BAH Posted March 28, 2009 Report Share Posted March 28, 2009 I can just emagine the mess you would make every time that filter is changed. Why is it the designers put all the frequently changed stuff in the most awkward spot. Quote Link to comment Share on other sites More sharing options...
18speed Posted March 29, 2009 Report Share Posted March 29, 2009 You're right cg, not good enough. However, I don't think most machines are much better. A few years back we stopped for fuel (212) in Yorkton, Sask. for fuel on one of our cross Canada fire flaps. There was a Bell 205 sitting on the ramp with an oil covered tailboom. It seems that on short final the MBG oil pressure dropped to zero. Very shortly after landing the blades ground to a shuddering halt and pivoted the machine on the skids about 20 degrees. Total time from initial pressure drop to MRG seizure....less than 3 minutes!!! Ever since I saw that I have always kept one eye permanently glued to the MRG gauge. Was that 205 ETK? Quote Link to comment Share on other sites More sharing options...
splitpin Posted March 29, 2009 Report Share Posted March 29, 2009 Was that 205 ETK? Long since forgotten the reg. Can't even remember the colour or who it belonged to. Happened about 9-10 years ago. Any info??? Quote Link to comment Share on other sites More sharing options...
06HeliMAN Posted March 29, 2009 Author Report Share Posted March 29, 2009 Wonder what causes the studs to break? Could it be vibration and fatigue? Are the new studs merely patching a poor design? Quote Link to comment Share on other sites More sharing options...
light Posted March 29, 2009 Report Share Posted March 29, 2009 What is the approximate size of this filter housing ? Quote Link to comment Share on other sites More sharing options...
18speed Posted March 29, 2009 Report Share Posted March 29, 2009 Long since forgotten the reg. Can't even remember the colour or who it belonged to. Happened about 9-10 years ago. Any info??? Yes it was ETK when Venture leased it from Eagle, a picker truck had to move it away from the fuel pump. Were you crewing OKW? Quote Link to comment Share on other sites More sharing options...
Emory Posted March 29, 2009 Report Share Posted March 29, 2009 so this may be the wrong place to be asking this question, but given the incident involved it might be appropriate... i have very limited engineering/design/mechanical smarts (so i expect a quick "duh" response from smart engineers ) but i find myself wondering if it would be possible to put some kind of freewheeling unit on the rotor mas itself, effectively keeping it seperate from the MGB? i guess it would need another swashplate, which would be added complexity/weight, and it would probably be less durable, and im sure it would need some interesting bearing system to be able to spin freely while supporting the aircrafts weight. but is this plausible? or is there a complete duh factor that im not thinking about here? Quote Link to comment Share on other sites More sharing options...
BAH Posted March 29, 2009 Report Share Posted March 29, 2009 So here is your quick "duh" responce : Astars, the models with the roller bearing mast, actually have a shear point just below the bearings and above the epiclyclic drive (planetary gears) for this reason. The lower drive portion of the transmission could fail (say from lack of oil) and the inertia of the rotor system would shear at this area allowing autorotation to the ground. The newer roller bearing masts that are in Astars now do not have this feature, (guess Eurocopter does not think it necessary). Eurocopter put both upper and lower mast support bearings above the drive gearing making this possible. Most other helicopters manufacturers have the mast support bearings above and below the rotor drive gearing. Quote Link to comment Share on other sites More sharing options...
skullcap Posted March 29, 2009 Report Share Posted March 29, 2009 Have also seen this "sheer point" in Astar training manuals, but have seen a few horrendous crashes involving the rotor system smashing into the earth and have never seen the mast sheer,,,not saying it won't but just don't understand the forces required to make it sheer. For example a 350B hit a steel vent pipe which caused the machine to fall down and flop all over the place, mark on ground from chineese hat but yet main rotor drive still intact...four other unsurvivable crashes and still the main drive intact? Also in some types of helicopters(204,205,212 for expample) the main trainsmission drives the t/r thus if transmission fails you also lose t/r drive. Quote Link to comment Share on other sites More sharing options...
splitpin Posted March 29, 2009 Report Share Posted March 29, 2009 Yes it was ETK when Venture leased it from Eagle, a picker truck had to move it away from the fuel pump. Were you crewing OKW? No 18, I was crewing a "Yellow 212". Joined Canadian a few months later. Were you involved with ETK at the time and is she still around? Quote Link to comment Share on other sites More sharing options...
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