{"id":14428,"date":"2021-08-10T10:48:02","date_gmt":"2021-08-10T14:48:02","guid":{"rendered":"https:\/\/ops.group\/blog\/?p=14428"},"modified":"2021-08-11T10:55:44","modified_gmt":"2021-08-11T14:55:44","slug":"fire-onboard-a-pilots-worst-fear","status":"publish","type":"post","link":"https:\/\/ops.group\/blog\/fire-onboard-a-pilots-worst-fear\/","title":{"rendered":"Fire Onboard: A Pilot’s Worst Fear?"},"content":{"rendered":"

Ask a pilot what their worst fear is and one of the responses you will probably hear the most is FIRE! Ironically, an aircraft’s engines only actually work when they are “on fire” so not having a fire “onboard” could be problematic…<\/p>\n

But a fire in the cabin or cargo hold is a rather different deal. So, here is a look at what many consider to be one of the most challenging and concerning problems they could encounter in-flight.<\/p>\n

For those who don\u2019t think it is that scary.<\/h4>\n

A CAA study back in 2002<\/a> looked at aircraft crashes due to fires onboard and discovered a rather fearsome statistic – the average time it took for an aircraft to become catastrophically uncontrollable was under 20 minutes.<\/strong>\u00a0Various fire tests saw that a fire allowed to spread through the aircraft’s overhead area could become uncontrollable in just 8-10 minutes.<\/p>\n

The average time for a crew to get their aircraft onto the ground was around the 17 minute mark.<\/strong><\/p>\n

So, not much time to spare.<\/strong><\/p>\n

The infamous Nimrod ditching<\/a> (a favourite CRM example of decision making) shows how quickly a fire can disable an aircraft.<\/p>\n

The problem is\u00a0aircraft are built to burn.<\/strong><\/p>\n

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Aircraft skin is thin and can burn fairly rapidly with high temperatures<\/p><\/div>\n

Well, not literally, but there is a significant amount of flammable, combustible and generally burnable bits onboard. Add in the fact there are very hot bits (the engines) linked to big chambers full of fuel and the risk of an un-contained fire suddenly seems a lot worse.<\/p>\n

Un-contained being the important word here.<\/h4>\n

Engines have fire identification and protection systems in them. So do cargo bays. So do cabins for that matter (Cabin Crew make wonderful fire detection and fire suppression systems).\u00a0Aircraft interiors, and cabin fire fighting procedures, and the monitoring of Dangerous Goods transit<\/a> have also developed significantly over the last decade or two.<\/p>\n

So, the means to prevent or control fires before they become uncontrollable have increased.<\/strong><\/p>\n

Unfortunately, though, so have the number of devices coming onboard which could start a fire<\/strong> in the first place.<\/p>\n

Lithium Ion batteries burn hot. They are hard to put out, and every passenger on your flight probably has at least one, probably nearer three of them (phone, second phone, computer, tablet, smart luggage, spare power banks, watches, electric toothbrushes…)<\/p>\n

And of course phones are not the only potential fire hazard onboard. There are ovens (hot), hydraulic fluid (thankfully not in the cabin, but very flammable), electrical things (seats, tvs, lights), waste bins (in toilets for hiding illegally smoked cigarettes in), oxygen systems (a food delicacy for fires) and a multitude of wires.<\/p>\n

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Interior from the Swissair 111 accident in 1998 – caused by faulty wiring<\/p><\/div>\n

An FAA study from 1995 to 2002<\/a> found reports of nearly 400 wiring failures<\/strong>. 84% of these were burned, loose, damaged, shorted, failed, chafed or broken. And this is probably not a representative number given how many might go unreported.<\/p>\n

The Swissair accident was due to faulty wiring, with a secondary prominent factor being the flammability of materials that ignited and propagated the fire. The crash occurred just 16 minutes after the first alert message.<\/a><\/p>\n

Let’s take a look at what can burn in the cabin.<\/h4>\n

Seat coverings, blankets, cushions, other furnishings, clothes\u2026 basically everything inside the cabin can burn.<\/p>\n

In 1993 a Northwest Airlines B727<\/a><\/strong> had a fire in the cabin and it turned out they were using 100% polyester blankets. Polyester actually melts more than burns, but it gets really hot when it does and tends to set alight to everything else around it. The incident led to the FAA developing new fire performance test methods<\/a> and criterion for all blankets.<\/p>\n

Interesting fact: Emirates actually make their economy blankets out of recycled plastic bottles. 28 of them per blanket.<\/em><\/p>\n

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Her hairspray is the most flammable thing, closely followed by the 1970s fabric<\/p><\/div>\n

Actually, the burning ability of everything onboard is now monitored.<\/h4>\n

Since 1990, aircraft interiors have had to comply with a maximum total heat release of 65 kilowatt minutes per square meter<\/strong>, and specific optical smoke density of 200. Basically burn less, burn less hot, and put out less smoke if they do burn.<\/em><\/p>\n

The current rules for what everything should be made of, and how burny\/smoky\/toxic they can be are contained in FAR\/JAR\/CS 25.853<\/a>.<\/p>\n

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An FAA fire test with 5000 lithium ion cells<\/p><\/div>\n

Crew training is important as well.<\/h4>\n

The training and ability of the crew to both fight the fire, and evacuate the aircraft is strictly monitored. The FAA require that an airplane can be evacuated in 90 seconds.<\/strong> For big commercial aircraft (these are Boeing stats) this means the slides have to be able to inflate within 10 seconds<\/strong> (15 if it is a big wing slide), and they need to be able to support 60 people sliding down at once.<\/p>\n

It doesn\u2019t take into account the huge heap of people at the bottom of the slide, but once they are out and away from the fire all bets are off.<\/p>\n

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90 seconds to evacuate 500+ people<\/p><\/div>\n

But accidents still happen.<\/h4>\n

Between 1990 and 2010 there have been 18 major accidents involving in-flight fires<\/strong> which resulted in fatalities. During the 1990’s, the US saw, on average, one flight a day diverting due to smoke; and a report by IATA suggests there are more than 1,000 smoke related events annually.<\/p>\n

That\u2019s about 1 in 5,000 flights\u00a0<\/strong>which is a pretty big number when you consider how many flight you will do in your career, or how many movements there are worldwide every day.<\/p>\n

In 2010, a UPS B747 freighter crashed in Dubai<\/a> following a main cargo deck fire which ultimately led to loss of control of the aircraft. The pilots were incapacitated earlier however due to the rapid build up of smoke in the flight deck.<\/p>\n

What to do. The important bit.<\/h4>\n

1. Troubleshoot.<\/strong><\/p>\n

Finding the source should be a top priority. That means working out where the smoke is coming from.<\/p>\n

If it is coming from something\u00a0avionics\u00a0<\/strong>related then you are going to want to switch it off.<\/strong> If it is something in the\u00a0cabin\u00a0<\/strong>then it might be locatable, reachable and extinguishable. Don’t forget to get your crew to check the lavs.<\/p>\n

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The terror…<\/p><\/div>\n

2. Communicate.<\/b><\/p>\n

One of the biggest challenges in dealing with a fire in the cabin is the communication between the cabin and the flight deck.<\/p>\n