PT6A Difference's

[pssincl]

Hi all,
Hopefully this is the right spot. Might someone be able to tell me the difference’s between the PT6A – 41 and the – 42. Have not been to find anything so far in my searches wrt to this question .
Cheers
pssincl

[vapilot2004]

From my King Air days I recall the -42 having a higher ITT rating which I think were due to ducting changes and (mostly) a higher-spec hot section. Impoved the above-STD hot days and climb performance of the big lovely.

Cheers

[halas]

Many years since l flew the beast. The mob l worked for had nothing but -41's, except on the contract aircraft l was on with the -42's

If l remember what the engineers said, it was the ability to operate with hotter temps. This was accommodated by the single-chrystal turbine blades. l guess that means the -41 had multi-chrystal blades. But otherwise the motors were much the same.

We also had the hydraulic under-carriage which was a nice touch too.

halas

[His dudeness]

ITT Redline -41: 750°C (KingAir 200)
ITT Redline -42: 800°C (KingAir B200)
Both torque redlined at 2230 ft/lbs.
Thus more power vailable at higher levels.
I think the fuel purge system is also different. (-41 Tank and Pump, -42 P3 Air System)

[pssincl]

Thanks all for the replies,
…. After a bit more hunting around I have also found out that that the –42 has a 12% (or there about) larger compressor section giving a max operating altitude of 35000’ and cabin diff. of 6.5 psi (compared to the –41’s 30000’ and 6.1 psi).
Cheers,
PSSINCL

[halas]

Highest l got one was 31,000' and nearly sh@t myself when the FO's windscreen cracked.

T'was a dark night just before Christmas, from Tulla to Orange with wicked storms every where, aaargh.......

halas