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Everything posted by AlphaOneSix
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Control linkages and hydraulics question
AlphaOneSix replied to msalama's topic in DCS: Mi-8MTV2 Magnificent Eight
The controls in the cockpit are linked via control tubes to the hydraulic servos (or actuators or boosters whatever you want to call them). The servos then connect to their respective bellcranks or whatnot that connect them to the main rotor swashplate (lateral and longitudinal bellcranks for the cyclic, collective lever for the collective, and a pulley and cable system for the tail rotor). When the hydraulics are working, your inputs are boosted and the flight controls move. When the hydraulics are not working, the servos act like a static link in the chain, and your inputs go directly to the "control surfaces" (that seems like a good way to describe it). If you're strong enough, the controls will move with no hydraulics. I can do it with the tail rotor although I almost have to stand on the pedals with all my weight to do so. I have never been able to move the cyclic or collective without hydraulic power. Maybe it's easier to do with the rotor actually spinning but I'm not going to try it so who knows. Well, someone knows, just not me. -
How it Works: Mi-8 Fire Protection System
AlphaOneSix replied to AlphaOneSix's topic in DCS: Mi-8MTV2 Magnificent Eight
Well our original aircraft had it and we removed it. I think that having GPS installed was a primary driver for that decision, although I don't know that for sure. Our "newer" aircraft don't even come with it in the first place, making me wonder if it's just another factory option that most people don't bother with. -
You're very welcome. I'm just happy that some people find those presentations useful. Besides my coworkers, I mean. Although they don't read them for fun like you guys do. ;)
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If the ice itself was radioactive then I suppose they wouldn't get a warning, other than the visual one, along with other evidence that ice buildup could be occurring. But that scenario takes an awful lot of "what ifs" to get to. That particular system probably took me 5 days, roughly. Maybe 20-30 hours of actual work. I'm very American. :D The Mi-8/17 is everywhere. ;)
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The item pictured is a visual ice detector. It's nothing more than a probe marked with 5mm paint stripes so the pilot can visually identify ice buildup if the automatic system isn't working. As far as the automatic detectors go, which are installed in the oil cooler fan inlet... The RIO-3 is older and uses a radioactive isotope in the detector. As ice builds up on it, a sensor receives fewer and fewer radioactive particles and once it gets below a certain threshold it trips the ice warning. On the newer SO-121 detector, the detector just vibrates at a high frequency. Ice buildup causes the vibrations to slow, and once the vibration frequency gets below a certain threshold, it trips the ice warning. I did. I suppose I could have made it shorter but that's just how it came out. Making training presentations isn't my primary job, after all. ;)
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The -10 is incorrect. While I love the TSMO manuals, they do occasionally misinterpret the Russian manuals. Stabilization duty is when the pilot's feet are OFF the pedals and the yaw channel is maintaining aircraft heading.
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Mi-8 Cold Start transfer pumps failure
AlphaOneSix replied to Holton181's topic in DCS: Mi-8MTV2 Magnificent Eight
Yay for the Mi-8! :D -
Autopilot altitude control behaviour
AlphaOneSix replied to Lixma 06's topic in DCS: Mi-8MTV2 Magnificent Eight
Yes. No. It's for testing the system. It's not meant to be used in flight. No. -
As much as I'd love a Chinook in-game, it would be an absolute travesty if the Apache and Black Hawk didn't come first. But I could be talked down to just having the Cobra first. ;)
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Failed to restart APU after shutting down
AlphaOneSix replied to jetstorm96's topic in DCS: Mi-8MTV2 Magnificent Eight
As per the flight manual (the real one) the maximum altitude for starting the APU is 4000m. Take from that what you will. -
That's a radio control panel.
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Modern cockpit for the Mi-8?
AlphaOneSix replied to VWJII's topic in DCS: Mi-8MTV2 Magnificent Eight
There is no end of modernized digital cockpits for every variant of the Mi-8, the factory will build whatever you order. We have Mi-17s with Honeywell (EADI and EHSI) cockpits as well as full Garmin (G3X) cockpits. (Although, to be fair, those are both aftermarket cockpits.) -
Autopilot operation with rudder?
AlphaOneSix replied to WildBillKelsoe's topic in DCS: Mi-8MTV2 Magnificent Eight
That's not true at all. I apologize for being so blunt. The relationship between the pedal locations and the corresponding tail rotor pitch will always be the same. Likewise, different atmospheric conditions could result in different pedal positions in a hover as the main rotor requires more or less pitch to maintain a hover. Also, as I've mentioned before, the tail rotor pitch limiter is a completely separate system from the trim and autopilot systems and doesn't interface with them at all except to momentarily disable the yaw autopilot when a "pitch limited" condition occurs. The purpose of the tail rotor pitch limiter is to limit the amount of pitch you can safely put into the tail rotor. I hate that I have to type it like that since it seems like I'm just retyping the name of the system. But I think it bears emphasizing. Anyway, the tail rotor pitch limiter cannot move the pedals or put pitch into or out of the tail rotor blades. It works by sensing the ambient air temperature and pressure, and then moving a spring-loaded stop closer to or further away from a spring cartridge on the flight control rod that connects to the yaw hydraulic servo actuator. The "spring-loaded" stop is just there so that if the stop comes into contact with the spring cartridge, it disables the yaw autopilot channel until they come back out of contact. Just like the microswitches on the pedals. Also, when the stop is in contact with the spring cartridge, the pilot must overcome the spring pressure in the spring cartridge in order to push the pedal more to the right. The whole purpose of this is to warn the pilot not to exceed certain tail rotor blade pitch settings at lower altitudes/cooler temperatures. The location of the stop corresponds to the white vertical bar in the sight window on the pitch limiter control panel. When the bar is all the way to the left, the stop is fully retracted and will not contact the spring cartridge on the flight control rod before the pedals hit their own built-in stop. This means that the pitch limiting system is not limiting pitch at all in this circumstance. As the white bar moves to the right, the stop is coming closer and closer to the spring cartridge on the yaw flight control rod. With the stop fully retracted, you can push the pedal to it's full right limit, corresponding to a tail rotor blade pitch angle of 23°20’. With the stop fully extended, you cannot push the pedals all the way to the right unless you "push past" the force of the spring on the spring cartridge. In this case, the tail rotor blade pitch angle is limited to 17°20’, although you can force the pedals through the spring force and get the full pitch in an emergency. -
Autopilot operation with rudder?
AlphaOneSix replied to WildBillKelsoe's topic in DCS: Mi-8MTV2 Magnificent Eight
The red button above the radio on the pedestal sounds like the on/off button for the tail rotor pitch limiter which is not the autopilot yaw channel. The yaw channel has 100% authority. The other channels only have 20% authority. When the yaw channel is engaged (green light is illuminated for the yaw channel on the autopilot control desk) and you remove your feet from the pedals, it should begin to move the pedals as required to maintain the heading at which the feet were removed from the pedals. -
Autopilot operation with rudder?
AlphaOneSix replied to WildBillKelsoe's topic in DCS: Mi-8MTV2 Magnificent Eight
This. Are you talking about the tail rotor pitch limit system (SPUU-52)? If so, that system has absolutely nothing at all to do with the autopilot system whatsoever. Okay, I'm lying. They work together in the sense that the autopilot, even though it has 100% authority in the yaw channel, will not push beyond the pitch limit set by the pitch limiting system. But for all practical purposes, they have nothing to do with each other. The only other red button is the one under the green one for the yaw channel, and it just turns the yaw channel off. -
DCS: Mi-8MTV2 game vids
AlphaOneSix replied to EvilBivol-1's topic in DCS: Mi-8MTV2 Magnificent Eight
TL;DR That's actually a very good approach angle. For a "normal" approach, the approach angle should be between 8 and 12 degrees, this according to the U.S. FAA's Rotorcraft Flying Handbook. So the approach angle in the video is pretty much spot on for a normal approach. A "steep" approach is around 15 degrees. Note that steep approaches are considered "advanced" maneuvers, requiring "more finesse and understanding of the helicopter and the surrounding environment. When performing these maneuvers, you will probably be taking your helicopter to the edge of the safe operating envelope." At least that's what the RFH has to say about it. A normal approach is a basic maneuver that's simpler and safer. I should also point out that these angles are where the approaches generally start and they tend to flatten out at the bottom. In fact, below about 100 feet, a typical approach angle is closer to 5 degrees, while 8 degrees is almost considered steep by that time. -
DCS: Mi-8MTV2 game vids
AlphaOneSix replied to EvilBivol-1's topic in DCS: Mi-8MTV2 Magnificent Eight
What's wrong with it? -
Thank, Huggy Bear! If I had a dollar every time I or someone else has said this, I'd be able to buy a pretty nice DCS rig. ;)
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I am not a helicopter pilot, although I have many hours flying them. More importantly for this discussion, I am a crew chief and we routinely do this sort of thing and it takes several people working together to make it happen. But I will say that it's not always easy, it does take practice not just with the controls but with the communication required. EDIT: I am not a Chinook crew chief nor do I have a great deal of experience with them, but everyone tells me that they are really easy to fly.
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Okay I understand a bit better now. You're referring to a flow meter that tells you how much fuel has gone through the flow meter, usually placed in fuel lines on their way to the engine. The Ka-50 doesn't have such a thing. If I remember correctly, the gauge moves properly when the gauge is switched on but "sticks" when the gauge is switched off. That is proper behavior. Lots of cars do this exact same thing. When you turn the car off, the fuel gauge "sticks" at the level when the car was switched off, if you then put fuel in it then turn it back on, the needle should move to the correct position. Does this not happen in-game? I'm probably mis-reading something. In other words, the fuel gauge in the aircraft should show the correct fuel level any time the switch is in the ON position and should "stick" any time the switch is OFF, but then return to the proper level indication when turned back ON. If that's not what happens then there is probably a bug to be reported.
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I'm not sure what this means exactly, please forgive me. The fuel gauges read what they are told to read based on the output of the fuel level sensors. I'm not sure what you mean by "metering system" unless you're referring to the manual on page 6-80 where it says "Fuel metering system ON/OFF power switch". Maybe it's a translation issue? The Russian word "ТОПЛИВОМЕР" translates to "Fuel Gauge", not Fuel Metering System. They do. That's exactly what it's for. They do that as well.
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It does, just not using a float. It uses a capacitive fuel level sensor in the forward and aft tanks.
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Yep, it's a common maneuver. The hardest part is putting the wheels where the crew chiefs are telling you. Once you get the wheels on the ground it's pretty simple. As mentioned above, this is definitely a maneuver that requires good coordination between the entire crew. Also, there is no such thing as the rear rotor collective. The pilot was using the cyclic to do that, mostly. Along with the thrust lever, of course. Don't ask me why Chinook guys call the collective a thrust lever, separate discussion.
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Fair enough. My personal flying experience is with the Mi-8 (and about 3 hours front seat in an AH-64A) but the pilots I've flown with do the same thing and so really my comment is valid for Mi-8, AS332, B412, and AH-64A. I understand that my comment may not be as valid for different aircraft.
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I think this really depends on the maneuver being performed. For example, in my experience, if I push against the cyclic, and therefore against the spring tension, when I "click" the trimmer, the stick always jumps slightly as that spring tension is released immediately. So if I am just moving the cyclic a tiny amount, then yes, I could see that "clicking" is the preferred method. But (and again this is just my personal experience) when moving the cyclic more than maybe an inch or two, I need to press and hold the trimmer or else I'll get a big control jump when I finally do press it. Also, in a hover, I find that I like having that sensitivity, so while hovering I'll typically just hold the trimmer down until I get it almost perfect then release and make small adjustments against the springs.