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I had thought it was the Navy who was orginally testing this new prop out and the AF was waiting for results. I wondered what the results were.

If AFMC is using the Vmca as an excuse well that just shows what kind of thoughtless engineers we have at the SPO as well as OPs in general. It is that kind of pointless decisions that lead to less than capable airframes. The mentality that thinks everything in terms of Max power. That is/was the issue with that latest 1-1 fiasco. What the 130 needed is Vmca charts for less than max power. Vmca problem solved.

The B-29 had a bad Vmca problem on three engines. Funny how that issue went away with the B-50 and more powerful engines.

Ok, my main concern was for the Vmca excuse. I really do understand the other stuff. If it was a plethora of things then that makes more sense. Funny but aren't some of those other issues also applicable in the "J"? No "J" bashing here! My understanding of the 8 bladed prop too was on the -15 motor produced almost as much thrust at the "J" motor. Perhaps that was incorrect info then. Did the Navy test it on a Herk on just an E-2? Which engine? Series 4 on the E-2's!

My thoughts on the Vmca thing though is as I mentioned using the B-50 as an example. The reason the Vmca was not such an issue on it as opposed to the B-29 is because of the increased 3 engine power available they could reduce power on the assymetric engine thus reducing Vmca affect. Same for the Herk. More power does not necessarily have to translate to increased Vmca speeds. I tried explaining this during an AMC/1-1 conference before I retired. Unfortunately the powers to be either did not comprehend or were unwilling to flinch.

The main issue is that Vmca is based on Max power on remaining engines. Here is an example scenario: Cold day Vmca is higher than warm day Vmca due to increased engine output thrust. In scenario 1, max torque is 19,000 and in scenario 2 max torque is 15,000. Depending on circumstances most missions would take off using a reduced power setting anyway and only advance throttles as needed. So if the herk in scenario 2 can make a safe takeoff with a lower max power available then why can't the herk in scenario 1 just use the lower torque settings to base it's Vmca speeds on? In that case Vmca would not have as much affect as lower power settings are being utilized. Even in an emergency three engine scenario the "H" -1 calls for applying power on remaining engines "as required", or it did anyway! The main idea is that if the plane in scenario 2 could make a safe takeoff in a 3 engine emergency with the lower max power available the the same holds true for the plane in scenario 1. The only difference is that Vmca was affecting scenario 1 more so than 2.

This is why reduced power Vmca charts are needed.

This would not be applicable in all situations like heavy weight/short field where maximum ACL is needed however in normal operations this would practically illiminate those Vmca/Vmcg enduced limitations.

The other thought is to go to "Uh Oh" split throttle takeoffs. lol I think the AWACS already utilizes this procedure due to limited rudder effectiveness caused by the rotodome on top.

I do understand the money thing. Believe me. I also remember the talk of re-engining the herk in the late 80's. Not sure if they were looking at series 3 or series 4 motors though. That talk was that the engine upgrades would pay for themselves in fuel saving alone in 5 years. Not a bad deal especially since from what I understand the cost to overhaul a -7 motor now is more that a -15 since the -7 components are not manufactured anymore.

But this whole wing crack thing has really shaken up the Herk world.

Edit:
Well the way some of your post read I had assumed you were at the SPO but according to your profile you are a FE at Dyess. I had assumed that you were speaking like you had some inside track on what went on with the testing of the 8 bladed prop. Well I'm retired now and really don't keep up as much as I used to anymore. But I did retire from Robins and used to work with the SPO quite a bit. I did see some of the stuff that goes on there.