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V-any

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Everything posted by V-any

  1. Lol, was just an easy example. I'm always interesting in learning, so I'm going to explain this the way I understand it in hopes that you either concur, or can explain why I'm wrong. However, I can say without hesitation that if this was as simple as the power required chart being the total drag chart multiplied by speed, then the power required would trend towards zero at zero airspeed, which it obviously doesn't. In the case of helicopters, we're turning a shaft, not thrusting the aircraft (within linear thrust like a jet engine). In a helicopter, the engine power isn't thrust multiplied by speed, it's torque multiplied by RPM. We can assume that RPM (N2) is constant, so that makes torque linearly proportional to horsepower. This means that regardless of flight condition, at any given torque, the engine is producing the same amount of horsepower (work) and burning the same amount of gas. The engine is producing the same amount of power hovering at 80%Tq as it is flying 100kts and pulling 80%Tq. So, power available is torque available (multiplied by some constant). Thus, the point at which you require the least amount of power should be the point at which you have the lowest amount of total drag. As long as fuel burn is linear with torque, maximum endurance speed will be the lowest torque setting, which should be the lowest point on the total drag chart. --- As an aside, there are a few things that I think often obfuscate this topic: One is that you could be talking about the power produced by the engine specifically (which is more natural from a pilot perspective, because we have engine gauges) OR you could be talking about the power produced by the entire power train and aerodynamic surfaces. The second factor is that the engine is a turboshaft. This is different than a turbojet or rocket engine, where thrust available is linear and relatively constant and power increases as speed increases (due to multiplying by speed). The third is that the rotor system directly produces both lift and thrust, not primarily thrust like in an airplane. So, at a hover, the system in it's entirety isn't producing any work (because the helicopter isn't moving). However, it is producing an upward force equivalent to its weight, and the engine is producing power in the form of turning the drive shaft.
  2. I look forward to being told that I'm wrong, and how, but to me that chart doesn't make sense. An aircraft in a steady state is in balance. It's losing energy continuously due to drag. The aircraft has to make power to replace that energy to keep it in a steady state. Therefore, minimum total drag should be the point where the least power is required. So, by my understanding, max endurance should be somewhere near minimum total drag, aka least power required. The only caveat I can think of is that power produced at the rotor blades might not necessary scale linearly with fuel flow, and ultimately, it's fuel flow that we're concerned with; it's a factor in both performance measures. Max range is knots/fuel-flow. Max endurance is simply the speed where fuel-flow is the least. If you want to find max endurance, go to to your cruise charts and find the cruise configuration where your fuel flow is the least.
  3. You're right about the R44. If you own it for a full 12 year cycle, you need to fly it a couple hundred hours per year to keep the hourly cost from skyrocketing. However, you may be able to find one that has a lot of calendar time left but not a lot of hours. A ship with five years left on it and only 500 hundred hours left might be had a nice discount. And, don't forget, if get a good deal on the overhaul, there's money to be made by overhauling it and selling it with fresh components.
  4. There's absolutely nothing wrong with pay to ferry. They have an empty seat. That seat has value. The business dealings outside of that transaction are entirely irrelevant. Anyone who thinks otherwise either (1) doesn't understand economics, or (2) believes that for-profit helicopter operators should give away services of value for free. However, that isn't a competitive price. For $5/hr more, $380/hr, you can go get dual instruction in an R44 and work on whatever you need to work on instead of fly in a straight-line. Nothing wrong with the concept, but the price isn't particularly good.
  5. Trim and balance (ball in the center) are two different things.
  6. Neither the inclinometer nor the Aspen will tell you if the helicopter is in trim. Only the string will. The string points straight back when it's in trim. This was answered in the first reply. Everyone pay attention: ... It's just a string. Not a magical string that knows where the pilot sits and points to him when it's in trim, it's just a damn string. When air hits it from the front, it points aft. When air hits it from the side, it points to the opposite side. ... sometimes helicopter pilots amaze me.
  7. It's just a piece of yarn. When when the wind is directly from the front, it pushes the yarn directly aft, and it's in trim.
  8. Or they can afford to self-insure up to $80k. Many robust companies self-insure.
  9. That's a little lower than I would expect it to be. Keep in mind that training beats up aircraft. Even if they fix the big stuff that htey break, there's a lot of wear in tear in the training environment.
  10. JohnnyB's post is spot on. A small school, or even a freelance instructor, can be great, or terrible. The lack of a formal organizational structure isn't necessarily a bad thing. However, there's probably greater variance in the quality of instruction you find at schools that meet that description. (Worse bad experiences, better good experiences.) The bigger, more formal schools are more consistently mediocre, in my opinion. That's not necessarily a bad thing. There's certainly advantages to a known quantity. So, it's really situation dependent. A great instructor can thrive in the environment you describe. A poor instructor in the same environment can cost you a lot of money, time, and get away with being less safe. On a separate note, are you training in/near North Carolina?
  11. This it? http://www.tech-tool.com/catalog/robinson-helicopters/robinson-r22/windshields-full-view-cabin-comfort-replacement-do/
  12. I need a charger, too. I did some research today and settled on this one. It's $15, and puts out 24 watts, which is enough to charge two iPads. (iPads charge on 10-12w.) It claims to be good up to 30v, which should handle the R44's 28-ish volt system with a little wiggle room. On the advice of a friend, I also bought a long iPad cable to go with it. I bought one of these "Amazon Basics" iPad cables because they're 6' long, 8 bucks, and "Apple Certified". I'm going to see how well it works to run the cable behind the PIC seat and up the right side, so it's not crossing any controls. I just ordered this stuff tonight, so I can't attest to it's quality/performance. If anyone's curious, let me know, and I'll post a follow up when I get to fly with it.
  13. Not a gulf pilot, but just a tid bit of wisdom. Don't become dependent on it. It's a consumer device with consumer standards for reliability. There are a lot of reasons it might not be there for you when you need it: overheatingsoftware instability (the OS, or the app you're using, or some other app that's running)settings you changed and didn't realize might be a problem while flying (like screen auto-shutoff)you put gloves on and can't put in your PIN to unlock the screenyou spill something on it or crack the screenthe sun hits it at the right angle and the glare makes it unreadableThe iPad has very powerful apps built for it, but it's not a particularly good device from a hardware perspective. We all say "yea, yea, I won't become dependent on it", but over time it can lull you into complacency and many people start to slack off on using the certified avionics.
  14. Winds from left can cause LTE. Winds from the right require more power. Pick your poison, based on the situation you're in.
  15. Sure! The offer is limited to no autorotation training at all. Here's why: When someone charges $500+/hr for R44 time, they're making a nice little profit on the helicopter. They can set some of that aside to pay for the occasional overspeed, tailstrike, split skids, and other common training incidents that result from the higher-risk maneuvers, like autos. The problem is that occasionally people need cheap hours more than they need to do those (relatively) high-risk maneuvers. These people typically have to pay the full price of the helicopter, even if they're exposing the helicopter to much less risk than the other renters. What I'm trying to do is offer an alternative for those people who just need cheap time. If they are willing to stick to low-risk flights and buy in large blocks it will simply cost less over time to operate the helicopter, and I can pass that savings on to the client. This setup certainly won't appeal to everyone, but I hope it can benefit those people that really need more R44 time in their logbook and don't have a lot of money to do it with. For $7,500 and three days of their time, they can leave with 20 hours logged, with as much of it night, cross-country, or simulated instrument as they'd like. I hope that answers your questions!
  16. Haha, I feel ya. Yea, just find an aircraft that's stable to fly, maybe even with an autopilot, and with a panel that you like. Home simulators are pretty terrible at perfecting your aircraft control, but they're great at practicing procedures. The IFR procedures are so similar between airplanes and helicopters, that you're hardly losing anything by just flying the airplane. Use the sim to practice what to do and when to do it. Good luck!
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