Ki-27 otsu

This page is about the Japanese fighter Ki-27 otsu. For other variants, see Ki-27 (Family).

Ki-27 otsu

Ki-10-II C

Ki-43-I

Ki-27 otsu

Ki-10-II C

Ki-43-I

Japan

I Rank

Battle rating:

AB	RB	SB
1.3	2.0	1.3

Class:

Fighter

Research:2 900

Purchase:700

Show in game

Description

The Ki-27 otsu, designated as Type 97 Fighter (九七式戦闘機), was a monoplane fighter aircraft designed by Nakajima Aircraft Company for the Imperial Japanese Army Air Service in 1937. It was the Army's first monoplane fighter and had a low wing loading that gave it excellent manoeuvrability. The Ki-27 served as the main fighter of the Japanese Army until 1940, and participated in battles over China, Mongolia, Southeast Asia and the early stages of the Pacific War. It gained air superiority against Chinese and Soviet fighters, but was outperformed by newer Allied planes. The Ki-27 was also operated by Manchukuo, Thailand, and the Reformed Government of the Republic of China. A total of 3,368 Ki-27s were produced before production ceased in 1942, when it was replaced by the Ki-43 in frontline service and relegated to training and reserves.

It was introduced in Update 1.43. The Ki-27 distinguishes itself as a low-level dogfighter: its performance below 1,000 m is superb and it can manoeuvre away from nearly any other comparable fighter. Like the Ki-10 series before it, the Ki-27 otsu suffers from its poor armament (twin 7.7 mm Type 89s) and weak armour, which means it makes for a poor interceptor despite its high speed, but the Ki-27 makes an excellent escort for bombers and flying boats to provide cover for their allied bombers.

Nicknames

• IJA Pilot Abbreviation: Kyū-Nana Sen (九七戦, "9-7 Fighter").
• Allied reporting name: Nate
• CBI reporting name: Abdul

General info

Flight performance

Max speed

at 3 500 m495 km/h

Turn time10 s

Max altitude8 500 m

EngineNakajima Kotobuki 41

TypeRadial

Cooling systemAir

Take-off weight2 t

Like its Ki-10 predecessor, the Ki-27 relies on its manoeuvrability for its survival. Therefore, turnfighting is vital for a Ki-27 pilot. Avoid diving on opponents, due to the Ki-27's fuel feed issues, and focus on scaring enemy pursuers away from bombers rather than chasing a kill. A lone Ki-27 is easy prey for allied energy fighters. Like most Japanese fighters, engaging an enemy head-on is not recommended. If fighting an enemy energy fighter head-on, a good strategy is to turn away (usually a slight turn as you'll want him to miss you, but also pass you), and hope that he turns to follow.

Like the comparable A5M4, the Ki-27's carburettor engine suffers from fuel feed issues in negative G manoeuvres, like diving. Nosing down will cause the engine to choke out. Positive G manoeuvres like the Split-S are preferred. This issue will allow enemies to out dive the Ki-27, so engaging at low altitudes is preferred.

Additionally, the Ki-27 runs hot and will overheat at 100% throttle on all but the coldest maps. To cool off, ease the throttle back to 40% or 50% and, if possible, try to gain altitude. If the engine overheats during a dogfight, try to break off if the opportunity presents itself. No pilot can outmanoeuvre on an overheated engine.

Compared to the Ki-43-I, it has marginally better manoeuvrability with a very low stall speed around 91 km/h (49 knots) with landing flaps deployed. However, the Ki-27 retains the power-to-weight ratio of the Ki-10 biplane, allowing it to climb very steeply at a 45° climb angle.

Characteristics	Max Speed (km/h at 3,500 m)		Max altitude (metres)	Turn time (seconds)		Rate of climb (metres/second)		Take-off run (metres)
	AB	RB		AB	RB	AB	RB
Stock	476	465	8500	10.2	10.6	8.5	8.5	180
Upgraded	517	495		9.8	10.0	18.6	12.8

Details

Features
Combat flaps	Take-off flaps	Landing flaps	Air brakes	Arrestor gear
X	X	✓	X	X

Limits
Wings (km/h)	Gear (km/h)	Flaps (km/h)			Max Static G
		Combat	Take-off	Landing	+	-
554	550	N/A	N/A	220	~10	~7

Optimal velocities (km/h)
Ailerons	Rudder	Elevators	Radiator
< 350	< 350	< 350	> 296

Compressor (RB/SB)
Setting 1
Optimal altitude	100% Engine power	WEP Engine power
3,300 m	705 hp	846 hp

Survivability and armour

Crew1 person

Speed of destruction

Structural554 km/h

Gear550 km/h

The Ki-27 does not have any armour, so your great turn rate is the only real defence. The fuel tanks aren't self-sealing either, which only strengthens the need to use your great turn rate. There is one fuel tank above and behind the oil cooling system; the rest are in the wings, with 2 in each wing.

Modifications and economy

Repair costBasic → Reference

AB103 → 128

RB184 → 230

SB113 → 141

Total cost of modifications2 970

895

Talisman cost190

Crew training200

Experts1 000

Aces20

Research Aces96 000

Reward for battleAB / RB / SB

10 / 20 / 60 %

100 / 100 / 100 %

Modifications

Flight performance	Survivability	Weaponry
Fuselage repair Research: 200 Cost: 60 40 Radiator Research: 200 Cost: 60 40 Compressor Research: 330 Cost: 100 65 Wings repair Research: 250 Cost: 75 50 Engine Research: 250 Cost: 75 50 Engine injection Research: 480 Cost: 145 95	Airframe Research: 330 Cost: 100 65 Cover Research: 480 Cost: 145 95	type89_belt_pack Research: 200 Cost: 60 40 type89_new_gun Research: 250 Cost: 75 50

At this rank, the order of research is mainly personal preference, though the Ki-27 Otsu will benefit significantly from defensive and performance enhancing modifications.

Armaments

Offensive armament

Weapon 12 x 7.7 mm Type 89 machine gun

Ammunition1 000 rounds

Fire rate900 shots/min

The Ki-27 otsu is armed with:

• 2 x 7.7 mm Type 89 machine guns, nose-mounted (500 rpg = 1,000 total)

Usage in battles

A superior dogfighter for turnfighting, the Ki-27 is the first plane to begin showing the features typical of the Japanese "Zero" but with none of the bite. Its speed and manoeuvrability are plagued by engine problems, with no armour and a standard armament.

In battle, no Allied fighter can outturn you, except for biplanes, but most will outgun you (and even most biplanes match the Ki-27 in armament).

Biplanes make easy prey for the Ki-27, and it can easily outmanoeuvre the P-36C, the F2A-1 and the I-16 type 24, but their stronger armaments will knock out a Ki-27 in a single good burst. Simply outrunning any of them is an excellent evasive manoeuvre. Hurricane Mk I/Ls can strictly compete with the Ki-27 Otsu in manoeuvrability, but the Hurricane's heavier armament (four times that of the Ki-27) can also quickly shred a Ki-27. Additionally, outrunning a Hurricane in a Ki-27 is not possible. The I-15bis will be the bane of a Ki-27s existence, as their excellent turning ability will force it into energy bleeding manoeuvres or Boom & Zoom style combat.

Enemies worth noting

Despite its low battle rating, you can face some challenging foes when flying the Ki-27. Biplanes will give you a run for your money in terms of manoeuvrability, while some early monoplanes will be faster and more heavily armed than you. Therefore, it is important to judge your foes accordingly.

From America, you will face the P-26. They are quite good divers and have a decent roll rate, but will not be able to outmanoeuvre you in a turn fight. The P-36 is more challenging. Faster and well-armed, you will have to rely on your turn rate to try and outmanoeuvre them.

Then from Germany you also have the He 100 D-1, which is fast. Its energy energy retention is good as which means that it will bleed speed far slower than you. The best way to fight it is to lure it into a dogfight to bleed its energy. If the He 100 D-1 breaks off the engagement, runs away and is out of your shooting distance, you should just break off too but be prepared for it to come back.

One of the most challenging opponents is the I-153 M-62 Chaika. It is not a mere upgraded I-15bis, but in all performance aspects equal to the Nakajima Ki-27 fighter. Also on the Soviet side, the MiG-3 is a significant threat. It is one of the fastest aircraft in its battle rating and has powerful armament. In skilled hands, it can be an almost impossible opponent to combat, especially when using Boom & Zoom tactics against you. Your only defence will be to try and outmanoeuvre it or to lure it into a turnfight.

Manual Engine Control

MEC elements
Mixer	Pitch	Radiator			Supercharger	Turbocharger
		Oil	Water	Type
Controllable	Controllable Not auto controlled	Controllable Not auto controlled	Controllable Not auto controlled	Separate	Not controllable 1 gear	Not controllable

Pros and cons

Pros:

• Great manoeuvrability, on par with biplanes
• Good stability in turns
• Good speed, for its tier
• Excellent climb rate

Cons:

• Limited firepower
• Engine overheats rapidly on hot maps
• Engine chokes in negative G dives
• No armour

History

Development

The Nakajima Ki-27 otsu began as the Ki-11, a competitor for the Kawasaki Ki-10 biplane. While faster and more modern than the Ki-10 biplane, the Ki-11 wasn't adopted because the Imperial Japanese Army valued manoeuvrability over speed. Nakajima continued development of the design before finalising the Ki-12, a modern monoplane with a liquid-cooled engine and retractable landing gear, but the Army denied it outright as too maintenance heavy for forward airbases in Manchuria and China. The redesigned plane instead featured a radial air-cooled engine, fixed landing gear and fully enclosed cockpit and received the designation Ki-27.

In 1936, the Ki-27 competed against the Kawasaki Ki-28 (a prototype design fated to never enter production) and the Mitsubishi Ki-33 (a de-navalised A5M). While the Ki-33 outperformed the Ki-27 in most regards, the Imperial Japanese Army was loath to adopt a "navy fighter", and approved the Ki-27 with minor modifications. The Ki-27 entered service as the Army Type 97 Fighter.

Service History

While the Ki-10 would not be finally phased out from front line service until 1942, by 1940, the Ki-27 was the primary army fighter on the front lines. It was unmatched by any plane in the Chinese air force inventory, and outperformed the Soviet I-15 and I-16 fighters in the Battles of Khalkhin Gol, with some pilots scoring 11 kills against Soviet planes in a single day. Against Chinese Curtiss P-36 Hawks, veteran Ki-27 pilots achieved similar, but not as impressive kill rates.

Over China, the Ki-27 was unmatched until the deployment of the P-40 Warhawks with the American Volunteer Group. After America's entry into the war, the Ki-27 also fared poorly against the US Navy's F2A Brewster Buffalo and F4F Wildcat and was removed from most front line service within the first months of the war, replaced by the much-improved Ki-43. However, it remained a front line fighter in Thai service, where the Ki-27 scored recorded kills against P-51s and at least one P-38.

Because of their high production numbers and relatively few losses, Ki-27 would see a renewed role late in the war as Kamikaze planes.

Media

Skins

• Skins and camouflages for the Ki-27 otsu from live.warthunder.com.

See also

Links to the articles on the War Thunder Wiki that you think will be useful for the reader, for example:

• reference to the series of the aircraft;
• links to approximate analogues of other nations and research trees.

External links

• Official data sheet - more details about the performance
• [Wikipedia] Nakajima Ki-27