Starting the F-16

First, let me tell you where I'm coming from. I spent 3 years, 9 months, and 11 days in the United States Air Force, from March of 1949 to November of 1952. Although I was trained to repair airborne radar at Keesler I wound up in an A.C. & W. squadron in Germany and didn?t see many aircraft up close. (Our squadron had an L-5 for a while.)

I got interested in the F-16 after reading Boyd: The Fighter Pilot Who Changed the Art of War by Robert Coram. The airplane is but a part of a fascinating story about a controversial Air Force fighter pilot.

I?d like to know more about how the engine of the F-16 is started. I understand that a piece of ground equipment called a ?-60" is used to produce compressed air that is piped to the aircraft using a flexible hose. (What do crew chiefs call the ?-60?? Do they say ?Dash Sixty? or what?)

Just where is the hose connected on the F-16? Does the air then hit the fan blade or a compressor blade or what? Does anyone have any specs on the air in terms of cubic feet per minute at standard temperature and pressure or equivalent. Anything on the dimensions and material used in the hose would be appreciated. I understand ?-60" also powers the aircraft electrically during the starting process. What powers the ?-60??

If anyone can point me to a website with more on this subject it would be greatly appreciated.

Stinsons forever!!!

This sounds like a good question for our resident crew chief. I know what goes on inside the cockpit during engine start but not outside.

Lets clear the air here. The -60 is used for putting power on the aircraft first thing in the morning to comfirm fuel, lox, lighting ect....

The aircraft has what is called a J.F.S. which stands for Jet Fuel Starter. This JFS starts the aircraft engine, not the -60.

In the bottom of the engine bay of the F-16 are 2 long skinny yellow tubes called the JFS / brake accumulators. These bottles are pressurized to 3000 PSI each. The pilot selects battery power in the cockpit, then he selects JFS start 1 (which blows 1 bottle) or JFS start 2 (both bottles). On the aircraft's left side right behind the main landing gear door are 2 small panels that open once the JFS switch is engaged. 1 door is an air intake for the JFS, the other is an exhaust for the hot jet gases.

The JFS spins up to speed and starts to turn the main engine through a shaft that is connected from the JFS to the main gear box of the engine. This shaft is called the PTO shaft. Once the engine is spinning at enough RPM's, the pilot takes the throttle over the horn into "idle"

Fuel and air is mixed into the engine and and the ignitors are sparked. Now the engine is running.

Several seconds later, the JFS kicks off and the doors close.

The previous guest has got it pretty much down. That's basically what happens in very simple terms.

-Crew chief stationed at Nellis

Isn't the box that starts up the engine called a Palouste?

First off, I thank all respondents to my inquiry. I have no clue now as to where I got this idea that a -60 was used to start the F-16 engine.

I do not understand the connection between the 3,000 psi "long yellow tubes" and the JFS. Is this used to start the JFS. And why would one expend the brake accumulator? If both accumulators are "blown" does the aircraft take off with empty tubes?

Here's something I got off of an F-15 website: (I paraphrase.)

(1) Crank up the Jet Fuel Starter. The Jet Fuel Starter (JFS), is a small gas turbine which connects to the engine through a gearbox and turns it for starting. It also provides limited electrical power. (2) Engage the JFS connection to the engine.
(3) As the JFS spins the engine through 20% RPM, push the throttle forward out of cutoff and into idle.

After that it is not stated specifically that an air/fuel mixture into the engine is ignited but I assume from what has been stated here that that is what happens.

And I find that the -60 was used to start the F-4 Phantom and the T-37. Anyone in the crowd a crew chief on either of these craft?

The "long yellow tubes" are JFS/Brake accumulators. They do dual duty. They are used to provide power to start the JFS. After the engine starts and hydraulic power is established then they are recharged and they become available for either further JFS starts or emergency brakes should they be needed for that.

This is great! Thank you.

I assume, then, that hydraulic fluid from the accumulator turns a hydraulic motor that starts the JFS? Yes?

Precisely... it's called the "jfs hydraulic start motor"

really interesting information, thanks guys !

I'm a bit puzzled though by the dual purpose of the JFS/Brake accumulators.

they become available for either further JFS starts or emergency brakes

Does this mean they are used to open the airbrakes ?

marsu

Here's something on the jfs hydraulic start motor from another site:

The F-16 Hydraulic Start Motor is a fixed wobbler axial hydraulic motor used in the engine starting system. The hydraulic start motor provides rotational power needed to accelerate the jet fuel starter to starting speed. It is linked to the jet fuel starter by the central gear box. Dimensions: Ht 3.5", Width 3.0, Depth 3', Weight 2.6 lbs.

Emergency brakes refers to the wheel brakes.

For the DACO book, the JFS

GF!
Skippy

Marsu,

Obviously the 16 is small and has alot cramped into it so anything with a dual purpose is a great thing. The JFS/Brake Accumulators provide the wheel brakes with a short amount of emergency braking power for anytime the B system hyd fail. Also for brake operation with out the engine running and just battery power applied.

The above picture shows a good view of the JFS, side view of the ADG, HSM, B system hyd pump, the front of the Left JFS/Brake accumulator, and many other cool parts.

Hey Dave, could you point out where in the pic those other ancillary parts are? I mean I know that's the JFS in the center, so start form there.
Thanks!
Gotta fly!
Skippy