Auxiliary Air Box Retention SB

We have a new service bulletin for auxiliary retention of the air box on up draft sump installations.

This service bulletin is NON-Mandatory and can be complied with at the owner?s discretion.

This service bulletin only applies to aircraft using Lycoming, Lycoming clone engines with up draft sump with Van?s filtered air box assembly. Only installations using FM-100, FM-200 and FM-200A model fuel injection systems apply. FM-150 installations or front sump inlet (horizontal inlet) installations do not apply.

A hardware kit is available at no charge. If this applies to your installation please contact Airflow Performance (864-576-4512) or email to [email protected]) with the serial number of the fuel controller on your installation, and we can send you the hardware kit in the mail

This service bulletin will be on our web site in the near future.

Don

April Kit Planes article

I am writing this in response to the article that was written in the April 2015 Issue of Kit Planes

First off, I was contacted by Amy Laboda at Kit Planes either in September or October last year, asking if I would like to comment on if I knew there was a problem with the air box mount plates coming off on installations using Airflow Performance fuel injection. At that time I did not have any more information than that, so I chose not to comment on something I had insufficient information on. Looking further into our records and doing a search on the VAF I found that we had 430 of this type of installation in the field and there were 4 to 5 incidents that the air box came loose. Looking at the design, the air box plate material was made thicker to eliminate incidents of cracking. With the increase in stiffness of the plate the loads were transmitted to the ring. Some issues were found with the installation. Insufficient clearance of the air box inlet to the cowling caused rotational force to be transmitted to the clamp ring when the engine was started and shut down. Tightening sequence of the air box mounting bolts to the pinch bolt tightening was sometimes not done correctly resulting in the clamp ring not being completely tight on the throttle body. And incorrectly installing the air box mount plate and approach clamp ring on the throttle body would be causes for the air box to come loose. With over 800 lbs. of clamping force on the clamp ring to the throttle body, we were confident that the attachment method was adequate for the part being supported and we felt there was adequate instruction in our Installation and Service Manual spelling out the correct installation procedure for the air box mount plate and approach clamp ring. In any case we designed and had fabricated some tab washers that would allow additional retention of the assembly. This Service Bulletin came out in January 2015.

Somehow I did not get a copy of the April Kit Planes magazine issue the article was in and one of our customers (who has several RV-s with air boxes installed) asked if I had seen the article and wanted to know if all of his air boxes were installed improperly as they did not look like the picture in Kit Planes. He sent me a copy of the article and at first glance was able to see that the picture shown in Kit Planes had the air box mount plate and approach clamp ring mounted incorrectly. This could very well be the reason it came off. The instructions in our tech manual (Appendix C page 1), show the correct way to mount all the parts on to the fuel controller and air box. It is very unfortunate that we were not notified to review an article that featured our equipment for correctness to fact. Again it is not the content of the article that we want to edit but to make sure the facts are presented correctly (like a picture of how our equipment is to be installed) before this goes to press and the wrong information is sent out to the world.. Again, a Service Bulletin 1-29-15 was issued addressing this issue. It is non-mandatory and done at the owner?s discretion.