Prist when and with what to use it
 

Hate the stuff especially in pressure tins! Many fuellers wont go near and even had one who refused to fuel even with me doing the Cans.
Some fuel has additive yet a fueler stated his fuel was good to -47 and didnt contain additive?
Do those who need to use Prist use it in summertime on low level trips or just high in V cold conditions?
There is a poring variety which sounds better?

Pace

Why on earth do you need to use it? Why isn't the fuel you buy up to spec?
Are you sure H & S allows you to handle it? I wonder.

A simple internet search will reveal how it is packaged and why the delivery pipe needs to be clipped to the fuel nozzle (which is no doubt also clearly explained on the can) which should answer your "poring" (sic) question.

You don't carry this stuff around on the aircraft, do you? How do you manage when fuelling away from base?

We use Prist once a month because it´s a good precaution against bacteria growth in the fuel tank (citation cj1+), no matter at what altitude you are flying or at what season. Water freezing in fuel is a thing of the past with
the fuel-to-oil heat exchanger.

Cecco

Min.Fuel Temp. according our AFM: -30 Celsius

1. It's not an anti fuel-icing additive - it's an anti-water additive. The fuel is quite possibly good to -47ºC but the water that's disolved in it, isn't.

2. It's not particularly nasty stuff. You don't want to be drinking too much of it, and I understand that it should not be used as an eye wash, but you won't die if you do either.

It is carried on 525s routinely - even the 525A. One of the fuel companies did have a standing instruction for a while not to allow it during refueling but I've never been refused.

Ah! Now I've been stung into reading Prist's webiste all is clearer.

My recollection of using the stuff (large company) was that we treated it as though it was highly toxic even by skin contact.

Interesting too that I see no mention of use as a bug killer on the manufacturer's website, or did I miss it?

I know the Learjet 35 ops manual recommends using Prist. Will the plane fly OK w/o it...99%...sure. But there was a crash several years ago relating to the icing up of fuel and Lear then said that you should use a can for every x amount of gallons pumped into the aircraft.

Obviously, there are other aircraft that still use it, but I know the older Learjets definately purchase the little cans of the stuff.

The CJs with heat exchangers are still required to use a Biocide (I don't have the reference in front of me, but it's in the AFM) that'll be the 525A and it seems the 1+ and I assume the 2+ and the 3.

The CJs without heat exchangers use it for both fuel biocide and to soak up water.

One of the major problems with it is that if it is not adequately homogenised with the fuel it can clump and those clumps can then block the same filters it was introduced to keep clear.

This problem used to occur on the EBJ fleet with some regularity because we used to use the pouring cans rather than the aerosols.

I know it kills all the bugs living in the fuel tanks who have a taste for gourmet Jet A1 but am concerned about its cancer inducing chracteristics?

The Cans are notoriously unreliable and the dispensing caps even more so.
Pouring with rain you have to stand outside with the refueler finger firmly pressed on the dispensing button for what seems like an eternity.

I use surgical rubber gloves but even then some cans blow back when attaching so you have to look away while attaching the nozzle.

I believe refuelers are stopped by H and S from handling the stuff yet we do.
This is on a Citation 2 and while used most of the time there can be an occasion when the cans dont work or you dont have it.

I was interested as to when its vital to use Prist or when you can get away without? or use lower amounts than recommended?
Plus getting fed up getting soaked (by rain :) every time we refuel. The co has a habit of vanishing at refuel times.

Pace

The only important thing is what it wrote in Pilot Operanting Handbook.

Depenting of aircraft oil/heat exchanger is not enough to ensure safe operation.
(See crash of Boeing 777 at heathrow few years ago.)

Last september, we don't put Prist in tank (lack of time :ugh: ) Fuel Temp on Ground 15°C, Total Fuel Quantity nearly 2600 Lbs. After two hours at FL260 , OAT-30°C, both fuel pump came "on" and fuel filter by-pass pop out.
30 minutes later we were safe on ground and only during taxi, Fuel pump came "off".

As stated before, Prist is a glycol based liquid that works magic preventing water dissolved in fuel to freeze up in ice crystals and block filters. IMO Not much different than wing anti-ice. Prist does not advertise themselves as a anti-fungal/anti-microbial additive. Bio-Bor is the product used to kill living things inside fuel tanks.

Old generation citation I and II's to needed Prist as a regular basis to avoid this same problem, and some pilots i know still use it in Beechjets, i think they do not have fuel heaters.

Just as a note, The citation Bravo, due to a good Oil to Fuel heat exchanger do not need that stuff, but not long ago i had a "FUEL GAUGE" light in the master warning panel, indicating an error on the fuel gauging system, possibly caused by long term fuel contamination. the option to fix it was defueling the airplane, opening the wet wing and change on one the offending capacitor probes (read expensive). An old mechanic told me to try first putting pre-mixed Prist in Jet-A at any airport that offers it and monitor... You know what? the fuel gauge problem went away in just five flights and has not recurred agin in two years, so I found another use to Prist.

Regarding the toxicity and cancer potential, I think is no worse that some airport food I've had to eat in some long days...

Hmm, interesting discussion here. My question is as "prist" is an aerosol and classified as UN1950, do all these Citations have dangerous goods licenses to carry this on board?

This is a quote from the Prist website:

http://www.pristaerospace.com/hi-fla...ety/index.html

From their own data sheet:

I have never seen a Citation Jockey on the ramp with an apron and goggles on...



Furthermore, the HSE states referring to UN 1950:
BAMA Fact Sheet - Transport of Aerosols by road, sea & rail - British Aerosol Manufacturers' Association (BAMA)

This brings back memories when I operated citation 500 and 550 back in early 90s we used prist 100% of time we always had a case stored in front lockers .later on ce 650 no requirement to use it.

We carry the stuff and no dangerous goods but makes disturbing reading. Know there is a pouring alternative which seems more secure to use although not sure of the difference or mixing ability?

Pace

Prist is a UN 1950 with risk R12, that makes it subclass 2.1 if I am right. Anyone got an updated Dangerous Goods manual handy? I am not sure if it is even allowed to be carried on passenger aircraft or is that one limited quantity only? Google is a bit ambiguous on that one.

Anyone with the right reference?

Anti-ice additive (Prist, Dice, etc.) is REQUIRED in Lear 20 and 30 series aircraft. This is not a "recommendation," it is a limitation as spelled out in the AFM.

It is also required in the Pilatus PC-12.

A lot of the fuel you put into your aircraft has prist premixed already. It is a required additive on many aircraft clearly stated in the limitations section and yes it is hazmat that shouldn't be carried on board passenger aircraft. So when you are operating to a remote location are you going to bring the cans of prist or operate out of limitations?

If the manual says use it then use it. Dual engine flame out is more harmful than the potential danger of pouring prist in the fuel.

And as stated, it is not about lowering the freezing point of the fuel but rather to make sure that the water in the fuel doesn't cause problems. Some engines have good fuel heaters, some have fuel filter de-icing capabilities (like the RR Viper) and some need additives.

If you are uncomfortable about using these additives you can sometimes get fuel with the stuff already in it (like Shell Aerojet). You can't get it everywhere but it is a way of lessen the exposure.

Lots of useful info. We have to carry the stuff I have yet to find a supply away from base without getting some from another Pilot / aircraft.
Spray cans are a potential hazard especially with a product as dangerous as this.
The instant pour variety has to be better? We realistically have to carry Prist but would be interesting to know the CAAs view on carriage and dispensing by Pilots.
Maybe rubber gloves, goggles and a mask should be a must as how many of us really knew how dangerous this stuff really is and have not handled it safely?

Pace

One outfit I flew for had a permit to carry prist (IIRC 3 tins).

Some fuel trucks can tank with prist mixed in, happens somewhere near the pump. Thankful we havent got to use that stuff anymore.

German LBA published a letter how to tranport Prist in limited Quantities:

http://www.lba.de/cae/servlet/conten..._antiicing.pdf