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Dumb Questions???


txflyer
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Dumb Questions?? I thought maybe some vets could shed some light on a rookie. Thank you

 

1) What is the purpose of using statute miles AND nautical miles? Other than their actual distance differences, what is the difference between the two?

 

2) For rotor and engine tachometers, why are they rated over 100%? It seems like 100% should be the maximum performance.

 

3) Why is the R22 not required to have fuses readily available to the pilot during flight as stated in the FAR/AIM book?

 

4) Is carburetor heat a required piece of equipment on a Robinson piston driven heli? (I know that governor, outside air temp, alternator, and low rpm system is required through Robinson)

 

5) Why are anti-collision lights not necessary on a helicopter for day VFR but are required on smaller civil aircraft?

 

6) Is fog a cloud?

 

7) If you have had 3 takeoffs and 3 landings within the preceding 90 days at night, will this also meet the daytime requirements?

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2) For rotor and engine tachometers, why are they rated over 100%? It seems like 100% should be the maximum performance.

 

Ok, I'll take this one. Have you done autorotations yet? Rotor RPM can very easily exceed 100% if you do not properly apply collective. You want to be able to see any overspeed condition, of the engine or the main rotor. Also, when flying with manual throttle (governor off) you can exceed engine/rpm limits. Or a malfunctioning governor might take you over the limits. The goal is to NOT overspeed either component, but if you do, its very valuable to know how much you exceeded it by.

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4) Is carburetor heat a required piece of equipment on a Robinson piston driven heli? (I know that governor, outside air temp, alternator, and low rpm system is required through Robinson)

 

 

Ok, I dont have any of my references in front of me to check so I'll take a different approach. Several areas of the Pilot Operating Handbook (POH) REQUIRE that you apply carb heat. So, you could not fly the R22 in those required scenarios without carb heat. Notice the sticker that says to apply carb heat when flying in visible moisture? Or below 18" of manifold pressure?

 

So I guess if you can fly the thing, avoid visible moisture, avoid all temperatures conducive to carb ice, and never drop below 18 inches of MP, then you're golden.

 

This is all off the top of my head however, great question. I'll have to dig into the R22 books when I get home.

 

Goldy

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Dumb Questions?? I thought maybe some vets could shed some light on a rookie. Thank you

 

1) What is the purpose of using statute miles AND nautical miles? Other than their actual distance differences, what is the difference between the two?

 

2) For rotor and engine tachometers, why are they rated over 100%? It seems like 100% should be the maximum performance.

 

3) Why is the R22 not required to have fuses readily available to the pilot during flight as stated in the FAR/AIM book?

 

4) Is carburetor heat a required piece of equipment on a Robinson piston driven heli? (I know that governor, outside air temp, alternator, and low rpm system is required through Robinson)

 

5) Why are anti-collision lights not necessary on a helicopter for day VFR but are required on smaller civil aircraft?

 

6) Is fog a cloud?

 

7) If you have had 3 takeoffs and 3 landings within the preceding 90 days at night, will this also meet the daytime requirements?

 

1. You can thank PanAm for that one. They brought nautical terms into aviation. And the rest of aviation followed. The difference is about 800 feet.

 

2. You would think so. However, the 100% mark is set where ever the manufacturer decides it should go. For example the AW139 the max power with two engines is around 85%, However, during single engine operations, you can go to around 160%. You go by what is in the limitations section of the flight manual.

 

3. The R22 like most 'modern' helicopters uses circuit breakers not fuses. The regs were written to cover all aircraft.

 

4. Yes it is required. You would be surprised on where you can get carb ice.

 

5. The reg in question 91.209 states airplanes manufactured after a date in 1996 must have and use anti-collision lights. The reg states later that aircraft must have them to operate during night time. An airplane according to Part 1 is a fixed wing aircraft. Whereas an aircraft refers to all categories of aircraft.

 

6. yes

 

7. yes. The currency for daytime does not specify lighting or hours. However, night currency specifies night operations.

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#3. Yeah, all circuit breakers except for the one fuse that is located under the Cowl door beside the little test light (push button)switches on the same panel. It blows whenever there is a belt actuator motor overload before the relevant circuit breaker trips and turns off the clutch caution light(you know the yellow one that shouldn't be lit in flight for more 8 seconds or so). We ARE required to carry a spare for that. It's located in the FAR's somewhere(probably 91.205), where it says that we need to carry spare fuses for all fuse systems on board up to a maximum of 3 spares.

 

The spare is usually carried on the same little test light switch panel beside the actual fuse(in use. Hope this helps, there's never a FAR's book around when you need it!!

 

EDIT; Would you look at that, this is my 150th post!!!!

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5) Why are anti-collision lights not necessary on a helicopter for day VFR but are required on smaller civil aircraft?

 

 

5. The reg in question 91.209 states airplanes manufactured after a date in 1996 must have and use anti-collision lights. The reg states later that aircraft must have them to operate during night time. An airplane according to Part 1 is a fixed wing aircraft. Whereas an aircraft refers to all categories of aircraft.

 

 

Let me expand on #5. The regs also state that an aircraft equipped with an approved anticollision light system must have it turned on during flight.

 

Edit: Let me add, the cliche that there are no dumb questions is totally wrong. There are dumb questions. I get asked them all the time. (i.e. I had someone ask me if I could turn off the main rotor to stop a vibration {needed to be tracked}... in flight.)

 

That being said, yours are not dumb questions.

Edited by PhotoFlyer
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whats the rate of fire on that little gun mounted on the front of all helicopters?

 

 

300 rounds/per minute. Its not a gatling after all, and that barrel can get really hot. Which is why some aircraft may have a Pitot Gun Heat light that turns on if you're firing too much and not letting it cool between shots.

 

Wow- that was a stretch to get there.

 

Goldy

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A nautical mile is equal to one minute of longitude at the equator. This goes back to early marine navigation methods. A statue mile is an arbitrary measurement originating in England long ago. It's possible to use any length measurement in navigation, be it statute or nautical miles, or kilometers, or light years or parsecs. Nautical miles turns out to be a convenient measurement, because it makes conversion of GPS coordinates and time estimates easier.

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A nautical mile is equal to one minute of longitude at the equator. This goes back to early marine navigation methods. A statue mile is an arbitrary measurement originating in England long ago. It's possible to use any length measurement in navigation, be it statute or nautical miles, or kilometers, or light years or parsecs. Nautical miles turns out to be a convenient measurement, because it makes conversion of GPS coordinates and time estimates easier.

 

I thought parsecs was a measurement of how fast someone could eat Christmas cookies. Obviously, the drier the cookie, the fewer parsecs you can obtain while eating them. :huh:

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A nautical mile is equal to one minute of longitude at the equator. This goes back to early marine navigation methods. A statue mile is an arbitrary measurement originating in England long ago. It's possible to use any length measurement in navigation, be it statute or nautical miles, or kilometers, or light years or parsecs. Nautical miles turns out to be a convenient measurement, because it makes conversion of GPS coordinates and time estimates easier.

 

Thanks Gomer, I always wondered how the nautical mile originated. It's good to learn new trivia!

 

Any idea why the metric system never took off here?

Edited by heli.pilot
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Thanks Gomer, I always wondered how the nautical mile originated. It's good to learn new trivia!

 

Any idea why the metric system never took off here?

 

Not just trivia, but can be useful by using each degree of latitude on a sectional to estimate 60 nautical miles. Just don't use the lines of longitude, except if you're at the equator!!

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2) For rotor and engine tachometers, why are they rated over 100%? It seems like 100% should be the maximum performance.

 

3) Why is the R22 not required to have fuses readily available to the pilot during flight as stated in the FAR/AIM book?

 

4) Is carburetor heat a required piece of equipment on a Robinson piston driven heli? (I know that governor, outside air temp, alternator, and low rpm system is required through Robinson)

 

6) Is fog a cloud?

 

2) On the 100% deal, you're right. You [usually] fly at 100% rotor RPM in normal flight. You may be allow 2-3% on either side of that. For power off, you may be allowed 10% on each side. So, 100% is your middle of the road target, and you can keep it on either side you like.

 

When you get into turbines, 100% is for takeoff, then you may have to back it off to 85, 80, or 75% for cruise. In some cases, if your helicopter has some sort of increased power kit you may be allowed to 105% for a certain amount of time. It's the same as Limit Manifold Pressure (5 min t/o) and Max Cruise Pressure in the R22.

 

3) Like another said, the only fuse in the R22 is the clutch motor. Robinson wanted to force people to land and look in that bay if the motor blew the fuse. Keep in mind, if that motor fails while engaged, you will not be able to restart the helicopter due to the clutch engage lock out system. Good CYA move by Robinson on this one. (There's actually another fuse--Hobbs meter has it's own under the bus panel. )

 

4) Good question. It doesn't say anything in the limitations section about the system, nor keeping the indicator out of the orange. It just lists what the limits on the gauge must be. Plus, yellow means "caution", not "do not exceed/enter". It's only when carb icing condition could occur, too. This could take up a full thread, but the simple answer is "no" without lots of paperwork.

 

Next question is, do you have to have a working cylinder head temp gauge in a R22? Never got solid answer on that either. It has a red line, but you also have an oil temp gauge to cross-check it. hmmmmm.

 

5) Fog is a [ground based] cloud, but it's considered an obstruction to the NWS. Clouds cover a percentage of the sky and have base ceilings. Obstructions (fog, haze, mist, etc.) have visual range that you can see through them--that's what defines their name. Sometimes a vertical visibility is given too. So, yes, same thing, but it's coverage vs. visibilty.

 

Good thread.....let's keep it going.

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Next question is, do you have to have a working cylinder head temp gauge in a R22? Never got solid answer on that either. It has a red line, but you also have an oil temp gauge to cross-check it. hmmmmm.

 

Reading the POH (Section 2, Page 6), I'd say... no. Alternator, governor, LRPM warning and OAT are the only listed requirements.

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100% is just an arbitrary figure. It's 100% of something, but it's not necessarily a limitation. In the S76, the standard Nr is 107%. For some models there is a range, but for the A++, C+, & C++, you aren't supposed to fly it below 107%. Don't get too wrapped up in the percentage, it's just a number. Keep it in the green and it's all good.

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Next question is, do you have to have a working cylinder head temp gauge in a R22? Never got solid answer on that either. It has a red line, but you also have an oil temp gauge to cross-check it. hmmmmm.

 

One thing that's handy about the cylinder head temp gauge in the 22 is that it's on the same circuit as your warning lights. So if you notice that it goes out in flight, you can assume that you no longer have those operating either. Otherwise you wouldn't have any indication of this. I've even heard that the test buttons you check the lights with on your preflight don't operate through the same wires, so you aren't in fact checking the chip lights when you do this. At any rate, the more warnings the better...

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Not just trivia, but can be useful by using each degree of latitude on a sectional to estimate 60 nautical miles. Just don't use the lines of longitude, except if you're at the equator!!

 

By "trivia" I meant "facts, details, particulars etc"... not that the information was "trivial" :P

 

I agree, very useful indeed... :D

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Even in the southern US, a degree is close enough to 60 NM for a first approximation. It's not exact, but it's not that far off. For me, it's especially useful to know that one minute is approximately one mile. When I get GPS coordinates for a scene, then new coordinates, it's easy enough to see how far off the first set was, and how far off my first guess may have been. Sometimes I just put in a city or a previously known point to get started in the general direction, pending accurate coordinates. A quick glance shows how far in which direction I need to correct, and then I can take the time to get the correct coordinates into the GPS. Sometimes I don't even bother, I can just correct in my head from what I already have there. Conversely, if the coordinates I get are miles off what I've been told, I know I need to question them and try to get an update. Whether one minute is exactly one nautical mile or not isn't really important, it's close enough for quick headwork.

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