3D Printed Fire Extinguisher Mount

[JordanGrant]

For the past many years, my Halon fire extinguisher has been mounted in-between the seats in our RV-6. It's actually kind of a pain to get to there, and it has been getting knocked around and beating up the mount lately. So this year, I decided to move the fire extinguisher down to mount on the the front of the wing spar, underneath the pilots legs. I designed and 3D printed a custom mount (ABS plastic), and I ended up attaching that to some bars that are held in place by the wing spar bolts. Here are some pics to share the idea:







Any mounting location for a piece of emergency equipment will be a compromise to some degree, but so far I like how it turned out. We'll see how I like it after getting some time flying in this configuration.

Cheers,

[Snowflake]

Keep in mind that in the event of an off-airport excursion, that fire extinguisher will be somewhere around your rudder pedals when the metal stops moving. If you're counting on it being available after a crash, mount it on the aft surface of something solid. Battery box, seat back, back side of the flap brace (in the baggage compartment) etc.

[snopercod]

Very nice. The traditional mounts with the bale on them are a PITA.

[upperdeck]

In the event of a sudden stop, I'd be afraid it would become a projectile and pulverize my ankles and impede my egress. At least a metal bail has a chance of keeping the extinguisher in place.

[lr172]

Originally Posted by upperdeck

In the event of a sudden stop, I'd be afraid it would become a projectile and pulverize my ankles and impede my egress. At least a metal bail has a chance of keeping the extinguisher in place.

+1

That design would scare me. That bottle is a relatively heavy metal object and would not want it loose during a crash. I am not even sure it won't break loose in heavy turbulence.

Larry

[alpinelakespilot2000]

+1. Good concept though. Just needs some sort of secondary safety to keep it immobile.

Originally Posted by Snowflake

Keep in mind that in the event of an off-airport excursion, that fire extinguisher will be somewhere around your rudder pedals when the metal stops moving. If you're counting on it being available after a crash, mount it on the aft surface of something solid. Battery box, seat back, back side of the flap brace (in the baggage compartment) etc.

Originally Posted by upperdeck

In the event of a sudden stop, I'd be afraid it would become a projectile and pulverize my ankles and impede my egress. At least a metal bail has a chance of keeping the extinguisher in place.

Originally Posted by lr172

+1

That design would scare me. That bottle is a relatively heavy metal object and would not want it loose during a crash. I am not even sure it won't break loose in heavy turbulence.

Larry

[bruceh]

I would add a slot behind the mount and at least put a velcro cinch strap or wire tie around the extinguisher to hold it in place.

[Canadian_JOY]

I once bought a wrecked version of my "other airplane" for parts... It had gone into an earthen berm at about 70mph. This particular aircraft features a glare shield which is primary structure, made of riveted aluminum with heavy aluminum angle reinforcement under it.

This particular aircraft had its fire extinguisher mounted on the forward side of the bulkhead that formed the demarcation between the baggage area and the tail cone. The extinguisher was mounted in its factory-supplied mount, horizontally, bolted very well to the bulkhead.

On impact the extinguisher broke free, rocketed forward, hit the angled windshield, was deflected downward, stove in the glare shield, then rocketed aft and stove in the aft baggage bulkhead. I mean stove it in, as in a dent the shape of the extinguisher as though it had been hydro-formed about 1.5" deep.

If a passenger had been in the seat at the time of impact they would have been killed by blunt force trauma to the head by that flying extinguisher.

I'm sorry to say it, but your extinguisher mount, as well executed as it is, would almost guarantee massive damage to your legs, even in a very survivable crash.

[fl-mike]

DO-160G imposes a crash safety load of 20g's in the forward direction. The purpose of the test is to ensure that equipment stays attached in the event of a crash and does not become a hazard to the occupants, fuel systems, etc. (note that DO-160 is not a set of requirements, but rather a set of standards that may be called out in other requirements documents)
If that's a 2.5 lb extinguisher, you should design the mount and bracket to restrain a minimum of 50 lbs of force.
By inspection, I can tell you will not achieve anywhere near that with your design.

Note that velcro straps are no longer allowed for ELT mounting for just this reason.

[RVDan]

Originally Posted by fl-mike

DO-160G imposes a crash safety load of 20g's in the forward direction. The purpose of the test is to ensure that equipment stays attached in the event of a crash and does not become a hazard to the occupants, fuel systems, etc.
If that's a 2.5 lb extinguisher, you should design the mount and bracket to restrain a minimum of 50 lbs of force.
By inspection, I can tell you will not achieve anywhere near that with your design.

Note that velcro straps are no longer allowed for ELT mounting for just this reason.

Well the DO-160 ref is accurate, the Part 23 Reg?s that our airplanes were designed to call for 9 g?s ultimate. The later Reg?s called for 18g for items of mass in occupied spaces, which is what drives the DO-160 20 g test. But still, the bracket won?t likely hold 9g. The ELT Velcro straps were eliminated because of the variables caused by less than perfect alignment of the straps, and deterioration of the hook and loop over time. When initially qualified, the ELT straps passed the DO-160 testing, but it was found that these variables resulted in poor performance as the installations aged. I personally don?t like Velcro for the retention of items of mass.