Confessions of a US navy Orion Pilot

[Arlo]

If the P-3 uses the same wing and engines as the C-130, why is the vertical stabilizer so much smaller?

Same engines ... not same wing.





And the engines are mounted differently. Nothing like stepping into the wheel well, looking up and seeing a sign overhead that says 'no step.'

As far as design is concerned, the P-3 was adapted from the Lockheed Electra:



The C-130 was always a pure military design. I'm sure both were designed for stability with their specific fuselages and missions in mind.

[DaveBB]

Good point. I noticed the C-130s wing has a much larger surface area than the P-3 (as well as being much longer to keep nearly the same aspect ratio), but both aircraft weigh the same.  The C-130 can carry about 20,000 lbs more, but still.  It appears the P-3 has quite a big higher wingloading.

[colmbo]

If the P-3 uses the same wing and engines as the C-130, why is the vertical stabilizer so much smaller?

They have different missions.  The P-3 operates off of long, hard surfaced runways where the C-130 may be called upon to operate from short unimproved strips.  Short field work means lower airspeeds, lower airspeeds require positive yaw control.