Hard Landing - No Real Damage Pictures

I received an email from Spencer E:

Chris, 

"I’d like to put a plug in for applying CA adhesive to the ends of body tubes during construction that I first learned about on your blog. My preferred launch location is a long and wide salt flat next to the Great Salt Lake in Utah. The salt forms a ¼’’ hard crust with compacted wet sand and muck beneath. It’s not uncommon to pop a fin off even with the softest of landings. 

This past weekend I launched my BT-55 Tomahawk D-Region with a D-12 and near apogee the nose cone ejected but the parachute remained wedged in the tube. After the rocket completed its arc it descended straight down with the nose flapping against the side and did a “salt dart” into the crusty salt and sand. Instead of a crumpled or bent tube I found that the tube sliced right through the crust making it about an inch into ground. The end of the tube was filled with salt and wet sand much like a core sample. After removing the debris and wiping everything down there was some chipped paint but very little damage otherwise. I couldn’t believe it. Very lucky indeed. Thanks for the tip. 

Thanks, Spencer E

My response:

Hi Spencer,

You lucked out on that landing! Hard hits like that usually lead to some buckling of the tube.

The BT-55 is probably the strongest LPR body tube out there. The right balance of wall thickness and tube diameter.

A BT-70 or even a 101 tube is the same wall thickness as your BT-55. Those larger tubes feel weak to me.

I don't really apply CA glue around the tube lip for hard landings like yours, but no doubt it helped here!

I do a CA wipe for strength hoping it might prevent a zipper. The CE glue on the lip allows me to sand the tube edge flat and clean.

Thanks for writing and the pictures!