T-56A Series IV and -21

[Dominion]

Is the T-56A series IV another name for the -15 or is it some kind of an upgrade?

I had also heard scuttle that there was a -21 variant in development..in words on that?

[victorp1]

The T-56 Series IV is on the E-2C aircraft and the AE2100 is on the C-130J.

Vic

[Gmon]

Series IV is the upgrade to the T56A-15 aka Series III. It\'s significantly differently from T56A-15 and AE2100.

[Lkuest]

You can search Allison T56 in Wikipedia to clear any confusion as to the different T56 variants. I haven\'t heard of the -21 variant, but if there is one, it is probably for the Air Force. The Navy uses even-numbered designations with the exception of the T56-a-425 and -427 variants. The Air Force usually designates it\'s T56\'s with odd numbers.

[Guest]

I have a copy of a (proposed) performance chart for a T56-A-100 from the late 1980s---but this was only proposal data. The chart shows max T56 shaft horsepower at sea level static (13820 RPM), with the ambient temperature at 59 degrees F:

dash 7----3755

dash 15----4591

dash 100----5293

Derating the performance due to ambient temperature at 103 degrees F:

dash 7----2990

dash 15----3696

dash 100----4240

And 4240 shaft horsepower is denoted as \"the aircraft power limit\".

Old stuff, but kinda interesting. I wonder if the -100 became the AE2100

John

[Lkuest]

If I had a guess I\'d say the proposed -100 was most likely the Air Force version of the -427 as it was under development in the early 80\'s. Also, the AE2100 has shp figures closer to the -15 than they are to the -427. Just a guess.

[Gmon]

Does the series IV use the 54h60 prop? It is listing @ 5250 shp.

[Lkuest]

I suppose you could use either the 4 or 8-bladed, but the navy has equipped the T56-a-427 with the NP2000 on their E-2C+ aircraft. Both propellers have been equipped on their C-2\'s with the T56-a-425.