bellblade2014 sez:
There was no flight attitude issue related to the Horizontal stabilizer... Your comment makes no sense. The old design had a much longer moment arm and would have been even better for nose down angle... Do the math..
What? No, it's *your* comment that makes no sense, bub.
To achieve 135 knots in forward flight the rotor disk is going to have to be tilted forward at a pretty good angle. This is true of any helicopter. The fuselage is going to naturally want to follow along at that angle - we know this; it's not rocket science. It's why Bell put the cambered horizontal stabilizer on the 206: to pull the tail down in forward flight. To say that's not the case is just silly. A drastic nose-down attitude in cruise is uncomfortable (e.g. Bo-105, FH1100). You can ameliorate this to a degree by tilting the mast forward (206), reclining the seats, or both (505). But as Star Trek's Mr. Scott always used to admonish Captain Kirk,
ya canna change the laws of physics! When I used to weigh 170 (thirty pounds ago, ugh), if I was in an L-3 and was empty and wanted to cruise at 80% torque I'd usually be right at the forward cyclic stop. Straight-arm the bitch!
To say that the 505 is "less draggy" than a 206 or 407 and therefore will scream along at 135 knots is, again, just silly. Bell *might* have cleaned up the nose, but there's a whole lot of...you know...
helicopter aft of the bubble. All those sticking-out bits create drag. Bell probably couldn't get it to do a steady 135kts if they retracted the landing gear - no matter what the marketing geeks say. How much drag do we have to take away for every extra knot of airspeed increase? There's gotta be an aerodynamic formula for that...
Another thing: If slowing the L-4 rotor system down 3% did such great things, why didn't Bell just tell us to beep our L-4's down to 97% for cruise? Seems to me I could've been really hauling ass at 130+ knots instead of dogging along at 106 knots, no?
Oh, and anyone who thinks that the 505 won't spout winglets/endplates on the horizontal stab is just dreaming. Dreaming. Repeat after me:
It. Will. Have. Them. Why? Simple, really. Moving the mast behind the cabin did a bad thing: It upset the proportions. It put more cabin area ahead of the mast. Not good, aerodynamically. Look at *every* helicopter that goes faster than 100 knots. See something in common? What's that you say? A huge fin (fenestron ships) or lots of fin area (conventional tail rotor ships)? Yup.
Okay, let's talk about that horizontal stab. Bell first put the 505 stabilizer back on the vertical fin, opposite of the t/r gearbox. Bad choice. That didn't work, so they moved it forward, under the rotor again where it's going to affect autorotation behavior just as it did with the 206. We shall see how this all works in flight testing. I suspect we'll eventually see a regular ol' 206-type cambered horizontal stab (with endplates!) before the thing gets certified. (Unless they install a helipilot with yaw damper as standard equipment.)
Speaking of certification... Do we remember Bell's initial projections...about how the 505 would be certified in early 2016? They probably wanted to piggyback it on 206's original TC, #H2SW like they did with the LongRanger...and 407. But at some point the FAA ACO must've said, "No friggin' way - get a new TC!" ...Which is why that particular detail didn't surface until, what, June of 2015? I'm sure that's why the certification date has...what term did Bell use?..."slightly slipped." Yeahhhhh, we're not going to see certification in 2016.
Look, I don't hate Bell. I've got six or seven-THOUSAND hours in 206's. It's my favorite aircraft of all time. A friend of mine just got on with a 206 operator after a stint flying big Sikorskys. When I admitted that I was envious he said, "Come on over! We still have room for a PIC with 206 experience." And I'm tempted, honestly. It'd be great flying the old girl again. But my days of flying full-time are over, thank you.
I'm just not impressed with this 505. I'm not awestruck by Bell's slick marketing scheme. Some of you fawn over this thing like teenage girls at a Justin Bieber concert. If Bell does produce the 505 (and I still think that's a big "if"), I don't see it doing the kind of things the 206 became famous for. It'll probably be a good personal helicopter to rival the R-66, but it doesn't seem like it'll be a good replacement for a 206B or 206L. Maybe LEA, or ENG (good God, does every TV station *need* a 407 or Astar??). And maybe those segments alone can justify certifying it and putting it in production. Then again...
The Bell fanboys on this site keep talking about how many *orders* Bell has for the 505. Yet all I ever see from Bell are numbers of "Letters of Intent"...which number about 240(?) at last press release. Letters of Intent are not orders, gang. A LOI is not binding. Maybe Bell will tell us how many actual orders-with-non-refundable deposits they've gotten? I doubt they'd release that info. I wouldn't.
As I've said before, Cessna was so sure that their 162 (the 150 replacement) would set the world on fire. It didn't. Beech was sure that the Starship was the wave of the future! It wasn't. Throughout history so many manufacturers have tried to re-invent the wheel with disastrous results. Will Bell succeed with the 505? We shall see. So far they've been hyping it up pretty good. Don't be fooled by the hype. The 505 probably has a long way to go before it gets certified, and a lot can and probably will change before then. And the final numbers will *not* be as impressive as the sales/marketing guys would like you to think now. Like I said, we've seen this all before.
Oh, and one last thing? Engineers don't go to trade shows to answer questions from the great unwashed. They stay home where they're busy doing engineer stuff and figuring out how they're going to get some more speed out of the pig since the sales guys are making promises that are hard to keep. Sales and marketing guys go to the shows. Keep it in perspective, folks.