Canard Community Forum  

Go Back   Canard Community Forum > Landing Gear, Wheels, Tires, and Brakes
FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #31  
Old 12-05-2005, 02:14 PM
ShaleDC ShaleDC is offline
Member
 
Join Date: May 2004
Location: Alexandria, VA
Posts: 673
Default

Wayne,

I've seen the pictures of a nose down landing, and understand why you want to avoid that damage.

But have you considered that in a nose-gear down landing, that steel plate will spray sparks all along the bottom of your airframe?

I could see a situation where you're in a forced landing due to a ruptured fuel line, land short, and those sparks get sucked into cowling and ignite the fuel.

Or you hit a landing light, rupturing the strake tanks, and which are then ignited by the sparks.

I would use phenolic plate or a 20-ply Kevlar layup as your skid plate/backing, to avoid sparks if at all possible.
__________________
Plans #000

Redesigned 4-place canard.
500+ hrs into prototype build, Start Oct. 1, 05

(also build a MkIV fuselage, w/plans #1279)
Reply With Quote
  #32  
Old 12-05-2005, 03:12 PM
Wayne Hicks Wayne Hicks is offline
Member
 
Join Date: May 2004
Location: Carrollton, VA
Posts: 1,376
Default

When I land gear up, it's gonna be because I FORGOT to lower the gear. So, I’m not worried about whatever the noze skid is doing except for it being thick enough to do the job. In a forced landing, the noze skid is the last thing on my mind. We’ve been preached to enough to deploy the gear in an off-field landing. (I just have to remember to do that.)

Shower of sparks? I'm sure there will be a few sparks. But down the whole length of the fuselage? Too much Hollywood in that disaster movie.

I mentioned SS on my website, or "some other suitable material." I'm finding out that SS is tough to work with, so I'm contemplating others. My personal opinion is, if it's soft enough, pliable enough to cut and shaped by a grinding wheel on the workbench, it's probably not durable enough for a skid plate. Phenolic would certainly work. Delrin will certainly work. A block of maple wood would work. Heck, a kevlar pad would work too. But how thick do those materials have to be to protect in a prolonged skid? I've done no tests, but I'm guessing they’d have to be thicker than I had in mind.

Whatever I use, I'm going to stick with my “be replaceable” concept. If I glassed a kevlar pad to the nose cap and skidded on it, I’d still want to repair it, replace the layers, repaint it. The steel plate or suitable other offers protection from multiple skid before simply unbolting it and replacing it. I won't be in any hurry to cosmetically and/or structurally repair it after the first gear up.
__________________
=============
Wayne Hicks, Cozy Plans #678
http://www.maddyhome.com/canardpages...cks/index.html
Reply With Quote
  #33  
Old 12-05-2005, 04:10 PM
Glos Glos is offline
Member
 
Join Date: Mar 2005
Location: Roselle, IL
Posts: 252
Default

Hey Wayne

One thing I did not factor in for you earlier.

Normally when I land ,I like to plant the mains and hold off the canard untill it stops flying. That being said, the speed I got just before the nose drop was only about 40 to 50 kts and not 60 to 90 Kts.

This was quite a while ago, but I remember that the actual skid was about 50 yards maybe 100 but not more. Time was about 5 very long seconds.

I expect that the impact drop was less at these lowered speeds because the air pressure pushing down had to be less.
Reply With Quote
  #34  
Old 12-05-2005, 04:22 PM
ShaleDC ShaleDC is offline
Member
 
Join Date: May 2004
Location: Alexandria, VA
Posts: 673
Default

[quote=Wayne Hicks]
Shower of sparks? I'm sure there will be a few sparks. But down the whole length of the fuselage? Too much Hollywood in that disaster movie. /QUOTE]

I'm thinking about the times I've seen a car drag a muffler. Quite a few sparks there! (though not as bad as that cool tv footage a few weeks ago of the airbus landing with the twisted nose gear!)
__________________
Plans #000

Redesigned 4-place canard.
500+ hrs into prototype build, Start Oct. 1, 05

(also build a MkIV fuselage, w/plans #1279)
Reply With Quote
  #35  
Old 12-05-2005, 04:37 PM
Wayne Hicks Wayne Hicks is offline
Member
 
Join Date: May 2004
Location: Carrollton, VA
Posts: 1,376
Default

The thinner the metal, the hotter it gets (locally), I imagine the more sparks. That's why I want my skid plate to be wide. Yes, there will be sparks. They just won't exist for very long. And as I recall, the airbus landed at a mucho higher speed than normal in case the pilot had to go around. Still, I didn't recall seeing a huge shower of sparks. I do recall seeing the fire from the hydraulic fluid.

It is very common to see stock cars bottoming out during NASCAR races. There are sparks, but more of a flash than prolonged showers. And that's at 190+ MPH.

Again, I'm not worried at all about catching my plane on fire from the measly 5 seconds of metal sparks.
__________________
=============
Wayne Hicks, Cozy Plans #678
http://www.maddyhome.com/canardpages...cks/index.html
Reply With Quote
  #36  
Old 12-05-2005, 06:01 PM
Dust's Avatar
Dust Dust is offline
Super Moderator
 
Join Date: Apr 2004
Location: Troy, Michigan
Posts: 7,963
Default

Wayne - for you SS is probably the best solution. if the trouble you are having is cutting it, you should be able to make a plywood templet and take it to a welding shop and have any shape plasma cut for next to nutin.

they can follow the templet with a duplication set up - or - just use it to hand guide the torch. find a shop and ask them if they want the templet to size or undersize

For drilling - just sharpen bit after each hole and use cutting fluid
__________________
Enjoy the build,njut av byggandet, godere il costruire, nyd bygningen, geniesse den Bau, apolafse tin kataskevi, disfrute la construcción, curta a construção, Pidä hauskaa rakentamisen parissa, bouw lekker,uživaj grade?inaslajdaites postroikoi, geniet die bou
dust

maker of wood, fiberglass, foam dust, metal bits and one day a Cozy will pop out and swiftly whisk me from meeting old friends and family to adventures throughout the world
Reply With Quote
  #37  
Old 12-06-2005, 11:13 AM
dpaton's Avatar
dpaton dpaton is offline
Future Cozy Driver
 
Join Date: Oct 2005
Location: Streamwood, Iiilnois
Posts: 259
Default

Wayne, have you thought at all about hard bronze? There's a reason they make tools out of it for explosive environments. No sparks.

-dave
__________________
This is not a sig. This is a duck. Quack.
Reply With Quote
  #38  
Old 12-06-2005, 11:46 AM
Wayne Hicks Wayne Hicks is offline
Member
 
Join Date: May 2004
Location: Carrollton, VA
Posts: 1,376
Default

Bronze? I know that bronze makes for some good handbells because I play with $50,000 worth every weekend. Seriously, thanx for the suggestion. I'll have to take a look at that!
__________________
=============
Wayne Hicks, Cozy Plans #678
http://www.maddyhome.com/canardpages...cks/index.html
Reply With Quote
  #39  
Old 12-06-2005, 08:02 PM
Nathan Gifford Nathan Gifford is offline
Nathan Gifford
 
Join Date: Oct 2004
Location: Tickfaw, LA
Posts: 897
Default

You know this seems like it would be easy to build a test rig and drag behind a truck to simulate a gear-up landing.

My thinking is that if it survives one gear-up event it has done it job. For what it costs, it could be easily replaced (if designed that way).
__________________
Nathan Gifford
Tickfaw, LA USA
Cozy Mk IV Plans Set 1330
Better Still --> Chapter 9
Reply With Quote
  #40  
Old 12-07-2005, 09:14 AM
Wayne Hicks Wayne Hicks is offline
Member
 
Join Date: May 2004
Location: Carrollton, VA
Posts: 1,376
Default

Yep, I've thought of doing a test. But it's fifth in line behind handbell concerts, microing my plane, hanging Christmas lights, and annualling the III. I need to go back abd dig up some old email concerning the skid pad. Nick Ugolini and others long before me had figured out a thickness.
__________________
=============
Wayne Hicks, Cozy Plans #678
http://www.maddyhome.com/canardpages...cks/index.html
Reply With Quote
  #41  
Old 12-07-2005, 11:02 AM
dpaton's Avatar
dpaton dpaton is offline
Future Cozy Driver
 
Join Date: Oct 2005
Location: Streamwood, Iiilnois
Posts: 259
Default

Nathan, It might be easier to grab a belt sander with a low hard grit and have at a chunk of material. No, it won't be accurate relative to asphalt or grooved concrete, but it will give you a very good relative wear rating for the various compounds. I can see cutting out a bunch of 12" squares of 3/4" plywood, and then building up a nose-like layup schedule for a few samples. OFf the top of my head, likely candidates might include:
Just glass
Glass with the rubber puck
Glass with Kevlar
Glass with an embedded steel plate
Glass with an external steel plate
Glass with both
Glass with bronze
etc.

It would be a matter of building a balance out of 2x4s so you could apply an accurate amount of force to the belt sander, but I'm sure an enterprising person with a warm garage could pull this off for at least a couple of the possibilities (we already know pretty well that the rubber puck doens't work well, and that an external steel plate is ground down too).

I'd volunteer, but my garage is 1F right now, and my heater won't be installed until next winter. I can't do layups inside as I'm sensitized to the fumes, and I don't like the idea of wearing my full-face mask to bed.

Just my $0.02 of course, worth precisely what you paid for them

-dave
__________________
This is not a sig. This is a duck. Quack.
Reply With Quote
  #42  
Old 12-09-2005, 11:16 AM
Wayne Hicks Wayne Hicks is offline
Member
 
Join Date: May 2004
Location: Carrollton, VA
Posts: 1,376
Default

New picture showing the template and relative scale.
__________________
=============
Wayne Hicks, Cozy Plans #678
http://www.maddyhome.com/canardpages...cks/index.html
Reply With Quote
  #43  
Old 12-09-2005, 11:19 AM
Wayne Hicks Wayne Hicks is offline
Member
 
Join Date: May 2004
Location: Carrollton, VA
Posts: 1,376
Default

Okay, where art thou photos?
Attached Thumbnails
Click image for larger version

Name:	13puck1.jpg
Views:	52
Size:	23.5 KB
ID:	1627  Click image for larger version

Name:	13puck2.jpg
Views:	57
Size:	26.5 KB
ID:	1628  
__________________
=============
Wayne Hicks, Cozy Plans #678
http://www.maddyhome.com/canardpages...cks/index.html
Reply With Quote
  #44  
Old 12-09-2005, 03:17 PM
Ben Ben is offline
Member
 
Join Date: Apr 2005
Location: Earth
Posts: 149
Default Not Hollywood, and another skid variation

To add to the discussion,

A Varieze based out of Falcon Field in AZ caught fire on roll(grind)-out at the home field one day secondary to sparks from the skid entering the engine compartment. The pilot was able to put out the flames with his on-board fire ext. He later lost his life in the same plane.

For those interested in other ideas for a skid, check out the nose close-up shot:

http://ez.org/feature/F0412-1/fran.htm
Reply With Quote
  #45  
Old 12-10-2005, 12:59 AM
Lynn Erickson Lynn Erickson is offline
EVOLUTION EZE
 
Join Date: Nov 2005
Location: Chino, CA
Posts: 535
Default Best Nose skid material?

The mid west guys should know this one. here in california we use ones with the Kings logo on them. Hockey pucks have been used for years on many ez's and have been well tested. There is a cozy III out here that has tested his no less than 4 times and reports that they last about 1 1/2 landings. he just floxes it on and builds a teardrop fairing around it. I was with him once on one of his nose skid test flights and when the canard stops flying you only skid about 200 feet more. You could say it works a lot better then his memory.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 11:59 AM.


Powered by vBulletin® Version 3.6.7
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.