JF-17 Thunder’s Avionics

JF-17 Thunder – All round view                                         Chapter 5 : JF-17 Thunder’s Avionics

JF-17’s Weapon and Mission Management Computer:

The creation of Weapon and Mission Management Computer (WMMC) was a critical task. The design have to be made in such a way that will allow the pilot to bring the aircraft to its limits with a complete confidence of getting the control back from the aircraft at his will.

JF-17 has Type 634 quadruplex  digital Fly-By-Wire (FBW) for pitch axis and duplex analog FBW in roll axis. The maximum G and maximum Angle-of-Attack (AOA) values are set at limited values for different levels of flight. During a deep stall, JF-17’s computer compares values of pitch, Angle-of-Attack, speed and attitude with default values of normal stall. Based on its instincts it decides to recover automatically.

At higher speeds the pitch rate is automatically limited to avoid overstressing the airframe. Similarly, value for maximum G is also set to 8.5g. The aircraft uses MIL-STD-1553 bus for Data transfer an MIL-STD-1760 for weapon interface.

Its basically one main Weapon and Mission Management Computer (WMMC). It has sub modules like Fire Control Computer (FCC), Environment Control System (ECS), threat  management system etc. JF-17 has Type  quadruplex digital Fly-By-Wire (FBW) for pitch axis and duplex analog FBW in roll axis. Means one is automatic and other is manual.

JF-17’s cockpit modules including Radar Warning Receiever (RWR), Optical Electronic Self Protection (OESP) system, Inertial Navigation System (INS), Identification of Friend or Foe (IFF), Stores Management System (SMS), Weapon and Mission Management Computer (WMMC).

Avionics tool kit (rugged laptop):

Seen above is a rugged laptop used as a portable maintenance aid to maintain avionics of the aircraft. The maintenance aid provides e-manuals , data analysis tool kit and aircraft configuration information. The technicians views graphical representations of weapon configuration before clearing the aircraft for flight. Depending upon each mission, operational needs can be visualized before loading the aircraft. Errors and discrepancies between observed values and actual values are displayed in it as well. This toolkit provides efficient means of locating cause of Malfunction (MAL) messages during loading the aircraft.

JF-17 Test and Evaluation (T&E) team analyzing the aircraft data in multiple rugged laptops connected to the avionics compartment of the aircraft.

Avionics shelve:

JF-17 crew working on the avionics shelve above the starboard air intake. The yellow wires are attached to the avionics data unit, which are downloaded in a rugged laptop for further analysis.

JF-17 Thunder’s Cockpit

JF-17 Thunder – All round view                                         Chapter 4 : JF-17 Thunder’s Cockpit

JF-17 Cockpit:

The man-machine interface of JF-17 Thunder is kept very simple and flexible at the same time too. The cockpit consists of three Multi functional displays (MFDs) supported by a smart Heads Up Display (HUD). The symbology and functionality of the controls is kept very much similar to SAAB’s Gripen aircraft – an aircraft evaluated by PAF in the past. Implementation of HOTAS (Hands On Throttle-And-Stick) is visible in the design. The commonalty of the cockpit helps in decreasing time and training costs thus making a speedy fighter conversion to the aircraft.

Cockpit illustration:

A detailed labeled illustration of JF-17 cockpit.

Stick & right auxiliary control panel:

JF-17’s stick with buttons for weapon release (red one), missile override (top right), display management (top-left), countermeasures management (front bottom). Options included on the other side of stick are communication switch, air-to-ground mode selection, trigger, cursor control etc.

The right auxiliary control panel includes various types of sensors information including secondary voice communication panel, avionics power management, aircraft data storage and transfer management, cockpit lights management and HUD management options.

A labeled picture of JF-17’s Integrated Control Panel (ICP), data entry display and Multi Functional Displays (MFD). JF-17’s cockpit has three 6X8 inch wide MFDs. The information displayed on all these MFDs is interchangeable and pilot can easily switch information among them.

JF-17’s Man Machine Interface (MMI) with three MFDs, throttle and stick.

Heads Up Display:

A labeled picture of JF-17’s Heads Up Display (HUD). The symbology and functionality of the controls is kept very much similar to SAAB’s Gripen aircraft.

HUD, Digital video recorder and Cockpit audio recorder:

A close up of front instrumentation panel that includes Smart Heads Up Display(S-HUD), cockpit audio recorder and Airborne Video Tape Recorder (AVTR). The elevated design of this panel also helps in decreasing the sun flare from entering the cockpit.

An AVTR camera is located in the front of the instrumentation panel. AVTR includes a Digital Video Recorder (DVR) which has four video channels and one audio channel. DVR receives videos from MFD, Targeting/Navigation pod and stores it all in a data cartridge capable of storing upto 64GB of data. Later in mission debriefs, this data is discussed and analyzed for further mission planning.

JF-17 simulator:

In present day, simulator based training have been widely used around the globe. It not only saves time but also provide much training opportunities to trainee pilots in a simulated real world scenario. In past eight years of JF-17 program, all pilots have used simulator for conversion onto this aircraft. The development of dual seat fighter/trainer version of JF-17 is under discussion too.

A good simulator has to be realistic as much as it can be done. In different stages of pilot training they are asked to wear helmet, oxygen mask, gloves, g-suit etc. Various real life flight emergencies, false alarms on radar and threats are simulated during his training flights. The final stage is the real combat scenario, where he faces enemy, leads a formation, fulfills given objectives in specified time and handles in flight emergencies too.

All of the above mentioned scenarios are performed by the student with no help from the instructor. If he is eligible enough he gets a flight in the real aircraft or his deficiencies are specified, improvements are suggested and he is given another chance to fly simulator again. Failing to meet up with the defined standards means any end of student’s conversion on JF-17 Thunder.

The good thing in JF-17 programme, is that the people who have involved in building the airplane have also documented its operating procedures, lessons and testing procedures too.

Ejection seat:

JF-17 uses a zero/zero Martin Baker PK-16LE ejection seat. In early 2008, PAF signed a contract with Martin Baker for accusation of 50 PK16LE MK16 zero/zero ejection seats. The Chinese  ejection seats (TY-6)  of earlier SBP examples (07-101 to 108) were also replaced with PK16LE seats. The response of PK-16LE ejection even at various altitude and immense angles has saved lots of precious lives. In the past, PAF had installed Martin Baker ejection seats in F-6, Mirage, F-7P and F-7PG aircraft as well.

PK-16LE MK16 ejection seat also has an ejection sequencer, which manages the separation time of ejection seat and parachute of the ejectee pilot. The main features of PL-16LE MK16 are the rearward firing headbox, leg restraints and enhanced cushions. Beneath the seat cushions are the pilot’s survival kit which includes a rescue flares, small boat, medicine, food and some other accessories.

The 30 degree inclined seat, gives a 1G tolerance to the pilot. Seen on both sides of ejection seat are the warning notes for the aircraft crew. Words like ‘DANGER – DONOT PULL HANDLE’ are often found on it. Located in its rear are the oxygen cylinders and under it are the rockets that propel the ejection of seat in the air.

 

JF-17 Thunder’s Middle Fuselage

JF-17 Thunder – All round view                                         Chapter 3 : JF-17 Thunder’s Middle Fuselage

Fuel Cells:

Fuel cells are visible on the fuselage of a specially painted JF-17.

Another close up of fuel sections on JF-17 fuselage. The aircraft can carry a total of 2330 kg (5,130 lb)of fuel in fuselage and wings. To enhance more range, an 800 litre droptank can be mounted on the aircraft’s center line station and two 800 or 1100 litre droptanks can also be mounted on the two inboard under-wing pylons.

Gun:

JF-17 has one multi barreled 20mm GSU-23 gun, mounted under the port air inlet. The ammo box present adjacent to the gun, which is capable of holding up to 250 20mm bullets.

The side view of JF-17’s gun. Note various points to keep the barrel cool during rapid use.

Navigation lights:

 

Navigation lights are present on both sides of intakes near the RESCUE marking. Similar lights are also present on both sides of the wing too.

A JF-17 moments after takeoff, four navigational lights are visible on intake and wings.

Baggage compartment :

Each year different fighter squadrons are deputed to remote air fields/airbases as a part of their operational readiness training. During such deployments 4-6 aircraft are flown, with a bunch of air crew and aircraft spares  in supporting transport aircraft. In such out of station deployments, transportation of related equipment is mandatory. Some necessary pilot related luggage (including ration, electronic equipment, maps and rescue items) are carried by the same fighter aircraft itself. For e.g. F-16s around the globe use MXU-648 baggage pod to carry such items. MXU-648 occupies one pylon, it could be pylon 3/7 or centerline pylon 5. Baggage pods are also used in air ferry missions, air show and exercises deployments.

In JF-17, a baggage section is made behind the port side intake. Air crew inserts luggage in this dedicated compartment and then close it by tightening the screws. After reaching the desired location, air crew opens the same section and extracts the baggage. Such salient feature s embedded in its design will allow attachment of more weapons on either side of the wing. Needless to say a free pylon can also become useful in war time deployments too.

JF-17 crew placing luggage in the specialized baggage compartment. In the last photo, two members of ground crew are finalizing this work.

The baggage section is located just before the landing gear door on the port side of the aircraft. The components in similar section on starboard side is the Jet Fuel Starter (JFS).

This picture shows the direction of air flow via intake. The green arrows represent the areas left above and under the luggage section, to continue the rapid flow of air through the aircraft.

Jet Fuel Starter (JFS) point:

JFS is a ground based electric power unit, that runs the aircraft engine when aircraft is not on its own power. JFS is a military version of Auxiliary Power Unit (APU) present in the airliners to start their engines. In JF-17 the JFS cable is inserted inside the aircraft’s power unit located behind the starboard air intake.

A 60KVA power JFS mounted on a mini truck, that power the JF-17 engine. A JFS can start engine in less than 3 minutes. Note the cable leaving JFS and going inside the aircraft’s power section.