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Static port drilled in fuse wrong bulkhead Argh!!

Davea320

Well Known Member
After studying the drawing 28 (RV7) numerous times to determine the exact location to drill in fuse skin, I ended up measuring and drilling referencing the wrong fuse bulkhead. So, I call Van?s this morning and they say no big deal. Can?t tell me if it will affect the static system or not. In other words I won?t know if I get wrong input from static port until flying. My static port will be approximately 2 feet forward of where Van?s calls out the proper hole location.

Has anyone out there done this and have any ill effects with the static system?

I can drill new holes in correct location and ?fill in? the wrong 1/4? hole now or just roll the dice and hope all works well.

Lots of aircraft I?ve flown have a more forward static port, but Van?s must?ve put it that far aft for a reason. Open to all opinions.

Dave
 
static port

You have one each side so did you drill both or just one?
I would fill and redrill in the correct location. My opinion.:D
 
Just my opinion -- patch it, put the static port in the location as per the plans.

Don't wig-out about the patch; just debur both sides of the hole, slather a little JB Weld on a small piece of scrap aluminum (1/2" square or thereabouts) and glue it to the back side of the fuse skin, scrape off the excess that oozes out, then sand flat when dry.
 
Dave, I hesitate to admit, but I did exactly as you did a few years back. Absolutely no adverse affect on airspeed pitot/static.

Jim @lock Haven, Pa
7A
 
Static port has been depicted in both locations over the years & different plans sets. Static error is one of the things you validate in the Flight Test process.
 
Just my opinion -- patch it, put the static port in the location as per the plans.

Don't wig-out about the patch; just debur both sides of the hole, slather a little JB Weld on a small piece of scrap aluminum (1/2" square or thereabouts) and glue it to the back side of the fuse skin, scrape off the excess that oozes out, then sand flat when dry.

Or dimple it and set a nice flush rivet in there!
 
Or

Or use two nested tinnerman countersunk washers with a #6 screw. Never see it and it closes the hole perfectly...
 
Already drilled to full size. 1/4”

Install static Ports and move on.... it will make little to no difference. Not even Van can make their mind up.

http://www.vansairforce.com/community/showthread.php?t=97509

Keep in mind there is NO PERFECT PLACE FOR A STATIC PORT. THE BEST PLACE IS ABOUT 100 FEET BEHIND THE RUDDER..... Seriously.

https://www.youtube.com/watch?v=kZsi4A5PcTw

Airflow around the skin of the airplane, corkscrew air from prop SUCKS everywhere around the fuselage.... It is all a compromise. Cessna puts the static port on one side behind the firewall, terrible place and single port. However good enough for a certified GA plane.

Having both ports at the the same station is good. It will cancel out the error from slip and skid. As long as you are aft of the wing trailing edge you are good. Piper use to put the static port on the pitot (blade shape combo pitot and static).

When you do your test flying you will test indicated verses actual AS. You will fly GPS ground speed (triangle hdgs 120 apart) and average it out GPS and compare to IAS. You will be within a few MPH of indicated. It never will be perfect. If you are worried do like the video and get a good static source and compare to your static source.
 
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Just my opinion -- patch it, put the static port in the location as per the plans.

Don't wig-out about the patch; just debur both sides of the hole, slather a little JB Weld on a small piece of scrap aluminum (1/2" square or thereabouts) and glue it to the back side of the fuse skin, scrape off the excess that oozes out, then sand flat when dry.

No...don't do this...the skin is structural. Follow 43:13 to make a patch.
 
I put mine in the wrong place because the idiots at Van's had the plans wrong. Or the canoe was upside down but my thinking wasn't 🛶🙃😅
In any case, I put a flush rivet in the hole and put the port in the right place. Then, because I know how we are, I put another rivet to nowhere in the corresponding wrong place on the other side. Now the wisenheimers at Oshkosh aren't sure if it's a mistake or a super secret mod that they can't live without 😉
 
Ralph is right, over the years the static ports HAVE been depicted on both locations. The RV6 plans, RV7 plans and Vans pitot/static kit all may show different locations. I located the static ports on my RV6 & RV7 in the same (old, forward) location, and it has worked just fine. Even the gang at Van's signed off on it. Leave them where they are and build on.
 
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They will be fine

I put mine here in 2005 and they have been fine. the directions said to install them here, after I did the drawing showed them further back.
Mine work just like they should.
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May just put in Van?s static port in wrong holes and Safeair ports in new correct holes and tell folks I have a double redundant system.

That?s what makes it unique to the builder right? See if folks at OSH can figure it out.

Dave
 
I did a static port mod years ago on a certified a/c to improve the airspeed accuracy, so I've been there.
The general effect of fore and aft location of the static port on the aft side of a low wing aircraft is:
forward toward the wing = higher indicated air speed,
rearward toward the tail = lower indicated air speed.
I have no idea what the effect of vertical location on a slab sided a/c would be, though I guess it would be slight if it is well away from the top or bottom edge.

Related story: I asked why the altitude hold of the company's Aero Commander was crazy. The answer was that it had made the rounds to all the various shops in socal and no one could fix it. I noticed in the air, though, that if I bumped the nose up, the VSI would initially go down then up. Well that was it, it all has to do with the factory location of the static port and the effect of the high wing balanced by the fuselage pressure pattern giving good steady state static pressure results, but poor dynamics. Even the big boys get it wrong from time to time. Be glad you've got Van.

Ron
 
That's interesting. On my QB RV-8 the Static Ports are much lower than the plans call for, about 4" UP from the lower longeron (but at the correct longitudinal location). They should be 4" DOWN from the upper longeron. It's as if the Static Port holes were drilled at the factory with the canoe upside down and the plans were misread. I have done 3 and 4 leg GPS runs and my indicated TAS is about 4 MPH fast, but I haven't done anything yet to fix that.




Correct vertical location is 4" DOWN from the upper longeron:



My previous QB RV-8 has the Static Ports in the correct vertical and longitudinal location.

I am 99% sure that the QB assembly facility has never installed static ports so I am pretty sure that mistake was done by the builder.

For the OP, there is a lot of data that indicates that the actual static port that gets installed is far more important than which of the two bulkheads it is coincident too.

A flush static port like was being sold by a couple of the custom parts vendors a few years ago is a guaranty of static errors and instrumentation problems.
 
Static Error

I have done 3 and 4 leg GPS runs and my indicated TAS is about 4 MPH fast, but I haven't done anything yet to fix that.

You really need to test this at several speeds throughout your speed range because static errors can be dependent on airspeed (i.e. larger error at higher speeds).

Skylor
 
Thanks. Yes, I'm sure the QB assembly facility does not install static ports per se. The question is whether they drill holes, or pilot holes, for them.

The reason I ask this is, when I queried the builder about the non-standard location of the static ports, he said that the holes were already there, on both sides of the fuselage. Since he knew the static ports were generally located in that area, and there was nothing else in that location the holes could be intended for, he assumed Van's intended the static ports to go there.

I am not aware of them ever drilling pilot holes for static ports.
 
Yours appears to be exactly what mine looked like. I measured down from the upper longeron, except that it was only the "upper" longeron due to the canoe being upside down at the time. The proximity to the rudder cable concerned me, and led me to discover my error.
 
I am 99% sure that the QB assembly facility has never installed static ports so I am pretty sure that mistake was done by the builder.

For the OP, there is a lot of data that indicates that the actual static port that gets installed is far more important than which of the two bulkheads it is coincident too.

A flush static port like was being sold by a couple of the custom parts vendors a few years ago is a guaranty of static errors and instrumentation problems.

Plus one based on my experience.

Also for all fliers, unless they have tested and verified the accuracy of their pitot/static system, they can't claim that it works fine. It certainly works but it might/might not be accurate
 
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