Category Archives: Brittany RC field

Skywalker Fly-away $#^$@!

Lost the Skywalker with the Gopro 3 Black and Mobius cameras a-blazing yesterday.    The first indication I was having a problem was the LCD screen on the monitor blacking out.  At this point the plane was not flying very high nor far.. probably not more than 80′ up. The control response were also squishy but I was able to manage to align the plane on the field for a landing but was coming in too high and decided to make another round which was a mistake, at this point even the EzUHF transmitter shut down. This could mean 2 things either the 12v BEC I used for power distribution for the EzUHF transmitter, monitor, DVR and VRx has failed or the LiPO has discharged.  Running back to the field tent to get a spare battery I saw the plane do an RTL and do at least one circle over the launch area.. so far so good.  Couldnt find the spare battery for the transmitter and decided to disconnect the rest of the electronics and just power the ezuhf, at this point I can still the hear the buzzing plane above.. then silence.

Went around surrounding area for a couple of hours but couldn’t find it.

Lessons for this one:

1)  VERIFY, VERIFY that the transmitter battery is at least at 90%.. this is the 3rd flight I made for the day and I remember starting with about 80% (I’m using a Tiger 4S 2800), usually I charge this the night before but not yesterday =(  Checking the battery after showed it was only generating 11.1v.  I completely under-estimated the power drain by the system.
2) Nevertheless, the APM2.6 seems to have gone on a fail safe which dropped to the RTL. I was expecting the plane to loiter above after reaching ‘home’ waiting for a signal (or the battery drains) but this did not happen.  The correct behaviour should have been with long RC signal loss, the APM 2.6 should loiter or RTL and Circle and not make do a hardware fail safe, either that OR the ESC has fail-safe’d, and finally;
3)  At the first sign of power and control issues…land!

G R O A N.

FPV flying in beautiful Batanes, the Philippines

Batanes has three major islands: Batanes (the main island), Sabtang and Itbayat.  A couple of airlines have daily flights to the capital Basco.   Unlike the rest of the Philippines, the Batanes islands, because of its location, has 4 seasons similar to other northern climes ie Winter, Spring, Summer and Autumn. The only thing it doesnt have is snow!  This means that for most of the year, its a little colder and, on average, windier than the rest of the country.  For FPV flyers it just means more patience (and luck!) is needed for most of the months.  The locals say the winds are calmer from mid-March until May.

Ok here’s the lowdown:

1)  Safety –  Batanes only has 17,000 people spread across several islands. Even in the capital of Basco, rush-hour means seeing a couple of vans going around (mainly shuttling tourists).   The areas I’ve flown in are largely uninhabited and I was told the airport does not accept air traffic from 3pm onwards.  The runway also has a “one-way in, one-way out” — the words of our pilot — policy landing from the west-end and taking off in a west-ward direction regardless of wind direction.  Good info to know if one is flying several hundred meters (or km!) up.

2) Wind – hills and small valleys, can make for an exciting landing.. I soon learned that landing on small roads on ridges on a windy day is a big no-no.   Thats because after hitting the side of a hill, wind speed accelerates as it escapes on top.  It gets worse in the intersection of two hills which forms a funnel-like valley.   The best option is to land on the side of the hill with no wind. Which means, higher throttle on the approach — as you will lose the head wind  since the hill where you will be landing will now acts as a barrier — and then pitch up at the last minute, so you’re basically landing uphill.

Here’s what I took away from this visit:  Hills = Gusts.  Sea Headwind < Land Headwind.

3) Interference –  Virtually none.

4) FPV Locations – the best bet location (for safety, wind and scenery) for long range FPV is the “Songsong Iraya” coastal road.  It’s located in the north-west part of Basco and its the road leading to the garbage disposal facility.  No villages, just some cows and lots of open space to crash in =)

For a little bit of challenge (wind!, some tourists but the best scenery) go to the “Marlboro Country”, this is on the east side of the island (yes facing the Pacific) and the scenery is breathtaking.. you’ll be able to take videos of the farm lands, a defunct (but well kept) light house, the ocean and the surf!  Hill-side landing is the key to an intact plane here.

I saw at least 7 spots thats excellent for FPV in Batanes and Sabtang Islands.. but only flew in 4 of them.  I’ll post the vids of them soon.  In the meantime, here’s the vid of the 2.5km flight from “Songsong” road:

 

 

FPV!

Last saturday was a great day for flying FPV.. I flew several relatively long flights (ie at least 15 minutes anyway), the first flight was at dawn, 6:30AM and I flew more than 1.4km before turning back and chickening out =)  altitude was about 250m.   I noticed the that the APM2.6+minimosd is heating up quite quickly.. positioned in the compartment under the wings it seems like there’s not much ventilation there in the Skywalker.

After lunch, I used a plastic spoon to create an air scoop and glued that to a small hole in the fuselage to ventilate the APM system.. it proved to be very effective, lowering the temperature from 39.2C (while on the ground) to 36.9C (while cruising).

Took a couple of longer flights and was able to get to 560m in altitude and 1.5+km out.

Manila Bay
Manila Bay from 500m+ in cavite
Home Base!
Home Base from 1.5km away
Metro Manila
Metro Manila from 500m in Cavite. Manila Bay on the left, Laguna de Bay on the right.

Skywalker FPV checkout flight

Had a successful checkout flight of the on-board FPV equipment:

1)  2014 1.9m Skywalker (very much already a crash veteran even at a tender age of 2 months)
2) ImmersionRC EzUHF with diversity for the R/C
3) 700TVL sony ccd camera
4) 2w VTX mounted on the tail boom just before the tail assembly
5) APM2.6 (with 2.78b firmware) and minimOSD for the auto-pilot and OSD respectively
6) 80A Hobbywing ESC (previous 60A ESC was damaged after a crash)
7) 4S 5000mah battery

A week before, during a first test, I had an issue with the GPS and experienced TBE’s during loiter and auto modes.. turns out the external GPS was being affected by the APM power supply.. moved the UBlox GPS and APM to another location (in the compartment under the wing)  and the problem just disappeared.

The day before this test, I upgraded to the APM 2.78 firmware which unfortunately had a bug rendering one of the servos params to be uneditable..a big problem for me since my Ailerons needs to be reversed with the auto-pilot is engaged. Fortunately 24 hours after releasing the software, the developers released a patch 2.78b which solved the problem.

The auto mode in particular is pretty good, as there was a 23kph crosswind.  The APM was able to compensate for the wind and made automatic adjustments in the final approach landing the plane a few meters from the target.  Though in the future, when setting waypoints, one has to give allowance for the typical crosswind direction of a known field and set the waypoints several meters opposite the wind direction.

 

 

Project SBSW (Update 12) Flight tests

Here’s a video* of the Scratch-built skywalker in a couple of flight tests in Brittany R/C field over the weekend.   I had to make a couple of changes in the motor thrust angle as the plane had a tendency to pitch down when the throttle is applied.  It was a tad too windy for a flight test, but I was able to fly the plane in previous tests in a similar condition…  I wont certainly fly in this condition if it were a maiden flight.

I recently bought the real thing, a 1.9m 2014 Skywalker.  I’ll post some build images and the maiden soon.

 * courtesy of the wife =)

Project SBSW (update 11) Take off!

The new wings I’ve been working on for the last couple of weeks was well worth it.

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Here it is last night, with the skin on:

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And finally, this morning ater a successful flight:

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And:

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The 1.4kv turnigy aerodrive motor, 10×6 prop and 5000mah battery gives ample thrust.. the plane can fly really fast.

Stall speed is low.. even lower (it seems) than my 1.4m hitec skyscout. No doubt the airfoil (as close to NACA 4412 in case you’re interested) made a huge difference.

However throttling up causes the plane to pitch down negating the lift.. nothing which some up elevator cant fix though. It looks like I need to put in some more down angle to the motor now that the CG is known.

The elevator also needs to be secured more firmly to prevent it from rolling (wagging really) which affects the flight characteristics somewhat specially when banking.

Will post a video soon!

FVP using 2W 5.8Ghz VTx

Finally got an SD DVR recorder to record some FPV videos over Britanny RC airfield.  The setup has a 2.8mm lens on a 700TVL camera and a 2W 5.8Ghz Video transmitter.

The camera gets totally washed out when it’s pointed directly to the sun (I understand some cameras automatically superimposes a black dot of extremely bright objects like the sun).. not really a big issue.

The stock Yagi Antenna’s on the VTx and VRx are good enough, although once the plane is directly overhead and goes through the ‘donut hole’ video signal is lost.  Simply shifting position / angle of the receiver or the Video Receivers antenna easily fixes it though.  Circular polarized antennas a.k.a. Cloverleaf should give better performance.

Here’s the vid:

IcarusFPV takes to the air! First FPV flights.. check!

The long holiday gave me enough time to finish the assembly of the video transmitter and portable ground station.   The $9 Carbon Fiber holder mount bracket  from AliExpress.. was all the scaffolding needed to screw or tie up everything.

 

Made 2 flights yesterday.. the first saw the plane go into a stall.. making a beeline for mother earth from 100 ft.. recovered just in time and land behind some trees. Fortunately the plane and electronics were practically undamaged.  The 2w VTx proved its worth, and continued transmitting from the ground.  The second flight was better and your professional crash pilot was able to FINALLY fly real FPV (and enjoy the view!).. could not have been possible without the invaluable help from club residents Kevin, Bryan and Emil who provided the spotting and FPV flying tips!

What an excellent FPV day!

Here's my FPV training platform =) 25% glue!
Here’s my FPV training platform =) 25% glue!