916 fuel pump alternatives

I don’t have a Facebook account, so I don’t know what Mike posted regarding Lockwood’s alternative, and this might be a repeat of that. However, a few years back when Rotax had a fuel pump shortage for the injected engines (do to problems with the pumps), I saw a few factory built 912iS aircraft delivered with the Andair duplex pump.  I believe it was the Andair PX375-S serial duplex pump. There was some talk that it was actually a superior pump, but just too expensive to be selected by the factory as OEM. It’s also an all-in-one unit so I don’t think you can replace one of the two pumps.  The aircraft I know that are using it have not had any problems, except for an initial recall on the pump that was simply changing a single screw to a smaller head size/shape so it would not chafe a wire. I’m not advocating the use of this pump, but it looks well made and seems to function well. 

https://www.andair.co.uk/product/serial-duplex-pump-for-38-fuel-lines/

The issue with the Andair pump was due to the fact it had a onboard circuit that was from a different commercial source. (rc aircraft I was told)  As such they were not able to pass the required certification testing according to Rotax.  The pump problems were finally more or less resolved in 2021.  

The BIG problem is the type 916 CANNOT get enough fuel from the early version pumps used on the type 912iS.  ( and by extension I would say the 916 also) Do NOT use those on the type 916.  I would recommend the newer Bosch ones as they are designed for the pressure and flow required when you get into high HP settings.  

Cheers

I’ll see if I can find the information on the increased TBO. Mine was the first S21 w/ 916 (N512TX). I’m in Texas. 

Thanks for the recommendation

I visited Lockwood Aviation and spent some time with their Engineer Tayler who showed me their pump assembly.

It is a well engineered piece of hardware that replaces all of the connecting fittings with a beautifully designed manifold made out of solid aluminum. The manifold attaches the pumps solidly and provides a good platform to mount to the frame. I had to design my own custom fitted mounting plate utilizing the back of the autopilot mount . Their pump must NOT be grounded to the frame so they provide rubber insulating bushings as well as the need to replace some of the braided steel hoses with rubber hoses to insulate the pumps from frame grounding. As Tayler explain the ROTAX electronics are very sensitive to electrical disturbances and this ensures that the pumps do not interfere with the sensors. They have all of the installation instruction on a .PDF file for easy reference.

I am working out the install to have clear access to the pump assembly ensuring that it fits under the RANS seat and securing the the whole system to avoid any movement that would effect the stability of the header tank fittings at the shutoff valve as this is also a major concern to the installation for safe operation. I'll upload a photo when I am done.