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JustPlaneChris · Apr 21, 2009, 10:38 PM

I guess it was inevitable, but my Swift finally suffered a major catastrophe today after almost two years of trouble-free flying.

After work today Liz and I headed for the ARCA field with the Swift and Protos for a little before dinner flying. I was anxious to see how well the new Swift canopy showed up in the air. Very well, as it turns out!

On the second flight, I'd been out doing fast flight, big loops, rolls, etc and was coming back in for some low-and-slow. When I was directly nose-in and about 50 feet away, BOOM! The Swift fell to the ground, the battery pack bounced end-over-end down the runway, and silence reigned over the field.

So, what happened? A blade grip broke right at the bolt hole. You can see in one of the photos below that the break is different colored (circled area) which on metal would indicate a pre-existing crack. I'm not sure if that holds true with plastic, but I'm guessing it does.

These are the original grips, and have (according to my transmitter timer) logged about fourteen hours of flight time. They've not been through any crashes, but have spent the majority of their life spinning 550mm blades at 1900-2000 rpm. It is my opinion that this is simply too much stress on the stock plastic blade grips, which were designed for 515-520 blades. I would advise any of you flying 550s at or near 2000 rpm with the stock plastic grips to inspect them carefully before each flight, or upgrade to metal. I can tell you from first-hand experience that it's pretty damn scary when a blade is thrown, especially in close proximity to yourself. The thrown blade was located about 30 yards from the point of impact, thankfully away from me, not towards me.

EDIT:The more I think about this, the more I think these grips may simply have reached the end of their fatigue life. Two years of flying, lots of rough autos... maybe we should just change out these plastic grips every year as a preventative maintenance item.

The timing of this event was ironic, because after the first flight today I commented to Liz that poor Swifty just can't compete with my Protos or Knight when it comes to performance and flying pleasure. I guess it's time to retire Swifty, so look for a Neu 1910-1.5Y / CC 45-HV going up for sale soon.

The other thing I find interesting (knowing myself, and my tendency to have a short temper) is that I am not the least bit upset. The more I think about it, I'm sobered by what could have happened if the blade had thrown in a different direction, but I guess we just have to say "stuff happens" and move on.

-Chris

Apr 21, 2009, 10:38 PM	#3258
JustPlaneChris www.insideheli.com Join Date: Sep 2005 Location: Austin, TX Posts: 9,575	Another Swift down! I guess it was inevitable, but my Swift finally suffered a major catastrophe today after almost two years of trouble-free flying. After work today Liz and I headed for the ARCA field with the Swift and Protos for a little before dinner flying. I was anxious to see how well the new Swift canopy showed up in the air. Very well, as it turns out! On the second flight, I'd been out doing fast flight, big loops, rolls, etc and was coming back in for some low-and-slow. When I was directly nose-in and about 50 feet away, BOOM! The Swift fell to the ground, the battery pack bounced end-over-end down the runway, and silence reigned over the field. So, what happened? A blade grip broke right at the bolt hole. You can see in one of the photos below that the break is different colored (circled area) which on metal would indicate a pre-existing crack. I'm not sure if that holds true with plastic, but I'm guessing it does. These are the original grips, and have (according to my transmitter timer) logged about fourteen hours of flight time. They've not been through any crashes, but have spent the majority of their life spinning 550mm blades at 1900-2000 rpm. It is my opinion that this is simply too much stress on the stock plastic blade grips, which were designed for 515-520 blades. I would advise any of you flying 550s at or near 2000 rpm with the stock plastic grips to inspect them carefully before each flight, or upgrade to metal. I can tell you from first-hand experience that it's pretty damn scary when a blade is thrown, especially in close proximity to yourself. The thrown blade was located about 30 yards from the point of impact, thankfully away from me, not towards me. EDIT:The more I think about this, the more I think these grips may simply have reached the end of their fatigue life. Two years of flying, lots of rough autos... maybe we should just change out these plastic grips every year as a preventative maintenance item. The timing of this event was ironic, because after the first flight today I commented to Liz that poor Swifty just can't compete with my Protos or Knight when it comes to performance and flying pleasure. I guess it's time to retire Swifty, so look for a Neu 1910-1.5Y / CC 45-HV going up for sale soon. The other thing I find interesting (knowing myself, and my tendency to have a short temper) is that I am not the least bit upset. The more I think about it, I'm sobered by what could have happened if the blade had thrown in a different direction, but I guess we just have to say "stuff happens" and move on. -Chris Attached Thumbnails This is where it fell, right in the middle of the runway. 127.7 KB · Views: 198 Circled area shows the different color in the break. Pre-existing crack? If it were metal, that's what I'd diagnose. 50.6 KB · Views: 241 It's the new "high tail" modification. 115.4 KB · Views: 192 Solid main shaft - bent 96.4 KB · Views: 193 Pathetic! 101.8 KB · Views: 218 A123 pack has some minor scuffing on the corners after a bouncy-bounce across the runway. 88.7 KB · Views: 171 Last edited by JustPlaneChris; May 06, 2009 at 10:29 PM.