RV-14 ADAHRS Bracket [3.0 hours]

I originally mounted a bracket in the empennage for the Garmin magnetometer. Years ago. Then I switched to Dynon avionics, so I was going to have to make a new bracket for the Dynon ADAHRS, and wasn’t looking forward to crawling into the tailcone to install it.

Then I came across the Van’s RV-14 ADAHRS bracket, which looks like a clever design. It goes in the left wing, inside the inner access cover. The RV-14 wings are the same as the RV-10 wings, just shorter. I looked at the drawings and the dihedral appears to be the same, so I ordered the following parts from Van’s:

W-00012A
W-00012B
W-00012C
W-00012D
W-00012E

With these in hand, I prepared an installation for the left RV-10 wing using the following procedure:

  1. Prepare the parts using the RV-14 instructions on page 20-03 of the RV-14 wing manual.
  2. When fluting the W-00012C parts, do not simply hand hold the part and hit it with the fluting pliers. Mark the distance in common with the W-00012B parts, and securely clamp the W-00012C between a block of wood and the workbench so that this area remains flat. Then, use the fluting pliers only on the exposed part – see the picture.
  3. Cleco the parts together. Position on the LH inner bottom wing skin, and verify you have the correct orientation.
  4. Draw a line between the center of the two wing rib holes, these are the fourth holes down from the J strut. Reposition the bracket to be aligned with the center of the access cover, and match drill/cleco the end two holes in the Z bracket through the bottom skin. I used a #42 drill bit, and once all holes were drilled, match drilled with a #40 reamer.
  5. Remove the W-00012A bracket, drill the remaining holes from the Z bracket through the bottom skin.
  6. Remove the Z bracket, de-burr the holes just drilled in the Z bracket and the skin. Dimple the holes for flush rivets, and reassemble all parts.
  7. Keeping the bracket aligned so it is not “twisted”, match drill #40 from the W-00012A bracket into the J strut, cleco’ing as you drill each hole. Enlarge all holes to #30. Disassemble and de-burr.

That’s it. I’m not going to assemble the bracket until I prime the parts, but with the pieces cleco’d together I checked the position and clearances. You can see from the photos that there is plenty of room for the cables and air connections. The OAT sensors can be mounted in the bottom wing skin, near the access cover – see the RV-14 instructions for a typical hole position (I haven’t drilled these yet).

The RV-14 instructions call for countersinking the W-00012C retaining strips for AN426AD4 rivets. The strips are too thin for this, the countersink would need to continue on into the W-00012B parts. I see no purpose for using countersink rivets here, so I’m going to use regular AN470 rivets instead, obviating the need for countersinking the parts.

I have to mount the OAT sensors, make up a wiring harness with tie downs and re-route the air lines. I’ll do these jobs once I’m ready to close out the wings.

  • f46a
    f46a
    RV-14 ADAHRS bracket parts and instructions
  • f46b
    f46b
    Fluting the retainer strips
  • f46c
    f46c
    RV-14 ADAHRS bracket parts prepared/deburred
  • f46d
    f46d
    Drilling the bottom wing skin
  • f46e
    f46e
    Deburring holes added to the bottom wing skin
  • f46f
    f46f
    Dimpled new skin, Z bracket holes
  • f46g
    f46g
    Match drilled holes into J strut
  • f46h
    f46h
    Checking Dynon ADAHRS fit
  • f46i
    f46i
    Bracket in place, old air line routing will have to change.
  • f46j
    f46j
    Bracket cleco'd inside bottom wing skin, all fits OK
  • f46k
    f46k
    Looking up through access cover. Plenty of clearance all around.

 

Finished right flap trailing edge [3.5 hours]

I’ve kept the straight edge I match drilled the right flap leading edge into clamped to the edge of one of the workbenches, to remind me to finish the flap. Today was the day to do that. Same process I’ve described previously – bind the trailing edge with double sided construction tape, then keep drilling 13mm holes out of the straight edge, using a squeezer through the holes to set rivets. Once again it worked a treat, and the right flap trailing edge is perfectly straight. This is also the last trailing edge I have to do – that’s all seven now done and they’re all dead straight. That leaves bottom skins, wiring and fairings for the wings – which I’m putting off for a while so I can make progress on the fuselage.

  • w60a
    w60a
    Right flap, trailing edge wedge, scuffed and cleaned ready for tape
  • w60b
    w60b
    Wedges taped in, cleco'd down to previously match drilled straight edge
  • w60c
    w60c
    After second round of riveting, every second hole done.
  • w60d
    w60d
    Finished trailing edge - dead straight - and scrap straight edge

Right flap construction [28.5 hours]

The right flap is now done, except for riveting the trailing edge. This is the last control surface assembly, and it seemed a bit odd to realize after I’d countersunk the trailing edge wedge that I wouldn’t need the drill jig any more. Assembly was straightforward, except for some reason about half a dozen holes on one end of the trailing edge were offset slightly, just enough for cleco’s to not fit. Match drilling through these holes worked fine without any enlargement so they weren’t that far off.

A long time ago on the empennage I messed up a VA-140 trailing edge wedge, and stole one from the wing kit. That left me one short. An RV-7 builder in Melbourne kindly obtained one for me along with his empennage kit. I finally unpacked it last week and used it for this flap – so thanks Joe!

Still plenty left to do on the wings, but I have some primer expiring towards the end of the year and a few months of mild weather coming up so I’m going to make a start on the fuselage in the coming weeks.

  • w57a
    w57a
    Skins cleco'd onto right flap skeleton
  • w57b
    w57b
    Replacement VA-140 - thanks Joe!
  • w57c
    w57c
    Match drilling right flap
  • w57d
    w57d
    Riveting right flap skeleton
  • w57e
    w57e
    Ready to rivet top skins
  • w57f
    w57f
    Ready to rivet top skins
  • w57g
    w57g
    Ready to install bottom skin for trailing edge match drilling
  • w57h
    w57h
    Match drilling trailing edge
  • w57i
    w57i
    Match drilling trailing edge
  • w57j
    w57j
    Finished match drilling right flap trailing edge
  • w57k
    w57k
    Trailing edge after dimpling, edge relief visible on both top skin and bottom of nose skin
  • w57l
    w57l
    Straight edge has #40 holes match drilled from trailing edge
  • w57m
    w57m
    Countersunk trailing edge wedges, the last use of my awesome wedge drill jig
  • w57n
    w57n
    Riveted bottom skins to main spar

Right flap started after (yet another) break [8.5 hours]

I’ve had yet another break from building, but this time it was for a good reason – a flying trip! We went on Aussie Flyaway’s latest air safari “across the top”. This is the second time we’ve gone on one of Tony and Angela’s organised air safaris. This time there were just five aircraft, shared by a group of thirteen. It was a fantastic trip, covering a bit over 4,500 nm in two weeks. We were originally going to rent a 182 out of Redcliffe, but then changed over to going in a friend’s Cessna Corvalis. Apart from a diversion to Birdsville (where we got stuck for two days) due to thunderstorms while enroute to Alice Springs, the weather was fantastic and the trip went off without a hitch. More incentive to get on with the build!

The last major assembly yet to do for the wings is the right flap. I started this over the past few days, and have it up to the point where all the ribs, spar and flap brackets are de-burred and assembled into the right flap skeleton. Next step is to match drill and de-burr the skins.

  • across_the_top
    across_the_top
    Actual flight path for the trip, which originated and finished in Mildura
  • w55a
    w55a
    Right flap skeleton assembled

 

SERVICE BULLETIN SB 16-03-28 adventures [5.5 hours]

Carrying on from the previous post on this matter – here – I completed the replacement of the left wing aileron bracket, again with no dramas. I then did a trial fit of the left aileron, and immediately ran into problems. Big problems, in fact.

The new bracket is much “wider” on the base than the old bracket, adding 1/8″ each side of the main bracket structure, due to the use of 1/8″ angle for mounting to the rear wing spar. The AN470AD4 rivet manufactured heads, when added to this 1/8″, remove all clearance previously available for the aileron to swing freely, and so the aileron with the standard spacer/washer setup (per Figure 1 on page 21-10 of the construction drawings) now rubs across the top of these rivet heads – see the attached pictures.

I contacted Van’s, and they suggesting changing the washer/spacer arrangement to move the aileron outboard. I tried this, but with only 3/32″ between the outboard edge of the aileron and the manufactured heads of the rivets on the outboard bracket, there just isn’t enough room to solve the problem this way and still maintain reasonable spacing between the sides of the aileron nose and the rivet heads.

So, I contacted Van’s again, and asked them if it would be acceptable to replace two of the existing AN470AD4 rivets with AN426AD4 rivets. Van’s response was as follows:

Using the 426 rivets should be no problem if that is what works best for you there. The bracket is more than thick enough to be countersunk and the rivet strength is the same.

The only problem then is how to actually do it, since the brackets were already installed on the wings and these are very long rivets. I used a long 3/32″ drill to carefully drill out the rivets,  and a 3/32″ punch to drive them out. Countersinking was easy with a right angle drive bit. I didn’t actually have any AN426AD4 rivets that were long enough, I had some -9’s but these were too short. I went looking in the hardware of the slow build fuselage kit, and found a bag of ten AN426AD4-16 rivets, so I stole a couple of these and used a rivet cutter to trim them to the correct length. My guess is the right size would be either AN426AD4-10 or AN426AD4-11. The new rivets were easy to set with a pneumatic squeezer and 4 inch yoke.

The aileron now swings freely without any problems. The pictures show the standard spacer/washer arrangement. When it comes time to do the final rigging, I expect I’ll shift the aileron by one thin washer width, to even up the clearance gaps on the inboard and outboard sides.

Now I have to go back and do the same change to the right wing bracket. It would have been sooooo much easier to have installed AN426AD4 rivets in these positions in the first place.

August 11 update: I did the same with the right aileron bracket, no issues and quite a bit faster the second time around. I’ve added some pictures covering this change.

  • w54a
    w54a
    Trial fit of left aileron, after replacement of aileron bracket
  • w54b
    w54b
    Inside web of aileron rubs across rivets on the new bracket
  • w54c
    w54c
    Aileron alignment is OK, gap is 0.17" - a bit lower than the nominal 0.25"
  • w54d
    w54d
    Preparing to drill out AN470AD4 rivets. Damage on rivet heads is from aileron scraping
  • w54e
    w54e
    Rivets punched out
  • w54f
    w54f
    Old rivet shanks after drilling and driving out
  • w54g
    w54g
    Set up for countersinking holes
  • w54h
    w54h
    Holes countersunk
  • w54i
    w54i
    Set up for squeezing AN426AD4 rivets
  • w54j
    w54j
    AN426AD4 rivets in place
  • w54k
    w54k
    Aileron now swings freely. Probably needs one more 416L washer spacing to balance up inboard/outboard gaps.
  • w54l
    w54l
    Another view of replaced rivets
  • w54m
    w54m
    Old bracket held in front, showing how the new bracket has 1/8" less clearance inboard of aileron
  • w54n
    w54n
    Now I have to fix up the bracket on the right wing...
  • w54o
    w54o
    Rivets drilled and driven out of right aileron bracket
  • w54p
    w54p
    Rivets drilled and driven out of right aileron bracket
  • w54q
    w54q
    One perfect drillout, one that impinged a bit on the hole but OK
  • w54r
    w54r
    New rivets in place
  • w54s
    w54s
    Rivets set
  • w54t
    w54t
    Right wing aileron hung
  • w54u
    w54u
    Same fit as left, needs to be shifted outboard slightly but OK for now.

Right wing leading edges [11.5 hours]

Time to deal with the right wing fuel tanks. Although it isn’t very pretty, I like to prime at least the surfaces that overlap others, such as along the rivet line to the main spar. I can’t allow any primer to get on the pro-seal though, so I taped off everything except those parts I wanted primer on.

With the tanks primed, I fished out the fuel lines I already fabricated, and the emergency transfer pump. As with the left wing, I joined the two leading edge sections (main tanks, and outboard leading edge / aux tanks) together on the bench, and installed the fuel lines etc. I then pressure tested the entire assembly, which includes the fuel lines and fittings around the emergency transfer pump. Each tank had previously been pressure tested, so I wasn’t expecting any problems. There weren’t any.

I then joined the leading edge assembly up with the wing box section. Just like the left wing, these all went together really well – which says something for the precision of the Van’s kit. I modified the right side of the wing rack to take the new assembly, once it is in the wing rack I can finish the riveting. I still have to put the left wing on the bench to replace the aileron bracket.

  • w53a
    w53a
    Fuel tanks after a bit of priming
  • w53b
    w53b
    Right wing centre bay, note access panel on bottom of wing.
  • w53c
    w53c
    Another view of right wing centre bay
  • w53d
    w53d
    Right wing fuel tanks, outboard leading edge
  • w53e
    w53e
    Main fuel tank joined up with outboard leading edge. Fuel lines and emergency transfer pump ready for assembly.
  • w53f
    w53f
    RIght wing leading edge sections joined up
  • w53g
    w53g
    Fuel lines and emergency transfer pump in place (wing is upside down)
  • w53h
    w53h
    Pressure testing both tanks and fuel lines as an assembly
  • w53i
    w53i
    Manometer level stays constant with a stable temperature and barometric pressure
  • w53j
    w53j
    Ready to join leading edge assembly with wing box section
  • w53k
    w53k
    Leading edge and box section all joined up
  • w53l
    w53l
    Preparing wing stand for the new right wing assembly
  • w53m
    w53m
    Right wing assembly ready to go back into wing stand
  • w53n
    w53n
    Riveting bottom side
  • w53o
    w53o
    Bottom side riveting complete

Replacing aileron brackets – SB16-03-28 [4.0 hours]

A couple of months ago, just after I’d finished riveting the flap and aileron gap fairings onto the wing box sections, Van’s released a service bulletin http://www.vansaircraft.com/pdf/sb16-03-28.pdf which applied to all aircraft models. In the case of the RV-10, there has been no reported cases of cracks in the inner aileron support bracket, and there is no requirement to replace the existing bracket on “fully completed wings” if no cracks are found. My wings aren’t fully completed yet – the bottom skins are still off. This means I have much better access to replace the aileron brackets. I thought about this for quite a while, and ordered the replacement bracket kit. After the parts arrived, I thought about it some more, and elected to go ahead with the replacement because:

  • I felt comfortable doing the drillouts without making a mess of the spars
  • My wings are still open on the bottom, making the job a lot easier
  • Van’s themselves are replacing the brackets on all new quickbuild shipments
  • The new brackets are substantially more robust than the old brackets, indicating a desire on the part of the designers to greatly strengthen this part.
  • By doing this I avoid having to periodically inspect the area in accordance with the service bulletin

I separated all the parts, match drilled and de-burred them, and primed. I had ordered new bearings along with the brackets themselves. Assembly of the parts was simple.

Then it came time to pucker up, cut the aileron gap fairing, and drill out the old bracket. I did this on the right wing box section, because it doesn’t yet have the leading edge assemblies in place and was easier to put up on the bench. I drilled out two rivets to trim the aileron gap fairing properly, plus the eight rivets holding the old aileron bracket in place. Taking a lot of care with this, I was able to punch out all of the rivets without causing any hole enlargement. I took a picture of the area after removing the old bracket, since I did such a good job of this, and found out that evening that I’d lost a whole series of pictures because the camera had an episode and corrupted its SD card. I was able to recover some pictures, but not the ones that counted.

I riveted the new bracket on, and everything looked good. Last job was to reinstall the two rivets I had removed from the aileron gap fairing. I then discovered that at least one of these should have been set before I had installed the aileron bracket. In the last picture, you’ll see that this rivet is sitting right up against the rear bracket stiffener. If I had set the rivet first, it would be OK. As things stand, if I try and buck this rivet I suspect it’ll just make a mess behind there. I’ve sent a picture Van’s and asked them if it is acceptable to install an MSP-42 pulled rivet in this location.

Apart from that problem, right wing all done, and I have the new bracket ready for installation on the left wing.

  • w51a
    w51a
    Cutting W1013 parts
  • w51b
    w51b
    Cut W-1013F,G parts
  • w51c
    w51c
    Match drilling new aileron brackets
  • w51d
    w51d
    New aileron bracket parts ready for priming
  • w51e
    w51e
    Left aileron bracket ready for assembly
  • w51f
    w51f
    Assembled left and right aileron brackets, ready for installation
  • w51g
    w51g
    New right aileron bracket installed, except for rivet in modified gap fairing
  • w51h
    w51h
    New right aileron installed
  • w51i
    w51i
    Problem gap fairing rivet - should have been set before aileron bracket

Finish right aileron [4.5 hours]

After a break from building, I got back to work today and finished the right aileron. Riveted the bottom skin to the main spar, the trailing edge, and CS4-4 rivets on each side. Used the same method (construction tape) as before, with the same result – dead straight trailing edge. I’ve shown a few different views to complement the previous descriptions of this technique.

  • w52a
    w52a
    Right aileron TE wedge secured with tape, cleco'd down to straight edge
  • w52b
    w52b
    Preparing for second riveting pass, after which every 2nd rivet will be set
  • w52c
    w52c
    Preparing for second riveting pass, after which every 2nd rivet will be set
  • w52d
    w52d
    Preparing for 3rd riveting pass
  • w52e
    w52e
    Scrap metal (after doing both ailerons)
  • w52f
    w52f
    Completed right aileron

Finished left aileron [9.5 hours]

I finished the left aileron. Uneventfully. Did a trial fit to the left wing, it lined up perfectly with the flap! It’s good to complete all the external surfaces for the left wing, the end is still a fair way off for the wings but it is at least now in sight…

  • w50a
    w50a
    Left aileron ready for final assembly steps
  • w50b
    w50b
    Previously installed platenuts for static wicks
  • w50c
    w50c
    Ready to match drill trailing edge wedge
  • w50d
    w50d
    Match drilling trailing edge wedge into large angle aluminium straight edge
  • w50e
    w50e
    Match drilling trailing edge wedge into large angle aluminium straight edge
  • w50f
    w50f
    Overdone clecos, match drilling finished
  • w50g
    w50g
    VHB tape on trailing edge wedge, ready for installation
  • w50h
    w50h
    Trailing edge wedge taped and cleco'd in place
  • w50i
    w50i
    Trailing edge wedge taped and cleco'd in place
  • w50m
    w50m
    Left aileron trailing edge riveting completed
  • w50j
    w50j
    Aileron test fitted to left wing
  • w50k
    w50k
    Left aileron and flap align nicely
  • w50l
    w50l
    Left aileron top side

Riveted left flap trailing edge [3.5 hours]

To rivet the left flap trailing edge, I used the same method that worked so well on the rudder and elevators. It was a bit tedious because there are a lot more rivets on the flap – but the trailing edge turned out straight as an arrow.

I temporarily fitted the flap to the left wing, and it looks awesome. To do this, I made up a couple of temporary bushings. Normally, a 3/8″ bronze bushing is pressed into the flap brackets. This interferes with bottom skin placement/removal while still under construction, apart from which if the bushing is fitted now it has to be masked off for painting. I made some temporary bushings, using 3/8″ soft aluminium fuel line. Take off some of the outside diameter with an abrasive wheel in a die grinder, until it will just easily fit into the flap bracket hole. Then use a band saw to slice small sections off, about 1/4″ long, and de-burr. These temporary bushings go in place so the flap can be trial fitted to the wing.

  • w49a
    w49a
    Set up to squeeze every 7th rivet in left flap trailing edge
  • w49b
    w49b
    Set up to squeeze every 7th rivet in left flap trailing edge
  • w49c
    w49c
    After squeezing with flush die, to partially set rivet
  • w49d
    w49d
    After squeezing with angled die, to set double flush rivet
  • w49e
    w49e
    Set up to squeeze every second rivet
  • w49f
    w49f
    Set up to squeeze every second rivet
  • w49g
    w49g
    Set up to squeeze every second rivet
  • w49h
    w49h
    Filling in more rivets
  • w49i
    w49i
    Set up to squeeze remaining rivets, only two cleco's left
  • w49j
    w49j
    Scrap aluminium (after other flat used for right flap)
  • w49k
    w49k
    Trailing edge rivets, top side
  • w49l
    w49l
    Left flap temporarily installed
  • w49m
    w49m
    Left flap temporarily installed
  • w49n
    w49n
    Hard to tell but trailing edge is dead straight