Pt6

[dynamite dean]

I of course like all pilots operate Inertal Seperators in accordance when the manual says so however had quite a few pilots say to me" the PT6 can take quite a lot of moisture before the flame goes out"....Just wondered does anybody actually know JUST how many buckets of water you can throw at a PT6 before the flame goes out. If your in the single engine it aint worth trying I guess!:suspect:

[Elliot Moose]

I've run an awful lot of water through PT6's and never seen a cough. Of course I'm an awful chicken too and always used the seperator as per the book (lots of flying Caravan's and Pilatus PC12's as well as B200 and 1900)! We used to use the separators all the time on dirt runways as well and that made huge differences in the life of the engines from times previous to that policy. They really work well at keeping the merde out of the engines, so use 'em!

[CJ Driver]

I've looked at the inside of a PT6 cowling intake duct, and been surprised at how "low tech" it is, especially towards the engine end. Apart from the turn in the duct at the inertial separator, the air at the end of the duct makes some fairly low-energy sharp turns into the actual engine inlet. I suspect that a bit of drizzle sucked through the intake (and the PT6) is not a big problem, but I also suspect from looking at the shape of the duct that if you fly in snow/sleet (or anything else on the solid side of "visible moisture") without the separators deployed, it'll collect in the duct pretty darn quick.

[bobrun]

Been flying PT6-27 for a few years.......very reliable, and water is not really a concern, even in heavy tropical rain...of course following the AFM is always a good idea....:D

[captain marvellous]

May they rest in peace. (http://www.caa.co.uk/docs/33/factor200310.pdf)

[haughtney1]

Having just read that report with some interest......the a/c I fly have various models of PT6....114, 34, 27...etc...it begs the question (and if im wrong on this..someone please correct me..as I dont want to cast any ill will to those invloved)....wouldn't this ingestion problem have been easily solved, if it was company SOP to replace intake covers after any significant period of shutdown/overnight etc...? Am I being overly simplistic?

Just a thought

:hmm:

[BoeingMEL]

Installing blanks is good practice...even when not covered by SOPs. The question however (as I understand it) refers to ingestion rather than accumulation.

1: Yes, the PT6 in its various forms can ingest planty of water
2: In icing conditions however, accretion can result in a shockingly short time....... resulting in a deafening silence - no matter how many engines you have!

Humble suggestion to keep your enquiry hypothetical rather that determination by trial and error!

Good luck and happy flying...... if in doubt operate the vanes and accept the slight drop in torque! bm

[haughtney1]

Boeing..forgive me I was referrring to the accident report covered in a previous post.....I should have clarified that to one and all.

Regretfully, when you read it, it was (in my opinion) completely preventable....a brief preflight inspection with a torch should have highlighted the problem of accumulation in the intakes whilst on stand..then the required corrective action could have ensued. Or.....intake covers should have been available...(always carried on any TP a/c I have operated..PT6 & TPE 331). What concerns me about this accident, is the apparent lack of awareness of the dangers of accumulation & consequently ingestion (both company and crew) that the report seems to highlight.
If nothing else comes out of this........ANYONE operating T/P aircraft TAKE YOUR INTAKE COVERS EVERYWHERE YOU GO....they are lifesafers.



:O

[otto the grot]

The other problem with the pt6 is the wire mesh surrounding the engine intake. If ice vanes are not used in icing conditions, ice will form on this mesh. If a large enough lump of ice forms and then is subsequently ingested when it breaks off, damage can be caused to compressor blades.

[Loose rivets]

Having spent nearly an hour with the intake of a PT6 so iced up that you couldn't have put your fist in the hole, and the engine not missing a beat, I think that the power unit is the least of problems with this aircraft. Get it near water or ice, and it's bad news.

On one flight, so much water dripped into the electrics that I spent 30 mins with stick shaker and buzzer running. No big deal, but in blackness, moderate turbulence and lashing rain, I wondered what was going on for a moment or two.

On another flight I had rather a memorable 40 mins with frozen elevator and elevator trim. Nothing...totally locked solid. After five house of maintenance I carried my luckless passengers to JSY, at night in a blizzard, only to find that I couldn't reduce the power on one engine due to the same kind of problem. Iced up control runs.

I think the Shed, or Skip as some of my passengers called it, is only suitable for fair weather ops.. Or perhaps a museum.

[one dot right]

Having had virtually the same experience as you loose rivets(albeit the frozen elevator trim was on a 3-30) I wholeheartedly concur!