It is a holiday. Early morning I already prepared my Raven for the fly. Filled up the tank at home.
8am, reached Putra Heights new field.. this place is nearer and more convenient.
I am the second person reach there.
Without wasting my time to wait for others, I started the Raven's engine. Did one tank fly, doing my normal figure 8 maneuver. Also this time I beginning to familiarize myself with a "shallow stall turn", at about 45 to 60 degree.
Then when my turn again, to fly, I continue to build up my confident with with my normal flying and the new maneuver "shallow stall turn". I wondering when will I be confident enough to flip and invert the heli.. well not in this session.
Here is the you tube video of my second tank flying, captured and uploaded by warhark:
After I landed, I packed my stuffs and went back home for breakfast. That is about 930am.
I return back to the field at about 11am. Filled up the tank, ready for my third flight of the day.
HOWEVER, looks like I got the engine into hydro locked. So I flushed out the fuel in the engine by taking out the glow plug and running the starter. After putting back the glow plug, I tried to start the engine again. This time it worse, I have broke the fan again!!
I had the same problem as before, the engine won't start. After 15 minutes trying I decided to follow the troubleshooting procedure did on last Sunday by the fellow fliers: 1. Open the plug. 2. Close the HSN fully 3. Run the starter while closing the muffler (priming) 4. Make sure fuel is spraying out through the plug whole. 5. Put back the plug 6. Set the HSN to 1 turn 7. Run the starter
It works!!
Did a quick in-flight check. Landed, on idle for about 20 second. Looks like the engine is stable.
So took off again. I took this opportunity to try half-stall turn with about 45% angle.
Also at a few turn, I tried negative pitch, and the response is good.
Today is my birthday.. well I it is a Saturday so I will be flying my Raven!
Reached Putra Height Aircraft Flier field at about 9:15. I already have half tank of fuel loaded and ready to fly at the minutes I reached there.
After saying hi to other fliers, I started my Raven's engine. Continue with normal in-flight check hover. Everything just nice and smooth, I continue to fly familiarizing with figure 8 (still!)
Afird (the guy who came to visit sometimes ago) also was there and giving me some few valuable tips. I will need to familiarize with "stall turn" start with shallow 45% angle. Than I can build up the vertical angle and continue with flip/loop.
Err... but not on this session.
So I flew for few more minutes quickly to realize that my main fuel tank already empty. Landed the Raven and shutdown the engine. Then I refueled.
Then watch others with their aircraft.. here is Bard with his new Esky Belt-CP
After a while the field was clear, I started the Raven engine, and continue with my normal flight. Now I am more confident since previously the TR3703 has flew with out any problem. In this flight I noticed that the Raven is not leaning to left side anymore, instead, it is a bit leaning to right side. This is much better, since that is what I aspact when I check the center gravity before.
When the second tank almost finished, I landed the Raven. I think this is the first time I fly the Raven for long time consecutively.
I refueled TR3703 for the third time. And started to prepare for another flight. However, this time I was not able to start the engine!!
I keep trying, doing all kind of thing to troubleshoot the problem, including took out and put back the plug, use different glow heater, checking fuel line etc. Still no luck and I was not able to start the engine.
22:00 I checked again the glow plug and fuel line and then decided to try to start the engine. Outside my house I tried, after a few try it started ok!! I wonder why it was not ok before.
And later in the afternoon, HAPPY BIRTHDAY TO ME!! Had a moderate celebration at my elders brother's house in Selayang.
09:30 Just found out that today PHAF team is using the alternate flying field. While it is neared to my house, this field is actually more human and flier friendly. There are many trees giving us good shades and the open space is much neared to the road where we can park our cars.
With all of the equipments ready I tried to start the engined with unsuccessful result. Some how it just won't start. I changed the glow plug using a brand new one, try different glow heater and now even adjusted the High Speed Needle (HSN) setting on the engine.
After a while of unsuccessful tries, Yed, Sidi and others come over to have a look and help me. We tried different glow heater, bypassed the glow extender, checked the fuel lines, did 'priming' etc. At one time we got the engine hydro locked. Just clear that by rotating the starter shaft without the glow plug installed and closing the exhaust. Then continue to troubleshoot.
Then we decided to reset the HSN to 2 turns setting. With this setting we were able to start the engine!
Then, with a bit more of HSN tuning, turning it back to less than 1 turn position, I able to spool up the rotor and take off to hover. Landed from the hover, in idle throttle for few seconds suddenly the engine died. Sensing temperature on the back plate, it was very hot!! So we set the HSN richer and started the engine again. This it is much better. I was able to fly it as normal including figure 8.
I have able to get the replacement for the broken fan. Fixed the fan up, also I have tighten the screw to secure the bar at the bottom of starter shaft. Hopefully this problem will not occur again.
Added Second Battery and Switch
I also have installed another set of battery in parallel of the first one together with the harness switch. This is to have redundancy, in case of one of the battery has no power or damage another should still able to support. During the installation only I noticed that I have run out of receiver channel to plug the battery connector in. I already utilized the AUX2 socket for battery volt indicator. This means that I need a Y connector to connect both battery and the voltage indicator as well. This morning, I decided to disconnect the voltage indicator and test out the dual battery configuration.
The photo below shows that now I have 2 switches and 2 sets of batteries.
While fixing up the battery I also looking at adjusting the Center Gravity of my TR3703. I noticed that while hovering TR3703 tend to lean to its left and tend to drop the nose to go forward. However when I check the balance by holding the flybar, looks like the opposite of that. Till now (when I writing this) I still could not understand this finding. Anyway, I still continue to offset the CG based on my test with the second battery. To balance the CG, I put the battery a bit to the left and front of the TR3703.
After the installation, I switched on the transmitter, then switched on the first battery. Checked that the controls works, then I switched on the second battery and switch off the first one. Checked the controls again and yes they also working.
Test Flight
Time for the real test, in-flight testing. This test was very quick one so I decided just to do it in front of my house.
I switched on both batteries, I started up the engine. Then started to hover, check the control while hovering, everything works smoothly. While doing the hovering and in-flight checking, a neighbor car passing by, I have to move the Raven to hover nearer to my house gate, quite small space for a person like me to hover a helicopter. The car passed by as if I am not flying the Raven. Deep in my heart I was very afraid that something bad will happen, since I do not have the comfortable space and extra safety margin. Luckily nothing bad happened; I was able to land the Raven safely.
From the video below you can see how small the space, putting a car in the middle of the road will reduce the space a lot. Too risky, I'll need to remind my self not to repeat this.
Test result, dual battery configuration is cool!
Update on 2008-12-19
I have installed Y cable. Now I have original first battery connected as normal to the battery input to the receiver. Second battery is connected to the Y cable together with my voltage indicator, plugged into AUX2 channel on the receiver. It works!
However need to stop halfway because it started to rain suddenly. It was very light rain but I do not want to take any risk of damaging any part from the water.
We have new visitor Bad, flying his ESky Lama V4 (the heli has been modified).
I was quite amaze with the very good design of this Century Raven helicopter. It very easy for me to access the fan and top part of the engine. I just need to separate the top frame and bottom, which can be done very easily.
Here is the air filter I had installed much earlier. I think every body should have it, to make sure that no foreign object enter the engine - number one cause of engine problem.
Did a quick test flight, to ensure the engine can starts ok. After about one week holiday.. just to make sure it still can fly. Seems that I have to much thing at work, don't really have much time for my Raven. Hopefully I will have time on the coming weekend.
The weather is not that clear, but at least it was not raining.
Let me share few important item for Remote Control Aircraft pilot. It is important to realize and pay attention to these in order to have happy ending on each of our flight.
Safety
Safety is always the first – must be safe for you, for other people, for properties and for your aircraft.
Extra caution when starting up the engine, double check and triple check the initial transmitter switches position and stick position.
Make sure you have bigger space than you need. You will need the extra space when familiarizing with new things or new maneuver or to save it from a crash due to pilot or aircraft failure.
Make sure crowds are aware that you are flying your dangerous aircraft
Be extra caution on kids and pet. Make sure their parent/owner is paying attention to their behavior.
Do not overfly crowds or people properties
Do not fly directly overhead, you may easily loose orientation
Do not let the aircraft fly between you and other people
Be aware about other fliers and their aircraft. Even though it is rare, mid air collusion can happen easily.
If you are not sure any of those you should postpone your flying session or look for other place. If you are already flying, you should land quickly when it is safe.
Be sensitive to others
Loud sound from a nitro engine make it not suitable to be used near houses
The smoke will get neighbors irritated as well
Do not fly at a public park or children playground when there are people utilizing it.
Ensure that the aircraft is fit to fly. Here are things to check for Nitro Helicopter.
Preflight Check
Check all mechanical links.
Screws are all tight enough
All ball links able to move smoothly – link rode can be rotated easily
Ball links fit do not easily come off, try gentle push as you want to take it off, it should not come out easily.
Canopy is fit firmly
Servo horn able to move easily and smoothly, with not click sound
Put in enough Fuel for the flight
Switch on the electronic
Always switch on the transmitter first – Check transmitter switches and sticks movement
Then switch on the aircraft power – be extra careful if it is an Electric Power!! (EP)
Check electronics – Gyro, Governor, Servos, Voltage indicator. They should initialize with proper light indicator and response accordingly during control check.
Check all controls – Rudder, Aileron/Roll, Elevator/Pitch, Blade Pitch, Throttle Control
Start the Engine
Always take extra caution, check and triple check the initial transmitter switches position and stick position.
Do not forget to remove the glow heater!
Make sure the engine response properly to throttle stick, no bogging. If needed retune the engine
Check control movements again,
refer to tail blade shaft for rudder
refer to swash plate for aileron and elevator
can see the movement of swash plate up and down for blade pitch
refer to engine sound and smoke for throttle
No funny/unexpected sound
Just before the take off make sure it is safe, confirm location of other fliers, other aircraft, spectator and kids.
If any of this did not meet, need to abort the takeoff, the aircraft need to be grounded until the issue fixed. On the ground the aircraft will not able to do any harm to itself, to you or to the public.
Anyhow, you should smile even if your aircraft grounded. It can be much worse if you still try to fly it!
In-flight Check
Make the first 30 second hover as a in-flight check session
Hover just above head height
Confirm blade tracking is ok.
Try slight movement on all controls and make sure it respond as expected - Rudder, Aileron/Roll, Elevator/Pitch, Blade Pitch, Throttle Control
Do the same for Normal and Idle-up mode
Check battery voltage indicator level
Reconfirm the fuel level - no fuel dripping
Recheck fuel level and voltage indicator occasionally during your flight, can bring it to hover or a slow pass.
Land immediately if
Any parts dropped from the aircraft
Any funny movement noticed
Any funny sound
Be always ready for autorotation, especially if for some reason the engine died
Be always ready to flip off the throttle to kill the engine (this can save your money on parts replacement) if
It is 150% sure that it is going to crash
No chance of saving the situation
Just before hitting the ground (less than 1 sec and less then 1 meter?)
This is my first time trying night flying with TR3707. I have been looking for a good place for me to fly at night near to my house.
This weekend I will be taking long 8 hours or more journey to my home town in Kelantan for Hari Raya Aidiladha holiday, will only be back to Selangor on Wednesday. So before I leave my Raven alone, I need to fly it!
I decided that my ragular place is best place, while it is very near to my house, it also should have enough lighting which come from big spotlight provided by telco company for the nearby Surau BaitulrRahman.
At 2200, I brought all the equipment. Filled up the tank and started the engine and fly it.
Filled up the tank, quite hard to see the fuel level since it was actually quite dark.
Started the engined without any problem. Looks like the glow heater is quite loose, need to ensure that it plugged properly to the glow plug extender.
Started the engine, took off to hover. The head speed seems to be much faster now with the Funky blade compared to previously used Wooden Blade. This blade is much thinner, that could be the reason for the higher heads peed. I adjusted the throttle curve a bit, but found that I can't get better than what I already have.
I can't really see the bladed when it is rotating, so I don't dare to fly higher than the heights of my. Probably if I put some florescent stickers I will be able to see the rotating blades... yes probably.
After a few hover and touch down, suddenly the engine died when I just about to take off again. Looks like the tank is already empty!! I was not able to see the fuel level while hovering or even when I landed. This is very risky to continue to fly. I'll need to find a brighter place if I am going to fly at night some more.
Ok. So the root cause for the limited negative pitch during looping is due to the binding of one of the blade grip with the rotor head.
Last night I have taken out the spindle bar, replaced it with a new one.
However even after I replaced the spindle bar, it seems that the binding issue is still there. Hmm.. looks like the head itself is not quite symmetry and the blade grip screw holder is thicker. I used 'file' to remove some thickness and remove a bit on the rotor head surface. Now it has smooth movement, no binding any more.
Fix up the new (old?) Hurricane Main Blade, it is a Fiber Reinforced blade. This blade came standard with Century Raven 50 (http://www.heli-world.com/detail.aspx?ID=5822). It looks superb.
Starting up the engine is the story by itself. Cranking the starter, but the sound of the rotation is indicating either glow heater connected or blown glow plug. I took out the glow plug, connect the glow heater directly, not light. I open up my brand new spare glow plug and tried on that. Still the same, even the new plug also not the glowing. Then I tried to connect back to the old glow plug, play with the connection a bit, then only it started to glow. So it is because the connection is not firm enough.
Ok, so I put back the glow plug in. I tried to start the engine again. It works!
Let the engine warm for about 30 seconds. Then started to take off, hovering. Then, I checked the blade tracking, accent and descent rate.
Here is the result:
Engine started ok, using the remaining fuel which was in the tank since 4 days ago and it is ok.
Blade tracking is almost perfect.
With this new blade, the response is much faster.
The head speed seems to be faster as well.
After about 5 minutes (or less), noticed that it started to utilize fuel from the header tank. Landed safely with header tank almost empty.
Last night I spent some time to check.. still my mind can't rest from thinking what went wrong during the loop.
I started to check my pitch curve and throttle curve. The pitch curve is ok, the throttle cure, even though it is quite slow (65% at point 3, and 95% at H), that should not be the reason.
Then I started to inspect the linkage, rotating the main rotor slowing while I moved the sticks to far extremes. Then I noticed something, at a certain position, the flybar cannot be titled without buzzing the servo.
This part is binding, one side of the blade grip is pressing against the main mast head at very high negative pitch:
Reached at Putra Heights Aircraft Flying site to find the field is not in good condition to be used due to heavy rain the night before. My car was all dirty with the mud, thank God, Alhamdulillah, I manage to go in and out without getting stuck there!!
Looking for other place to fly I called AXDFZ to find he is at Puchong Putra Prima Flying site. It took me about 20 minutes, with clear direction from him I found the place with no problem.
There are different Helicopters being flown here. They are Hirobo, Raptor, Knight and TRex as well.
I filled up my Raven's fuel tank, and then watched other flyers flew their airplane and helicopters. I realize that for heli they have a dedicated fly pad, which will ensure heli skid will not dirty at all for the flying session. Neat! However the usage of the pad is not a must and flyers are free to utilize other parts of the field for helicopters as well.
Started with normal hovering, make sure the controls are ok, then checked the throttle/pitch response with rapid hover climb.
Then started my normal fly and thinking if I should try a loop inverted flight today (?).
These are what I have during the fly:
Familiarizing with normal mode and idle-up mode flight and switching between them.
Fast figure 8. Familiarizing with the control and improve my precision. I don't think the figure 8 I made is good enough, need to improve on altitude control and rate for cornering.
I tried half-stall turn climb, where I not yet dare to turn the tail at the stall attitude, instead, I leave the heli facing the same site. Just stop/hover before turning to the other side.
Then the time came where I am confident to try the loop.
So instead of I push the elevator back to level up, I keep pulling until it was upside down.
Then I noticed that the Raven stop climbing, I pull down the throttle stick, which should give full negative pitch but, now the Raven started to drop!
Well I begin to panic, at the same time looks like the Raven also a bit rolling to a side.
I continue to pull the elevator hopping that it can complete the loop before it reach the ground!
Then I see another opportunity to safe it, since it was rolling I push the aileron further to assist and finally I manage to get the main blade on top again and it started to climb!
I still thinking and thinking what actually happened, I need understand and the overcome the problem next time, looks like this is quite the same as before when Fendi tried the Loop maneuver with the Raven. Now I suspected these few things
Head speed has slowed down during the inverted posture, it started to slow when climbing and reached the minimum there.
The wooden blade is not giving enough lift (width is about 75% of other blades)
Center Gravity is not balanced, resulting on the unexpected roll (which helped me to recover)
Luckily I have enough heights, if not, I won't be smiling now!
After that I landed my Raven, packed up and join the group for a quick break at a nearby restaurant.
Thanks for very good hospitality from the PPPF gang!
Today, this what I manage to execute: 1. All flight is done in Idle-up2 mode. 2. Faster figure 8 maneuver. 2. Forward flight transition to hover flight 3. Forward flight to stall turn, but still facing the same side (still scared to rotate the tail)
Again, when I landed, I have less than 1/4 fuel in the tank! Need to improve this one, i MUST NOT make this kind of mistake.
Finished flying at 0750, with big smile on my face.
I already fill up the TR3703 tank last night. This morning I need to have a good fly to build up my confident. It is very cloudy, thank god that it is not raining so I have the opportunity to fly the Raven.
Arrived at the field just to find that I left my glow heater at home. Quickly return to take the glow heater.
I started the engine without any problem. So for this flight:
Start with hovering check ok, from the last hard landing by Fendi. This is the proper hovering to check all the controls functions.
Familiarizing myself with idle-up switch.
Familiarizing with the current setup
throttle curve setup (65% at point 3) and
expo setup for idle-up (25%)
Build up confident with figure 8 maneuver. After few figure 8, I feel more comfortable and confident.
At the end of the session I landed with very low tank capacity, less than ¼ of the header tank. Next time I need to remind myself not to take such risk.
I have a slight problem with the Fan, need to change it. Now I am more familiar on taking the top and bottom frames apart. The design of Century Raven (I believe it is quite the same for Hawk, Predator as well) is very good. For me to access to the fan and top of the engine, just need to detach the upper frame from the bottom.
I need to use the piston stopper to remove the damaged fan. Thanks for the kindness from Cikgu Vanan, I don't have to pay a single cent for the new Fan and the Piston Stopper!
Just before the sunset, after work yesterday I reached Rinching fly site. I was really lucky because another Sifu, Fendi was there. I have setup the blade pitch before at about -10/+10 and really hopping that it is sufficient for the inverted flight.
He flew my TR3703 Raven, test it, started with Hovering, while familiarizing with the sensitivity of my controller and helicopter. Then he did the Inverted Flight! Great!!
Zali (left) and Sifu Fendi (right) starting up TR3703 engine
Then he tried a loop.. however suddenly the Raven is dropping fast at the half loop (at inverted posture)! He managed to correct it with hard landing on the ground. According to him suddenly there was not lift during the invert. Before I had notice the battery indicator lighted red just before the loop, that must be the reason.
Luckily, there only some scratches on the blade. I tested to hover, and it still fly nicely!
Lesson learn: 1. Land immediately when red or yellow battery indicator 2. Need to make sure battery is charged enough, 2 days or longer.
These are comments from Sifu Fendi: 1. Need to check center of gravity for more stable inverted flight and 3d maneuver 2. Need to make cyclic control more sensitive, slowly reduce the expo configuration to 15%, for fast 3D response. Current setup is 35%.
Here I am sharing my journey, knowledge and experiences I gained in the Remote Control Helicopter Hobby.. mainly on Century Raven 50 CCPM (2008-10-09), HoneyBee King 2 (2008-08-27), HoneyBee FP (2008-07-31) .
Information here is based on my own experience with my TR3703 and other RC Helis. What I put here are mostly facts or what I believe are the facts which may not be the same believe as everybody in the world. Feel free to comment.
Ref for Flight ID (FID) : Heli no-Engine No-Galon No-Tank No- Flight no
TrueMax - Putra Heights, Subang Jaya, Selangor, Malaysia.
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