Diesel Fuel

[The Range]

Can diesel fuel be used in a jet engine?

[Intruder]

Some older turbojets were certified for it; I don't know of any current ones off hand.

OTOH, the new General Aviation Diesel engines are being certified on Jet-A.

[onetrack]

No. Despite diesel fuel and Jet-A/Jet A-1 being classified as "kerosene-type" fuels, they are refined to different standards... and diesel is refined to different standards in different countries.

In the U.S., the original Diesel fuel standard as set by the ASTM in 1931, is ASTM D975. Diesel did not exist as a fuel formulated to a standard, prior to this date. Any heavy oil, refinery residue, could be called Diesel, prior to 1931.

This ASTM standard has been modified over the years, in particular with regard to ever-lowering levels of sulfur. The U.S. diesel ASTM standard is now D975-10c.
Originally, allowable sulfur levels were up to 2%. It was found that high sulfur levels were detrimental to engines and the environment, and sulfur is gradually being reduced to barely measurable, low PPM levels.

Diesel is refined into 7 grades in the U.S. - many more grades than other countries, due to severe climatic extremes, market demand, and the size of the market.
Each Diesel grade is aimed at a specific market and has relatively narrow parameters in the standard, as compared to aviation fuels.

Diesel in Europe is refined to European Standard EN 590.

Diesel in Australia is refined to the Australian, "Fuel Standard (Automotive Diesel) Determination 2001", which is more closely related to the European fuel standard for diesel.

Jet A/Jet A-1 are refined to ATSM D1655. The differences between D975 and D1655 standards are typically in the following parameters...

Freezing point
Flash point
Cloud point
Water and sediment level
Carbon residue
Ash level
Viscosity
Sulfur level
Copper corrosion
Cetane number
Lubricity
Conductivity

The differences in freezing point levels in the refining standards, between Jet A/Jet A-1 and Diesel are substantial.

Jet A-1 freezing point: < -47°C (-52.6°F)
Jet A freezing point: < -40°C (-40°F)

Diesel fuel, because it is refined to numerous grades, has a varying freeze point.
However, even the lowest Winter grade diesel will begin to gel and clog filters at -30°C to -40°C. For this reason up to 3% methanol is added to Diesel tanks of diesel road vehicles, in those countries with severe Winter temperatures, to prevent gelling.

Jet A/Jet A-1 have additional, or increased additives, as compared to Diesel, such as lubricity improvers and corrosion inhibitors, specifically designed to combat the extreme, or peculiar operating conditions inside jet engines at high altitudes and extremes of temperature, that are not regularly encountered on the surface of the Earth.

[Snikers]

Deisel fuel can be used on gas turbine engines just not in aircraft. The marine world use diesel fuel all of the time for gas turbine engines which are a derivative of the aero engine. When I say diesel I mean gas oil, similar to that which you would put in a "diesel" powered vehicle. Diesel is really dirty gas oil and from lower on the tower. (32sec to 38/40 sec Redwood.) Jet A1 being about 28 sec Redwood - I think.

[grounded27]

From what I understand the simple difference between diesel and Jet A is lubricant. We used to dump a few quarts of oil into a 500 gallon tank of sumped jet a and run our GSE off it.

Onetrack is correct but just that, you asked can you and I would say hell yeah, now over time these additives may clog up small fuel controll ports, performance may not be the same but I do believe any engine, jet engine would run on diesel. I just can not say for how long.....

[SNS3Guppy]

The simple answer is yes, you can. In most cases, it's a simple fuel control adjustment. Diesel #2 runs just fine in turbine engines.

Insofar as legality, that really depends on the circumstances and place.

[onetrack]

My answer was based on the jet engine being used in an aviation environment. A jet engine running in a relatively static ground position, within moderate temperature ranges (above freezing; 32°F or 0°C) would run on Diesel... however, the internal components lifespan may be affected, and you would possibly no longer have an engine certified for flight, after running for a period, on a fuel that was outside the manufacturers specified fuels list.

Diesel is a heavier fuel, and has a higher energy content, pound for pound, than JetA/Jet A-1, and burns for longer during combustion, and at a higher temperature.
The major restriction on Diesel energy output is the amount of air fed in with the fuel.
Jet fuel has an S.G. of .62 -.88... Diesel has an S.G. of .82-1.08.

[SNS3Guppy]

My answer was based on the jet engine being used in an aviation environment.

Yes, mine was, too.

...and you would possibly no longer have an engine certified for flight, ...


Not true.

[oz in dxb]

Onetrack, just one amendment,

Jet A1 freeze point is -47C and Jet A is -40C.

[Brian Abraham]

Diesel is an approved fuel in some applications. Here is one such TCDS http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/c5724721927d08cd862568f6004c3de6/$FILE/E3WE.pdf

[Machinbird]

We had a scooter (J-52 powered A-4) fueled with diesel in California from a fuel truck with the wrong load that ended up flying back to ABQ. No one had a clue until fuel samples were taken at home plate following the next fueling.
Corrective action was to completely drain and refuel with JP-4-- so it appears that the engines don't really see much difference.
Good thing he didn't encounter fuel freezing.:ooh:
With a single stovepipe, that wouldn't be good.

[rigpiggy]

Pratt and whitney has certified P-50 as an alternative fuel for the PT6. it is #2 arctic diesel thru a 50 micron filter. I have the SB, but can't get the pdf to work.

[Brian Abraham]

Here you are rigpiggy.www.mmopa.com/gallery/160_SB1244R21.pdf

[Saint Jack]

Q. Can diesel fuel be used in a jet engine?
A. Yes.

Q. Can diesel fuel be used in a jet engine-powered aircraft?
A. It depends.

For the ENGINE, the correct grades of fuel together with the alternate types of fuel (if any) that can be used, plus the time limits and mix ratio of alternate fuels, will be found in the engine maintenance manual.

However, this does NOT automatically mean that they can be used in the AIRCRAFT. For this, the correct grades of fuel together with the alternate types of fuel (if any) that can be used, plus the time limits and mix ratio of alternate fuels, will be found in the aircraft flight manual. These requirements, if different from those of the engine manufacturer, and they occasionally are, take precedence.

[PBL]

Can diesel fuel be used in a jet engine?

It is as well to distinguish several different meanings of the word "can". Various of the answers here refer to those different meanings.

1. Will the engine produce thrust if you inject it?

2. Will the engine run for a substantial period of time, say a short flight, using it?

3. Will the engine run for a substantial period of time using it, without suffering major structural disadvantages or maintenance problems?

4. Is it allowed by some ops manual (through STC)?

You have to ask the same questions for the use of mogas in small-aircraft Otto-cycle engines. Caveats there have mostly to do nowadays with ethanol content and vapor lock. Given the lack of context of your question, I imagine the biggest caveat might well be temperature, since diesel fuel for ground use isn't really suitable for environments with the substantially low temperatures found at the flight levels at which jets are most efficient.

PBL

[The Range]

Thanks guys,
It's that I was watching Apocalipse Now last night and they put diesel fuel
from a boat in a UH-1 helicopter and I didn't know if that can be done.

[barit1]

Big difference if you are doing low-altitude agricultural work vs. long-range stratospheric flight.

[SNS3Guppy]

Big difference if you are doing low-altitude agricultural work vs. long-range stratospheric flight.

No. 2 Diesel is used in ag operations.

The biggest difference isn't in the fuel purity, but in the fuel control setting. It's a simple adjustment in most cases.

As for upper atmospheric work, the USAF has been doing long range research and work using biodiesel. You're not going to toast an engine.

Additives can be provided for lower temperature use, and there's always fuel heat.

It's that I was watching Apocalipse Now last night and they put diesel fuel
from a boat in a UH-1 helicopter and I didn't know if that can be done.

You bet it can be done. If it's a military craft, chances are that it's already using JP-4.

Corrective action was to completely drain and refuel with JP-4-- so it appears that the engines don't really see much difference.

JP-4 is a cut fuel; kerosine and gasoline, and the approximate equivalent of civil Jet B. One of it's chief advantages is a low freezing point.

[DERG]

Anyone know if JP8 is in use yet please?

[kenparry]

JP8:

According to Wiki, yes, it's in use.

See JP-8 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/JP-8)

[galaxy flyer]

Considering the wiki article says:

Commercial aviation uses a similar mixture under the name Jet-A.

I'd say it has been in use for a long time.

GF

[DERG]

That ain't JP8 then.

[Brian Abraham]

I do wish people would do a modicum of research before posting opinions.

http://www.exxonmobilaviation.com/AviationGlobal/Files/WorldJetFuelSpec2008_1.pdf

[DERG]

That's a useful link Brian. Not all of us are as skilled in using the search engines. Thank you.

[rigpiggy]

SERVICE BULLETIN
P&WC S.B. No. 1244R18
Jul 24/75 PT6A-72-1244
Revision No. 18: Feb 14/2000 Page 16 of 16
TURBOPROP ENGINE
ENGINE FUELS AND ADDITIVES - REQUIREMENTS AND APPROVED LISTING

3. Accomplishment Instructions (Cont’d)
TABLE 13, Emergency Fuels Approved Fuels Subject to Restrictions on Use
Fuel Type ASTM IATA
U.S. Federal
U.S. Military
Canadian
CGSB Restrictions on Use
Automotive Diesel Fuel (CPW46)
(Arctic Grade)
D975 No. 1D - VV-F-800
DF-A CAN 2-3.6
M88 Type A Shall not be used below +5 °F (-15 °C) ground OAT

Automotive Diesel Fuel (Winter Grade)
- - VV-F-800 DF-1
CAN 2-3.6
M88 Type A Shall not be used below +20 °F (-7 °C) ground OAT

Automotive Diesel Fuel (Regular Grade)
D975 No. 2D - VV-F-800
DF-2
CAN 2-3.6
M88 Type B
Shall not be used below +40 °F (+5 °C) ground OAT

Aviation Gasoline
(Grades: 80, 100
&
100 LL)
- - MIL-G-5572 CAN 2-3.25
M82
Shall not be
used for more
than 150 hours
during any
period between
engine
overhauls.
NOTE: 1. Unless otherwise specified intermittent or continued use of this fuel for up to 1000
hours is allowed provided satisfactory fuel nozzle inspection results are achieved at the approved
intervals.
NOTE: 2. Unless otherwise specified continued use of this fuel for more than 1000 hours is
allowed provided periodic fuel nozzle inspection results are found acceptable by
P&WC.
NOTE: 3. After the use of diesel fuel containing dyes of Grade 80 aviation gasoline, the fuel
system must be flushed.
4. Appendix
Not applicable.
PRATT & WHITNEY CANADA
SERVICE BULLETIN
P&WC S.B. No. 1244R18
Jul 24/

[piggybank]

The Lama helicopter runs well on vehicle quality diesel fuel. I have used it several times. However a engine log book entry gets made and there is a limit of how much running can be done that way between overhauls. If my memory serves me right, in the case of the Lama its 75 hours per overhaul period.

[Brian Abraham]

Aide Memoire on Fuels in NATO

AVIATION FUELS

NATO CODE

F-18: is an aviation gasoline (low lead) in limited use by certain NATO nations. Also known as AVGAS 100LL.
F-34: is a military kerosene type aviation turbine fuel with Fuel System Icing Inhibitor (FSII) (NOTE 1) used by land based military gas turbine engined aircraft in all NATO countries. (NOTE 2) Also known as JP-8 or AVTUR/FSII.
JET A-1 or AVTUR + Additives (NOTE 3) = JP-8 or AVTUR/FSII.
F-35: is a military kerosene type aviation turbine fuel equivalent to that used by most civil operators of gas turbine engined aircraft. Also known as JET A-1 or AVTUR.
JET A-1 or AVTUR; therefore F-34 = F-35 + Additives.
F-40: is a military wide cut type aviation turbine fuel with FSII used by land based military gas turbine engined aircraft (NOTE 2). Also known as JP-4 or AVTAG/FSII. Within NATO it is an emergency substitute for F-34/F-35.
F-44: is a military high flash point kerosene type aviation turbine fuel with FSII used by ship borne military gas turbine engine aircraft in most NATO countries. Also known as JP-5 or AVCAT/FSII JET A and JET B (See NOTES 4 and 5)

NOTES:

1. FSII NATO Code S-1745. Additive to aviation turbine fuels as system icing inhibitor.
2. Until 1986, F-40 was used by land based gas turbine engined aircraft in all NATO countries except France and the United Kingdom which had converted to F-34 some 15 years earlier. Following a decision by NATO Defence Ministers all nations except Turkey switched from F-40 to F-34. The conversion (known as Stage 1 of the Single Fuel Concept) was completed in 1988. Turkey completed its conversion from F-40 to F-34 in 1996.
3. The term "additives" used in this Aide Memoire can include FSII corrosion inhibitor/lubricity improver additive and static-dissipator additive (SDA).
4. JET A is a civil grade of kerosene type aviation turbine fuel only supplied for operations in the United States. It has a freezing point of -40°C max which differs from JET A-1 (-47oC).
5. JET B is a civil grade of wide cut type aviation turbine fuel which has a different freezing point (-50oC) from F-40 (-58oC) and does not normally contain FSII.
6. For further details about these fuels, see Annex C to STANAG 1135.

GROUND FUELS

GASOLINES

F-46: is a military fuel used in certain armoured and non-armoured vehicle spark ignition engines in NATO Europe areas outside Denmark and the United Kingdom. Also known as gasoline automotive: Military (91 RON) or COMBATGAS. Availability of this fuel is now limited and has been replaced by F-57.
F-57: low leaded gasoline introduced to replace F-46. It is interchangeable with commercial gasoline automotive (98 RON).
F-67: unleaded gasoline automotive interchangeable with commercial gasoline (95 RON).

DIESEL FUELS

F-54: is a military fuel used in compression ignition engines in NATO Europe areas outside Denmark, Greece, Italy, Portugal, Spain and the United Kingdom. Also known as Diesel Fuel: MILITARY or DF-2. It has a Pour Point specification of 18°C maximum.
F-65: low temperature diesel/kerosene fuel blend.
F-75: is a military fuel used in compression ignition engines in Denmark and Greece. It is normally referred to as FUEL NAVAL DISTILLATE, low pour point. (See Naval fuels).

NOTE: For further details about these fuels, see Annex C to STANAG 1135.

NAVAL FUELS

F-75: is a naval fuel used in compression ignition engines and in naval gas turbines and ships' boilers for steam raising. Also known as FUEL, NAVAL DISTILLATE, low pour point. (See Ground Fuels).
F-76: is the primary naval fuel used as for F-75 above but it may require special handling and storage due to low temperature characteristics. Also known as FUEL, NAVAL DISTILLATE (NOTE 1).
F-77: is a naval residual fuel used for boiler steam raising for certain ships in France, Greece and Turkey. Also known as FUEL, RESIDUAL, light viscosity boiler or 50/50 FFO (NOTE 2).

NOTES:

1. Alternative turbine/diesel engine fuel for use in certain naval helicopters.
2. F-77 may also be used in slow speed diesel engines.
3. F-44 Naval aviation turbine fuels - see Aviation Fuels.
4. For further details about these fuels, see Annex C to STANAG 1135.

NATO Logistics Handbook: Chapter 15: Fuels, Oils, Lubricants and Petroleum Handling Equipment (http://www.nato.int/docu/logi-en/1997/lo-15a.htm)

[onetrack]

It's not helpful that there is conflict between the FAA advisory on fuels for certain engines (as posted by Brian in post #10), the ExxonMobil World Jet Fuel specs brochure, and the P & W Canada, Service Bulletin.

From the FAA advisory - "Diesel Fuel approval limited to TPE331-1-101Z engine only, and usage at ambient temperatures above +15°F.
Aviation gasoline MIL-G-5572D, Grade 80/87, not in excess of 1000 gallons per 100 hours of operation, may be used for emergency fuel operation.

As regards the ExxonMobil World Jet Fuel specs brochure (post #23)... the word "diesel", cannot be found anywhere in that document...

ExxonMobil do have a bold and unambiguous statement (page 41) that, "(ExxonMobil) does not support or approve the use of automotive gasoline or diesel fuel in piston engine powered aircraft".

And from the P & W bulletin, as linked in post #13, above...

CAUTION: ALTHOUGH DIESEL AND HEATING FUELS ARE CHEMICALLY SIMILAR TO JET FUELS, THEIR COLD FLOW, VISCOSITY AND FREEZING POINT
CHARACTERISTICS ARE SPECIFICALLY CONTROLLED DURING REFINING TO A LEVEL GENERALLY NOT SUITABLE FOR USE IN AIRCRAFT. (in bold, capitals, and very large print, as in the original).

A temperature limitation of +15°F makes diesel fuel, a tightly conditions-restricted fuel, once you get airborne.

[Brian Abraham]

It's not helpful that there is conflict between the FAA advisory on fuels for certain engines, the ExxonMobil World Jet Fuel specs brochure, and the P & W Canada, Service Bulletin.No conflict at all really onetrack. The Exxon document confines itself to fuel refined purposely for aircraft use.

The FAA has given by its own authority operators of TPE331-1-101Z engines to use diesel. From what I can ascertain operation of this engine is confined to agricultural operators.

P & W approve the use of diesel subject to the limitations given as you note (temperature).

Also note NATO F-76 diesel may be used in certain helicopters.

"(ExxonMobil) does not support or approve the use of automotive gasoline or diesel fuel in piston engine powered aircraft".This is merely the company giving its position for possible liability action. The FAA, and many other aviation authorities, have given approval for the use of automotive gasoline of approved quality in certain aircraft. I've not checked diesel powered aircraft as to whether diesel use is permitted against the usual jet fuel.

[Dan Winterland]

Some military aircraft are, or have been in the past, cleared to use deisel. The British Scout helicopter and Russian SU25 are two.