Zhongbin Zb.25

The Zhongbin Zb.25 is a twin   (ASW) aircraft designed and built by Zhongbin Aircraft Company for the Imperial Kodeshi Navy. It was the first dedicated ASW platform in service with Kodeshia and played a vital role in the Great Kesh War. Introduced in 1957, the Zb.25 and its Zb.26 and Zb.27  derivatives saw service in the Imperial Kodeshi Navy until the mid-1980s.

History
The 1940s saw a rapid advancement of aircraft design and following the events of the 1940s Chez-Akitei war the Imperial Kodeshi Navy issued an Outline Specification inviting the industry to bid on a new type of aircraft that sought to replace the existing Hunter/Killer teams then in service with a single, self-contained platform that could detect, identify, track and destroy enemy submarines in an ocean environment and in all weather. Additionally it was to be operable from all of the Navy's carriers, ranging from the small Linggui-class escort carrier all the way up to the new Jingwei-class then underdevelopment.

Design
Zhongbin Zb.25 has a conventional mid-wing, twin-engine aircraft of all-metal construction with a span of 18.5 m (61 ft) and a length of 14.6 m (48 ft, 10 in). The outer wing panels would stow for more compact deck storage by rotating the leading edges up and folding the panels aft. The Zb.25 also featured a bulbous forward cabin for the four-man crew and a fixed, aft belly radome containing the Nangong N-3J/JL-1M5 search radar. A single Mk. 41-1 light-weight torpedo was to be carried in the weapons bay, along with rack-mounted sonobouys. Additionally six 5” rockets could be fitted, three under each wing. Multiple access panels, doors and hinged sections for easier maintenance were an integral part of the proposal. Aircraft sub-assemblies were also designed for simplicity in construction and repair. The engine nacelles were to be fully interchangeable as part of that goal. Initially propulsion was to be provided by two 1,600 kW (2,100 hp) Xunyi XF-18C-11 radial engines, each driving a 3.6 m (12 ft) diameter 4-bladed Dongfang propellers. Designed for catapult launch at 137 km/h (73 knots) airspeed, the Zb.25 could also accommodate two 1587 kg (3500 lb) thrust JATO (Jet-fuel Assisted Take-Off) units for short, 91.4 m (300 ft) deck operations. The choice of the radials was quickly changed during the early design stages and replaced with the new Koudezhou KVT-01P-II turboprops, 2,796 kW (3,749 hp).

Kodeshia
The Zhongbin Zb.25F-1 entered Imperial Kodeshi Navy service in 1957. The first deployment was aboard the aircraft carrier Fenghuang during 1958.

Since entering combat during the Great Kesh War, the Zb.25 has served the Imperial Kodeshi Navy, where it performed various missions such as, , , cargo transport, and pioneered and  missions during the war. The Zb.25 operated from both s and land bases, such as Zhuhai Naval Base. The Zb.25 also supported Operation X, a naval blockade of the coast of Selengeria to prevent infiltration of supplies and personnel by sea.

The Zb.25 was often armed with rockets for self-defense and. Some Zb.25s were modified to carry napalm canisters or cluster bombs. The Zb.25 also carried s and s for missions, but these were rarely used in combat. The Zb.25’s main weapon against submarines was the torpedo, which had a limited range and effectiveness against fast-moving targets.

The Zb.25 faced several challenges and dangers during the war. The Zb.25 was vulnerable to enemy fire from anti-aircraft guns and surface-to-air missiles. The Zb.25 also had to deal with poor weather conditions, such as s and s. Some aircraft were modified to perform the airborne early warning role and were to prove very effective with a detection range of 100 km; 54 nmi against large air targets and 25 km; 13 nmi against fighters while waiting for the arrival of dedicated purpose-built airborne early warning aircraft which would come with the Zhongbin Zb.27KY-1 itself a derivative of the Zb.25.

Despite these difficulties, the Zb.25 performed well and earned respect from its pilots and crew. The Zb.25 was praised for its reliability, versatility, and endurance. The Zb.25 also contributed to several notable achievements, such as rescuing downed pilots, locating enemy vessels, and providing vital intelligence. The Zb.25 was credited with sinking numerous Selengerian submarines over the course of the war, although these claims are disputed by some sources.

Variants

 * Zb.25YM-0
 * Y = 原型; Yuánxíng ("Prototype"), M = 模型; Móxíng ("Model")
 * Initial prototype, without electronics.


 * Zb.25YM-1
 * Designation of the first 10 production aircraft used for development, later rebuilt as a standard Zb.25F-0


 * Zb.25F-1
 * F = 反潛; Fǎnqián ("Anti-submarine")

Initial production anti-submarine warfare version fitted with a Nangong N-3J/JL-1M5 airborne surveillance radar, 185 built.
 * Zb.25J-1
 * J = 教練機; Jiàoliàn Jī ("Trainer")

Trainer conversion of Zb.25F-1.
 * Zb.25T-1
 * T = 通用; Tōngyòng ("Utility")
 * Utility conversion of Zb.25F-1 with seating for nine passengers.


 * Zb.25ZZ-1
 * ZZ = 照片侦察; Zhàopiàn zhēnchá ("Photo-reconnaissance")
 * Photo reconnaissance conversion of Zb.25F-1.


 * Zb.25F-2
 * F = 反潛; Fǎnqián ("Anti-submarine")

Improved anti-submarine warfare variant fitted with updated electronics primarily the new Nangong N-4J/JL airborne surveillance radar.
 * Zb.26T-1
 * T = 通用; Tōngyòng ("Utility")
 * Utility conversion of Zb.25T-1 see Zhongbin Zb.26


 * Zb.27KY-1
 * KY = 空中预警机; Kōngzhōng yùjǐngjī ("Airborne Early Warning Aircraft")
 * AEW conversion of Zb.26T-1 see Zhongbin Zb.27

Current

 * Kodeshia
 * Imperial Kodeshi Navy – Naval Air Arm Approximately 185.