#214712 - 27/04/2004 16:49
I flew a helicopter today!
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old hand
Registered: 15/02/2002
Posts: 1049
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Hi everyone,
This feels a bit stupid, but I just had the GREATEST time of my life flying a small helicopter today and I am so excited I wanted to tell someone. It was incredibly fun and extremely difficult.
It was my first lesson in the Robinson R22 helicopter. This is a very small piston-engined helicopter commonly used as a trainer.
We spent the first 40 minutes or so doing level flight, climbing, descending, and turns at altitude. The last 20 minutes we spent with me trying to hover. Apparently, it takes an average of 5 hours of cumulative hover practice for most people. I can see why! It is extremely difficult. I had read a lot about it, had flown computer simulators, and I am a mechanical engineer who knows a bit about controls (and over-controlling), so I knew beforehand that the biggest issue was over-controlling the system. It didn't matter... I *did* manage about a 10 second controlled hover, though. That may not seem like much, but it IS. After about 10 seconds, I started drifting some way (right, I think) and when I corrected the right drift I ended up flying backwards, then I corrected that and was flying right again and I ended up "chasing" it and was out of control in a few seconds.
By "out of control" I mean that I would have crashed and died if there hadn't been an instructor along. The thing is *so* twichy and unstable. I was told to rest my right forearm on my leg and control the cyclic (the stick that controls fore/aft, left/right -- the center stick) using only very small wrist movements. Flying the thing requires CONSTANT adjustment to the controls because the helicopter is inherently unstable.
Anyhow, sorry to blather. I could go on and on. It was so much fun. I can't wait to go up again!
I recommend it to anyone!
Jim
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#214713 - 27/04/2004 17:38
Re: I flew a helicopter today!
[Re: TigerJimmy]
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pooh-bah
Registered: 16/06/2000
Posts: 1682
Loc: Greenhills, Ohio
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"There's no sensation to compare with this
Suspended animation a state of bliss
Can't keep my mind from the circling sky
Tongue-tied & twisted just an earth-bound misfit, I"
Good luck to you. My dream was to fly a Stearman but after 7.3 hours logged in a Cessna 152 I ran out of funds and also decided that I was too directionally challenged in the air to find anything.
_________________________
Laura
MKI #017/90
whatever
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#214714 - 27/04/2004 17:51
Re: I flew a helicopter today!
[Re: TigerJimmy]
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carpal tunnel
Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
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Too cool. My fear of flying would have me tweaking out in no time, I think, but this sort of thing remains cool. My desire for control might override the fear, though. Who knows?
Anyway, too cool.
_________________________
Bitt Faulk
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#214715 - 27/04/2004 18:11
Re: I flew a helicopter today!
[Re: TigerJimmy]
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pooh-bah
Registered: 25/08/2000
Posts: 2413
Loc: NH USA
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Excellent! I have an airport out my window aqt work and watch people practice on helis all the time. I'm jealous. I really must get off my ass and get at least fixed wing certified.
-Zeke
_________________________
WWFSMD?
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#214716 - 28/04/2004 00:03
Re: I flew a helicopter today!
[Re: TigerJimmy]
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carpal tunnel
Registered: 13/02/2002
Posts: 3212
Loc: Portland, OR
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Anyhow, sorry to blather. No apology necessary -- that's a great story! I looked into the cost of heli lessons several months ago, and ended up deciding they were a bit too expensive at the moment. It's great to hear some of the challenges...
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#214717 - 28/04/2004 03:37
Re: I flew a helicopter today!
[Re: TigerJimmy]
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pooh-bah
Registered: 16/04/2002
Posts: 2011
Loc: Yorkshire UK
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I once asked a helicopter pilot over Chattannooga how hard it was to fly (Daft Question). In a lovely southern drawl, he said: "Well if y'all balance one ball on top of another, then balance on a plank on top of the two balls, that'll give you some idea!".
The only thing that looks harder to me is flying a model helicopter!
_________________________
Politics and Ideology: Not my bag
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#214718 - 28/04/2004 05:29
Re: I flew a helicopter today!
[Re: TigerJimmy]
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addict
Registered: 23/12/2002
Posts: 652
Loc: Winston Salem, NC
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Kudos. I've always been intrigued by how a helicopter works.
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#214719 - 28/04/2004 08:00
Re: I flew a helicopter today!
[Re: TigerJimmy]
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old hand
Registered: 30/07/2001
Posts: 1115
Loc: Lochcarron and Edinburgh
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I have the utmost respect for the RAF[**] pilots who can hold a helicopter for minutes at a time without it moving. The closest I've been was when some climbers I'd given a lift to overestimated their abilities and available time, and nightfall found them still only half-way up a slightly overhanging sea cliff at Gogarth (Holy Island, just of Anglesey, north Walas). The helicopter hovered a few feet above the cliff edge (where it would catch every slight updraught) whilst the winch man (is that the right term?) was lowered on a line to swing in under the overhang and lift the lads to safety. The whole process took 20 or 30 minutes, and it was all inch-perfect.
[**] presumably also of other organisations worldwide, but the RAF is the only one I have any experience of.
_________________________
Toby Speight
030103016 (80GB Mk2a, blue)
030102806 (0GB Mk2a, blue)
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#214720 - 28/04/2004 08:43
Re: I flew a helicopter today!
[Re: TigerJimmy]
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carpal tunnel
Registered: 30/04/2000
Posts: 3810
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Nice story. Speaking of helicopters, I stumbled across this article yesterday about a New York Times photographer who likes to shoot from helicopters. The work is amazing, but just imagine trying to keep down your lunch.
"And you can rarely hover at those altitudes. You're usually looping around something, and when you're looking through a four to six hundred millimeter lens, it really gets you. I'm really good with heights. I never get sick. But when I shoot with those long lenses, I do generally want to hurl."
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#214721 - 28/04/2004 10:29
Re: I flew a helicopter today!
[Re: DWallach]
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addict
Registered: 11/01/2001
Posts: 579
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So I guess fiddeling with the buttons on my empeg while trying to fly a chopper would me out of the question? 
_________________________
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#214722 - 28/04/2004 15:32
Re: I flew a helicopter today!
[Re: belezeebub]
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carpal tunnel
Registered: 23/08/2000
Posts: 3826
Loc: SLC, UT, USA
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So jealous. That's one of my lifetime goals... to learn to fly a helicopter. One of my girlfriend in high school's father was a model helicopter nut. I begged him to teach me.. but he just handed me a controller plugged up to a computer and said "once you can hover in the sim for 5 minutes, i'll consider teaching you." I gave up after 30 of the most frustrating minutes of my life. hahah. Then i got to watch Rob Vreeland fly his model out on the lake beds last year with precision. Afterwards he was visibly drained and sort of shakey. He said EVERY time he flys it it's so nerve racking that he doesn't even want to do it anymore. Which reminds me... he's selling it... really nice carbon fiber everything piece of kit. =]
anyhow.... congrats!
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#214723 - 29/04/2004 15:04
Re: I flew a helicopter today!
[Re: loren]
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old hand
Registered: 15/02/2002
Posts: 1049
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Hey you guys, thanks for all of the cool comments! I felt pretty silly making my post, but it was just the greatest thing I had ever done!
I would recommend this experience to anyone. You don't have to commit to an entire training program, and you can often get a special price on an introductory flight. I opted for a first lesson. I paid $215(US) for the "ship" and $40 for the instructor, plus about $25 in taxes and airport fees. That isn't cheap, but it was worth every penny! I got to fly for 95% of the hour and I got to spend about 20 minutes trying to hover, which was a blast (and really hard).
I can't stop thinking about it. I keep having dreams about flying the thing. All of that instability means that the machine is extremely responsive. Its like the ultimate 3 dimensional sports car. I've looked into the machine I flew, a Robinson R22, and it is 850 lbs (dry) and 190 hp. That is in the neighborhood of sportbike power to weight ratio. Not that its fast; it only goes about 100mph.
The thing that makes it fun is the same thing that makes it difficult -- the instability.
As far as "lifetime goals" are concerned (and this definitely was a lifetime goal for me!), under $300 is a pretty great deal. Why did it take me so long?!?!?!
Life is short!
Thanks again for all of the great comments.
Jim
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#214724 - 29/04/2004 15:20
Re: I flew a helicopter today!
[Re: TigerJimmy]
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carpal tunnel
Registered: 23/08/2000
Posts: 3826
Loc: SLC, UT, USA
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Holy crap... it's really that cheap? I always figured you have to do a whole flight school and never even bothered to look. Hrmm.....
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#214726 - 30/04/2004 09:42
Re: I flew a helicopter today!
[Re: loren]
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old hand
Registered: 15/02/2002
Posts: 1049
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Exactly! Go do it! I'm so happy I did!
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#214727 - 03/05/2004 14:06
Re: I flew a helicopter today!
[Re: TigerJimmy]
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journeyman
Registered: 30/12/2001
Posts: 83
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As an ex-professional pilot with 4000+ hours, I welcome you to the world of aviation.
I only fly for fun nowadays, but I do miss the job sometimes.
Have fun!
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#214729 - 13/05/2004 18:53
Re: I flew a helicopter today!
[Re: loren]
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carpal tunnel
Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
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#214730 - 13/05/2004 19:13
Re: I flew a helicopter today!
[Re: loren]
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journeyman
Registered: 30/12/2001
Posts: 83
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Yeah, I saw that one. The interesting part is how young the kid doing the flying looks.
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#214731 - 13/05/2004 19:36
Re: I flew a helicopter today!
[Re: loren]
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pooh-bah
Registered: 25/08/2000
Posts: 2413
Loc: NH USA
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How does it hover upside down? Do the blades cant so that the air is pushed away from the frame of the copter? Do real helicopters do this?
Very cool vid. Thanks, Loren!
-Zeke
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#214732 - 13/05/2004 19:58
Re: I flew a helicopter today!
[Re: CommOri]
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Carpal Tunnel
Registered: 08/02/2002
Posts: 3411
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That's a display of some serious talent. As far as my googling can tell, that kid is about 17 and is already regarded as one of the masters.
_________________________
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#214733 - 14/05/2004 06:18
Re: I flew a helicopter today!
[Re: Ezekiel]
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carpal tunnel
Registered: 14/01/2002
Posts: 2858
Loc: Atlanta, GA
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Do real helicopters do this? Not with people inside! 
OK, OK. I know by "this" you meant changing the way the blades rotate, but couldn't you just see someone riding in a helicopter doing all that?
_________________________
-Jeff
Rome did not create a great empire by having meetings; they did it by killing all those who opposed them.
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#214734 - 14/05/2004 06:42
Re: I flew a helicopter today!
[Re: DWallach]
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carpal tunnel
Registered: 29/08/2000
Posts: 14493
Loc: Canada
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This is an archaic technology that's just crying out for modern control systems.. pretty amazing most heliocopters are still flown using such a primitive control system. It's like evolution just stopped dead once they got the first one off he ground.
I wonder what's blocking progress in this field? Feedback driven control loops would make flying a 'copter really really easy.
Cheers
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#214735 - 14/05/2004 07:14
Re: I flew a helicopter today!
[Re: JeffS]
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pooh-bah
Registered: 25/08/2000
Posts: 2413
Loc: NH USA
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Let me rephrase the question:
Are modern helicopters capable of inverted hovers?
-Zeke
_________________________
WWFSMD?
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#214736 - 14/05/2004 08:04
Re: I flew a helicopter today!
[Re: mlord]
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old hand
Registered: 30/07/2001
Posts: 1115
Loc: Lochcarron and Edinburgh
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There's a natural conservatism with technology that's so obviously safety-critical. Pilots just don't like the idea of fly-by-wire, no matter how safe you tell them it is. If something works well enough, they say, don't mess with it.
Of course, those same pilots then drive home in their ABS-equipped cars on cruise-control...
_________________________
Toby Speight
030103016 (80GB Mk2a, blue)
030102806 (0GB Mk2a, blue)
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#214737 - 14/05/2004 08:13
Re: I flew a helicopter today!
[Re: tms13]
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carpal tunnel
Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
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Yeah, but, you know, if your ABS fails, you don't fall from the sky.
_________________________
Bitt Faulk
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#214738 - 14/05/2004 09:07
Re: I flew a helicopter today!
[Re: wfaulk]
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carpal tunnel
Registered: 18/01/2000
Posts: 5683
Loc: London, UK
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Yeah, but, you know, if your ABS fails, you don't fall from the sky.
Yeah, but, you know, most cars are designed and built by reasonably competent engineers, rather than by defense contractors .
_________________________
-- roger
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#214739 - 14/05/2004 09:21
Re: I flew a helicopter today!
[Re: Roger]
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carpal tunnel
Registered: 23/08/2000
Posts: 3826
Loc: SLC, UT, USA
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How does it hover upside down? Okay, i'll preface this by saying i'm no expert in this area by any means. But the blades don't change rotation direction, they pivot around their own axis. The blades in a 'copter can tilt and each can rotate around it's Z axis. Imagine taking a ceiling fan, grabbing the end of the blade, and twisting it so the blade tilts in the opposite direction. That's what's happening with the RC helicopter. As for whether or not real helicopters are capable of inverted hover... I remember reading somewhere that the recently scraped Comanche was supposed to be capable of pretty impressive maneuvering such as inverted flight. I've seen helicopters do barrel rolls but as far as i'm aware there hasn't been any inverted flying helicopters. But, again, i don't know squat about helicopters.
Correct me if i'm wrong those in the know.
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#214740 - 14/05/2004 13:21
Re: I flew a helicopter today!
[Re: wfaulk]
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pooh-bah
Registered: 13/09/1999
Posts: 2401
Loc: Croatia
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Yeah, but, you know, if your ABS fails, you don't fall from the sky. In most cases planes crash because pilots fail. Totaly automated planes would probably be safer than ones provided with pilots.
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#214741 - 14/05/2004 13:37
Re: I flew a helicopter today!
[Re: bonzi]
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carpal tunnel
Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
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Don't get the pilots started!
For that matter, don't get ME started.
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#214742 - 14/05/2004 14:00
Re: I flew a helicopter today!
[Re: tfabris]
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journeyman
Registered: 30/12/2001
Posts: 83
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Ahhh, the 'ole "coputers are safer" argument...here's a short story from my corporate flying days...
On an ILS into Sacramento with my brother as co-pilot, I decided to let the autopilot fly the approach since the weather had gone below minimums AFTER we reached the outer marker. About 1/4 mile out the autopilot found itself a bit high and dove to find the glide slope. All I remember was the radar altimeter light and bell going off and punching the throttles and the autopilot shut-off (overboosting the turbines in the process) for an emergency missed approach. All you could see out all the windows was the fog flashing as we passed over the approach lighting system. As it turns out, I pulled things out at 50 feet above the gound. Significantly lower than the 200 foot minimum at the missed approach point.
In other words, had I let the "computer fly it", both my brother and myself would be dead.
And then there's this (Real Player required)...when the computer went into autoland mode and wouldn't let the pilot override...
Fly-by-wire is fine, but you DAMN well better have a hard-wired safety override. A good pilot's "feel" and knowledge of a plane is often WAY better than an engineers.
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#214743 - 14/05/2004 14:07
Re: I flew a helicopter today!
[Re: CommOri]
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carpal tunnel
Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
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Your pilot-speak confuses me. Are you saying that the computer almost plowed you into the ground before the runway even started?
_________________________
Bitt Faulk
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#214744 - 14/05/2004 14:22
Re: I flew a helicopter today!
[Re: wfaulk]
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carpal tunnel
Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
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Correct, that is exactly what he's saying.
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#214745 - 14/05/2004 14:38
Re: I flew a helicopter today!
[Re: wfaulk]
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journeyman
Registered: 30/12/2001
Posts: 83
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Yeah, that's the gist of it. It would have put us into the ground about 50 yards short of the runway because it was "chasing" the glide slope.
The glide slope is a radio beam shot from the appraoch end of the runway into the air at about 3 degrees. It, combined with the "localizer" (the same thing but aligned horizontally) gives you the ILS path (ILS=Instrument Landing System). It's basically the road you follow through the muck to the runway.
As you get closer to the runway the sensitivity of the ILS becomes greater, so smaller control inputs are needed as correction. For some reason, the autopilot overcontrolled to get back onto the glideslope. We had the plane put into maintenance because of the problem and the shop reported that they could find nothing wrong with the system.
I don't think I ever let the autopilot in that particular plane fly an ILS again (at least not in IFR).
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#214746 - 14/05/2004 14:52
Re: I flew a helicopter today!
[Re: wfaulk]
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old hand
Registered: 01/05/2003
Posts: 768
Loc: Ada, Oklahoma
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Maybe we should have waited until after Amersfoort to tell Bitt this story...
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-Michael West
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#214747 - 14/05/2004 15:05
Re: I flew a helicopter today!
[Re: mwest]
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carpal tunnel
Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
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No. I'm always pretty confident that this is the usual state of affairs. It's the coming to grips with it that's the hard part.
_________________________
Bitt Faulk
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#214748 - 14/05/2004 16:09
Re: I flew a helicopter today!
[Re: CommOri]
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pooh-bah
Registered: 13/09/1999
Posts: 2401
Loc: Croatia
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Ahhh, the 'ole "coputers are safer" argument... Yeah, and pilots are supernatural, infallible beigns... You do read NTSB's preliminary investigation report digests, don't you? Not many navigation equipment breakdowns, plenty of pilot judgment errors. In other words, had I let the "computer fly it", both my brother and myself would be dead. OTOH, had those Ukrainian pilots over German/Swiss border listened to their TCAS and not the human controller, 70-something childern would be alive...  Fly-by-wire is fine, but you DAMN well better have a hard-wired safety override. A good pilot's "feel" and knowledge of a plane is often WAY better than an engineers. I follow this kind of discussion in AW&ST and Flying for ages. Pilots on your side of the fence would say 'So what if I overstress the plane a bit in dangerous situation? Better wrinkled wing skin than hole in the ground.' Yes, but why are they so sure they would 'just wrinkle the wing', not break it, or enter accelerated stall, or stay too far from the limit and fail to use all of the plane capability?
Engineers don't feel the airplane, they model it (then measure its actual performance, then refine their models...). Enourmous amount of feedback from development, testing and early customer pilots is taken (mostly regarding engonomy, consistency of symbology etc). The result is something like A320 where, for example, a pilot deciding a go around is called for just yanks the joystick fully backward: the plane applies TOGA power, raises the gear, retracts the flaps and tries to achieve the best angle of climb airspeed pulling up at the edge of stall (or something like that). A friend who transitioned from ancient B-737-200 to A320 tells me he would not change back for anything.
It is in principle possible to make software as close to bug-free as one wants; it is just a matter of time and resources, that is, money. OTOH, it is impossible to eliminate human error beyond some level quite far from perfect.
_________________________
Dragi "Bonzi" Raos
Q#5196
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MkIIa #040103247, 60GB blue
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#214749 - 14/05/2004 16:16
Re: I flew a helicopter today!
[Re: bonzi]
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carpal tunnel
Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
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It is in principle possible to make software as close to bug-free as one wants; it is just a matter of time and resources, that is, money. OTOH, it is impossible to eliminate human error beyond some level quite far from perfect. Funny. I would have made the exact opposite argument. It's possible to train and educate a human being to be very safe and to use good judgement, but impossible to find every possible bug in a piece of complex code, and impossible to code something so that it can deal with all possible contingencies.
I don't think any rational person argues for "all computer control" or "all human control". Everyone agrees that we still need people in the cockpits because electronic systems, while good and useful, can't do everything. I don't think anyone in their right mind is arguing for electronic systems that can't be overidden.
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#214750 - 14/05/2004 16:33
Re: I flew a helicopter today!
[Re: tfabris]
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journeyman
Registered: 30/12/2001
Posts: 83
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I appreciate the arguments on both sides, but as (1) an ex-professional pilot and (2) a current software engineer, let me say this...
I would much prefer to fly a plane with my hands (or the hands of another competent pilot) than fly a plane by wire that I (or other programmers) programmed.
Also, in reference to my story above, if I hadn't been able to overboost the turbines I may not be here today. A computer likely wouldn't have let me do that. Yes, assuming there was a special-caase programmed in, then yes it would have, but a "keep it within the envelope" system wouldn't have.
Fly-by-wire systems are great for reducing pilot work load (and joysticks are just plain cool), but when the sh*t hits the proverbial fan, I want to control the plane.
Just food for thought. Of course, all of this ignores aircraft that NEED fly by wire systems, like the experimental dynamically unstable designs of new fighters. No to mention, different pilots will have different preferences (hence the never-ending discussion).
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#214751 - 14/05/2004 16:45
Re: I flew a helicopter today!
[Re: tfabris]
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pooh-bah
Registered: 13/09/1999
Posts: 2401
Loc: Croatia
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Funny. I would have made the exact opposite argument. It's possible to train and educate a human being to be very safe and to use good judgement, but impossible to find every possible bug in a piece of complex code, and impossible to code something so that it can deal with all possible contingencies. Again, read those NTSB reports, and see about 15000+ hour pilots doing the most 'stupid' (and fatal) mistakes. As for code, it can be made arbitrarily close to bug-free; it's just that it is too expensive to do for 'ordinary' stuff you and I enconter. I don't think any rational person argues for "all computer control" or "all human control". Everyone agrees that we still need people in the cockpits because electronic systems, while good and useful, can't do everything. I don't think anyone in their right mind is arguing for electronic systems that can't be overidden. This sounds as a religious statement, Tony! You have been exposed (as was I) to too much expensive but lousy code. Many people in aerospace industry believe that completely automated airplanes would be safer than piloted ones (not perfectly safe, of course, just safer than human-operated). Chances are we will soon be able to find out, with UAVs and UCAVs operating in 'regular' airspace. BTW, while it is possible to overide automated navigation equipment, all Airbuses from A320 on, all fourth and fifth generation fighters, all stealth planes and drones and to some extent B-777 are completely fly-by-wire when operation of control surfaces is concerned. There are no direct mechanical or hydraulic links (again, with partial exception of 777).
_________________________
Dragi "Bonzi" Raos
Q#5196
MkII #080000376, 18GB green
MkIIa #040103247, 60GB blue
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#214752 - 14/05/2004 16:47
Re: I flew a helicopter today!
[Re: CommOri]
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carpal tunnel
Registered: 29/08/2000
Posts: 14493
Loc: Canada
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There's a huge difference between a defective autopilot system and some basic level-flight assistance under human control.
In a heliocopter, the pilot is doing everything except pedalling to turn the rotors around -- there's a motor for that job. There should really also be some motors under feedback control to do other jobs, like keeping the machine level and in one place when the pilot wants that to happen. This is quite a bit different from having the pilot just lean back and let a computer fly the whole deal.
-ml
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#214753 - 14/05/2004 16:57
Re: I flew a helicopter today!
[Re: bonzi]
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journeyman
Registered: 30/12/2001
Posts: 83
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Yeah, my dad just retired from United and flew 737, 767/77 and ended up with the 747-400 (among others). I don't think most traditionally trained pilots are too concerned about fly-by-wire (maybe I'm wrong), but my software experience certainly taints things for me.
My thoughts tend to drift into wondering how close to the edge of the envelope will the computer let me go? The answer is obviously a moving target as technologies and, indeed, testing environments and modeling systems change.
Also, even in the traditional "all hardware" flying model my life is hanging by some engineers' idea what is an acceptable failure rate anyway. To quote JP, "Oh God, our lives are in the hands of engineers". As we saw in Sioux City, even redundant hardware systems fail.
It's always an interesting discussion. I just hate adding potential software failure points to a systems that already has enough points of failure in the hardware. Even though I know that we're trading in some hardware failures for software (i.e., no long wires/pulleys or hydraulic lines/valves to fail).
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#214754 - 14/05/2004 17:11
Re: I flew a helicopter today!
[Re: CommOri]
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pooh-bah
Registered: 13/09/1999
Posts: 2401
Loc: Croatia
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Yeah, my dad just retired from United and flew 737, 767/77 and ended up with the 747-400 (among others). I don't think most traditionally trained pilots are too concerned about fly-by-wire (maybe I'm wrong), but my software experience certainly taints things for me. Well, I was concerned, too, when I read that Avidyne's MFD OS was WinNT-based My thoughts tend to drift into wondering how close to the edge of the envelope will the computer let me go? The answer is obviously a moving target as technologies and, indeed, testing environments and modeling systems change. Agreed Also, even in the traditional "all hardware" flying model my life is hanging by some engineers' idea what is an acceptable failure rate anyway. To quote JP, "Oh God, our lives are in the hands of engineers". As we saw in Sioux City, even redundant hardware systems fail. True, who knows how many screws, hoses and flanges are non-redundant points of failure in your average light plane? Actually, it amazes me how often trivial mechanical components feature in those accident reports (right behind judgment errors or just plain lack of skill in low-time amateur pilots). It's always an interesting discussion. I just hate adding potential software failure points to a systems that already has enough points of failure in the hardware. Even though I know that we're trading in some hardware failures for software (i.e., no long wires/pulleys or hydraulic lines/valves to fail). Again, agreed: in principle, simpler system should be inherently more reliable. But, let me repeat: the human component is often the weakest link... 
_________________________
Dragi "Bonzi" Raos
Q#5196
MkII #080000376, 18GB green
MkIIa #040103247, 60GB blue
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#214755 - 14/05/2004 17:45
Re: I flew a helicopter today!
[Re: bonzi]
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carpal tunnel
Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
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Dare I point out that humans also create the software?
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Bitt Faulk
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#214757 - 15/05/2004 10:26
Re: I flew a helicopter today!
[Re: wfaulk]
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pooh-bah
Registered: 13/09/1999
Posts: 2401
Loc: Croatia
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Dare I point out that humans also create the software? Heh, Bitt, I expected this
People are not very good at split-second decisions, keeping focused on boring task for long time, judgment free of preconceptions, pressures etc; our sense of orientation, acceleration and turn rate in 3D is easily fooled; when judging speed and distance we automaticaly use cues that might or might not be appropriate... In all this, essential for safe operation of aircraft, machines can be made to perform better (since the problem space is relatively small, predictable and easily defined).
Of course, being written by humans, aircraft control and/or navigation software will contain errors. My point was that, given enough time and resources, software (possibly in complex setup like multiple-redundant 'voting' systems with different, independently designed and implemented hardware and software) can be made arbitrarily close to error-free. I think we are near (or perhaps even past) the point where cost of such a system (plus the cost of residual errors) is lower than the cost we are willing to pay for human errors. This cost of human-replacing control systems is, of course, non-trivial: couple of hundred thousand bucks will not cut it...
_________________________
Dragi "Bonzi" Raos
Q#5196
MkII #080000376, 18GB green
MkIIa #040103247, 60GB blue
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#214758 - 15/05/2004 10:34
Re: I flew a helicopter today!
[Re: mlord]
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pooh-bah
Registered: 09/08/2000
Posts: 2091
Loc: Edinburgh, Scotland
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This technology already exists and is used - my kid brother used to fly Sea Kings on search and rescue and anti-terrorism missions. When hovering with a sonar buoy dropped, they push a button and they hover at fixed height and position. Admittedly he did say it was utterly boring and he has since moved to Gazelles - apparently like going from driving a bus to a formula 1 race car.
Oh, and there are a couple of helicopters which will fly inverted. The most famous is the Lynx. The critical issue is that most choppers have blades which flex - they bend up when lift is applied. Normally this is fine, but when inverted this bend means the blades will chop off the tail! Barrel rolls are fine as the centripetal force means your feet always feel 'down' but you need rigid blades to do 'real' inverted flight. And it isn't recommended even in a Lynx, as this brings it very close to limits.
_________________________
Rory
MkIIa, blue lit buttons, memory upgrade, 1Tb in Subaru Forester STi
MkII, 240Gb in Mark Lord dock
MkII, 80Gb SSD in dock
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#214759 - 15/05/2004 10:44
Re: I flew a helicopter today!
[Re: CommOri]
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pooh-bah
Registered: 13/09/1999
Posts: 2401
Loc: Croatia
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...when the computer went into autoland mode and wouldn't let the pilot override... Ah, I didn't follow the link because I don't have Real, but have just read Roger's post. This "computer wouldn't let pilot..." is urban myth (conspiracy theorist would say perpetuated by Boeing ). I remember that investigation has shown exactly the opposite: the plane's control system was switched to "direct contol laws" (closest to "manual" there is in A320) and pilots misjudged the altitude (ignoring assorted horns, beeps, "terrain, tarrain!"s and "pull up, pull up"s). Flight deck conversation indicated the morons intended to do a very low altitude fly-by (I don't remember who was to be impressed by it).
So, as a rough translation of a Croatian saying would put it, this "diverts water to my mill".
_________________________
Dragi "Bonzi" Raos
Q#5196
MkII #080000376, 18GB green
MkIIa #040103247, 60GB blue
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#214760 - 15/05/2004 10:52
Re: I flew a helicopter today!
[Re: frog51]
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pooh-bah
Registered: 13/09/1999
Posts: 2401
Loc: Croatia
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And it isn't recommended even in a Lynx, as this brings it very close to limits. Frankly, it is hard to imagine why it would be recommended, but it certainly is cool.
_________________________
Dragi "Bonzi" Raos
Q#5196
MkII #080000376, 18GB green
MkIIa #040103247, 60GB blue
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