We have lift off !

There is no bigger reward to someones dedicated hard work on a project, than seeing it take flight in the sky in a flawless flight.

Yesterday after 9 months since we started this adventure, we finally assembled the "Pelican" super goat ultralight, and took it down the runway for it's maiden flight. It was just wonderful.

Here in Peru, March is in the middle of summer season and the weather is just spectacular. Conditions where CAVOK with a sunny 26 Celcius (79F) and a light breeze from the ocean. The flying club at is best, with Gerardo at the Parrilla (BBQ Grill) cooking all sorts of good stuff for a great gathering.

The news of the first flight of the pelican had already reached most of the club regulars, so they showed up with friends and families. By noon the crowd grew to twenty something flight aficionados.

To the side Gamal and Juan where ready for the final assembly of the wings and cabling. The assembly process went slow, as we had to deal with many assorted details and obstacles typical of the last details of any project.

Assembling the wings was piece of cake, by now we done it so many times, we knew all the tricks.. We recruited a few volunteers to hold the wings, two at the root with the bolts ready and two on the tips helping to align the wing as it got connected.

The order of assembly is simple.. wings to the plane, struts to the wing and finally struts to the plane. this order and a little oil on the connecting points made our life a lot easier.

Regulating the cables for ruder and elevator, took time and patience as Gamal who is a perfectionist (Which in this kind of ventures is very good!) carefully adjusted the connectors to keep the controls perfectly centered.

Next where the ailerons, rod connectors and fixed flap adjustment. Meanwhile I worked checking the aircraft for proper weight balance. (We added a few kilos at the nose, to make it go down like the manual calls for)

A hundred other details showed up, which through out the afternoon were taken care of, (including a well deserved lunch break for Parrilla!)

By 4 pm the aircraft assembly was almost ready, our great friend Daniel  ( an expert paraglider pilot with lots of experience winch towing) mounted a payout winch on to the back of his truck, preparing for our first tow.

A pay-out winch is a towing contraption that uses a regulated brake on the rope spool to "let go" of tow line whenever the tow pressure exceeds the set value. The idea is to keep the tow pressure on the glider equal at all time, regardless of wind gusts or vehicle speed.

By 5 pm everything was set. The glider was ready on the runway with the truck 50 meters ahead.
We connected the towline to our release system (Fashioned from a paraglider towing system) and ran multiple static release tests before the real flight.

With his safety helmet on, the pilot (Yours truly) sat in place, safety belts, wing runner briefed, communications headset tested.. everything checked alright.

1st flight.
Daniel set up the towing brake to about the same tow pressure as he uses for paragliders and Gerardo at the wheel took of for  steady 35 MPH over the dirt road that makes our runway.    Wind was almost straight at 5 MPH, the glider started moving slowly, (to slowly) and the nose digged-in against the road. I pulled the stick back as much as I could, but at this low speed the elevator had not much control to be of any help.  My wing runner was still holding the wing so we just kept going (the plane never actually stopped.. just bumped a bit) , this time getting a bit more speed.. A few seconds later I felt control on the flight controls, pulled the stick a bit, and the aircraft softly raised in the air.

Once in the air, I felt I had good control of the glider. I easily controlled altitude with the elevator to keep me below 3 meters in the air, the ruder was also quite effective while the ailerons less so.
At this point I am going along chasing the tow truck which raised a hell of a dirt road dust "smoke curtain" behind it !

Seeing the cloud ahead of me, half way down the runway I pulled the tow release and quickly got wrapped by the dust cloud, effectively making my first landing IFR !  visibility was at most 20 meters, but the glider flies so slow, I had all the time in the world to land with calm. I must have glided 50 meters from the release point and rolled 30 more on the ground.

The plane flew beautiful! The flight controls where perfectly centered, once you are flying they are responsive and gentle.  Landing was easy, and everything seemed to run on slow motion, as the speeds are so slow. It remind me a lot of landing a paraglider on a gentle wind.

Flight #2
We set-up the exact same way, this time adjusting the tow winch brake for higher pressure setting.. it seems that the initial low speed of the previous tow, was due to the spool releasing rope to easily, effectively keeping me to slow to fly.

Go, Go Go!.  I am in the air again, this time with much better control, off the ground, 1 meter.. now 2, then 3, 4 ... I leveled the aircraft at about 5 or 6 meters (~20 feet) of the ground. The tow vehicle now kept on the down wind side so the dust did not bother me. I flew for about 300 meters before releasing and gliding about 100 meters before touching down. Roll distance took 100 meters more.. I did not used the nose skid to stop the roll.


Flight #3  

Now confident that the flight characteristics of the plane are very gentle, and that the plane construction held on nice, we ventured for a bit more height. Once again we increase just a bit break pressure on the tow line. The wind also increased maybe to 10MPH right along the runway and the sun was getting low to the west.. getting close to sunset. The day was just beautiful for a true glider flight.

Plane ready. Tighten line. Go,Go Go!
This time The plane was airborne within a few meters and kept climbing steady. 10 meters, 15 meters, petty soon I have used half of the runway and I am 30 meters high. I realize at this pace I won't be able to land  straight ahead, as the glide ratio will probably put me over the fence ahead, so I keep the stick tight and keep on climbing as much as I can for an eventual 180 on to the taxi way.

Now the tow vehicle has reached the end of the runway and my line goes relaxed! I release the line and start a gentle right turn, (Maybe too gentle!) that did not allowed me to go back on the taxiway but set me up for a soft landing on a field to the north of our airfield. Once again the landing felt just like a paraglider landing, almost like in slow motion.

Even it was just my third flight, I felt, I had a lot of control to set the glider exactly where I wanted. With a minimum of a tail wind, the ground roll was about 50 meters before I dug the nose and came to a fast stop. feet down, wing gently on the ground..  Awesome.

After that, a nice celebration took place at the clubhouse with over 20 people toasting for our new plane !

Ready for prime time!

It has bee quite a while since my last post, as work has kept me (far) away from the Pelican project, but now I am back in Lima for a month or so, so we are moving full speed ahead on the project.

While away, had to find something else to do :)

While I was away, Gamal and Juan pretty much finished the fabric covering of the whole plane. The covering took a while (because of other planes getting on the way) but it was pretty much uneventful, except for an issue with the aileron tips.

The issue was with the tip of the aileron. Specifically, the when the aileron was covered with fabric, the tip area bent under the stress of the tightening fabric.  It could be that to the fabric was heated to tight... but my guess is that there should have been one more rib on the aileron between the last one it had and the end of the aileron.

The reason I think this, is because the aileron has ribs evenly separated, except the end rib, which for some reason is placed at twice the separation than the rest. I am guessing that this left the tip vulnerable to bending by the fabric pressure.  Our solution was to add another rib and an end plate before the re-fabric work.  So far it seems to be holding well, except for a little rubbing with a small spot on the plywood that covers the end of the wing. (our solution for this, was to file away the plywood "tip" )

As I mentioned before, we used Stewart Systems Ekobond as our adhesive and it has worked quite well, with the added benefit that it is easy to work on and a no "nasty fumes" chemical.

After the fabric work, a hand of Dope paint was applied and soon after a second hand with aluminum so to protect the fabric from UV.

At this point, the only thing missing is the cosmetic paint cover, to make the aircraft look good.

I am expecting that tomorrow , we might be able to give it a first tow to see how it behaves.

I will keep you posted!

Fabric time

Another week of work and we are making lots of progress.

Yesterday we finished the ailerons cabling, leaving the plane ready for fabric covering.

Gamal showing me how to apply anti-chafe tape

To cover a surface is not very difficult, but requires experienced hands to do a good job. Luckily we got our friend Gamal to give us a hand on it.

You start by cleaning all surfaces where you will be placing the adhesive and apply anti-chafe tape to prevent metal to cut through the fabric.

Cutting fabric

After the surface is ready you apply the fabric adhesive.  For this proyect we selected Stewert Sytems Eko-Bond adhesive mainly because it is a water based latex, so I had no problem bring it from the US on my checked in baggage.. Had customs asked about it, I was ready to say it is a new brand of hair shampoo :)

Applying the adhesive is quite easy, just "paint" a thin film of it and wait till it get sticky before placing the fabric on top.  ( a great video tutorial can be found At Stewart Systems youtube channel )

Applying the top layer of  fabric adhesive

Once the adhesive has cured, heat is applied to shrink the fabric to eliminate imperfections. Again, the process is not hard, but you need skill to do it right. I'll say it is more an art than a science. 

Water based adhesive, really nice to work with.

Gamal & Juan heat activating the sealant

Covered wing, ready for Aircraft dope

A good days work got us two wings covered and the prep work for the rest of the surfaces.

This week we should be finishing that and applying aircraft dope. With a bit of luck , the plane may be ready to test by next week.

All about cabling

Knowing how important is to properly set up the aircraft cabling, We recruited the help of our good friend Gamal Casas to help out in the process. Here in Peru, Gamal is sort of a legend among ultralight builders as he has assembled most of the flying ultralights in the region.

I've personally flew the first flight of the last Challenger ultralight he assembled, it flew hands off since the first run.

First we put together the GOAT and checked for symmetry between the wings and the fuselage.  To do this, we first installed the flaps and the ailerons with a few soft rivets to keep them in place. (We will remove those to fabric afterwards)

With that done, we measured and cut the structural cables to size, before assembling them with it's sleeves and nicos. Originally, the kit came with out any shackles. We decided to add them at on the main wings to make it easier to assemble and dis-assemble the kit for transport.  (Otherwise, it would have required the removal of bolts on the tail and nose every time)

Getting cables right is a slow and detailed process, always stopping to double check the symmetry of the structure and making sure the previous cable did not throw the alignment off.

We started with the tail section, and quickly found that  bottom cable connecting attachment was missing. I emailed Jon in NY who quickly replied with pictures of the prototype. With this Gamal was able to find a replacement from parts we had in the shop.

Tail bottom wires

Tail top wires

Wing to tail cables

Modified wing cable attachment point

The original cable attachment piece on the trailing edge of the main wing seemed to be a bit short in comparison to what we saw on the pictures, so we built a larger one to accommodate the for the flap angle.

Rear cables view

Rear cable split view

On the wing front cable attachments we added shackles for quick dis-assembly

Wing to nose cable

New rear cable attachment point with shackle for easy dis-assembly

Completed the structural cabling, we started the controls cables wiring with the pedals and rudder controls.

For this process we clamped the ailerons and tail surfaces in their middle position, then centered the pedals and the flight stick before clamping them too.

Once everything was in place, we cut and assembled the wires making sure that the control surfaces had proper travel 

Rudder controls view 2

Rudder controls

Pedals

Rudder pedals

Rudder pedals (springs located temporarily)

We paid particular attention to the ruder controls, as the ruder surface is quite large and did not wanted to allow over controlling of it.

Finally we routed the cables through the wing ribs by carefully wrapping the tense control cable with a piece of coarse sand paper (coarse side facing out of course) and sliding back and front till the tension disappeared.

Again, we put shackles on the cables so we could quickly dis-assemble the wings when needed. 

Control stick cabling

Cable routing through the ribs

Some dude posing as a pilot :) 

Weekend Update

This was a busy week!  We discovered some of the aluminum tubes where starting to build sulfate, so we decided to go ahead and zinc paint *everything*

Lots of work, one wing was pretty much done , the other had most ribs still missing, so starting Monday I had to wrap all the ribs with craft paper so the thinner wouldn't get to them. Tuesday I  painted the fuselage, the struts, the pedals.  Wednesday off, had to fly to paracas, Thursday finishing up  painting details.

Friday, a friend from Miami Fl, sent me 3 rolls of  fiberglass threaded tape (the same that came with the kit) and 3M aluminum tape. With this we where ready to assemble the rest of the ribs and get ready for 1st full assembly.

The flight club on Sunday's is usually quite busy, so we did not made a lot of work, but we managed to put the plane together with the wings finally ready. (also had an awesome meal cooked for all by our  latest student to solo. )

Tomorrow we will install the flaps and place the ailerons up with soft rivets so we can measure all control cables. (probably install the pedals and the seat too)

Finishing last details by the headlights of my truck

All about ribs

Today we spent the whole day working and made quite a bit of progress. 

First, we finished gluing the ribs and the corner edges through the ribs by shaving the inside of specific ribs .

A & B ribs shaved to fit the drag spar

After that, we riveted the few parts still being held by clecos and finally we covered the glued ribs with the aluminum tape.

Drag Spar in place

Close up of the taping 

Wing end corners

Another view of a corner 

The process is not hard but it is quite time consuming. 

To get a wing done we used three rolls of the fiberglass lined adhesive tape and almost two of the aluminum tape. This means i'll be short 2 rolls of the fiberglass and one of the Aluminum.. I've looked for it everywhere with no luck, so, I guess I'll have to get it imported from the US...

*Luckily some friends are coming to visit us for turkey day.. hopefully they'll bring me some.

finished with one wing and waiting for parts to do the next

Finished wing edge

Compresion tube suport 

Compression tube and aileron control mechanism

Completed wing

Gluing the ribs

Continuing with the wing assembly, yesterday we began the process of setting the foam ribs in place.

As described by the kit instructions, we start by applying a thin layer of Gorilla glue (previously mixed with water) on each end. Then, after setting them in place we wrapped them around with fiber glass tape. Gorilla glue expands quite a bit, so it is key to place *and tape* one rib at a time, otherwise you run the risk that the expanding glue will shift things around. The roaster jig that mike suggested we built for the wing, helped a lot in the rib setting process.

After the first set of ribs was in place, we decided to place the the drag strut diagonally through the rib holes.  We carefully shaved the rib's holes on the inside, just enough to allow the drug strut to fit in place with out bending any of the ribs.

By the end of the day , we finished the first section with pretty good results. All in all , the process is not difficult, it just takes a little patience to get the ribs placed right.

First section glued and tape wrapped

To be honest, the hardest part was to handle the amount of on lookers that kept dropping by, to chat and check things out !

See you next week!