Guest pokey Posted May 10, 2015 Report Share Posted May 10, 2015 as a mechanic,, we know what his piloting mistake was,,, free ice cream for the one who can spot it ! 2 Quote Link to comment Share on other sites More sharing options...
RagMan Posted May 10, 2015 Report Share Posted May 10, 2015 Sounds like the engine was at operating RPMs, and if that's the case, he should have pulled the aircraft into the air and got off the ground at the onset of ground resonance. I understand it happened in a heartbeat and maybe wasn't able to identify the problem quick enough to make the proper fix. Quote Link to comment Share on other sites More sharing options...
Spike Posted May 11, 2015 Report Share Posted May 11, 2015 Struts are missing...... Quote Link to comment Share on other sites More sharing options...
RagMan Posted May 11, 2015 Report Share Posted May 11, 2015 Rats... I suppose if i knew my way around an s300 i would have caught that! Quote Link to comment Share on other sites More sharing options...
adam32 Posted May 11, 2015 Report Share Posted May 11, 2015 Struts are missing......Yup. I'm pretty sure they knew it and were experimenting at what would happen. Why else would they be videoing, fire extinguishers, and a couple of the guys were definitely looking at the skids. Quote Link to comment Share on other sites More sharing options...
takefootoff Posted May 11, 2015 Report Share Posted May 11, 2015 In the beginning of the video, was he checking the elasto-meric dampers? (Forgive spelling) Quote Link to comment Share on other sites More sharing options...
eagle5 Posted May 11, 2015 Report Share Posted May 11, 2015 Missing struts isn't a piloting error. I noticed he didn't use a tourque wrench, but as I'm not an A&P I don't know if he's supposed to?...even so, that's also not a piloting error. He's sitting on the same side as the gas tank, but I can't tell if the other side has one, so I can't say that, also that's not really a piloting error either. Therefore I'm left with the only logical piloting error...he chose to fly a 300! Quote Link to comment Share on other sites More sharing options...
Spike Posted May 11, 2015 Report Share Posted May 11, 2015 (edited) Not 100% sure but, it appeared to be an A&P class with a Viet Nam helicopter pilot as the instructor (as mentioned in the prelog). Probably, a build-up from a donated machine and the reason for fire protection and video…. Thus, I can’t imagine the level of stupidity to purposely demonstrate ground resonance to the point of destruction which could possibly result in injury to onlookers… Especially, with Mr. long-hair-pony-tail-baggy-pants on scene (not to be judgmental but an obvious safety hazard). And, if I remember correctly, adjustment of the dampener does not require a torque wrench……. The mistake by the pilot was starting the engine and engaging the rotor....... Therefore, his 1st mistake was waking up and going to work........ Edited May 11, 2015 by Spike 1 Quote Link to comment Share on other sites More sharing options...
PondJumper Posted May 11, 2015 Report Share Posted May 11, 2015 This is a pretty popular video at my school since our primary trainer is the 300C. Some guys agree that this looks intentional. A couple of reasons I may disagree with that would be the fact that nobody is wearing any protective equipment (pilot helmet?), and it takes place on a ramp full of other aircraft. Not saying for sure, because honestly I have no idea but it just seems they would have taken better precaution if they knew this would happen. Either way, not having oleo struts was pretty much asking for it. Quote Link to comment Share on other sites More sharing options...
Wally Posted May 11, 2015 Report Share Posted May 11, 2015 Sounds like the engine was at operating RPMs, and if that's the case, he should have pulled the aircraft into the air and got off the ground at the onset of ground resonance. I understand it happened in a heartbeat and maybe wasn't able to identify the problem quick enough to make the proper fix. You CAN NOT get the aircraft off the ground fast enough to stop this with the collective at the bottom. Three main rotor rotations finishes the job, the rest is just normal crash.If you're LANDING, on the other hand, as you reduce collective to load the landing gear and the divergence starts, you can, indeed must lift to prevent ground resonance.The struts damp the oscillation or detune the airframe from resonating with the rotor. All of which start in the main rotor. Otherwise, the struts and gear have nothing to do with ground resonance. Quote Link to comment Share on other sites More sharing options...
Eric Hunt Posted May 11, 2015 Report Share Posted May 11, 2015 It started when he raised the lever, so a possible fix would be to dump it again....... Quote Link to comment Share on other sites More sharing options...
Flying Pig Posted May 11, 2015 Report Share Posted May 11, 2015 (edited) Double post Edited May 11, 2015 by Flying Pig Quote Link to comment Share on other sites More sharing options...
Flying Pig Posted May 11, 2015 Report Share Posted May 11, 2015 This has to be my favorite scene out of the entire video. Blades still spinning and all. 3 Quote Link to comment Share on other sites More sharing options...
SBuzzkill Posted May 11, 2015 Report Share Posted May 11, 2015 (edited) Seconds before it starts you can see him lower the collective. Doesn't look like he was light on the skids but he for sure had a little bit of pitch pulled in. Edited May 11, 2015 by SBuzzkill Quote Link to comment Share on other sites More sharing options...
takefootoff Posted May 11, 2015 Report Share Posted May 11, 2015 When the camera panned to the right @ 4:10 and you see some folks watching behind the cover of those crates, makes ya wonder. Bunch of dorks... Quote Link to comment Share on other sites More sharing options...
500E Posted May 12, 2015 Report Share Posted May 12, 2015 Looks like solid links in place of dampers, also there is a break torque for mechanical dampes.Did not hear freewheel check either. Quote Link to comment Share on other sites More sharing options...
Guest pokey Posted May 26, 2015 Report Share Posted May 26, 2015 (edited) yes, landing gear dampers missing, elsastomeric dampers is a good guess too (but they are the old friction type dampers). flying from the wrong side in a th-55 is also a good observation, waking up and going to work is closest. Initial setting of the old friction dampers does require an inch pound tork wrench and a special adapter B4 installing on the aircraft----yer gettin' even warmer ! once the engine was started, it was way past his 1st mistake. Take a look at what bolt he was turning in the beginning of the video, & which way he was turning it, i gave ya clue that is was a mechanic's mistake, for one? he was loosening the bolt to the arm that attached to the friction damper, for 2? you NEVER turn the bolt ! ! ! always the nut =unless it is impossible ( turning the bolt takes off the plating & that is necessary for 2 reasons((another time & place for that one tho)) His 1st mistake was clearly "pilot with wrench" and? dunno if it was just an error of the video taper, but? he checked the "phasing" of the blades twice on all but one on the blades. To elaborate on this, he had NO clue as to the importance of blade dampers/landing gear damper relationship & ground resonance, i hope his young A&P students learned something. oh HECK !! free ice cream for every one anyhow edit: not saying he left the bolt out, just has NO respect for aircraft bolts/hardware & shouldn't have a wrench Edited May 26, 2015 by pokey Quote Link to comment Share on other sites More sharing options...
Wally Posted May 26, 2015 Report Share Posted May 26, 2015 ... His 1st mistake was clearly "pilot with wrench" ... To elaborate on this, he had NO clue as to the importance of blade dampers/landing gear damper relationship & ground resonance, i hope his young A&P students learned something. oh HECK !! free ice cream for every one anyhow edit: not saying he left the bolt out, just has NO respect for aircraft bolts/hardware & shouldn't have a wrench The school isn't there anymore... Quote Link to comment Share on other sites More sharing options...
500E Posted June 2, 2015 Report Share Posted June 2, 2015 Still dont understand the mind set no dampers( struts?) there appeared to be no lower starboard screen leaking oil, incorrect friction damper adjustment ( almost as if they were seting it up to go ground resonance),& the stack of washers on blade does not give me any confidence in rotor ballance, with those old type blades it needs to be good for a ok ride watch the vibes at 3m40s on.Still not as dangerous as VN I suppose. Goldy no need to send ice cream Quote Link to comment Share on other sites More sharing options...
Goldy Posted June 6, 2015 Report Share Posted June 6, 2015 Hey now, Pokey said he would buy the ice cream! Not a 300 guy much so missed just about everything that Pokey pointed out! Which is why I call him if I have a 300 question! Quote Link to comment Share on other sites More sharing options...
500E Posted June 7, 2015 Report Share Posted June 7, 2015 SorryGoldyWill Collect from Pokey next time I am in USJust been in Check republic fo a couple of days with a 500 Notar that has problems Quote Link to comment Share on other sites More sharing options...
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