Handley Page Jetstream

[JayBee]

Does anyone out there know the answer to the following question, or where I might find the answer?

The original production Jetstream, with the Aztazou engines, and the Jetstream 3M (which should have become the C-10A for the USAF) with  TPE331 engines, had the propellers turning in the same direction.
However the BAe Jetstream 31/32, which also had the TPE331 engines, had the props turning in the opposite direction.
WHY?

Any serious answers would be greatly appreciated.

Jim

[kitnut617]

The photos of the Century Jetstreams in the Air-Britain article I mentioned in your other thread Jim, were TPE331 powered and show the props turn the same direction as the Astazou. These were all three blade props arrangements.  I'm wondering if the Jetstream 31/32 engines which have four blade props, were possible 'geared-down' for this. or maybe they wanted to use an existing prop 'off-the-shelf' so to speak.

[JayBee]

You could be partly right Robert.
The Jetstream 3M had TPE 331s rated at 904shp.
While the Jetstream 31 had TPE 331s rated at 1020shp, also it had water methanol injection so that it could operate at Max. AUW in hot and high conditions.
So maybe the four bladed props were required to take up the extra power.
However, why did they rotate in the other direction? Maybe it was as you suggest an availability issue.
One point though, the Dornier 228 had TPE 331s with four bladed props turning the same way as the Jetstream 31, but their engines were only rated at 778shp?

Jim

[famvburg]

Just because they are TPE331s doesn't have anything to do with rotation. Different dash models turn different directions AFAIK.