Collins to upgrade more C-130H propellers

Collins Aerospace has been awarded a contract to upgrade an additional 24 C-130H propellers for the Air National Guard. The upgrade replaces the existing propellers with the NP2000 propeller, currently used on the E-2 Hawkeye, as well as a digital electronic propeller control system. The EPCS will reduce sound in the cockpit by 15 db, as well as vibration caused by the propellers. They also will see a 20% increase in low speed acceleration.

During testing, it was expected that a 12% improvement in fuel burn, and a 25% increase in time on wing would be seen. The new propeller has 8 blades, as opposed to the current four, or the six on the C-130J. The new composite blades will also allow for individual blade replacement on wing, instead of removing the entire prop. The Navy currently has 24 C/KC-130 aircraft undergoing upgrade, and the ANG has 12 aircraft previously under contract to upgrade.

PARIS, June 18, 2019 /PRNewswire/ -- Collins Aerospace Systems, a unit of United Technologies Corp. (NYSE: UTX), has been awarded a contract by the NATO Support and Procurement Agency (NSPA) to support NP2000 propeller upgrades for 24 Lockheed Martin C-130H aircraft for the U.S. Air National Guard (ANG). This is in addition to the 12 NP2000 propeller upgrades Collins Aerospace has already completed, bringing the total number of C-130H ANG upgrades the company has been awarded to 36.

Collins Aerospace was previously awarded a contract to support NP2000 propeller upgrades for 24 Lockheed Martin C/KC-130T aircraft for the U.S. Navy's Naval Air Systems Command (NAVAIR). Today, the company also announced a new $25 million long-term repair contract with Naval Supply Systems Command to support maintenance of the NP2000's electronic propeller control system (EPCS).

The total value of the ANG and NAVAIR awards Collins Aerospace has received to date exceeds $300 million.

Source

Well, this is certainly an interesting idea for a thread. I don't think I ever thought I'd look on a forum and see a thread about propellers.

I'm really interested in the physics behind how this works. My guess is that by having 8 blades rather than 4, and a profile change of the blade itself, it either causes less severe shock waves. Although it could also be that they are acoustical tuned like a car muffler is, meaning that at most normal operational parameters the sound caused by each blade going through the air cancels out that of another blade on the prop.

But I'm just throwing bs out there... and really wish I knew

a reply to: Zaphod58

Modular design is the future!

That FBW stuff they are working on also sounds cool.

Erm.... why can’t Lockheed do this themselves??

(Yeah, 3rd party providers and all... but c’mon!)

a reply to: TEOTWAWKIAIFF

Because Lockheed contracts out the props and engines from the start. They are responsible for the airframe and final assembly, but don't do the props and all that.

a reply to: dubiousatworst

The electronic control system is able to synch the propellers better, so there's less vibration on the airframe.

This flew on a C-130 almost 15yrs ago. Surprised it's taken this long to kick more money loose, especially since early talk was re-engining and new blades would pay for itself in five years. Better a trickle than nothing, I suppose.

I'm really interested in the physics behind how this works. My guess is that by having 8 blades rather than 4, and a profile change of the blade itself, it either causes less severe shock waves

Essentially. Two things are happening. More blades with slightly smaller diameter, but more total area. That means the tangential speed (tip speed) is lower. That's where the vast majority of your noise/vibration comes from in a propeller or rotor (or screw, for that matter). At the same time, the new blades have twist and sweep which also helps mitigate shockwave formation in the event you get supersonic or transonic flow or the blade. That wave drag kills available thrust produced by the blade, further hurts fuel efficiency by adding drag, and adds a lot of noise.

The electronic system just has a feature for autobalancing, which means ground crews have to manually balance the blades far less frequently, and the blades spend more time optimized between less frequent downtime. The synchronization aspect makes the blades more responsive to throttle input (the engine is tuned to a specific RPM. Thrust is adjusted by adjusting the pitch of the blades).

Less noise/vibration means the airframe and the flight crew take less abuse. Higher available thrust and lower drag at same fuel burn/RPM, more responsive throttle control, less frequent maintenance, ability to change out blades instead of entire hub, etc, etc

thank you for the responses zaphod and robert