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Bell 412

Old 26th Jul 2005, 06:21
  #81 (permalink)  
 
Join Date: Nov 2003
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Quick and Easy Helicopter Pilot Training

Contact a guy named Tank. You'll find him somewhere in the Matrix. He has training programs for all types of helicopter.

Give him a ring and ask for a "Pilot Training Program for the B412 helicopter".

In 30 seconds all the knowledge you need to be able to fly the helicopter will be uploaded to your brain via the telephone network!

Clever, eh?!
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Old 26th Jul 2005, 08:11
  #82 (permalink)  
 
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MMMM... WE MEET AGAIN "MR ANDERSON" or should i say Neo...
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Old 26th Jul 2005, 09:28
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Hi,

Do you want any manual in particular or just the Flight Manual?

I bought a flight manual on CD ROM from a guy in Toronto on EBay. He had a whole selection of manuals copied onto CDROM. I can't guarantee it was legal, but he had his own business that specialised in that so I can only assume it was legit. If not, I'm sure Bell are onto him.

I did the usual Ebay thing and I had it in my grubby little hands in 10 days.

Do a google search or a search on ebay for flight manuals or pilot operating handbooks.

If you don't have any luck, PM me and I'll see if I can dig it up and give you more info.

Cheers
CB
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Old 27th Jul 2005, 00:06
  #84 (permalink)  
 
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Con...roger that thanks mate i will give it a go, and basiscally i'm trying to get a training manual on the a/c to start with....I can get my grubby hands on a " fright manual" at work. but the disk copies sound kool
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Old 27th Jul 2005, 12:12
  #85 (permalink)  
 
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Skitso,
Look I do have an acrobat copy of the FS 412 manual, I scanned the latest version and its on disk, saves lugging the two books about when on trips. However the files are rather large and not any good to send over the Internet, too slow and costly from my backwater of the unknown world. However if you want to PM me maybe we can sort an alternative.
Outhouse
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Old 1st Aug 2005, 00:10
  #86 (permalink)  
 
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412 ground resonance

Did you ever hear of a ground resonance incident in a 412?

I've done a search in the ntsb site without results.


Thanks
Aser
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Old 1st Aug 2005, 04:32
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Aser - Your havent been bouncing the Malta Gozo machine have you
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Old 1st Aug 2005, 06:49
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In the absence of drag dampers, undercarriage oleos or pneumatic tyres, it would seem unlikely to be a problem.
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Old 1st Aug 2005, 08:31
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But the RFM does make mention of it....something to do with the ability of the skids to slip in the rubber mounts or something as I recall....thus setting up a lateral input to the rotor system similar to an oleo.
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Old 1st Aug 2005, 09:19
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The Aft cross tube on the 412 has a support beam fitted not fitted to the 205 and 212, to give a single point attachment to the airframe to counter ground resonance if the elastomeric dampers sticks (fails) in the leading or laging mode. Thats what gives the 412 its rock from side to side when you move around on top the aircraft as the cross tube rolls within the support beam.
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Old 2nd Aug 2005, 00:01
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It's not unusual for a perfectly tracked and balanced 412 to 'pad' markedly on the ground at min collective pitch, particularly on concrete. Whilst it may be uncomfortable it is not divergent and can be stopped by raising the collective slightly.
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Old 11th Aug 2005, 22:11
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idle stop I know what you are talking about, I had the experience in one 412 and I thought it was going to self destroy


I believe the possibility of ground resonance in a 412 although very remote , exists.
The dampers , rubber in the crosstube, or one drop restrainer not in locked position after the previous shutdown... something can fail.
Maybe a pilot react intending to lift the helicopter and find himself hitting a nearby tree... ?
What do you think guys?
Ned-Air2Air: The machine is fine , I was just speculating about something I heard...

Thanks for your responses
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Old 12th Aug 2005, 04:11
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In early stages of vertical bounce, place cyclic right aft, if this does not work as it often will, pull a little collective as was suggested earlier. Be aware that you can increase the bounce if you hold the collective tightly causing it to have a pilot induced factor as well , Cheers Yabu
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Old 12th Aug 2005, 06:22
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Yabu

I would imagine if you pull the cyclic 'right aft' then your early stages of vertical bounce may well be replaced by broken tail rotor
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Old 12th Aug 2005, 11:44
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As all Bell 412 pilots know - those things LEAK with oil underneath. The rubber dampers on the aft crosstube gets hammered by this oil and can eat them away fairly quickly.

This can increase the ground bounce as well.

I have never had anything close to ground resonance in the aircraft in over 1000 hours of flying them.
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Old 13th Aug 2005, 07:26
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Spanish Waltzer, Moving the cyclic right aft is not to be read as a harsh manuever, and you will normally find a "sweet spot" at which time early stages of bounce will cease. I am only trying to aid, with my 4000 hours on the 412. If you think it is not a reasonable suggestion, then so be it. Regards
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Old 13th Aug 2005, 09:17
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Yabu, right and aft is where usually I move the stick to turn off the Cyc Center light, so what you are suggesting in finding the sweet spot sounds like a good idea , I was taught just to add a little bit of collective.

Best regards.
Aser
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Old 13th Aug 2005, 13:48
  #98 (permalink)  
 
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Ground resonance is a term we misuse the way we misuse LTE and Settling with power. Every time a guy runs close to pedal limits he calls LTE, every time he starts falling through on approach it is VRS and every time the aircraft wiggles on the ground it is ground resonance.

Some thoughts on true ground resonance:

1) It is possible to get it in any aircraft that has a lag degree of freedom, even the 412.

2) It takes something mis-adjusted or mis-maintained to get it, because all helos that have lag hinges have systems to quell it. Manufacturers have to prove they are immune to ground resonance to themselves and to the FAA. Those systems (oleos, dampers on skids, dampers on blades, elastomers on all the previous) do not cause ground resonance, they prevent it.

3) It is a destructive resonance where the blade goes out of lag position, and the ground restraint (gear, skids, chocks/chains) reflects the out of balance back to the rotor in such a way as to drive the blade further away from the center. This means the vibration amplifies with each cycle.

4) True ground resonance is fast, vicious and destructive. Usually the number of cycles is few (maybe 10 seconds) and the cure is to leap airborne (stops the ground from reflecting the wave back to the head) or shut down fast, slapping on the rotor brake (which drives all the blades forward and again breaks the cycle).

5) Some helos have spots where the main rotor dampers are less effective (sweet spots in the cyclic) while on the ground, and they shuffle or bounce in yaw, roll or pitch enough to be noticed by the crew. These areas of lower damping are not ground resonance.
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Old 13th Aug 2005, 14:18
  #99 (permalink)  
 
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Nick

I think the point that everyone has been talking about with the last few replies was in conjunction with the "Ground Bounce" (not ground resonance) which can feel a little harsh dependant on the track and balance of the particular aircraft, wind direction, quality of dampers on the rear crosstube, etc.

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Old 13th Aug 2005, 15:46
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Oogle,
Agreed! You can get it in a BlackHawk at very aft stick, for instance, when you land down-slope. It is a combination of dampers that are stroking alot, tail wheel lateral compliance and AFCS activity.
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