Power levers...
Commande Throttle dans X-Plane ou FSX.
Power levers provide control of engine power from FULL REVERSE through [IDLE and] TAKEOFF power. Increasing N1 RPM results in increased engine power.
Commande Throttle dans X-Plane ou FSX.
Power levers provide control of engine power from FULL REVERSE through [IDLE and] TAKEOFF power. Increasing N1 RPM results in increased engine power.
In the King Air series, the power levers control fuel flow in the forward range, and schedule propeller angle and fuel flow in the beta, or ground range. Beta is anything below flight idle.
The purpose of the power lever is two-fold – first it controls the fuel schedule by the interconnect from the engine cambox to the fuel control unit. Depending on the model of PT6 you can have different cambox operation – but in most cases the system will increase gas generator speed in the forward direction for increasing power to the maximum limit allowed and also will add gas generator speed when moved into the reverse position.
The second function of the power lever is to control the propeller blade angle (NOT SPEED) when the engine is operated in “Beta”. This is accomplished by the cambox operation through a push/pull cable (Teleflex) control that is linked to the beta valve on the forward face of the propeller governor and the connection for blade angle feedback that is through a carbon block in a beta ring attached to the propeller.
On the Beech King Air “Beta” range is from a degree or two above your prime blade angle – which is significantly ahead of the flight idle position. Beta in the case of the PT6a-42 in a King Air 200 for example starts at about +21 degrees of blade angle all the way to – 14 degrees in reverse. Flight idle is about 11 degrees.
BETA IS DEFINED AS THE RANGE OF ENGINE OPERATION WHERE THE POWER LEVER CONTROLS THE FUEL SCHEDULE AND THE BLADE ANGLE OF THE PROPELLER
Qu'est-ce que N1 ?...
On a King Air (like a B350) with a PT-6, "N1" is referring to a gauge called "Turbine RPM (%)". It's measuring the RPM of the higher speed section of the gas turbine engine sometimes referred to as the "gas generator" (and some N1 gauges are called "Ng" instead, with g for gas generator). To make things extra confusing turbojet and turbofan engines re-use the N1 and N2 nomenclature, only in a turbofan "N1" refers to the fan speed or speed of the low stage compressor/turbine section, while "N2" refers to the high stage compressor/turbine.
Dans la zone "Beta" le pas des hélices est inférieur au minimum requis pour voler, on ne doit donc utiliser cette position qu'au sol. Trois crans de "Beta" sont prévus dans le secteur de déplacement, avec des tractions faibles. Ces réglages sont utiles pour doser la traction nécessaire juste pour déplacer l'avion au sol à une vitesse inférieure à 25 Kts. On doit obligatoirement utiliser le secteur Beta au sol, sinon, en position plein ralenti l'avion va trop vite et on use les freins prématurément.
Dans notre cockpit on ne joue pas sur le calage des hélices, ce qui signifierait un potentiomètre de plus sur la manette des gaz, affecté à la voie "pas de l'hélice", mais on crée artificiellement une zone de super ralenti, en dessous du ralenti normal, en jouant sur l'étalonnage du potentiomètre normal des gaz.
Propellers levers...
Propeller levers operate springs to reposition the primary governor pilot valve, effecting an increase or decrease in propeller RPM.
The propeller lever is operated conventionally and controls the constant-speed propellers through the primary governor. The propeller RPM range is normally from 1,500 to 1,900.
It has 2 functions. When pull all the way aft it will feather the propeller. When pushed out of the feather detent it will be in the “LOW” speed or minimum governing setting – and when advanced increases the speed of the propeller to the “MAXIMUM” speed setting. When the power lever is moved from the flight idle gate the gas generator speed is increasing and the propeller blade angle is increasing as it is still in beta mode. Just above the primary blade angle check prop speed and torque for the day condition the system will transition from beta to constant speed mode – sometimes referred to as “ALPHA” mode. In this range the power lever will control only the gas generator speed and the propeller control lever will control the speed of the propeller through the constant speed governor.
Condition levers...
Condition levers have three positions:
- FUEL CUTOFF (Extinction des moteurs)
- LOW IDLE (Régime normal au sol)
- HIGH IDLE (Régime normal en vol)
The condition levers adjust ground idle fuel flow, and are used to shut off fuel.
Some prefer to move the condition lever to high for takeoff and will retard it to low after landing, for taxi. Some prefer to leave it low for all operations.
When the condition lever is in high, faster response to reverse is available on the ground with more reverse, while it also means more residual torque or thrust coming over the fence when landing. If one must go around, keeping the condition levers high on landing keeps the engine spooled up a little more, giving a faster power response.
The third lever on the control pedestal is the “FUEL CONDITON” lever. The original purpose of the fuel condition lever was to simply shut off or turn on the fuel to the engine. It is basically a HP (High Pressure) shutoff valve system that is operated by the flight crew to start and shut down the engine. It was modified on the Beech – as well as other aircraft – to include a low idle and a high idle position. The original reason for this was the small PT6 engines would bog down if you turned on the generator,bleed air, or the air conditioner compressor with the engine at idle. The extra loading at idle will cause an increase in fuel flow by the fuel control unit to keep the engine at the idle speed. Under this condition with only idle airflow through the engine - the Inter Turbine Temperature will increase to the point that it will cook the engine.
On some installations the flight crew must remember to advance the power lever to 68% or 70% minimum to obtain sufficient airflow through the engine so when loaded with the generator, bleed air, and/or the air conditioner compressor it had sufficient airflow to absorb the extra heat from the increase in fuel commanded by the fuel control unit.
So the fuel condition lever was modified/designed to “Bump” up – mechanically when advanced to the full forward position the linkage at the fuel control to give an easy way for the flight crew to obtain the correct gas generator speed.
The condition lever sets the desired engine RPM within a narrow range between that appropriate for ground operations and flight.
The condition lever on a turboprop engine is really just an on/off valve for delivering fuel. There are HIGH IDLE and LOW IDLE positions for ground operations, but condition levers have no metering function. Leaning is not required in turbine engines; this function is performed automatically by a dedicated fuel control unit."
Les jauges...
Videos...
Operations...
La pratique...
Vu sur les vidéos (par exemple) de décollages...
La théorie...
When activating the starter, one hand should be kept on the throttle. This allows prompt response if the engine falters during starting, and allows the pilot to rapidly retard the throttle if revolutions per minute (r.p.m.) are excessive after starting. A low r.p.m. setting (800 to 1,000) is recommended immediately following engine start. It is highly undesirable to allow the r.p.m. to race immediately after start, as there will be insufficient lubrication until the oil pressure rises. In freezing temperatures,
As soon as the engine is operating smoothly, the oil pressure should be checked. If it does not rise to the manufacturer’s specified value, the engine may not be receiving proper lubrication and should be shut down immediately to prevent serious damage. Although quite rare, the starter motor may remain on and engaged after the engine starts. This can be detected by a continuous very high current draw on the ammeter. Some airplanes also have a starter engaged warning light specifically for this purpose. The engine should be shut down immediately should this occur. Starters are small electric motors designed to draw large amounts of current for short periods of cranking. Should the engine fail to start readily, avoid continuous starter operation for periods longer than 30 seconds without a cool down period of at least 30 seconds to a minute (some AFM/POH specify even longer). Their service life is drastically shortened from high heat through overuse.
The constant-speed propeller keeps the blade angle adjusted for maximum efficiency for most conditions of flight. When an engine is running at constant speed, the torque (power) exerted by the engine at the propeller shaft must equal the opposing load provided by the resistance of the air. The r.p.m. is controlled by regulating the torque absorbed by the propeller—in other words by increasing or decreasing the resistance offered by the air to the propeller. In the case of a fixed-pitch propeller, the torque absorbed by the propeller is a function of speed, or r.p.m. If the power output of the engine is changed, the engine will accelerate or decelerate until an r.p.m. is reached at which the power delivered is equal to the power absorbed. In the case of a constant-speed propeller, the power absorbed is independent of the r.p.m., for by varying the pitch of the blades, the air resistance and hence the torque or load, can be changed without reference to propeller speed. This is accomplished with a constant-speed propeller by means of a governor. The governor, in most cases, is geared to the engine crankshaft and thus is sensitive to changes in engine r.p.m.
The pilot controls the engine r.p.m. indirectly by means of a propeller control in the cockpit, which is connected to the governor. For maximum takeoff power, the propeller control is moved all the way forward to the low pitch/high r.p.m. position, and the throttle is moved forward to the maximum allowable manifold pressure position. To reduce power for climb or cruise, manifold pressure is reduced to the desired value with the throttle, and the engine r.p.m. is reduced by moving the propeller control back toward the high pitch/low r.p.m. position until the desired r.p.m. is observed on the tachometer. Pulling back on the propeller control causes the propeller blades to move to a higher angle. Increasing the propeller blade angle (of attack) results in an increase in the resistance of the air. This puts a load on the engine so it slows down. In other words, the resistance of the air at the higher blade angle is greater than the torque, or power, delivered to the propeller by the engine, so it slows down to a point where the two forces are in balance.
When an airplane is nosed up into a climb from level flight, the engine will tend to slow down. Since the governor is sensitive to small changes in engine r.p.m., it will decrease the blade angle just enough to keep the engine speed from falling off. If the airplane is nosed down into a dive, the governor will increase the blade angle enough to prevent the engine from overspeeding. This allows the engine to maintain a constant r.p.m., and thus maintain the power output. Changes in airspeed and power can be obtained by changing r.p.m. at a constant manifold pressure; by changing the manifold pressure at a constant r.p.m.; or by changing both r.p.m. and manifold pressure. Thus the constant-speed propeller makes it possible to obtain an infinite number of power settings.
The engine is started with the propeller control in the low pitch/high r.p.m. position. This position reducesthe load or drag of the propeller and the result is easier starting and warm-up of the engine. During warm-up, the propeller blade changing mechanism should be operated slowly and smoothly through a full cycle. This is done by moving the propeller control (with the manifold pressure set to produce about 1,600 r.p.m.) to the high pitch/low r.p.m. position, allowing the r.p.m. to stabilize, and then moving the propeller control back to the low pitch takeoff position. This should be done for two reasons: to determine whether the system is operating correctly, and to circulate fresh warm oil through the propeller governor system. It should be remembered that the oil has been trapped in the propeller cylinder since the last time the engine was shut down. There is a certain amount of leakage from the propeller cylinder, and the oil tends to congeal, especially if the outside air temperature is low. Consequently, if the propeller isn’t exercised before takeoff, there is a possibility that the engine may overspeed on takeoff.
An airplane equipped with a constant-speed propeller has better takeoff performance than a similarly powered airplane equipped with a fixed-pitch propeller. This is because with a constant-speed propeller, an airplane can develop its maximum rated horsepower (red line on the tachometer) while motionless. An airplane with a fixedpitch propeller, on the other hand, must accelerate down the runway to increase airspeed and aerodynamically unload the propeller so that r.p.m. and horsepower can steadily build up to their maximum. With a constantspeed propeller, the tachometer reading should come up to within 40 r.p.m. of the red line as soon as full power is applied, and should remain there for the entire takeoff.
Excessive manifold pressure raises the cylinder compression pressure, resulting in high stresses within the engine. Excessive pressure also produces high engine temperatures. A combination of high manifold pressure and low r.p.m. can induce damaging detonation. In order to avoid these situations, the following sequence should be followed when making power changes.
It is a fallacy that (in non-turbocharged engines) the manifold pressure in inches of mercury (inches Hg) should never exceed r.p.m. in hundreds for cruise power settings. The cruise power charts in the AFM/POH should be consulted when selecting cruise power settings. Whatever the combinations of r.p.m. and manifold pressure listed in these charts—they have been flight tested and approved by the airframe and powerplant engineers for the respective airframe and engine manufacturer. Therefore, if there are power settings such as 2,100 r.p.m. and 24 inches manifold pressure in the power chart, they are approved for use.
With a constant-speed propeller, a power descent can be made without overspeeding the engine. The system compensates for the increased airspeed of the descent by increasing the propeller blade angles. If the descent is too rapid, or is being made from a high altitude, the maximum blade angle limit of the blades is not sufficient to hold the r.p.m. constant. When this occurs, the r.p.m. is responsive to any change in throttle setting.
Some pilots consider it advisable to set the propeller control for maximum r.p.m. during the approach to have full horsepower available in case of emergency. If the governor is set for this higher r.p.m. early in the approach when the blades have not yet reached their minimum angle stops, the r.p.m. may increase to unsafe limits. However, if the propeller control is not readjusted for the takeoff r.p.m. until the approach is almost completed, the blades will be against, or very near their minimum angle stops and there will be little if any change in r.p.m. In case of emergency, both throttle and propeller controls should be moved to takeoff positions.
Many pilots prefer to feel the airplane respond immediately when they give short bursts of the throttle during approach. By making the approach under a little power and having the propeller control set at or near cruising r.p.m., this result can be obtained.
Although the governor responds quickly to any change in throttle setting, a sudden and large increase in the throttle setting will cause a momentary overspeeding of the engine until the blades become adjusted to absorb the increased power. If an emergency demanding full power should arise during approach, the sudden advancing of the throttle will cause momentary overspeeding of the engine beyond the r.p.m. for which the governor is adjusted. This temporary increase in engine speed acts as an emergency power reserve.
Some important points to remember concerning constant-speed propeller operation are:
Operations...
La pratique...
Vu sur les vidéos (par exemple) de décollages...
- TAXI
- Condition Levers Low Idle
- Propellers Levers High
- Power Levers as required (gauche ou droite pour orienter l'appareil)
- TAKE-OFF
- Condition Levers High idle mais pas toujours ! Sont parfois pas loin du low idle...
- Propellers Levers High idle
- Power Levers as required
- AFTER TAKE-OFF
- Propellers Levers un peu en arrière (quasiment à mi-course hors feather zone (jauge ?))
- Power Levers as required (un peu en arrière en général...)
- LANDING
- Condition Levers au même point que le reste du temps (en général quasi low idle !)
- Propellers Levers High idle
- Power Levers as required
La théorie...
When activating the starter, one hand should be kept on the throttle. This allows prompt response if the engine falters during starting, and allows the pilot to rapidly retard the throttle if revolutions per minute (r.p.m.) are excessive after starting. A low r.p.m. setting (800 to 1,000) is recommended immediately following engine start. It is highly undesirable to allow the r.p.m. to race immediately after start, as there will be insufficient lubrication until the oil pressure rises. In freezing temperatures,
As soon as the engine is operating smoothly, the oil pressure should be checked. If it does not rise to the manufacturer’s specified value, the engine may not be receiving proper lubrication and should be shut down immediately to prevent serious damage. Although quite rare, the starter motor may remain on and engaged after the engine starts. This can be detected by a continuous very high current draw on the ammeter. Some airplanes also have a starter engaged warning light specifically for this purpose. The engine should be shut down immediately should this occur. Starters are small electric motors designed to draw large amounts of current for short periods of cranking. Should the engine fail to start readily, avoid continuous starter operation for periods longer than 30 seconds without a cool down period of at least 30 seconds to a minute (some AFM/POH specify even longer). Their service life is drastically shortened from high heat through overuse.
The constant-speed propeller keeps the blade angle adjusted for maximum efficiency for most conditions of flight. When an engine is running at constant speed, the torque (power) exerted by the engine at the propeller shaft must equal the opposing load provided by the resistance of the air. The r.p.m. is controlled by regulating the torque absorbed by the propeller—in other words by increasing or decreasing the resistance offered by the air to the propeller. In the case of a fixed-pitch propeller, the torque absorbed by the propeller is a function of speed, or r.p.m. If the power output of the engine is changed, the engine will accelerate or decelerate until an r.p.m. is reached at which the power delivered is equal to the power absorbed. In the case of a constant-speed propeller, the power absorbed is independent of the r.p.m., for by varying the pitch of the blades, the air resistance and hence the torque or load, can be changed without reference to propeller speed. This is accomplished with a constant-speed propeller by means of a governor. The governor, in most cases, is geared to the engine crankshaft and thus is sensitive to changes in engine r.p.m.
The pilot controls the engine r.p.m. indirectly by means of a propeller control in the cockpit, which is connected to the governor. For maximum takeoff power, the propeller control is moved all the way forward to the low pitch/high r.p.m. position, and the throttle is moved forward to the maximum allowable manifold pressure position. To reduce power for climb or cruise, manifold pressure is reduced to the desired value with the throttle, and the engine r.p.m. is reduced by moving the propeller control back toward the high pitch/low r.p.m. position until the desired r.p.m. is observed on the tachometer. Pulling back on the propeller control causes the propeller blades to move to a higher angle. Increasing the propeller blade angle (of attack) results in an increase in the resistance of the air. This puts a load on the engine so it slows down. In other words, the resistance of the air at the higher blade angle is greater than the torque, or power, delivered to the propeller by the engine, so it slows down to a point where the two forces are in balance.
When an airplane is nosed up into a climb from level flight, the engine will tend to slow down. Since the governor is sensitive to small changes in engine r.p.m., it will decrease the blade angle just enough to keep the engine speed from falling off. If the airplane is nosed down into a dive, the governor will increase the blade angle enough to prevent the engine from overspeeding. This allows the engine to maintain a constant r.p.m., and thus maintain the power output. Changes in airspeed and power can be obtained by changing r.p.m. at a constant manifold pressure; by changing the manifold pressure at a constant r.p.m.; or by changing both r.p.m. and manifold pressure. Thus the constant-speed propeller makes it possible to obtain an infinite number of power settings.
The engine is started with the propeller control in the low pitch/high r.p.m. position. This position reducesthe load or drag of the propeller and the result is easier starting and warm-up of the engine. During warm-up, the propeller blade changing mechanism should be operated slowly and smoothly through a full cycle. This is done by moving the propeller control (with the manifold pressure set to produce about 1,600 r.p.m.) to the high pitch/low r.p.m. position, allowing the r.p.m. to stabilize, and then moving the propeller control back to the low pitch takeoff position. This should be done for two reasons: to determine whether the system is operating correctly, and to circulate fresh warm oil through the propeller governor system. It should be remembered that the oil has been trapped in the propeller cylinder since the last time the engine was shut down. There is a certain amount of leakage from the propeller cylinder, and the oil tends to congeal, especially if the outside air temperature is low. Consequently, if the propeller isn’t exercised before takeoff, there is a possibility that the engine may overspeed on takeoff.
An airplane equipped with a constant-speed propeller has better takeoff performance than a similarly powered airplane equipped with a fixed-pitch propeller. This is because with a constant-speed propeller, an airplane can develop its maximum rated horsepower (red line on the tachometer) while motionless. An airplane with a fixedpitch propeller, on the other hand, must accelerate down the runway to increase airspeed and aerodynamically unload the propeller so that r.p.m. and horsepower can steadily build up to their maximum. With a constantspeed propeller, the tachometer reading should come up to within 40 r.p.m. of the red line as soon as full power is applied, and should remain there for the entire takeoff.
Excessive manifold pressure raises the cylinder compression pressure, resulting in high stresses within the engine. Excessive pressure also produces high engine temperatures. A combination of high manifold pressure and low r.p.m. can induce damaging detonation. In order to avoid these situations, the following sequence should be followed when making power changes.
- When increasing power, increase the r.p.m. first, and then the manifold pressure.
- When decreasing power, decrease the manifold pressure first, and then decrease the r.p.m.
It is a fallacy that (in non-turbocharged engines) the manifold pressure in inches of mercury (inches Hg) should never exceed r.p.m. in hundreds for cruise power settings. The cruise power charts in the AFM/POH should be consulted when selecting cruise power settings. Whatever the combinations of r.p.m. and manifold pressure listed in these charts—they have been flight tested and approved by the airframe and powerplant engineers for the respective airframe and engine manufacturer. Therefore, if there are power settings such as 2,100 r.p.m. and 24 inches manifold pressure in the power chart, they are approved for use.
With a constant-speed propeller, a power descent can be made without overspeeding the engine. The system compensates for the increased airspeed of the descent by increasing the propeller blade angles. If the descent is too rapid, or is being made from a high altitude, the maximum blade angle limit of the blades is not sufficient to hold the r.p.m. constant. When this occurs, the r.p.m. is responsive to any change in throttle setting.
Some pilots consider it advisable to set the propeller control for maximum r.p.m. during the approach to have full horsepower available in case of emergency. If the governor is set for this higher r.p.m. early in the approach when the blades have not yet reached their minimum angle stops, the r.p.m. may increase to unsafe limits. However, if the propeller control is not readjusted for the takeoff r.p.m. until the approach is almost completed, the blades will be against, or very near their minimum angle stops and there will be little if any change in r.p.m. In case of emergency, both throttle and propeller controls should be moved to takeoff positions.
Many pilots prefer to feel the airplane respond immediately when they give short bursts of the throttle during approach. By making the approach under a little power and having the propeller control set at or near cruising r.p.m., this result can be obtained.
Although the governor responds quickly to any change in throttle setting, a sudden and large increase in the throttle setting will cause a momentary overspeeding of the engine until the blades become adjusted to absorb the increased power. If an emergency demanding full power should arise during approach, the sudden advancing of the throttle will cause momentary overspeeding of the engine beyond the r.p.m. for which the governor is adjusted. This temporary increase in engine speed acts as an emergency power reserve.
Some important points to remember concerning constant-speed propeller operation are:
- The red line on the tachometer not only indicates maximum allowable r.p.m.; it also indicates the r.p.m. required to obtain the engine’s rated horsepower.
- Amomentary propeller overspeed may occur when the throttle is advanced rapidly for takeoff. This is usually not serious if the rated r.p.m. is not exceeded by 10 percent for more than 3 seconds.
- The green arc on the tachometer indicates the normal operating range. When developing power in this range, the engine drives the propeller. Below the green arc, however, it is usually the windmilling propeller that powers the engine. Prolonged operation below the green arc can be detrimental to the engine.
- On takeoffs from low elevation airports, the manifold pressure in inches of mercury may exceed the r.p.m. This is normal in most cases. The pilot should consult the AFM/POH for limitations.
- All power changes should be made smoothly and slowly to avoid overboosting and/or overspeeding.
- Condition levers, when set to HIGH IDLE, keep the engine operating at a minimum of 70% N1 for quicker reversing response due to less spool up time. Technical Manual
TRQ ou Torque, à la place de la pression d'admission (MP ou Maniflod Power) des moteurs à piston. Wiki X-Plane
So with a prop RPM increase in a King Air, I would expect the torque to drop (if power remains a constant) like Captahab said. If there is a fuel flow decrease, it may be an indication that there has been a power decrease (even though the throttle hasn't been moved).
On a real PT6 engine, the fuel flow does NOT change when the prop RPM is reduced. The torque certainly increases, however. Victor India and Captahab are correct about the relationship between power, torque and RPM. Note that it is the torque increase that causes the prop RPM to reduce. The "first" thing to happen - so as to speak - is the torque increase when pulling the prop levers back. That torque increase "drives" the shaft RPM down to the lower value.
The torque increases when you move the lever to effect a prop RPM decrease because the prop governor moves the blades to a more coarse (higher angle of attack) angle. The blades are thus taking a "bigger bite" of the air - and imposing more of a load on the drive shaft (exerting a greater torque, in other words). PPrune
On a real PT6 engine, the fuel flow does NOT change when the prop RPM is reduced. The torque certainly increases, however. Victor India and Captahab are correct about the relationship between power, torque and RPM. Note that it is the torque increase that causes the prop RPM to reduce. The "first" thing to happen - so as to speak - is the torque increase when pulling the prop levers back. That torque increase "drives" the shaft RPM down to the lower value.
If the air temperature is well above standard, you may hit the 695 degree ITT limit before you reach 1315 torque, so you must watch that too - i.e. set 1315 torque or 695 ITT, whichever you reach first. On some aircraft, at higher altitude, the 101.5% gas generator speed limit will come into play before hitting either the torque or ITT limit.
The PT-6 engine in the C90 has a tendency for the ITT to increase sharply if you push the power lever forward too quickly from idle. You could easily exceed the ITT limit if you are not careful. The general technique if the engine is stabilized at idle is to move the power lever gently until you see that the ITT has recovered from its initial sudden rise. The other issue you run into is that usually one engine will accelerate somewhat faster than the other if you move the power levers too quickly. This causes a directional control disturbance when the prop rpm reaches 2200 rpm at different times, and the prop governors start adjusting each prop pitch to control the prop rpm.
So, when setting take-off power, move the power levers slowly until the ITT has recovered from its initial sudden spike, then more them more quickly until both props have achieved 2200 rpm, then set 1315 torque. At higher altitude, or warmer temperature, the engine will each 695 ITT before achieving 1315 torque, so you must use the lower torque for take-off.
The whole thing, from idle to take-off power, will take perhaps 6 or 8 seconds.
So, when setting take-off power, move the power levers slowly until the ITT has recovered from its initial sudden spike, then more them more quickly until both props have achieved 2200 rpm, then set 1315 torque. At higher altitude, or warmer temperature, the engine will each 695 ITT before achieving 1315 torque, so you must use the lower torque for take-off.
The whole thing, from idle to take-off power, will take perhaps 6 or 8 seconds.
PPrune
ITT...Interstage Turbine Temperature. C'est la température du flux entre les étages basse et haute pression de la turbine. Attention à ne pas aller dans le rouge !
ITT...Interstage Turbine Temperature. C'est la température du flux entre les étages basse et haute pression de la turbine. Attention à ne pas aller dans le rouge !
PROP...
Le pas d'hélice et RPM : régime. Attention : certains avions ont un pas variable manuellement (King Air 200 par exemple) et on le gère comme pour les avions à moteur à piston, d'autres automatiquement, y compris pour les conditions de mise en drapeau (Pilatus PC 12) et dans ce cas, n'y touchez pas. Dans ce cas, la manette Condition gère toute seule la bonne combinaison mélange/pas.
N1 et N2...
C'est la vitesse de la turbine en %
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