 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
8wn(at)comcast.net
Guest
|
 Posted: Wed Apr 08, 2009 9:03 pm Post subject: Ground Safety |
 |
|
Thought I would report on an explosion in the right wing tank of my lightning while I was dusting the dirt off the wing last Wednesday
[img]cid:7A26256DF04E4925AD55C1EEC01E25DD(at)GayLaptop[/img]
Around 7:30 am I had my plane outside in the sun so I could do a final polish of the newly painted cowling and also improve the appearance of my year old paint on the remainder of the aircraft. I completed the polishing about 8:30 am and moved the plane back into Greg's hanger where I was going to reweigh it because of the new paint and new wing tips. Last year I had defueled the aircraft and removed the wings so I could install a new type on low fuel warning system that is independent of the current fuel probes.NOTE: This is not required for safety, I just do it to have something to do and being a retired military pilot (Army) I am use to triple backup systems and lost of lights and switches. I use the standard fuel probe with GRT, the fuel flow from GRT(which I recommend for those who like to fly long distance/hours), and an electronic optical system that will visually and audibly note when the fuel take is down to 2 gallons in either tank, amount is set by installer. We do have a 4th warning system for low fuel if all this fails, the prop stops.
Around noon after the aircraft had set untouched for over three hours I took a polishing rag I normally use to clean the canopy, 80% Polyester - 20% Polyamide, and started to dust off dirt that had settled onto the wing from a wind storm we were having. I started outboard moving inboard, as I touched the fuel cap (cap was installed and locked) the tank exploded. The Dragon had spit fire. I felt and saw the top skin rise, a 6 foot section of the top skin on the trailing edge split at the glue joint and flames came out removing the hair on my arm and embedding fiberglass in my glasses. As seconds passed I noted the fire was out and then remembered it was defueled.
After a few seconds I composed myself and noted the top surface looked fairly normal with only delimitation of a section of the top skin. Underneath the wing the tank had ruptured outboard (can't see where else) and the wing had numerous large tears and cracks around the tank area.
[img]cid:1E8A1244518E477CA91CE07730AD8A01(at)GayLaptop[/img] [img]cid:C024DE6BD73B4087B2802DD217967302(at)GayLaptop[/img] [img]cid:CB755812824C4973B1A15D63E7B6B51B(at)GayLaptop[/img]
This was an accident caused by static electricity. I have been in aviation professionally for 40 years and know the danger of static electricity and fuel vapors. I might have been able to prevent this by having the aircraft grounded, using a rag of different materials, properly removing all fumes from the tank, etc. Weather is also a major factor. Fuel tanks are more prone to have an explosion when low or empty of fuel.
I got off lucky. We can reduce the possibility of this happing to any of us. I will review everything, I have found a possible static transfer between the fuel cap and housing and will install a grounding cable between the fuel cap and housing. This is a standard procedure used on military and most civil aircraft and will reduce the danger. I inspected my Velocity XL-5 and another aircraft having the same cap, neither has a grounding cable. This is a very common fuel cap used by many builders and types of aircraft for years and I have never heard of this happing before. Before Installing I will follow all established procedures and purge the tank with argon or other inert gas. If we just follow good safety procedures this most likely would have never happened. An hour later I met with Greg Hobbs at the aircraft and started checking for signs of static buildup. He could not detect any static buildup so I reached down to touch the wing an immediately noticed a static build up. Greg put his arm near the wing and no sign of build up. Once again I placed my arm near the wing, about 6 inches from Greg and we noted a static build up between my arm and the wing surface (remaining hair drawn toward the surface). ??????
A DEFUELED TANK IS A BOMB WITH THE SAFETY OFF.
I would like to add that the lightning is an excellent structurally designed aircraft. I am positive that if I had this damage in flight the aircraft integrity would remain sound and make a safe landing.
I want to thank Nick and Pete for helping me with replacement parts at a very reasonable cost. Once again I see Arion going the extra mile to take care of the lightning family even in these difficult financial times. I have owned many aircraft in the past and Arion is at the top in support and service.
I will follow up with any information I discover.
Johnny Thompson
| | - The Matronics Lightning-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Lightning-List |
|
|
|
| Back to top |
|
 |
wampam
Joined: 20 Oct 2008
Posts: 49
|
| Posted: Thu Apr 09, 2009 8:49 am Post subject: Re: Ground Safety |
|
|
Gad Johnny,
I know how much work you have put into your plane to it back into flying shape again. I would be really interested in what you find out. I have wondered if simply grounding the plane at some metal part (exhaust) would be sufficient on a composite airframe. Composite aircraft that are to be IFR certified require to have embedded metal screening or some other conductive material in order for lightning protection. The Lightning does not have this. I am sure the plane would discharge but it may take some additional time compared to a metal airframe.
Walt Mefford
N881WP
| | - The Matronics Lightning-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Lightning-List |
|
|
|
| Back to top |
|
|
wampam
Joined: 20 Oct 2008
Posts: 49
|
| Posted: Thu Apr 09, 2009 9:39 am Post subject: Re: Ground Safety |
|
|
Has anyone determined if static wicks are effect on composite aircraft in flight?
W. Mefford
N881WP
| | - The Matronics Lightning-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Lightning-List |
|
|
|
| Back to top |
|
|
Clive J
Joined: 03 Nov 2007
Posts: 340
Location: UK
|
| Posted: Thu Apr 09, 2009 11:40 pm Post subject: Ground Safety |
|
|
| Quote: | From what I read the issue was having a cap that was not connected
(bonded) to the tank flange? I'm assuming that the tank flange is
|
grounded to the aircraft ground?
Is this the type of cap you see on Vans aircraft?
With composite aircraft all parts of the fuel system should be bonded
together. Either by design or by a wire. Even carbon fibre, although a
good conductor, aluminium it's not.
Those with Jabiru experience will know that from the fuel caps being
connected to the tank flange and everything else. It's not a bit of wire
to stop you losing the cap.
I hadn't thought of the significance before.
This is really bad luck of course, where a combination of circumstances
arrived to give some conditions that would be difficult to recreate if
you were to try.
| Quote: | From the look of such a sweet aircraft Jonny won't be long getting it
back to perfect but I know the sinking feeling of having to start again
|
when you think you've finished.
My Esqual is hanging upside down waiting for the new parts from Arion,
hopefully when I put it back together this time if will be for a bit
longer!
Thanks for sharing this, I've been thinking through my two builds to
make sure I've not missed anything in this important area.
Regards, Clive
--
| | - The Matronics Lightning-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Lightning-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
