Jet-B Vs. Jet-A

[Bell-powered]

I would like to know what people think of the jet b rather than jet a ful to run on a Jetbuggy..

Apart from more flammable, what is the pros and cons with Jet b?

Burning cleaner?

Is it better for the 250 engine or does it make any difference at all in that sense?

 

Thanks guys

[Batiskaf]

not again....

[heli_08]

jet b causes hotter starts that jet a. if your running a machine that had been running jet b for some time then switch to jet a your gonna have to adjust your starts cuz she'll drag and be colder than the dark side of the moon. I've found more carbon on fuel nozzles running jet A also, but that could be because of cold starts. I can't say which is better, they both have there place like anything.

[Guest 47yrLowTimer]

You will probably find the answers to all your questions here.

 

http://www.verticalmag.com/forums/can/index.php?/topic/20271-jet-a-vs-jet-b/

[Vast]

How often do you want to clean your tail boom?

[Bell-powered]

Since i do the cleaning myself, not very often. Haha

Reason for the question is the new flight manual supplement that came out. Pretty much what they are saying is that unless you use Jet B you can operate in the dead of winter in the north right?

 

Appart form the bigger danger with flammability, price and the hotter starts, is there any other drawback to the Jet b?

[Vast]

Since i do the cleaning myself, not very often. Haha

Reason for the question is the new flight manual supplement that came out. Pretty much what they are saying is that unless you use Jet B you can operate in the dead of winter in the north right?

 

"Helicopters equipped with airframe mounted fuel filter do not require the use of anti-icing additive at any ambient temperature."

 

I haven't seen this new supplement yet.

I've noticed over the last couple of years guys are moving from Jet B to Jet A because it's cleaner aside from the carbon it leaves all over the rear end.

 

 

[Over-Talk]

Years ago, the 212 was limited to -30c with Jet A.

However, this only became an problem after Jet B disappeared and operators started using Jet A.

 

Then Bell released 212 FMS31(?) about 5 years ago, which allowed lower operating minimum of -40c....if the Jet A was measured before start-up to be -30c or warmer.

 

This means you could start at -30c(fuel temp) and then fly to somewhere as cold as -40c (ambient).

 

This sounds similar to what Bell is now requiring for the 206.

It seems Bell doesn't like Jet A below -30c.

 

 

 

 

 

 

 

I have many friends flying and wrenching on 212s in the Canadian winter, but don't know any that measure the fuel temp. before start-up...........yet. I hate to think where this is all going.

If you want to fly a Bell below -30c, bring a thermometer and a lawyer.

 

p.s. Red triangle ???? Huh? What sort of safety device is that?

[Bell-powered]

Yes temperature measurement of the fuel... But i mean.. leave home base, heli is parked in the hangar, going for a 5 hour day lands shuts down,1 1/2 hrs later you gonna take off its -34 in the fuel... then what?

It´s so stupid... they are trying to cover their *****... I mean how many people will actually take a temp. measurement?

 

I guess the red triangle is just to alert us pilots in case the fuel is getting thick... and pressure goes down..

Or maybe its just simply cause they want to sell some gauges. haha

 

Anyhoo

Jet B it is i guess, even though the jet-a that we are using is getting freeze tested and dont start thicken up to freeze until -52°C and then i prefer to stay in bed anyways

[lamadriver1948]

Jet A has a density of 775-840 Kg/CM (cubic meter.)

Jet B has a density of 751-802 Kg/CM (Cubic meter.)

 

Thus Jet B has less density and has fewer BTUs per Kg. Some aircraft fuel controls need to be rescheduled when switching from Jet A to Jet B and vice-versa because the lighter Jet B has less density and needs more volume to compensate for that. Not an issue with a 250 engine.

 

Jet B burns cleaner. Ask any Bell 214 operator how long it takes for the tailboom to blacken with Jet A as opposed to Jet B. Blackening will start within minutes on Jet A.

 

Jet A has a MAXIMUM freezing point of -40C. For Jet A-1 it is -47C and Jet B it is -50C. Adding Prist only helps with prohibiting ice formation. Let fuel stand one hour per foot of tank depth after fueling to allow water molecules to settle before sumping the tank.

 

In Alaska, Jet B is only found in Talkeetna where the Mt McKinley rescue helicopter is based. Everywhere else in Alaska Jet A-1 is used. There is no Jet A because of the maximum freezing point.

 

Hope this helps