Friday, 7 March 2014

The BVLGARI of the air? Jet A-1 the way to go

As a 'part time' mission bush pilot who is not based in one particular country but has the privilege of helping out on several programs, when they are short of crew. I usually travel between assignments  el cheapo!' But I have to confess that I have received several times from BA and Emirates the  occasional up grade or the chance to use my air miles to move up and get a good nights sleep on a bed and Emirates are the bees knees at providing a very comfortable bivouac and they also give you a great overnight bag containing various men smells by BVGARI which are excellent.

There is nothing, absolutely nothing, quite like catching the scent of a turbine engine's exhaust fumes drifting on the the early morning air, of what is to become a glorious summers day. So I can but recommend, if you ever get a chance to stand downwind of a turboprop as it starts it's engine, seize the day, stand fast, stop, listen, sniff as you are in for a real treat, especially if it is a PT-6.  The sound of the engine spooling up as bursts into life and struggles to get the prop spinning, the engine notes move through the octaves, from a reverberating low growl to a high pitched whine followed by that delicious fragrance, oh so sweet, with perhaps caramel overtones.

Author with the magic liquor and his mount in the background in Pala, Chad
Jet A-1 is wonderful stuff, the fuel of choice for civilian commercial jets and also for an increasing number of Mission Aviation Fellowship's (MAF) fleet of over 130 aircraft. Whilst av-gas, a form of 100LL petrol is used in the piston powered Cessna 206 and Gippsland Airvan's and the last few 185 floatplanes, some of the the 206s are being phased out to either be replaced by piston Airvans or by our increasing fleet of turbine powered aircraft. This is made up of the incredibly kapable  Kodiak, consistent Caravan and somewhat surprisingly the small 4 seat diesel engined 182. We also fly the Twin Otter, King Air & PC-12.

Jet A-1 is much cheaper than the petrol equivalent, more readily available and safer. It is clear to straw coloured liquid, that unburnt smells pretty disgusting, makes your hands smell and tastes little better, no don't suck Jet fuel out with your mouth if you wish to syphon off the tanks of your 747. Though the fuel burns well in your hurricane lamp. It has a flash point of 38C, freezes at -47C and if you burn it out in the open the flames are about 300C but is essentially quality paraffin or kerosene.

In fact according to St .Wikapedia, the fount of all generally reliable info, this is for all you chemists out there, suggests the combustion reaction can be approximated as follows, with the molecular formula C12H26 (dodecane):
2 C12H26(l) + 37 O2(g) → 24 CO2(g) + 26 H2O(g); ∆H˚ = -7513 kJ

If you burn 5* Jet A-1 (RP-1) with liquid oxygen you can put your friendly Saturn V rocket into orbit! But my Jet A-1 does nicely in my 675shp PT-6 and drive sit along at abut 150kts and gets me in an rout of some tricky places with some amazing people making a real difference... bringing help hope and healing to many very remote communities around the world.

Leaving fuel in Bol for the very frugal diesel 182
However I use natural oxygen to power my Cessna 208 and the higher the better (usually around 9-12000ft) and it powers my chariot reliably. We burn about 300lb's an hour so you have 1000 litres in the 5 barrels in the photo above. Which will keep going for about 6hrs or 900 miles!

These donkeys would need to bring me about 8 jerry cans an hour! Actually I was dropping off fuel for the 182 in Bol, western Chad by the shores of Lake Chad.
 This 1979 Cessna 182 had it's old petrol/av-gas engine removed and a new diesel engine put in it's place, this SMA diesel burns paraffin and consumes a very frugal 35 litres of cheap Jet A-1. Cessna now do a brand new aircraft with the SMA installed at the factory, lovely machine but it is not cheap!


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