Forest Fires & Turbine Engines

[northernpilot]

Can anyone provide some insight on the following?

Is there much effect on turbine engines from Forest Fire smoke? Or any smoke for that matter?

For turboprops, I imagine the effect, if any, is reduced especially on those with reverse flow.

What about for Turbo Fan and Turbo Jet engines? Are aircraft diverting around smoke in the Los Angeles basin right now, for example? A few times over the past week, smoke plumes have been crossing directly through ILS GP and Track for active runways at some of the southern California area airports.

Just a thought.....any constructive input is welcome.

Thanks!
NP

[Panama Jack]

I wouldn't worry about this too much.

Here in the Middle East we operate on a regular basis in much worse, with visibility reduced as low as 400 meters or less in dust.

[northernpilot]

Yeah, i've operated in dust in the sand box as well....

what about any ash component in wood smoke?

[Captain X]

I was told by an AME who used to work for Conair that the microscopic ash can stick/weld itself onto the engine compressors/stators and will show a noticeable increase in temps and a decrease in power. The problem is remedied by doing compressor washes with some kind of detergent mix. He could be pulling my leg but it seems to make sense

[beechnut]

I agree with captain x Higher temps and a little less power. I spent all summer in California in a turbine on the fires.

[Driving Rain]

The PW 123 AF on the 415 allows the crew to have command of the handling bleed valve. This moves the engine away from compressor stall in high heat environs at the lost of about 25% tq
With the dirty air around YSB (air pollution from smelters) the stators and compressors of engines on the tanker thats based there show signs of errosion. Our engineers do a couple of compressor washes each season.

BTW the PW 123 is the same engine as on the Dash 8 300 with a few differences to make it more suitable for fire ops.
The fuel control is manual as opposed to computer regulated on the Dash 8
Manual control of the handling bleed valves.
High cam used to increase gas gen speed for water and ground taxi
This feature is needed because unlike the dash 8 the 415 has two prop redlines one at 1200 and one at 840 rpm because of the manual fuel control. High cams have to be selected on landing to get reverse thrust.
The prop on the 415 goes into a flatter pitch than the dash 8 which really helps to slow the aircraft down coming down hill or close to a target.

[scouty-dog]

Compressor washes alleviate loss of efficiency from dirty compressor blades. (ie: soot build-up) You will actually see a drastic change in the numbers when trend monitoring engine performance.

Allison 250's require comp washes too often when working in smoky spots. You need all the efficiency you can get out of the compressor on hot smoky days when working in the dead man's curve.

[iflyforpie]

I don't remember doing anything to Conair's CV-580s during winter maintenance. Maybe the water-meth injection keeps the compressors clean?

[Liquid Charlie]

I don't think I have ever heard of a 580 with water injection -- 600 - 640 yes with RR engines

[iflyforpie]

Not all 580s had water meth. But we modified a bunch for Conair to have them with nozzles in the intake and compressor discharge. It was an existing mod, we didn't engineer it.

Spent many hours lying in the nacelle under the 501 with my head on the RGB trying to get all the plumbing to fit and not leak.

[Liquid Charlie]

learn something everyday - and did you have to add external tanks to carry enough -- lol

[Flybabe]

Judging from the barrels of water meth with "Conair" written on them in Redding this summer, I'd say the 580's do indeed use it.

Ash in smoke can be very abrasive. Some times the ash component is worse than others. I'm certainly no expert at this, but I'd like to the the cumulative effects of fllights through smoke with ash on a turbine.

[gapper]

I wonder what the difference between Pratt vs. Garrett, considering the Pratt reverse flow/particle seperater advantage over the Garrett direct intake. I can't see the Garrett Thrush engines lasting long, while eating small birds and grasshoppers while spraying, or eating smoke and ash in SEAT operations. Any opinions on this would be appreciated.

[dashx]

Table 3 provides recommendations to reduce the rate of engine deterioration when
the engine is operated in adverse environments. Air pollution and salt are examples
of adverse environments. Chemical reactions with the fuel and heat in the engine
can produce severe corrosion. Gas path washing helps to reduce the rate of this
deterioration.

Performance recovery (Ref. 72-00-00)

As required by
ECTM (every
approx. 10°C
( 20°F) ITT/T6
increase) and
visual inspection of
impellers and gas
path

Desalination wash Occasionally salt-laden operating
environment

Biweekly (130 FH)
(adjust washing
frequency to suit
engine condition)

From the PWC 123 Maint manual. As always PW will always recommend you (as the operator) do this.

Now how did that commercial go ???? Oh yes You can pay me now or you can pay me later.......