generator off line and putting it back.
The leaving of the type II prop sync on is perfectly fine airmanship. The old saying is, you turn it on when you buy the plane and turn it off when you sell it.
I always wait for the ITT to stabilize before going to high idle because I was told once that until the ITT is stable the boundary layer of air that separates the fire from the combustion chamber wall is not fully formed.
I have seen historical data that shows the benefit of alternating starts when it comes to the cost of overhauls. The worry about amperage drop comes from the days of smaller gauge wires being used. The wires used now days is thick enough that amperage drop is negligible.
I've never understood the starting in feather unless you were starting both engines using a GPU so the person disconnecting wouldn't get blown away.
As I understand it, going to high idle prevents the engine from bogging down under the increased load. The start on newer models is still just using the battery until higher n1 it's just that the generator control unit (GCU) is taking care of taking the generator off line and putting it back.
The leaving of the type II prop sync on is perfectly fine airmanship. The old saying is, you turn it on when you buy the plane and turn it off when you sell it.
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I'm not sure I understand your question. By 5 bus do you mean a triple fed system with left and right gen, centre, triple fed and battery bus? If so, I believe most triple fed systems have the newer GCU's that won't allow you to do a cross start.
So there would be no reason to turn the generator off and then back on at a specific n1. In fact I don't think you would find a procedure that would specify the n1 required before putting the generator back online.
If you were using the older GCU's I wouldn't do a cross start often unless you wanted to purchase a lot of current limiters.
However I did notice that our engineers started our old straight 200 without turning off and on generators. When I asked them about it, they showed me the starting procedure in the maintenance manual it didn't indicate a need to turn off the generator. The manufacturer's POH did however.
So there would be no reason to turn the generator off and then back on at a specific n1. In fact I don't think you would find a procedure that would specify the n1 required before putting the generator back online.
If you were using the older GCU's I wouldn't do a cross start often unless you wanted to purchase a lot of current limiters.
However I did notice that our engineers started our old straight 200 without turning off and on generators. When I asked them about it, they showed me the starting procedure in the maintenance manual it didn't indicate a need to turn off the generator. The manufacturer's POH did however.
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m2f,
Yes, that is the system I am referring to, sorry if my last post wasn't too clear...
The C90A manual does not stipulate turning the generator off for starting the second engine. Indeed, when doing generator cross starts the current limiter is bypassed.
My question relates to generator assisted starts. In The King Air Book, Tom Clements suggests starting the second engine with both generators off, though once the N1 is through a certain value (not a book figure, just suggested) turning on the generator of the running engine. This will provide higher N1 and a cooler start.
He does say that this practice should not be used on the later models with the aforementioned electrial system. It seems a little strange to me that it is ok, as per the AFM, to do a cross start but not an assisted start. Any thoughts?
h
Yes, that is the system I am referring to, sorry if my last post wasn't too clear...
The C90A manual does not stipulate turning the generator off for starting the second engine. Indeed, when doing generator cross starts the current limiter is bypassed.
My question relates to generator assisted starts. In The King Air Book, Tom Clements suggests starting the second engine with both generators off, though once the N1 is through a certain value (not a book figure, just suggested) turning on the generator of the running engine. This will provide higher N1 and a cooler start.
He does say that this practice should not be used on the later models with the aforementioned electrial system. It seems a little strange to me that it is ok, as per the AFM, to do a cross start but not an assisted start. Any thoughts?
h
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Just leave it on. The system is designed to deal with the start and any other method would be superfluous.
In the straight 200 with the dual fed bus system using the method of turning off the generator until a specific n1 we would still loose current limiters from time to time. I don't remember ever having lost a current limiter in a triple fed bus system and I have 6 times the time on a triple fed bus system.
In the straight 200 with the dual fed bus system using the method of turning off the generator until a specific n1 we would still loose current limiters from time to time. I don't remember ever having lost a current limiter in a triple fed bus system and I have 6 times the time on a triple fed bus system.
Last edited by mad2fly; 5th Dec 2012 at 14:40.
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on idle cutoff 90-110#, slowly building till secondaries cut in around 220-250# this is -67 , don't remember the -42 numbers
In The King Air Book, Tom Clements suggests starting the second engine with both generators off, though once the N1 is through a certain value (not a book figure, just suggested) turning on the generator of the running engine. This will provide higher N1 and a cooler start.
cheers
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thats pretty correct. start one engine, turn on generator , load battery, turn off again, start the second and at lets say 30% ,when the current from the starter dropped , kick the opposite generator in.
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Hi guys,
On one of my very first flights on a A90 , I didn't notice the condition levers weren't in the cut off position before start. They were already both in the low idle position, what created the confusion they appeared to be in the cut-off position
I noticed it when I started the first engine because it lighted up much sooner as usual.. In other words, the N1 wasn't stable yet (around 15%) while fuel was already introduced...
Might it be damagable to any part of the engine ? Should it be checked?
Thank you
On one of my very first flights on a A90 , I didn't notice the condition levers weren't in the cut off position before start. They were already both in the low idle position, what created the confusion they appeared to be in the cut-off position
I noticed it when I started the first engine because it lighted up much sooner as usual.. In other words, the N1 wasn't stable yet (around 15%) while fuel was already introduced...
Might it be damagable to any part of the engine ? Should it be checked?
Thank you
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What was peak ITT? The higher the Ng prior to introducing fuel, the more airflow through the engine and therefore greater cooling. Starting the engine with Condition Levers at flight idle could cause an excessive temperature on start. Also, there may have been an accumulation of fuel in the combustion chamber when you engaged the Starter/ Ignition. This can cook an engine.
To answer your questions:
1) Yes, it might
2) Yes
h
To answer your questions:
1) Yes, it might
2) Yes
h
A77 considering. I did 9starts yesterday, and will do 5 tomorrow chances are it is a real PT6. On start when the condition lever is moved out of ICO, the minimum pressure valve will allow fuel to flow to the FCU, and the min flow valve, roughly 90-110#/hr or around 50% N1. The pneumatic bellows will not allow the fuel metering cup to distribute fuel until P3 air runs through to the fuel topping governor in the PCU . The pressure compresses the bellows, allowing the N1 flyweights to adjust fuel flow to the corresponding selected rpm. If somebody wants to send an email address, I will record a start or two if you will post it here
