RE: balancing Thunder Tiger Ecureuil scale fuse
Don't know as much about the aerodynamics of RC helicopters as I do about the real ones. As far as the inside tuck in a sharp turn, which direction are you turning in relation to the rotation of the main blade? You could find yourself in trouble if you are going to fast, over or close to gross weight and you do a sharp turn to the retreating blade side of the rotor system while in rotation. Try turning towards the leading blade side of the rotor system next time and see if that corrects the problem. It does sound like you might be carrying to much weight for your bird. The horizontal stabilator on the tail of your bird is designed to have a reverse airflow around it. This design is so that the horizontal stab acts like a reverse wing for the tail, thus drawing the tail downward for a more level attitude for the pilots while in forward flight. This effect shouldn't be noticed much as you decrease airspeed to come to a hover. On a similar note, this is the same reason that the vertical tail on helicopters is actually a canted wing designed to counter act the helicopters natural tendency to spin counter to the direction of the main rotor system and provide directional stability in forward flight. This is so the pilot flys with both feet even on the pedals as it is a more natural feel in flight. As for climbing in forward flight. Sounds like you're flying to fast and the retreating blade is stalling. This will cause the aircraft to nose upward as the stall takes effect 90 degrees later in the direction of travel of the main rotor system. This is called gyroscopic procession (aka. phase lag) Good luck and happy flying.
Posted on: 4/15/2010 6:35 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=9663563

RE: trex 450 with 4 or 5 blade head
That ballooning up on forward flight that you refered to is an aerodymanic indicator that you're outflying your rotor system. When you fly to fast you will reach retreating blade stall (look it up if you need to) and your helicopter will loose lift on the retreating blade side of the rotor system. This section stalls. (hence retreating blade stall) At this point your rotor section does not produce lift. Due to gyroscopic procession, this will take effect 90 degrees later in the direction the rotor system travels, and your helicopter will pitch up. So, you fly to fast, the retreating blade looses lift approximately perpendicular to the centerline of the aircraft, the stall effect is felt in the aft section of the rotor system due to gyroscopic procession, the helicopter pitches up and you loose speed. If you keep flying this fast your aircraft will continue exhibiting this trait. Confusing? Absolutely. Helicopters are not airplanes. If they were, the pitch, roll, and yaw inputs would be called pitch, aileron, and rudder inputs. A common misconception here when airplane guys talk about helicopters. [quote]ORIGINAL: ea01bg A friend of mine that flies scale has been flying a 4 blade head on his trex 450 for over a year now with no extra electronics. He added some wieght to the nose to help with it ballooning in forward flight thats all. [/quote]
Posted on: 5/21/2009 4:48 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=8788110

RE: Ground Resonance!!..watch this video for sure!!!
As stated above this is dependent on the M/R design. Anything with a fully articulated rotor head can get into ground resonance. Your OH-58D has 4 blades spaced out at 90 Degree intervals. Change just one blade to about a 80 degree/100 degree interval and you have an off balanced head. You would know your system better then I but I'm sure you'd feel it and have a problem. Most times, ground resonance is encountered when you set your aircraft down on the ground and the impact of the wheel/skid can cause a blade rotation independent of the main rotor. They tell you to come to a hover to get out of ground resonance. Good plan, but impossible when your 47 is chained down to the pad with now where to go. Happy Hooking
Posted on: 1/5/2009 5:33 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=8322446

RE: how to find large scale car kits
Great, Thank you. I see a lot of 1/10 and 1/12 scale. They look scale as far as body goes, but what about chasis, running gear and handling? Is Tamiya the only ones doing kits like this?
Posted on: 12/30/2008 2:49 PM by Author "Bxcar32" in the forum "RC Car General Discussions"
http://www.rcuniverse.com/forum/fb.asp?m=8299106

how to find large scale car kits
I have a curiosity question for everyone. It would seem that boat builders and large scale aircraft builders are intent on making working scale models but I don’t seem to see much of the same interest in cars. Are R/C car enthusiasts interested in cars scaled for form and function? Does anyone know of someone or a company building accurate large scale (1/6th, 1/12th, 1/18th) RC cars? I'm looking for something on the line of a Jeep CJ-5/7, Hummer or dune buggy (maybe even a street car or something) where I can stick my 12" GI Joe in and have it perform close to the real thing?
Posted on: 12/30/2008 10:59 AM by Author "Bxcar32" in the forum "RC Car General Discussions"
http://www.rcuniverse.com/forum/fb.asp?m=8298282

RE: Ground Resonance!!..watch this video for sure!!!
My apologies, I seem to have misspoken and not communicated my intended response. I was inferring that each respective aircraft community hears about mishaps and/or accidents before official information is dissiminated down from higher HQ’s, and substantually quicker then when the general public hears about it. Also, the un-commanded roll maneuver is believed (due to pilot report) to be due to a hydraulics gremlin and was not to be reproduced. Everyone fears something. For us, we accept that helicopters can be dangerous. To this point emergency procedures are continually discussed, studied and trained to the point of being instinctual. You get nervous at times when first starting out, and then with experience you gain more confidence with your ability, aircraft and operating environment. There is always the knowledge that something could happen. But pilots can’t function as pilots being afraid of this. The best analogy to describe this is driving a car. There are risks associated with driving that could kill or seriously injure you. Though the specific risks are different, there is still risk. Does this stop you from driving? Do you drive with the constant fear that someone will run into you? Most people accept the risk associate with driving and with experience you gain confidence in your ability, automobile and conditions. Pilots do the same thing. I have the video of that CH-46 crashing in the water. It is pretty interesting to see how fast the pilot was coming in. He just missed the deck. Anyway the CH-46 Sea Knight (civilian designation BV-107) (the Marines nicknamed it the Phrog) was manufactured in I think the early 60’s. So they pre-date the CH-47 Chinook (civilian designation BV-234) by a few years. The Navy had different requirements, so they are smaller, more ground crew friendly, and have a lower load hauling capability. Both have similar flight characteristics, controls, handling and shape. Happy Landings
Posted on: 1/4/2008 7:10 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=6854573

RE: Ground Resonance!!..watch this video for sure!!!
I'm not an engineer, but that's what I'm going to school for. I just fly them for the WA National Guard. They're a lot of fun. In military circles, information regarding type specific aircraft accidents or mishaps spreads rather quickly. The Chinook units knew about this shortly after it happened. I suspect that this is similar in the Blackhawk, Apache, 58 D, and other interservice helicopter type communities. Supposedly, this is the Chinook that performed an uncommanded roll maneuver (read actually inverted) while on a ferry flight from Corpus Christi with a contractor crew on board. Don't know if that's really the case, but man is that video fun to watch. I'm sure if you scour the net you'll find the pictures of the british (maybe even Australian) Chinook crew who decided to remove the aft pylon the old fashioned way, but striking the aft blades on the ground by exceeding the 20 degree nose high restriction during roll-on landings. Happy Hookin'
Posted on: 1/3/2008 11:21 AM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=6847082

RE: Ground Resonance!!..watch this video for sure!!!
Such a waste of a good helicopter. If you're able to watch the slow motion footage you'll see one of the aft blades break its blade damper grip. That is the cause of the aft pylon seperating from the fuselage. Take a closer look though at how the engineers attached the helicopter to the pad. No one in their right mind would disable the oleo strut function of an articulated rotor system helicopter. So this is the end result. Helicopter goes into ground resonance, aft blade lead/lags beyond perameters, aft blade damper grip fails, aft blade goes out of rotation, aft blade contacts forward blade, and aft pylon fails from imbalance in centrifugal force. General info. Each blade is 350# Rotor 225 rpm 60' rotor diameter (Blade tip rotating at appx 8 mpm or 480 mph or 704 fps) A Break down in repair. Blade $210,000 ea: need 6 ea Aft Transmisison $780,000 ea: 1 ea Enginge 1,000,000 ea: 2 ea Engine Transmission appx $280,000 ea: 2 ea Aft Vertical Shaft appx $160,000 ea: 1 ea Aft Pylon appx $????? expensive engine drive shafts, $???: 2 ea Hydraulics repairs, airframe repairs, drive shafts 1-9 replacements, I think they have to replace both heads, and the combining and forward transmissions as well. I would guess about 8-10 million easy in damage, and this is mostly the big stuff. But it doesn't take into effect the cost of pride and loss of major cool points. Happy Hookin'
Posted on: 1/2/2008 2:39 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=6842412

RE: LH or RH Rotation?
If you're interested in doing a scale project, the direction of rotation will be something you'll want to pay attention to. All us designed/manufactured helicopters rotate in the counter-clockwise rotation. Just about everyone else rotates in a clockwise fashion. There might be a few exceptions here and there, but as a general rule this is correct. On Tandem rotor helicopters, the forward head rotates in a counter-clockwise rotation while the aft head rotates clockwise.
Posted on: 12/20/2007 6:41 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=6783904

RE: Robotic automated RC heli aerobatics
Sooo, what's your point?
Posted on: 8/23/2007 7:19 PM by Author "Bxcar32" in the forum "RC Helicopter General Discussions"
http://www.rcuniverse.com/forum/fb.asp?m=6278352

RE: Cheap ebay Hong Kong Jet Ranger Fuse
That would depend on if the modeler wanted to model for form or function. It looks like gentleben1952 did a good job of modeling scale (form) for his helicopter. It looks great.
Posted on: 5/14/2007 12:06 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=5852704

RE: 1st heli flight : Scary
The way the rotor system in a Tandem vibes, that's the best nap you'll ever have. It just shakes in a way that relaxes you and puts you to sleep. A 20 minute nap feels like an hour.
Posted on: 5/1/2007 7:19 PM by Author "Bxcar32" in the forum "Helicopters - Full Scale"
http://www.rcuniverse.com/forum/fb.asp?m=5798330

RE: 1st heli flight : Scary
Scary? Exactly. Just looking at the configuration of the Robinson helicopters makes me nervous. Something about the cyclic stick design, small airframe and the low inertia rotor system combine to make me just as nervous as you. The Bell 206 series is a good small helicopter that is very forgiving of minor points of inattention when flying, primarily the autorotation. They have a good survivability rate, though the best survivability rate belongs to the Hughes 500. Next time, try a flight in a turbine aircraft and compare the differences. I've never flown in a piston, so I wouldn't know what the particular differences between the two. Happy Flying
Posted on: 5/1/2007 11:35 AM by Author "Bxcar32" in the forum "Helicopters - Full Scale"
http://www.rcuniverse.com/forum/fb.asp?m=5796507

RE: Ecureuil AS 350, 3 blade scale heli (video)
I had read earlier in this post about the discussion of Vortex Ring State (VRS) and Settling with Power. There are multiple forces acting on a rotor system at any given stage of flight. Vortex Ring State and Settling with Power will only be addressed here. All helicopter types, regardless of size and RRPM (N/R) are susceptible to VRS. When you enter VRS you may not necessarily be settling with power. VRS and Settling with power happen under the following conditions: Low forward airspeed, high rates of descent and minimal power applied. High GW increases both your power requirement and descent rate and decreases your available power and your ability to affect a recovery. Since you have to be descending (in steep approaches or vertical descents), with low forward airspeed to encounter these phenomena, forward flight through Effective Translational Lift (ETL) which is above approximately 40 KIAS and in ground effect hovering does not apply. The main difference between the two is that if in VRS and power inputs alone arrest the descent, then you have not entered Settling with Power. If in VRS and power inputs can not arrest, but increases the descent rate, you have entered settling with power. On a side note about hovering characteristics: If you find your helicopter descending in a hover, its caused by a shift in the airflow your rotor system is operating in by either wind changes or your own rotor wash. If you’re hovering in ground effect you’ll notice that even in a no wind day you’re helicopter will still require pilot input to maintain the hover. However, if you have a head wind while in a hover and the wind dies, you will see the helicopter loose some altitude. This might give the effect of VRS as someone stated earlier. I suspect that in an In Ground Effect (IGE) hover, if your helicopters altitude fluctuates that is more a function of rotor wash. My intent here was to help specify the differences between VRS and Settling with Power. It was hard to tell if the helicopter in the video had entered VRS or was more a function of steep approach and power application techniques. Nice helicopter and some really good scale flying.
Posted on: 4/13/2007 6:57 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=5711477

RE: Has anyone tried a Chinook?
Dave, I hope that clarifies yaw control for you. A couple of things to eliminate some possible confusion. It was stated correctly by 47Steve that yaw control is vectored thrust in opposing directions (pedal control). Roll control is vectored thrust in the same direction (lateral cyclic). However, Differential Collective Pitch (DCP) is applied to the pitch access only. You are correct that yaw control inputs apply torque along the airframe of the Chinook. All cyclic and thrust (collective) inputs apply torque to the body. But yaw inputs aren't as stressful on the airframe as other control inputs. Usually a twisted airframe is the result of high gross weight and overtorque combinations. Generally, if you've tweaked the airframe, there is a list of other inspections necessary as you probably overtorqued some aircraft component prior to.
Posted on: 4/2/2007 1:56 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=5653945

RE: Has anyone tried a Chinook?
Dave, To explain the aerodynamics associated with a tandem rotor helicopter I’ll discuss a few general helicopter aerodymanic phenomina. Helicopter controls are associated in the pitch, roll and yaw axis and are called pitch, roll, and yaw accordingly. I have noticed throughout the R/C world where most R/C helicopter pilots consistently call these inputs elevator, aileron, and rudder inputs. It is important that when we talk about helicopter controls we use the associated helicopter term. This will eliminate confusion among those who fly both fixed and rotary wing R/C aircraft. This is a general discussion and certain specifics are omitted in the interest of basic aerodymanics. In a single rotor helicopter, pitch inputs tilt the rotor disc forward and aft. This has the effect of changing the attitude of the helicopter into a nose low or high attitude respectively along the pitch axis. Example: given a set power setting in cruise flight, applying forward cyclic will increase airspeed and decrease altitude. Conversely, applying aft cyclic with decrease airspeed and increase altitude. Applying lateral cyclic tilts the rotor disc left or right. This has the effect of changing the attitude of the helicopter into a left or right bank along the roll axis. The degree of which is proportional to how much you move the cyclic. In a hover, this input slides the helicopter to the left or right according to the input selected. In flight, this input is used, in conjunction with pedal inputs, to turn the helicopter. Yaw inputs (or pedal inputs if you prefer), rotate the helicopter along the yaw axis (referenced as the vertical shaft). In flight, pedal inputs are primarily used to control aircraft trim and assist with turns. Collective pitch increases or decreases the pitch of all blades in a rotor system regardless of quantity of blades and location of each blade in rotation. Due to Torque Effect, application of collective pitch requires adjustment of yaw inputs to keep the alignment of the helicopter on your intended track. Torque Effect is the helicopters natural desire to offset the torque applied to the rotating rotor disc by spinning the non rotating porting of the drive system in the opposite direction. Most helicopters have a vertical “wing� at the location of the tail rotor to provide lateral “lift� in forward flight to offset the amount of yaw inputs needed to maintain helicopter control. Since single rotor helicopters are designed with either clockwise or counter clockwise rotation, yaw control will be designed accordingly. For the pilot, you just need to know which direction of rotation your helicopter has in order to apply correct yaw inputs with power application. For a Tandem Rotor helicopter these inputs have the desired effect through different application principals. To control the pitch of a tandem rotor helicopter, you must understand Differential Collective Pitch or DCP for short. DCP is differential pitch applied to the forward and aft blades according to the position of the cyclic. As you apply forward cyclic, the pitch in the forward head is decreased while simultaneous pitch in the aft head is increased. This is accomplished in a balanced manor where the helicopter will rotate along its pitch axis (located at half the distance between each head). Applying aft cyclic accomplishes the opposite effect; pitch in the aft head is decreased while simultaneous pitch in the forward head is increased. This is contrary to a single rotor helicopter since forward cyclic tilts the whole rotor disc. On a side note, it’s rather humorous how the effects of control application seem to be centered around the cockpit. Either that was by design or helicopter pilots think everything revolves around them. Hmmmm. Roll control is accomplished by tilting both the forward and aft rotor head in the direction of lateral cyclic input. Left or right input will cause the helicopter to enter a left or right bank. Yaw control is accomplished by tilting the forward and aft heads in opposite directions when yaw inputs are applied. When left yaw (pedal) is applied the forward head will tilt the same as a left roll and the aft head will tilt as if you had applied right lateral cyclic. Since the forward and aft head turn in opposite directions (coaxial rotor systems included), they cancel out torque effect. All power supplied from the engines go towards lift. Thus, tandem rotor helicopters apply 100% power to lift where as single rotor helicopters apply anywhere between 85% to 92%, (as example, specifics are per each helicopter design) engine power to lift, since single rotor helicopters must use some of their engine power to maintain directional control. The helicopter has the ability to turn about the axis of either the forward or aft head. The trick in understanding how to do this is to understand how the control inputs work on the rotor system. To turn about the forward or aft head, you should understand how yaw inputs work on the rotor system and also how roll inputs work. In flight, the Chinook has an Advanced Flight Control System (AFCS) that couples turns for us at airspeeds over 40kts. It also has the ability to adjust our airspeed with a few clicks of the “coolie hat� on the cyclic. This adjusts our DCP and power applications accordingly and in conjunction with each other. I will leave you to research Gyroscopic Procession, Translating Tendency, Transverse Flow Effect and Retreating Blade Stall, Loss of Tail Rotor Effectiveness (LTE), etc at your own pace as they tend to be a little confusing to discuss in a forum as this.
Posted on: 3/19/2007 1:47 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=5584541

RE: Has anyone tried a Chinook?
I found it. Check this link out. [link=http://www.rchelicopters.eu/]Dutch RC Chinook[/link]
Posted on: 3/15/2007 6:57 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=5566542

RE: coaxial rotor
try [link=http://MS Composit]http://www.mscomposit-usa.com/shoponline/products/ms/MS800overview.php[/link]
Posted on: 3/15/2007 5:51 PM by Author "Bxcar32" in the forum "RC Helicopter General Discussions"
http://www.rcuniverse.com/forum/fb.asp?m=5566220

RE: Has anyone tried a Chinook?
I've been pretty busy as well and have had to shelve the project for a bit. I did pick up an Autocad program to assist with the design and have seen other autocad chinook designs as well. I'll get you the website when I can find it again. Good luck on your model and keep me appriased of your progress.
Posted on: 3/15/2007 12:49 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=5564959

RE: Has anyone tried a Chinook?
A few years ago, a Chinook was on a ferry flight when the flight control hydraulic system jammed up. This caused the helicopter to enter into an inverted (rolled greater then 90°) and nose low flight condition. Luckily, the jammed flight control condition subsided and the crew was able to regain control (I believe the article in Flight Fax stated 300’) and land the aircraft. I was told that this aircraft is the one you see in the video. The Boeing engineers took the gear off (to the objections of the Flight Engineers) and strapped it down to the pad. I hadn’t heard of the other description, so it appears I might be mistaken. Just some miscellaneous information about the video, each blade weighs 350# (give or take a lb or 2) with the diameter of the rotor disk at 60’. Since the NR is 225 RPM, this makes approximately 8 miles a minute that the rotor tip is traveling. As the helicopter starts to buck and dance, one of the aft blade damper horns separates from the blade. And thus, the demise of a great (I’m a little partial) helicopter is inevitable. On an additional note, I have the slow motion angles if anyone is interested. Ground Resonance, as stated above, happens in articulated rotor systems due to its intended design. As the blade travels along its rotation, the CG will change with the rise and fall of the blade allowing for the blade to increase/decrease (lead/lag) its own rotational speed relative to the rotational speed of the rotor disk. The blade dampers installed at each blade assist in controlling the amount of lead and lag and dampening this effect. There are multiple actions that cause ground resonance. On the ground, oleo struts absorb the movement of the helicopter as the blades spool up. Where pilots get into trouble is primarily upon landing. If you smack the gear on the ground hard enough, the blade advancing to that side of the aircraft increases its lead and off sets the balance of the rotor system. Each successive blade will do the same until, it subsides (not possible with power applied), you come to a hover, or the aircraft destroys itself. Which you can see is pretty impressive. I’m sure that the Army has specified that this is not the preferred method of removing the aft pylon from the aircraft. There are photos on the web of the British removing their aft pylon in a similar fashion. Though theirs had help from the dirt.
Posted on: 3/15/2007 2:13 AM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=5563599

RE: Can you start a heli's blades mid-air?
Just for grins, check out this website. [link=http://www.griffin-helicopters.co.uk]griffin-helicopters[/link] You'll find some crazy real life helicopter videos. Have you ever seen a BO-105 do an inverted piroquet? There is also a video of a British MKII Chinook being put through its paces. Hope you all enjoy.
Posted on: 3/14/2007 7:52 PM by Author "Bxcar32" in the forum "Helicopters - Full Scale"
http://www.rcuniverse.com/forum/fb.asp?m=5561826

RE: Can you start a heli's blades mid-air?
I think I'll throw my two cents in. Theoretically it would be possible provided a few things happened before hand. Realistically though, it would be doubtful due to the reasons listed above. Theory was, a long time ago, that man couldn’t fly. Now we have the ability to exceed mach 2, live in space, land on the moon and hover OGE with a 9 ton external load. Given a few more years in development, and I’m sure that this could (though not sure how many people would want to try it) become reality.
Posted on: 3/14/2007 7:30 PM by Author "Bxcar32" in the forum "Helicopters - Full Scale"
http://www.rcuniverse.com/forum/fb.asp?m=5561716

RE: Cool heli pictures.
Here are some photos of the most heavy armed Helicopter in the world. This is “Easy Money� at Redstone Arsenal in Huntsville Alabama. This is the last surviving member of the ACH-47 “Guns-A-Go-Go� during Vietnam. The “Gun’s a Go-Go� were Armed with a 40mm in the nose, 5ea .50 cal machine guns (one on the Ramp), and a combination of 2 ea in wing stores, 2.75in rocket pods, 7.62 mini guns, or 20mm cannon’s. SN# 64-13151 “Stump Jumper� was lost in ’66 from a blade strike in a ground taxi incident. SN# 64-13145 “Co$t of Living� was lost in ’67 when the forward bolt on the 20mm dislodged and shot up the forward blades. SN# 64-13154 “Birth Control� was shot down in ’68. While waiting for the DART, the NVA destroyed her with mortar rounds. SN# 64-13149 “Easy Money� was retired after “Birth Control� was destroyed, she was restored at FT Eustis, VA. You can tell by the photo that she was restored with “D� model blades.
Posted on: 3/13/2007 3:32 PM by Author "Bxcar32" in the forum "Helicopters - Full Scale"
http://www.rcuniverse.com/forum/fb.asp?m=5555535

RE: Cool heli pictures.
A few more: Our Apache escorts in Afghanistan. One of our escort pilots.
Posted on: 3/13/2007 2:56 PM by Author "Bxcar32" in the forum "Helicopters - Full Scale"
http://www.rcuniverse.com/forum/fb.asp?m=5555399

RE: Cool heli pictures.
Here are a few pictures for everyone to enjoy. It would almost be blasphemous of me not to post Chinook photo's. This is "Rosie" circling for a supply drop at 11,500ft in April 2006 somewhere in the Konar Valley, Afghanistan. This is one of ours on approach to the “lumberyard� in the Korengal Valley, Afghanistan.
Posted on: 3/13/2007 2:46 PM by Author "Bxcar32" in the forum "Helicopters - Full Scale"
http://www.rcuniverse.com/forum/fb.asp?m=5555358

RE: Cool heli pictures.
RE: Speed limit is bogus Of course it's not real. I'm sure that anyone who has seen this photo and "objects in this mirror are closer then they appear" knows that they have been photoshop edited. The objective was humor and not realistic depictions of helicopter flight. I think they've succeeded in their intent and I enjoy them. Happy flying
Posted on: 3/13/2007 12:26 PM by Author "Bxcar32" in the forum "Helicopters - Full Scale"
http://www.rcuniverse.com/forum/fb.asp?m=5554828

RE: THREE BLADE HEAD DO I NEED GYROS
Oops, I was looking at the MSComposit site and forgot you were flying a Lama. Your rotor disc still has the clockwise rotation so the information will still work for you.
Posted on: 3/2/2007 1:19 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=5498985

RE: THREE BLADE HEAD DO I NEED GYROS
How fast were you flying when the nose pitched up on you? If you were flying fast, you probably had a aerodynamic phenomena called retreating blade stall happening. Combined with gyroscopic procession (which states in a rotating disc, inputs to the rotor disc take effect 90° later in the direction of travel) you will see the nose pitch up on you when you fly to fast. Aerodynamic classes for retreating blade stall are pretty in depth, so I’ll try to keep it simple. In a hover, the lift generated by each blade through out their entire rotation is equal. In forward flight, the retreating blade in a rotating disc has to increase pitch relative to the advancing blade to compensate for the loss of available lifting surface in the retreating blade. The faster you fly, the less efficient your retreating blade becomes and thus the less lift it can produce. When you have reached a speed where the retreating blade can not produce enough lift to compensate for the lift generated by the advancing blade, the retreating blade will “stall�. This retreating blade stalls at roughly 90° from the centerline of the helicopter. Because of gyroscopic procession, this retreating blade that has stalled on the right side of the helicopter, the stall will take effect at the aft section of the rotor disc. This has the appearance of the helicopter pitching up. That should explain why your helicopter pitched up on you. It also might help if you check out the following links about helicopter aerodynamics. You might find them useful as you continue to fly your Helicopter. One important note about these links is that they are written for rotor systems with a counter clockwise rotation. This makes some of the rotational information different as your AS 350 Ecureuil has a clockwise rotation in its rotor system. It is also advisable to read through the transverse flow effect as well since it acts on your rotor system similar to retreating blade stall. Some of the documentation about retreating blade stall combines these two effects on your rotor system as only retreating blade stall. Good luck and have fun. http://www.copters.com/aero/translational.html http://www.copters.com/aero/torque.html http://www.copters.com/aero/retreating.html http://www.copters.com/aero/gyro.html http://www.copters.com/aero/lift_dissymetry.html http://www.copters.com/aero/transverse.html http://en.wikipedia.org/wiki/Retreating_blade_stall
Posted on: 3/2/2007 1:15 PM by Author "Bxcar32" in the forum "Scale RC Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=5498969

RE: Scale aircraft carrier capable of landing scale rc planes on
I must say that I like the idea. This world is full of inventions and Technologies that started by someone with an idea who refused to listen to the ''nay sayer's''. I say go for it. I'd love to see this thing when its build. Who knows, maybe someday soon someone will invent a coupled precision approach guidance system small enough to fit in an R/C airplane. That would make your dream a reality.
Posted on: 2/22/2007 4:37 PM by Author "Bxcar32" in the forum "RC Scale Boating"
http://www.rcuniverse.com/forum/fb.asp?m=5458852

RE: Are my Falcon Main Blades too long?
You stated that this happened when you had a hard landing. You can argue whether or not your blades are to long or the fin is to high. Since you landed hard, your boom probably flexed upwards while your rotor disc plane was tilted aft and your blades flexed down on impact. Since you have a boom strike, it would be advisable to do a sudden stopage inspection on your drive train. If you find yourself doing a lot of aft cyclic inputs when you land hard, it might be advisable to move the vertical tail fin further aft so your blades won't contact it. Just my 2 cents as this is only a problem if you land wrong.
Posted on: 2/9/2007 3:16 PM by Author "Bxcar32" in the forum "RC Helicopter Beginners Forum"
http://www.rcuniverse.com/forum/fb.asp?m=5394328