Middle of the night thinking...

[Serenity]

So, it's midnight, I'm bored, and I got to thinking...

I wanna get into Helo flight. I've always had a soft spot for them. Now, as a humble Navy pilot I'll never have the money for a bell or similar. But I saw a kit build on a show and it got me thinking: If I built a kit helo, and got helo commercial certified, could I legally do commercial work of some form to help pay for running it?

[saggs]

Yes and no.

Here is a link to the relevant FAR 91.319

http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&sid=3efaad1b0a259d4e48f1150a34d1aa77&rgn=div5&view=text&node=14:2.0.1.3.10&idno=14#se14.2.91_1319

After a quick scan the only commercial use I see that is legal for EAB certificated aircraft is for glider towing.  Not very practical for rotor wing aircraft.

There are special exemptions one can apply to the FAA for. (called a Letter of Deviation Authority or LODA)  To allow for things like transition training, so perhaps if you can build a popular kit like Rotorway and become a transition trainer in it... that's about the only way I see.

[DaveBB]

I think you should put all your effort into learning how to land on a carrier first.

[Serenity]

I think you should put all your effort into learning how to land on a carrier first.

lol I'm about a year and a half from my first trip to the boat right now. All of my buddies who went maritime or helos will have their wings before I even touch a jet... I'm in the slowest pipeline, at the slowest wing, in the slowest squadron...

It's gonna be a LONG time before I remotely have the money for such an idea, but I have this secret love for helicopters (Ssssh! Don't tell anyone!) and I REALLY want one of these things! lol. And, post-navy, I really want to get into rotor flight professionally.

[caldera]

You want to fly in a home made helicopter?

"Speed Jive.  Don't want to stay alive, when you're twenty-five."  -  Mott The Hoople

[Serenity]

You want to fly in a home made helicopter?

"Speed Jive.  Don't want to stay alive, when you're twenty-five."  -  Mott The Hoople

I mean, preferably, I'd be in a UH-1Y, but there's no way in HELL I'll ever be able to buy one of those, so a home-built is about the only thing I can ever dream of owning lol.

[DaveBB]

Here's the problem with lightweight helos.  They don't have enough rotor momentum.  For example, in the little two-seat Robinsons, you have 1.7 seconds after engine failure to reduce the collective before the rotors become too slow to autorotate. Even the larger versions only give you about 4 seconds.  Extremely unforgiving.

So there is a major inherent design flaw in lightweight helicopters.

[Serenity]

Here's the problem with lightweight helos.  They don't have enough rotor momentum.  For example, in the little two-seat Robinsons, you have 1.7 seconds after engine failure to reduce the collective before the rotors become too slow to autorotate. Even the larger versions only give you about 4 seconds.  Extremely unforgiving.

So there is a major inherent design flaw in lightweight helicopters.

Hmmm... That's a really interesting point I never would have thought to consider. I mean, 1.7sec isn't TOO short IF you know what's happening... But, this is YEARS down the line, so maybe there will be something a bit better by then. Or, ya know, ballistic chute somehow?

[pembquist]

I thought you were the guy who was afraid of ultralights and gyros? It has been a while since I perused the kit rotorcraft offerings, what I remember is that they generally speaking had miserable performance. What I recollect is the Safari sounded like one of the best if not the best, (it was called the baby bell I believe before copyright issues arose.) There was that two stroke helicopter modeled to look like a Hughes 500 which sounded about as safe as gargling with razor blades.

[Serenity]

I thought you were the guy who was afraid of ultralights and gyros? It has been a while since I perused the kit rotorcraft offerings, what I remember is that they generally speaking had miserable performance. What I recollect is the Safari sounded like one of the best if not the best, (it was called the baby bell I believe before copyright issues arose.) There was that two stroke helicopter modeled to look like a Hughes 500 which sounded about as safe as gargling with razor blades.

Well, an ultralight is not a kit-build necessarily. It's funny you mention Safari, because that's the exact one I was looking at. I will never fly one of these again:



This has MUCH more robust engineering and control systems:



I don't expect much in the performance aspect of things, but I'm being realistic. Nothing I ever buy for myself will have the performance of my day job, lol. I'm just looking for something small and cheap I can buzz around with on the weekends, and take the future wife or kids up for a fun flight.

[Lusche]

 

[DaveBB]

Here's the source of my information:

Due to its light weight and low inertia rotor system, the R22 is not forgiving of pilot error or sluggishness. After an engine failure, real or simulated, you and the instructor will have 1.6 seconds to lower the collective and enter an autorotation. Any delay beyond 1.6 seconds will be fatal as the rotor speed, once decayed below 80 percent, cannot be recovered. Frank Robinson did not design the R22 to be a trainer; he designed the R22 for a fast cruise speed and fuel efficiency. The R22 thus has a fast cruise speed, high fuel efficiency, and is a terrible trainer. Why do so many flight schools use the R22 for training? It is cheap to operate.

If you are looking for a trainer, consider the Robinson R44 instead. The R44 has about 4 seconds of rotor inertia rather than 1.6. That gives a pilot time to hear the low rotor RPM warning horn, look at the gauges, come up with a plan, and implement the plan (i.e., lower the collective and enter the autorotation). Count out 4 seconds to yourself and then count out 1.6.

Another pro-safety factor in the R44 is the extra power. With two people sitting in a four-seat helicopter, there is a tremendous power reserve available to recover from ugly training situations. The heavier weight of the R44 also makes the machine much more stable in windy/gusty conditions. Students learn to hover and autorotate faster in the R44 than in the R22.

In the event that the R22 is used for training, the cabin remarkably robust for surviving the inevitable accidents. I have personally met five instructors who failed to catch student errors resulting in dynamic rollovers. One suffered a cracked rib and the other two were uninjured. (See "Teaching Hovering" for some ideas on how to avoid this kind of embarrassment.)

As of 2010, Robinson does not offer the Amsafe airbag seatbelts that have been standard equipment in most fixed wing aircraft produced since 2006 (all Cessna, Cirrus, and Mooney piston singles, for example).

http://philip.greenspun.com/flying/robinson-r22

[RTR]

I clicked the link and read your source.

I have a couple of hours helicopter time so here's my $0.02 worth:

Although this guy seems to have some credentials listed (ATP-H, CFI etc), I gotta tell ya that I read his whole blurb with a bit of horror. There is some blatantly false information there and a lot of embellishment. I don't think he has a grasp of flight dynamics at all. His description of landing at high altitude (6000 ft) and not being able to come into a stop at the hover tells me he screwed the approach (probably to fast and too high a rate of decent)His statements on autorotations are rife with ignorance and impart some dangerously incorrect information.

He has confused "vortex ring state" and "settling with power". They are two very separate things and the fact that he doesn't understand this would concern me. I suspect this guy has gained his credentials by flying around in circles for hours on end at his local airport. No real flying experience or knowledge of helicopter flight dynamics seems to be present in what he wrote.

Oh, and if it is "ridiculously windy" I would even attempt to land an R22 broadside to the wind.

The only thing he seems right about is the fact that the R22 was never meant to be a training machine. (yep flew one once...never will again).


I know and work with many very high time pilots, and I can assure you, not one of them has ever said the R22 is the most fun helicopter to fly.

I would recommend not getting that kind of information from some guys internet blog, and talk to some high time instructors. ( you know, those guys who have flown for a living in all kinds of conditions, terrain, altitudes etc.)

All that being said. If you want to fly helicopters and have a few dollars in your pocket at the end of the day, start out with a pocket full of a lot of dollars.

Rant off.

RTR

[Mar]

He has confused "vortex ring state" and "settling with power". They are two very separate things

This is incorrect, they are indeed the same thing.

http://www.copters.com/aero/settling.html

[RTR]

Ah, the age old argument LOL!

Settling with power is a direct result of the power required exceeding the power available ( or power used) and happens on descent. What it means is that your rate of descent is higher than the power available to arrest it. This can happen with out the helicopter entering vortex ring state. ( in fact I believe this happens more often than vortex ring incidents)

Vortex ring state happens when you allow the helicopter to slow below translation lift speed ( 15 - 20 mph ...ymmv) and you have a rate of decent of more than 300fpm. At that point the airflow through the disc is disrupted (you are sinking in your own wash basically) and the more you pull the worse it becomes. lowering the collective a bit and pushing the nose down to get forward airspeed will fly you out of VRS in short order.

Of course unchecked you are going to hit the ground if you are in a VRS scenario and don't arrest it ( along with now having tail rotor issues and associated Yaw).

In a nut shell:

Settling with power is a result of a limitation imposed on the helicopter by environment, pilot input or other mechanical issue and may occur without ever entering into vortex ring state.

Vortex ring state is an aerodynamic phenomenon. It can be induced by coming into an out of ground effect hover if you are steep in the descent with little forward airspeed coming into the hover. Close to the ground even though OGE, you are probably in for a hard landing.

Both can be flown out of, but you gotta have the altitude.

so, nope...not wrong.

(although this used to be an arguable point, the last 10 years or so we have kind of learned a lot more abut what is actually happening.)

cheers,

RTR