Hawkair Engine Failure

gonefishin' · Post by **gonefishin'** » Tue Oct 24, 2006 8:47 pm

Flying back to YVR tonight and heard Hawk 392 state they had an engine failure with 13 on board, they diverted to YXS, anybody know any more?

snag · Post by **snag** » Tue Oct 24, 2006 9:38 pm

Yup, heard them too. Don't know how the landing went. Do they have any staff in YXS? or do the pilots then become CSA's and look after arrangemetns for the 13 pax?

2low · Post by **2low** » Wed Oct 25, 2006 9:47 am

13 on board.... Not good loads.

blue-sky · Post by **blue-sky** » Wed Oct 25, 2006 10:08 am

Yeah they just lost one of the bleed air lines to their fuel metering unit so fuel + spark but no air. It was a quick fix, they just sent in another Dash8 to pick up the pax and bring in engineers and bring them on to YXJ/YDQ just a 2 hour delay. Just the way she goes sometimes!!!!

tripleseven · Post by **tripleseven** » Wed Oct 25, 2006 12:21 pm

I didn't know bleed air was a requirement for combustion.

complexintentions · Post by **complexintentions** » Wed Oct 25, 2006 12:34 pm

well no but air is.

The way I read the post the bleed air is used somehow by the fuel metering unit? If that was malfunctioning then I could see it preventing air getting to the fuel and ignition.

But I'm just speculating - any AME's out there shed some light?

Hey do you really fly the 777? cool.

tripleseven · Post by **tripleseven** » Wed Oct 25, 2006 2:53 pm

So maybe he meant to say spark, air, but no fuel. That would tend to cause a flame out.

And no, I don't fly a 777, but I suspect you knew that already. Wish I did though.

Sparkfarmer · Post by **Sparkfarmer** » Wed Oct 25, 2006 3:19 pm

Bleed air is used for fuel metering inside the Fuel Control Unit. Its like "Feed back" from the engine.

Buster · Post by **Buster** » Wed Oct 25, 2006 4:07 pm

tripleseven wrote:I didn't know bleed air was a requirement for combustion.

No, but I beleed combustion is a requirment for bleed air...no?

flaps40 · Post by **flaps40** » Wed Oct 25, 2006 5:26 pm

Hey guys/gals where were you during ground school. I can't believe the lack of knowledge out there on engine components. It is not rocket science. Look in the AFM. A Pratt is always a pratt just different sizes. Wow

tripleseven · Post by **tripleseven** » Wed Oct 25, 2006 5:38 pm

That is affirmative. I'll stop being an ass now.

ettw · Post by **ettw** » Wed Oct 25, 2006 5:55 pm

OK, firstly I have never done maintenance on the PW100 series engines but have a bit of time on the PT6s which in theory should be basically the same but I'm not sure so take this response with a grain of salt.

If you lose bleed air back to the FCU (on the PT6 this is P3 if I remember correctly), the FCU will roll back to a min fuel flow condition. For maintenance purposes we disconnect the bleed air to adjust min flow. This should not cause a flameout.

Additionally, once the engine is lit, the ignition is generally shut off unless SOP requires it on ie. heavy precip. Continuous fuel flow maintains continuous combustion. The turbine engine is a continous air flow engine unlike a piston engine so once the fire is lit, it'll stay lit with no further ignition source till the fuel is cut off.

On all turbine engines that I am aware of, there is no way to limit airflow mechanically to the engine except possibly engines that operate in the supersonic corner of the envelope where there is control required to ensure a shock wave does not enter the inlet area.

Only the maintenance dept for Hawkair have any idea as to why it quit.

Cheers,

ETTW

Hornblower · Post by **Hornblower** » Wed Oct 25, 2006 5:56 pm

P3 air is proportional to fuel scheduling, so if you lose P3 sense to the FC, it schedules back to flight idle (on the engines I’ve worked on, not sure about the PW 100s)

motox415 · Post by **motox415** » Wed Oct 25, 2006 6:58 pm

Correct: It is P3 air that is used as a reference pressure for the MFC or HMU depending which PWC 100 series engine. This pressure is also fed to the prop overspeed governor. If there is a leak in the P3 sense line, which this engine is prone to have you will not make T.O. power and you will have power leaver splits.

bob sacamano · Post by **bob sacamano** » Wed Oct 25, 2006 7:16 pm

tripleseven wrote:And no, I don't fly a 777, but I suspect you knew that already. Wish I did though.

Do you drive a bimmer?

oldtimer · Post by **oldtimer** » Wed Oct 25, 2006 8:23 pm

I have nil for experience on PWC 100 series engines but lots on PT6's and P3 air is used in the FCU and in some cases, the PCU as a reference for fuel scheduling, engine acceleration and prop overspeed because P3 air pressure is dependent upon engine speed or Ng. If the engine is overspeeding, it is sensed as increasing P3 pressure and the governors can overboard or reduce the pressure and as result reduce fuel flow which will reduce RPM. Wish I had my notes close at hand for a better explaination but that is in essence what happens.

Bubbaganoosh · Post by **Bubbaganoosh** » Wed Oct 25, 2006 9:20 pm

Sounds like HA may have a little more to be concerned about than the blither blather about what may have caused the engine shut down..

http://www.terracestandard.com/portals- ... 6106&more=

Darkhorse · Post by **Darkhorse** » Wed Oct 25, 2006 9:24 pm

Darkhorse · Post by **Darkhorse** » Wed Oct 25, 2006 9:42 pm

Bubbaganoosh wrote:Sounds like HA may have a little more to be concerned about than the blither blather about what may have caused the engine shut down..

http://www.terracestandard.com/portals- ... 6106&more=

I like that.. at the end of the article it mentions that you better watchout for the ones who may be lat go.... Look out guys.. here comes the knife

tripleseven · Post by **tripleseven** » Thu Oct 26, 2006 7:20 am

Unfornatly (again), I don't drive a bimmer. That's supposed to be a reference to when they were building airplane engines. The blue/white symbol represents a prop.

uncle · Post by **uncle** » Thu Oct 26, 2006 12:10 pm

PT6 prop overspeed determined is by govenor flyweight speed

yellowarc · Post by **yellowarc** » Thu Oct 26, 2006 6:01 pm

Good job fellas.