British European double engine failure at BRS
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RATBOY,
Dash 8s are fitted with P&WC 100 series engines. The DH8-100 PWC12x and the DH8 200 & 300 with PWC123.
The 1 in the PWC 12x/123 indicates that the engine is a straight flow one, that is, air enters the front and passes through the engine exiting at the rear. The only reversal of direction being the combustion chambers.
The PT6 however, as you mentioned is reverse flow, the air entering from the rear of the engine and travelling forward to exit at the front.
All the PT6s I have operated used an inertial separator, which deflected into the airflow inside the plenum causing some torque loss, for ice protection.
The PWC100s as fitted to the Dash 8 uses plenum design to cause the airflow to enter the intake, travel to the rear of the plenum, then forward and upward into the engine intake. (Damned if I know how the air knows to do this though!)
A bypass door at the rear of the plenum (no performance loss, regardless of position) provides an escape route for 'solids', this bypass door has a shear mechanism to allow large foreign objects to 'break through' and exit the plenum. For ice protection, the bypass doors should be opened manually, which also serves to energise the intake lip heaters (115V variable AC).
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bottums up !
[This message has been edited by Capt Claret (edited 23 March 2001).]
Dash 8s are fitted with P&WC 100 series engines. The DH8-100 PWC12x and the DH8 200 & 300 with PWC123.
The 1 in the PWC 12x/123 indicates that the engine is a straight flow one, that is, air enters the front and passes through the engine exiting at the rear. The only reversal of direction being the combustion chambers.
The PT6 however, as you mentioned is reverse flow, the air entering from the rear of the engine and travelling forward to exit at the front.
All the PT6s I have operated used an inertial separator, which deflected into the airflow inside the plenum causing some torque loss, for ice protection.
The PWC100s as fitted to the Dash 8 uses plenum design to cause the airflow to enter the intake, travel to the rear of the plenum, then forward and upward into the engine intake. (Damned if I know how the air knows to do this though!)
A bypass door at the rear of the plenum (no performance loss, regardless of position) provides an escape route for 'solids', this bypass door has a shear mechanism to allow large foreign objects to 'break through' and exit the plenum. For ice protection, the bypass doors should be opened manually, which also serves to energise the intake lip heaters (115V variable AC).
------------------
bottums up !
[This message has been edited by Capt Claret (edited 23 March 2001).]
Join Date: Jun 2001
Location: at the edge of the alps
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We fly the Dash 8 with bypass doors open all the time (unless the temperature goes above ISA+25 :-) so we don't have to open and close them all the time. We also plug the up (personally) for all night stops and extended stops with precip. Nasty but seems to help.
The only theory I can think of is snowfall during turn-around. There seems to be no way the nacelle plenum chamber can ice up during engine operation. A DHC engineer once told me they threw all kinds of objects into the nacelle during testing and never managed to get anything into the engine as all solids wouldn't go with the 270 degree turn the air is forced to make.
Vastly superior to the Dash 7 which lost lots of power with the intake deflectors open...when you needed it most.
The F.50 was retrofitted with a very elaborate system of heating mats in the bottom of the air intake to avoid freezing and later "spontaneous" departure of big chunks into the engine. Also some double flameouts before the mod came out.
The only theory I can think of is snowfall during turn-around. There seems to be no way the nacelle plenum chamber can ice up during engine operation. A DHC engineer once told me they threw all kinds of objects into the nacelle during testing and never managed to get anything into the engine as all solids wouldn't go with the 270 degree turn the air is forced to make.
Vastly superior to the Dash 7 which lost lots of power with the intake deflectors open...when you needed it most.
The F.50 was retrofitted with a very elaborate system of heating mats in the bottom of the air intake to avoid freezing and later "spontaneous" departure of big chunks into the engine. Also some double flameouts before the mod came out.
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Alpine flyer-- you are right that this incident occurred during turnround exactly as advertised in Supplement no 4(see previous post).
However, as far as icing during operation is concerned the last Bombardier advice (Oct 2000) was that the plenum chamber must be inspected if icing has been experienced in flight
However, as far as icing during operation is concerned the last Bombardier advice (Oct 2000) was that the plenum chamber must be inspected if icing has been experienced in flight
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I don't know too much about PT6's and PW whirly thingy's but Fuel + Sparks + a bit of air = lots of lovely flames - in the correct place of course.
if the AFM gives advice on the use of igniters, continuous or other wise it may stop a bad hair day if you comply.
Some Operators have issued internal memo's to restrict the use of igniters on replacement cost grounds ignore them.
It costs a lot more to replace an A/C let alone the grief it can cause on a personal level.
if the AFM gives advice on the use of igniters, continuous or other wise it may stop a bad hair day if you comply.
Some Operators have issued internal memo's to restrict the use of igniters on replacement cost grounds ignore them.
It costs a lot more to replace an A/C let alone the grief it can cause on a personal level.
