Not a C-170 Story

[N2865C]

Was it necessary to carry the thing with fuel in it? How hard is it to empty the tank of a weedwhacker and leave the gas behind?

OK, I'll confess to something that maybe I shouldn't be doing. I carry a quart of TCP in a steel can (you can buy it in those again), tucked into the pocket on the back of my rear seat (custom upholstery option), so that it stays upright and won't get loose in the back. I resisted carrying TCP for a long time because of the flammability issue, but because I often fill up away from home, that meant basically not using the additive.
Are there any good solutions out there?

TCP is pretty nasty stuff if you spill it on your plane or upholstery and very flammable as well. I kept mine in a Sta-Bil bottle in double plastic freezer bags and carried it in my "refueling kit", a small 6 pack size ice chest with a quart of oil, some rags, paper towels and plastic windscreen cleaner. This might help with your decision.... http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001211X12083

[jrenwick]

Regarding the ntsb report about a TCP fire: Yikes!! Thanks for that, and your suggestion of the bags and cooler, John. I may need to put together a kit like that. I've got an old ammunition can that might do the trick -- it seals really well.

[GAHorn]

Ammo cans (and anything else that seals tightly) can become a bomb. A proper container for flammables would include a vent system. The idea of a storage-box on the firewall to carry a qt of oil and a qt. of TCP has often entered my mind and I've several times thought about asking Del what he thinks about it. The trouble is that firewalls are so different between various models, and variations between aircraft are such that finding an accessible location is problematical.

I carry TCP in a sealed plastic bag, and that within a "tupperware" type of plastic box which keeps the TCP upright and secured in the baggage compartment.

Emptying the fuel tanks of portable engines may still be a serious hazard. I'll never forget a fire-department demonstration I once saw. A few DROPS of gasoline in a gallon can was ignited by a sparkplug and it blew that thing 50 or 60 feet into the air and dented a metal-ceiling (the latter wasn't anticipated even by the professional fire-department demonstrator.) It only takes fumes to make a bomb.

[Bruce Fenstermacher]

Yes remember it is the fumes or vapor not the liquid that ignites. A full tank is less likely to explode as there is no vapor inside.

I like the idea of the small plastic igloo type container over an ammo box because of the insulation value. Perhaps the more stable environment might keep the from venting from the inside container in the first place.

[Indopilot]

It used to be common practice for us to carry a large liquid propane tank (5ft tall) laying where the passenger seat normally sits as well a 55 gal drum of kerosene and a drum of gasoline on a supply flight. Until someone pointed out that any spillage from the propane would be liquid propane which would instantly vapourize and fill the cabin. All that was required for the disaster was any relay or solenoid behind the panel to trip, like hitting the transmit button to say you had a problem. If the 182 was taken out by a weed eater I would have been a spectacular fire ball

[jrenwick]

Thanks for all the replies and insight about carrying TCP. It now seems to me that my current practice of carrying it strapped to the back of the rear seat isn't too bad, considering that any fumes from it would be carried out to the tail through the baggage compartment (assuming that's the way the wind blows in a 170). I'd still like to come up with a bracket for it on the firewall, though. That would seem to be the safest arrangement.

Best Regards,

John

[Bruce Fenstermacher]

John I think you might find the wind or air is sucked into the cabin from the tail.

[jrenwick]

John I think you might find the wind or air is sucked into the cabin from the tail.

I wondered about that. I've got air coming into the cabin through the wing vents and cabin heat/cabin air controls from in front of the firewall. Where is that air leaving the cabin?

I didn't mention that I have an extended baggage compartment that's open on top, so the cabin is essentially wide-open to the tail cone.

John

[GAHorn]

Most incoming air from vents/heater/etc. exits thru the headliner, into the wing-root, and overboard. Air enters the rear fuselage and travels forward to the cabin in most Cessnas (unless they have had their baggage compartments rear/upper walls blocked.)

I had a friend whose straight-tail 182 always set-off his Carbon-Monoxide warning inflight, and we used a portable test-unit to research where the fumes entered the cabin. It turned out that exhaust entered thru the "stinger" at the tail, and thru the lower rotating-beacon mount, and travelled forward, soaked thru the rear headliner, and entered the cabin.

I installed a sheet-metal wall behind my hat-shelf area to belay that after I also once had the opportunity to sit in the back seat without a headset while someone else taxied my airplane on an ordinary taxi-way with tar-strips one time. I was amazed at all the oil-canning in-concert with the tailwheel crossing tar-strips, and rudder-cable-slapping that goes on back there, so I decided to block the sound AND the air. I removed my baggage-compartment back wall (to gain access) and laid down on my back and installed a sheet of Alclad 2024-T3 with PK screws to the hat-shelf rear wall (which is full of lightening-holes. I then re-installed the lower, baggage rear-wall.) Now my entire rear baggage/shelf area is solid sheet metal, with adhesive foam insulation pasted on it's aft side. I also added false side-walls to the bulkheads in my baggage compartment and covered them with grosse-point fabric. This not only adds insulation and sound-proofing, but it protects the fuselage skin from cargo injuries.

[jrenwick]

Thanks, George. That all makes sense. There's probably no shortage of negative pressure around the wing root.

John

[Bruce Fenstermacher]

I installed a sheet-metal wall behind my hat-shelf area to belay that after I also once had the opportunity to sit in the back seat without a headset while someone else taxied my airplane on an ordinary taxi-way with tar-strips one time. I was amazed at all the oil-canning in-concert with the tailwheel crossing tar-strips, and rudder-cable-slapping that goes on back there, so I decided to block the sound AND the air. I removed my baggage-compartment back wall (to gain access) and laid down on my back and installed a sheet of Alclad 2024-T3 with PK screws to the hat-shelf rear wall (which is full of lightening-holes. I then re-installed the lower, baggage rear-wall.) Now my entire rear baggage/shelf area is solid sheet metal, with adhesive foam insulation pasted on it's aft side. I also added false side-walls to the bulkheads in my baggage compartment and covered them with grosse-point fabric. This not only adds insulation and sound-proofing, but it protects the fuselage skin from cargo injuries.

All of this is of course mostly original for the right reason that Cessna should have done it that way. Right George?

(Can't wait another 2 weeks to have fun ribbing people in person at Duluth)

[GAHorn]

It was (mostly) my original idea. (And it was preventive mx so only a logbook entry.)

[hilltop170]

It's hard to tell what anyone would do in a case like that, but I hope I would reach under the pilot seat and grab the halon fire extinguisher and discharge it at the base of the flames. Everybody has one, right?

[GAHorn]

It's hard to tell what anyone would do in a case like that, but I hope I would reach under the pilot seat and grab the halon fire extinguisher and discharge it at the base of the flames. Everybody has one, right?

You're absolutely RIGHT, Richard! I talked about everyone getting a Halon extinguisher at Branson convention seminar, and I hope folks took the talk seriously. It's not just a matter of saving an insurance-company's airplane..... it's about saving lives. The numbskull in this story had removed the fire extinguisher because he found it "interfered" with his hand when he adjusted his seat.

He no longer has that problem.

Now... for you guys that did the right thing and got your Halon Fire Extinguishers installed....

a Trivia Question: How can you tell if your Halon Extinguisher is FULL? (serviceable)

[hilltop170]

Weigh it.