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Emergency Egress

SkywayCaptain

SkywayCaptain

Active Member
I noticed that several of you have purchased some type of emergency hammer to break the canopy for emergency exit use. I think this is a great idea no matter what type of canopy you have, so I bought one for my RV-7.

A week or so ago, I happened to be in the local maint. shop changing my oil and making a few adjustments on the 7. I was chewing the rag with the shop manager and he told me that they were going to break the windshield out of a Cirrus aircraft that was parked next to me in the shop as they were going to replace the windshield.

Seeing a chance to actually try out my emergency hammer, I asked and was allowed to use my hammer on the Cirrus windshield.

After smacking the *&^% out of the windshield for several minutes with the hammer, I got NOWHERE!

Now, I know that I am no "he man", but I consider myself at least average strength. The Cirrus windshield may be slightly thicker than the RV's and I don't know if they are made of the same material.

I know that they work well on tempered glass in autos, but this makes me seriously wonder if these emergency hammers are practical at all for RV's.

What do you guys think??:confused:
 
I think you should have pulled the chute and tried again.:D

Were you ever able to break the windshield?
 
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I wasn't ever able to do anymore damage than to put quite a few little puchmarks on it. The shop guys used a die grinder and some less elegant methods to finally remove the windshield.
 
SkywayCaptain said:
I noticed that several of you have purchased some type of emergency hammer to break the canopy for emergency exit use. I think this is a great idea no matter what type of canopy you have, so I bought one for my RV-7.

A week or so ago, I happened to be in the local maint. shop changing my oil and making a few adjustments on the 7. I was chewing the rag with the shop manager and he told me that they were going to break the windshield out of a Cirrus aircraft that was parked next to me in the shop as they were going to replace the windshield.

Seeing a chance to actually try out my emergency hammer, I asked and was allowed to use my hammer on the Cirrus windshield.

After smacking the *&^% out of the windshield for several minutes with the hammer, I got NOWHERE!

Now, I know that I am no "he man", but I consider myself at least average strength. The Cirrus windshield may be slightly thicker than the RV's and I don't know if they are made of the same material.

I know that they work well on tempered glass in autos, but this makes me seriously wonder if these emergency hammers are practical at all for RV's.

What do you guys think??:confused:
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Don't know what kind of hammer you have, but if it is that little plastic thing with the pointed metal tip it is worthless on our canopies.

You need serious mass to smash the canopy. Many of use consider the passenger control stick to be our canopy breaker since you can use two hands to inflict a really hard stabbing impact on the canopy. Somebody sells a heavy steel point to install on the bottom end of the stick.
 
I make a special lightweight hammer to do this job which worked ok with a big swing in the shop but not very well if you simulated the typical swing you might be able to do upside down inside an RV. I rely now on my survival pack hatchet if I could get to it after the flip over- maybe.

You really need something clamped up front or in the pocket of you flight suit so it is within reach. A pistol has been mentioned but we're not allowed to carry those in Canada. I'm looking at a couple other devices which might work.

I can say, the standard auto crash hammers don't do the job too well even when sharpened to a razor point.

If the plane is on fire, the pistol seems like the quickest way to exit. You need to be out within 30 seconds or less. Maybe a big red crash axe like they carried in DC3s would be the ticket.:rolleyes:

Maybe this: http://www.ramset.com/721.asp

And builders are so paranoid about cracking plexi when drilling or cutting!
 
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The hammer I have does have a plastic handle, but the business end has a fairly heavy chunk of metal on it. It is not as heavy as the older style crash axes I have seen in jet cockpits. I also tried standing outside the Cirrus and swinging as hard as I was able at the windshield, with the same results. I'm sure that a more massive hammer would help, but it would be nice to know if anyone has been able to use one of these heavier hammers to break out of a RV canopy.
 
just a guess, but it sounds like lexan[polycarbonate] to me. you could bang on that all day long with a 12# sledge hammer and not break it. it's a great choice for a windscreen especially with a duck heading at you at 150+ mph.
 
Car and Driver

When these hammers first came out
emergency-hammer-sm.jpg

Car and Driver took one to a junk yard to give it a try.

Not only wouldn't it break a tempered glass window from the inside, they couldn't do it from standing on the outside.

Also, the seatbelt cutter didn't cut. The belt just bunched up.

They recommended against their purchase.
 
Lexan vs. Plexi

bluezero513 said:
just a guess, but it sounds like lexan[polycarbonate] to me. you could bang on that all day long with a 12# sledge hammer and not break it. it's a great choice for a windscreen especially with a duck heading at you at 150+ mph.
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I have no personal expertise or knowledge on this subject, but just sharing something I read in an old RVator...

Van's canopies are plexi. They were questioned about using lexan instead, suposedly for it's higher durability and less tendancy to crack. Apparently they did some research, and found that (I think from Air Force tests) though lexan is indeed tougher, the increased flexibility posed other risks. In the case of bird strike, the theory (or practice... don't know if there were any actual cases) was that the lexan canopy could deform (cave in) from the impact, whack the pilot, and then pop back into shape. I can only imagine the NTSB report on that one...:eek:
 
Alternative.

And yet, these canopies seem to break so easily when building. Perhaps the best tool would ba a non-plexi drill and a portable battery powered drill. :)

Tracy.
 
In the years I've been flying my plane (9), I never found a tool that I thought was worth carrying in the plane. If I have to get out, and was able, it would be a matter of kicking the canopy and hoping you could get out. A long shot at best.

But with someone above mentioning the pistol, I think they're onto something. Maybe not a pistol - although a very good idea - but how about something similar to one of those boom-sticks used on sharks. A short, single-shot (reloadable) device that would fracture the plastic. I think you'll need the extreme velocity and shock (high impulse) of a shotgun blast to actually open up a canopy.

Now, the BATF would probably have a problem with a 6" shotgun. But some similar exploding device might *actually* remove large sections of Lexan in a bind.

And the more I think about it, a Saturday Night Special with a few extra rounds would be perfect! Just have to watch what state you fly into... Would also drop the probability of having your RV hijacked to essentially zero! :D
 
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There is no way a Lexan 1/4 inch thick, curved windscreen would cave in far enough to hit the pilot on an RV. If you have worked with this stuff, you know how indestructable it is. It does scratch easier but does not crack like Plexi.

This would be far more bird proof than Plexi but you could never kick it out or shatter it if you were trapped.

Maybe this with a 1/4 end mill stuck in the end: http://www.mytoolstore.com/panason/pan07-10.html
 
Heck....

With that Mossberg, you wouldn't have to worry about using a lexan canopy. Just point whatever direction might be up. Sheet metal, plexy, whatever... there will be a hole.
 
Although I like the "Super Shorty", I suspect if the plane is upside down, the canopy will already be broken and it is just a matter of finishing the job with your foot. Just remember to tell your passenger to "hang in there" until you clear a path.

There has to be one or two people reading this thread that have had the unfortunate experience of crawling out their upside down RV. If so, please tell us your story.
 
A dual use tool...

Now we're talking..I mean if a single shot deal would work then for $19 then why not?

Assuming you can load it and keep a saftey on...would't want to have to fuss finding the " bullets"
 
Bullets will not penetrate lexan. 1/4 lexan will stop a .303 at point blank. The sales people for lexan use to have pieces with the bullet just starting to get embedded into it. Security vehicles use it in between the panels to make them bullet proof.
 
Gloves

Consider some heavy leather gloves. From what I have seen the canopy cracks on its own and you need to grab edges to break them off, to affect an exit.

Also you might need to dig yourself out of the dirt under the canopy sill. A really large heavy duty (combat) knife with handle gaurd might be handy. I like the control stick pointy thing attachment as well. I never had to use any of them, hope I'll never have to. For auto glass a spring loaded center punch works well, saw it on Myth Busters :)

The Cirrus windscreen has a few advantages, its framed and no doubt thicker than a RV canopy. Not sure if the Cirrus windscreen is Lexan or Plexi (trademarked names), but they both have pros and cons. RV's I think is traditional Plexiglass, which is more brittle than Lexan.

Consider the clothes you wear, T-shirt, cutoffs and flip-flops might not be ideal. Leather jackets are too hot for summer and potentially might label you a poser, but one piece fire retardant flight/uniform suit might be practical in an emergency.

There was a nice long thread on rescue tools a year ago.
 
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Fowl balls

rv6ejguy said:
There is no way a Lexan 1/4 inch thick, curved windscreen would cave in far enough to hit the pilot on an RV. [/url]
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Ross,
When I was in Aero Eng class 30 years ago, we watched a development video for the F-16 canopy which was polycarbonate (Lexan). The video showed a 1/2" thick canopy of lexan being struck by the well known chicken cannon projectile. The pilot dummy was cold cocked. They needed to move up to 5/8" before the deflection was small enough to miss the pilots head.

In regards to impact speed, the tests were subsonic. Impact energy does go up by velocity squared but at the same time the canopy stiffness will change by thickness squared. The RV speed regime and canopy thickness for a tip-up are likely in the range of this danger zone. The slider is probably not an issue due to the short mounting span of the windscreen.

Mind you, I have nothing against a Lexan canopy. I find little difference between being hit by the lexan canopy or being hit by the actual bird and additional shards of a busted acrylic canopy.
 
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rv6ejguy said:
There is no way a Lexan 1/4 inch thick, curved windscreen would cave in far enough to hit the pilot on an RV.
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Ross,
In addition to what Bill said above, Van's himself has repeated this same thing, that during a bird strike Lexan can flex all the way in and wack the pilot in the head. Check out pg 104 of "21 Years of the RV-ator" where Van's wrote an aritcle on Lexan canopies in 1988.
 
Norman CYYJ said:
Bullets will not penetrate lexan. 1/4 lexan will stop a .303 at point blank. The sales people for lexan use to have pieces with the bullet just starting to get embedded into it. Security vehicles use it in between the panels to make them bullet proof.
Click to expand...

It's not Lexan. It's Plexiglass.
 
I've worked with Lexan for 25 years in the race car business. First of all, 1/4" will not stop a bullet. Second, if the windshield flexed enough to hit me in the face, it would have to come right out of the frame at that energy level (bird strike at 150 knots). The material is not that fluid or shall we say plastic. Done lots of sledgehammer deformation tests on anti vandal glazing for shops- I have it on all my windows here. Impressive stuff. Often times the material can absorb such force that the frames buckle, distort or fail while you just have some hammer dents in the Lexan. You can cut 1/16 Lexan with tin snips quite nicely.

For bird impact, I'd take Lexan any day over Plexi which just shatters, offering little protection and lots of shrapnel. What is the difference between being hit with the windshield or blinded by a shower of Plexi fragments and a 4 pound bird carcass?

For egress upside down in an RV, I want plexi because you are screwed with Lexan unless you have some serious type of saw. You cannot break it with any sort of hammer you could carry- ever.

I think Van's makes the best choice on RVs using Plexi.
 
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Use a knife

I have two issues with shooting my way out of an overturned aircraft:

  1. Shooting a weapon might ignite the ever-present gas fumes that seem to come along with an RV crash
  2. You might shoot someone that is just coming up to help you

I know of at least one pilot that got out of an overturned RV with a knife:

http://www.rv8.ch/article.php?story=20051007163110721
 
rv8ch said:
I have two issues with shooting my way out of an overturned aircraft:

  1. Shooting a weapon might ignite the ever-present gas fumes that seem to come along with an RV crash
  2. You might shoot someone that is just coming up to help you

I know of at least one pilot that got out of an overturned RV with a knife:

http://www.rv8.ch/article.php?story=20051007163110721
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Fire, shooting someone coming to help... details, details. ;)
 
How about breaking aluminum?

In all this talk about canopies, I think we're missing another potential exit: the aluminum floor bottom, which in a tip-over is now pointed skyward. Not blocked, not super tough, maybe kickable.
 
Upside Down Exit

rfinch said:
In all this talk about canopies, I think we're missing another potential exit: the aluminum floor bottom, which in a tip-over is now pointed skyward. Not blocked, not super tough, maybe kickable.
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So now if we see someone's RV named "Miss Poseidon," we will know how they plan an inverted emergency exit!!! :D
 
First, does anyone know what Cirrus uses for windshield material? Secondly, how thick? If different from RV's, then we have no useful data, but we may have cause for more researc:.

We have plenty of folks out there in RV land who have cracked & trashed their canopies, the $900+ mistake. How about someone with a dead canopy attaching it to a frame of some sort, suspend it upside down on sawhorses and reporting what it takes to break through? This would represent a worst case scenario, because Van's says that in a tipover, the canopy usually shatters. Of course if it were an RV-8 canopy, the results wouldn't exactly represent the RV-6, 7 or 9 case, then you have the tip up vs. slider comparison, but it still represents better info than speculation.
 
I will stand corrected that Lexan will not stop a bullet. I guess it was just hype from a smooth talking salesman. I then don't know what he was showing as an example. And the security van's must be using some other product than looks like lexan. I was told that is what it was. Sorry.
 
Army aircrew survival and egress knife

The Army has been using this knife for its aircrews since about 2004:


http://www.olive-drab.com/od_edged_weapons_tools_asek.php

There is a point on the metal end of the handle that is not shown in the picture. That point is used to break canopy glass. If the beating the canopy with the point does not break it, you used the point to score the canopy so that it can be more easily broken. I have not used it for that purpose and I hope the Army tested it well (I assume they did) before deciding to issue it for the purpose of emergeny egress from an aircraft.

I bought one on ebay (shop around there are several vendors). I removed the John Wayne looking staps and put the knife, in its sheath which also holds the separate strap cutter, in my flight bag. I hope that I never have to use it, but I feel better having it.
 
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rv6ejguy said:
If the windshield flexed enough to hit me in the face, it would have to come right out of the frame at that energy level (bird strike at 150 knots).
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For your slider windshield, true. The longer mounting spans of the tip up will let the lexan flex, though.

rv6ejguy said:
For egress upside down in an RV, I want plexi because you are screwed with Lexan unless you have some serious type of saw. You cannot break it with any sort of hammer you could carry- ever.

I think Van's makes the best choice on RVs using Plexi.
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An anecdotal note about breaking Lexan, in agreement with Ross above. I use a 3' square piece of 1/4" lexan for chopping barbeque.:cool: This is with the BIG heavy meat cleavers too, not the ones from your local mall. They are sharp as a razor and weigh about 3 lbs each. All I get is slight scratches on the surface of the lexan.
 
I might add that Lexan fractures at about 10% elongation at room temperature. Yes, on a tip up with little support in the front half, I could see a large deflection happening after a bird strike.
 
rfinch said:
In all this talk about canopies, I think we're missing another potential exit: the aluminum floor bottom, which in a tip-over is now pointed skyward. Not blocked, not super tough, maybe kickable.
Click to expand...

I always like it when someone brings humor to the forum. This was meant "in humor" wasn't it? I can't even imagine trying to do this. Better build that fuse and take a good look at it before you think this might work.
 
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