News broke out on the internet, the “Indian Airforce will acquire six planes from Air India and convert them into Airborne Early Warning and Control Systems”. The defense enthusiasts in India started speculating the probable platforms and type of the system that will be used for the AEW&CS.
In a major development, the Indian airforce will acquire six passenger jets of national airliner. These jets will be sent to France (please note this as it will be referenced later in the article) for the modification and then DRDO will be making six “Made in India” AEW&CS on these platforms. The estimated pricing of the deal will be Rs 10,500 Crore which in comparison with Phalcon is less than half. The estimated pricing of the two Phalcon AWACS was Rs 5,700 Crore.
Fleet of Air India
As the platform chosen will be sent to France for the modification the planes will be for sure an Airbus platform. Air India operates a fleet of 172 planes and of that only 87 are owned and remaining are leased units. Among these owned planes 26 are the wideboy aircrafts from Boeing and 44 narrow body aircrafts from mostly from Airbus.
The aircrafts in the fleet from Airbus are mostly Airbus A320 family planes with majority being Airbus A319 (19 Units) and A321 (21 Units). The other owned aircrafts from the airbus inventory are A320 Classic, 1 unit and A320 CEO, 4 units.
AEW&C aircraft & platforms.
The airborne early warning isn’t limited to large aircrafts, it is done with helicopters like Ka-31 Helix B and small business jets like ERJ-145. These systems have limited range, endurance and speed which results in compromised mission profile. In order to ensure the system, cover the complete spectrum and platform with 360⁰ coverage, longer endurance and high-power engine is needed.
The aircrafts are
- Boeing 737 – The AEW&C on these platforms are operated by the Royal Australian Airforce, Republic of Korea Airforce, Turkish Airforce.
2. Boeing 707 – United States Airforce, French Airforce, Royal Saudi Airforce, NATO, Chilean Air Force and Royal Airforce (UK).
2. IL76 – Russian Airforce, Indian airforce, and People’s Liberation Army Airforce (KJ-2000).
4. Boeing 767-200 – Japanese Air Self-Defense Force.
Based on the existing systems let’s explore the available options for the Indian airforce from the inventory of Air India. If the Indian airforce will have to acquire 6 aircraft from the inventory of Air India, then the plane would be either Airbus A319 or Airbus A321. As the Airbus A320 CEO and Classic together do not have number, Air India has just one Airbus A320 classic and four Airbus A320 CEO.
Airbus A319 as platform
If the airbus platform A319 is compared with the Boeing 737-200 on which the Boeing 737 AEW&C, The A319 offers far better parameters which will result in more stable and capable system.
But when the same platform is compared with the Boeing 707 on which the Boeing E-3 Sentry is made then the system is comparatively behind in performance* (Airbus A319 is a more efficient platform but parameters we are considering are related to the potential of these to be used as AWACS).
The Boeing 707-320 B with its four engines can generate collective thrust of 320 KN, while the two engines of Airbus A319 can generate 240 KN only.
So, if the power and load requirements of the DRDO AEW&CS is same as Boeing E-3 Sentry then the Airbus A319 is not the platform for the requirement.
However, the E-3 Sentry is an older system and new systems are expected to be low on power requirement and lighter in weight. Also, the Boeing E-3 Sentry uses a rotating radar dome (rotodome) above the fuselage and isn’t the best system for the comparison, though the parameters of A319 still aren’t convincing enough for a 360⁰ coverage system.
Airbus A321 as a platform:
If the platform selected for the requirement is A321 then the plane can provide much better performance than Boeing 737 and when compared with Boeing 707 on which the E3 is made the plane looks slightly underpowered.
If the A321 is compared with IL76 on which the Phalcon AWACS of the Indian airforce is made the A321 appears an overly under powered system.
Thus, to have a 360-degree coverage radar the Antenna mount for the system should be made lighter and the power requirement should also be less.
Embraer EJ 145 vs Airbus A321
Although after the initial report analysts now believe the system will be a dorsal type antenna mounted on A321/320 and will have a coverage of 240 degree.
In the year 2013 when the platform for the Netra was acquired, EJ145 after modification cost US$300 Million for 3 units. So, each modified EJ145 was US$ 100 million and the Indian airforce is satisfied with the performance of the platform. If the idea is to install a dorsal antenna then it’s not an efficient use of the capital (as the platform A320/321) will be comparatively costlier and with almost 10 times the payload its a wastage of potential.
|Length||29.87 m (98 ft 0 in)||44.51 m (146 ft 0 in)|
|Wingspan||20.04 m (65 ft 9 in)||35.8 m (117 ft 5 in)|
|Wing||51.18 m2 (550.9 sq ft)||128 m2 (1,380 sq ft)|
|Height||6.76 m (22 ft 2 in)||11.76 m (38 ft 7 in)|
|MTOW||24.1 t (53,131 lb)||93.5 t (206,000 lb)|
|Max payload||5.9 t||25.3 t|
|Fuel capacity||5,973 kg (13,168 lb)||24,050–30,030 L|
|Take-off Thrust||39.67 kN / 8917 lbf||133–147 kN (30,000–33,000 lbf)|
|Service ceiling||37,000 Ft||39100 Ft|
|Range||2,000 nmi (3,700 km)||5,926 km (3,200 nmi)|
Coverage 240-degree vs 360 degree:
The Antenna array unit of Netra has two planer antenna arrays on which the transmitter and receiver modules are mounted. Like shown in the figure below each panel offers a coverage of 120 degree and thus two panels collectively offer 240-degree coverage.
The antenna arrangement for the 360-degree coverage is not very different from antenna arrangement of Netra. Its just that to achieve the coverage of 360 degree the arrangement of antenna array either has to have triangular arrangement where each panel provides 120 degree coverage (As shown in figure a) or square where the panels will have to provide just 90 degree coverage (as shown in the figure B).
Theoretically, the Airbus A321/320 with 5 times the payload will have to accommodate and power one additional panel and at the same time compensate for the additional parasitic drag induced due to a change in the shape of the aerofoil.
If the antenna array units are made using the Gallium Nitride Transmitter and Receiver module then the system will be lighter and will require lesser power.
Thus, it’s difficult at this moment to conclude if the system will be a 240-degree coverage system or a 360-degree coverage radar. However, one thing is certain that if the idea is to install the 240-degree dorsal antenna then its not a good use of the potential that an Airbus A320/A321 offers.
Its time that will tell us how the final system will look like?
Let’s wait and watch…