Jump to content

AF buys 3.5 engine upgrade for Herk


Spectre623
 Share

Recommended Posts

Which brings up an interesting point.... any feedback from the NYANG? Didin't they have one/some of their aircraft modified with the 8-blade props? Be interested to see some data on how it worked out.

Back in the early J-model days the Dowty 6-blade did have some issues with delamination but I understand that's been cured. 

Link to comment
Share on other sites

The Rolls Royce Series 3.5 engine upgrade is separate from any plans to use the NP2000 (8-blade) prop. Series 3.5 is an internal upgrade to several components of the T56 to improve fuel efficiency. Coincidentally, USAF used the same Wyoming ANG bird for the NP2000 and single-engine Series 3.5 test at Edwards. Then NOAA conducted their own 4-engine test on their P-3.

Now, if USAF would combine the NP2000 and Series 3.5...that would be a sporty Herk.

Link to comment
Share on other sites

From what I can gather, the NP2000 prop has some weird performance issues in cruise. The AF had a hard time justifying it because they couldn't prove a fuel burn/cost savings. You'd think the maintenance cost savings (not to mention the savings in the WRSK bins) would justify it, but that's not how they look at it. 

Above all though, we need to have ADSB-compliant radios. All the fuel savings and improved performance don't mean a thing if you can't fly the mission.

Link to comment
Share on other sites

The NP2000 has been funded for several years I think...maybe just for the ski birds though.

I agree with you Railrunner, the maintenance savings on the new prop should have mx driving the change...just like the autopilot & radar upgrades.  We only got those because the cost of maintaining the E-4 & APN-59 were too high.

AMP increment 1 is intended to install ADS-B concerns, as far as I'm aware.  It's not the radios, it's the transponder & GPS.  A mil GPS system does not meet the requirements....just ask the J folks about that one.

Link to comment
Share on other sites

NP2000 evaluation has been funded on and off for the past several years, but I believe the props have only been installed on a WYANG bird for the formal flight test and a Skibird for an operational test. The Skibirds will be the first to get them (once funding is approved) since they need the extra takeoff thrust to get off the ice in Greenland and Antarctica without JATO. The Skibirds have been the driver behind NP2000 for C-130s...but of course several other groups are interested in the extra performance as well.

There is not much cruise fuel efficiency improvement with NP2000 (that's where the Series 3.5 engine really shines), but there is a major boost in low speed thrust. Plus many reliability and maintainability improvements over the 54H60.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...