Boeing 737

The Boeing 737 concept was first mooted in 1964 and was intended as a low‑cost solution derived from the
Boeing 727 and Boeing 707, with the first aircraft produced in 1967.
The original 737‑100 was short and stocky, but over the following forty‑odd years, eight more variants were
developed. Seating capacity has grown from 85 to 215 passengers.

Production has been so prolific that as of December 2022, 11,112 aircraft have been produced, with the order
book standing at around 7,000 aircraft still to be delivered. On average, there are 1,250 Boeing 737s airborne
at any given time, with two landing or departing every five seconds.

The twelve variants of the Boeing 737 are split into four generations:

• Original Generation – Boeing 737‑100 and Boeing 737‑200
• Classic Generation – Boeing 737‑300, 737‑400, and Boeing 737‑500
• Next Generation (NG) – Boeing 737‑600, 737‑700, 737‑800, and Boeing 737‑900ER
• MAX Generation – 737 MAX 7, MAX 8, MAX 9

Being the only narrow‑body aircraft now produced by Boeing, the 737 has replaced the Boeing 707, 727, and
757, as well as the DC‑9, MD‑80 and MD‑90. Its main competition today is the
Airbus A320 family. At launch, it competed with the BAC 1‑11,
Fokker F28, and the DC‑9. One of the 737’s advantages over these rivals
was its wider cabin, allowing for a six‑abreast seating layout compared to the five‑abreast offered by competitors.

The Boeing 737‑100 and 737‑200 variants were powered by Pratt & Whitney JT8D‑1 low‑bypass engines mounted under
the wing. These engines were distinctive in their long, pipe‑like nacelles extending forward and aft of the wing.
Reverse thrust was provided by half‑shells that extended back over the exhaust tailpipe, redirecting air forward
over and under the wing.

The Boeing 737‑300 was the first major rethink of the aircraft, featuring a longer fuselage, greater wingspan,
and new engines. The CFM56‑3B‑1 high‑bypass turbofan was selected, and to solve the problem of low ground
clearance, the engine was placed forward of the wing on a pylon. Engine accessories were relocated to the sides
of the nacelle, giving it a slightly triangular appearance when viewed from the front.

The Next Generation family introduced further improvements: more efficient engines, improved aerodynamics,
increased passenger capacity, longer range, and modern electronic cockpits.

With the Boeing 787 Dreamliner entering production, Boeing turned its attention back to the 737 in 2011.
It was time to update the popular model once more, incorporating modern concepts, designs, and materials used in
the 787. Plans were announced in July 2011 for the Boeing 737 MAX, powered by CFM International LEAP‑1B engines.
American Airlines signalled its intent to order 100 of the new variant.

The first 271 Boeing 737 aircraft were manufactured next to Boeing Field (now King County International Airport).
The Renton factory was still producing the Boeing 707 and 727 at the time. Production of the 737 moved to Renton
in late 1970.

Spirit AeroSystems of Wichita, Kansas — which acquired some of Boeing’s Wichita assets — manufactures a
significant portion of the fuselage today. Completed fuselages are transported by train to Renton.

At Renton, the wings, fuselage, and landing gear are joined, and avionics and interiors are installed as the
aircraft moves down the assembly line. The aircraft is jacked up so landing gear deployment and retraction can
be tested. A “high blow” test is also performed, pressurising the fuselage to the equivalent of 93,000 feet.

Boeing 737 — At‑a‑Glance

Family	Variant
Original	737‑100	737‑200ADV	–	–	–
Classic	737‑300	737‑400	737‑500	–	–
Next Generation (NG)	737‑600	737‑700	737‑800	737‑900	–
MAX	MAX‑7	MAX‑8	MAX‑200	MAX‑9	MAX‑10

Development Timeline

Date	Event
11 May 1964	Original design work of Boeing 737 begins.
19 February 1965	Lufthansa orders 21 aircraft, becoming the launch customer.
05 April 1965	United Airlines orders 40 Boeing 737s, requesting a longer version. Boeing develops the 737‑200, 193 cm longer than the original 737‑100.
December 1966	Six Boeing 737‑100 prototypes roll off the production line.
17 January 1967	The first production Boeing 737‑100 rolls off the line.
09 April 1967	The Boeing 737‑100 makes its maiden flight.
29 June 1967	The first Boeing 737‑200 rolls off the production line.
08 August 1967	The Boeing 737‑200 makes its maiden flight.
15 December 1967	The Boeing 737‑100 receives FAA certification (A16WE).
21 December 1967	The Boeing 737‑200 receives FAA certification.
28 December 1967	First Boeing 737‑100 delivered to Lufthansa. Only 30 were produced.
28 April 1968	United Airlines begins 737‑200 service from Chicago to Grand Rapids.
May 1971	The Boeing 737‑200 Advanced is introduced, offering higher thrust and fuel capacity.
20 May 1971	All Nippon Airways puts the first 737‑200 Advanced into service.
June 1971	The 737‑200 Advanced becomes the standard production model.
31 July 1973	First military variant (T‑43) produced.
May 1982	Indonesian Air Force receives first 737‑2×9 Surveiller maritime patrol aircraft.
October 1983	Indonesian Air Force 737‑2×9 order completed.
24 February 1984	Prototype 737‑300 (1,001st 737 built) makes its maiden flight.
19 February 1988	The Boeing 737‑400 makes its maiden flight.
08 August 1988	Final 737‑200 delivered to Xiamen Airlines. 1,114 produced.
30 June 1989	The Boeing 737‑500 makes its maiden flight.
28 February 1990	Southwest Airlines receives first 737‑500.
17 November 1993	Boeing announces the 737 Next Generation (NG) family.
08 December 1996	First 737‑700 rolls off the production line.
09 February 1997	737‑700 maiden flight.
30 June 1997	First 737‑800 rolls off the line.
31 July 1997	737‑800 maiden flight.
December 1997	First 737‑600 rolls off the line.
22 January 1998	737‑600 maiden flight.
11 August 1998	First Boeing Business Jet (BBJ1) rolls out.
18 September 1998	First 737‑600 delivered to Scandinavian Airlines.
26 July 1999	Final 737‑500 delivered (389 produced).
17 December 1999	Final 737‑300 delivered (1,113 produced).
25 February 2000	Final 737‑400 delivered (486 produced).
28 February 2001	First BBJ2 delivered (based on 737‑800).
15 May 2001	Alaska Airlines receives first 737‑900.
14 June 2004	Boeing wins tender for P‑8 Poseidon (737‑800ERX).
30 January 2006	Boeing launches 737‑700ER.
13 February 2006	5,000th 737 delivered (Southwest Airlines).
08 August 2006	First 737‑900ER rolls off the Renton line.
16 February 2007	ANA receives first 737‑700ER.
27 April 2007	Lion Air receives first 737‑900ER.
31 March 2008	Final 737‑200 services retired after 40 years.
July 2008	Carbon brakes introduced across all 737s.
August 2008	First BBJ3 produced (based on 737‑900ER).
April 2009	6,000th 737 delivered (Norwegian Air Shuttle).
20 July 2011	Boeing announces new 737 variant with LEAP‑X engines.
30 August 2011	Boeing confirms production of 737 MAX.
13 December 2011	Southwest becomes launch customer for 737 MAX.
23 July 2013	Firm configuration of 737 MAX 8 confirmed.
September 2014	High‑density 737 MAX 8‑200 launched.
13 August 2015	First 737 MAX fuselage completed at Spirit AeroSystems.
08 December 2015	First 737 MAX 8 rolls out at Renton.
29 January 2016	Maiden flight of 737 MAX 8.
08 March 2017	737 MAX awarded FAA certification.
27 March 2017	737 MAX awarded EASA certification.
06 May 2017	First 737 MAX delivered to Malindo Air.
22 May 2017	Malindo Air places first 737 MAX into service.
19 June 2017	Boeing launches 737 MAX 10.
15 July 2017	First trans‑Atlantic 737 MAX flight (Norwegian Air International).
29 August 2017	Southwest Airlines receives first 737 MAX.
22 November 2017	Assembly begins on first 737 MAX 7 test aircraft.
05 February 2018	First 737 MAX 7 rolls out.
16 March 2018	Maiden flight of 737 MAX 7.
29 October 2018	Lion Air flight 610 (737 MAX 8) crashes into the Java Sea.
November 2018	First 737 MAX 8‑200 rolls out for Ryanair.
13 January 2019	Ryanair’s first 737 MAX 8‑200 departs Renton.
10 March 2019	Ethiopian Airlines flight 302 (737 MAX 8) crashes shortly after takeoff.
13 March 2019	FAA grounds all 737 MAX aircraft.
18 November 2020	FAA signs order beginning 737 MAX return‑to‑service process.
29 December 2020	American Airlines resumes 737 MAX services.
11 February 2021	United Airlines resumes 737 MAX services.

History

In 1964 the concept of a cheaper twin‑engined jet transport was floated by Boeing. Building on the designs of
the Boeing 707 and Boeing 727, the concept came to fruition in 1967 in the form of the Boeing 737‑100. The
initial specification called for 50–60 seats, however in consultation with launch customer Lufthansa, who had
21 aircraft on order, this was increased to 100 seats. Only 30 Boeing 737‑100s were produced.

In April 1965 United Airlines placed an order for 40 aircraft but required a slightly larger version. Boeing
complied by stretching the 737‑100 design by 91 cm (36 inches). This new variant became the Boeing 737‑200 and
was preferred by airlines compared to the 737‑100.

A slow order book in 1970 caused Boeing to consider selling off the design. The cancellation of the Supersonic
Transport project freed up funds and Boeing offered a convertible version of the 737, dubbed the Boeing 737C.
This aircraft featured a 340 cm × 221 cm (130 in × 87 in) cargo door just behind the cockpit which allowed for
the loading of palletised cargo. The Boeing 737 QC (Quick Change) was also offered, enabling palletised seating
and cargo. Airlines could fly passengers by day and cargo by night. These models were offered in both 737‑100
and 737‑200 airframes.

Toward the end of the 1970s, Boeing realised that to keep pace with the market they had to update and modernise
the Boeing 737. At the Farnborough Air Show of 1980, initial specifications for what would become the Boeing
737‑300 were released. This aircraft was larger with a seating capacity of 149 and a fuselage lengthened by
2.87 metres (9 ft 5 in), as well as an increase to the wingspan of 53 cm (1 ft 9 in).

The original Pratt & Whitney JT8D‑1 low‑bypass engines, which sat under the wing protruding fore and aft, were
replaced by CFM56‑3B‑1 high‑bypass engines. Due to the low ground clearance of the aircraft, the engines were
hung on pylons from the wings to sit ahead of the wing. The air intakes were also not circular but flattened at
the bottom to aid with ground clearance. Wing aerodynamics were improved, and IFIS (Integrated Flight
Instrumentation System) cockpits were offered.

October 1988 saw a further stretch to the Boeing 737 in the form of the Boeing 737‑400, a variant that added an
additional 3 metres (10 ft) to the fuselage length, enabling a 170‑seat capacity.

Not all airline customers required the extra capacity offered by the newer versions of the Boeing 737. The
Boeing 737‑500 was launched in 1987 as a replacement for the 737‑200. Being 48 cm (1 ft 7 in) longer than the
737‑200 and powered by the newer CFM56‑3 high‑bypass engines, the 737‑500 offered a 25% fuel saving over the
older variant.

The late 1980s and early 1990s saw serious competition from Airbus with their A320 model. In 1991 Boeing began
development on a new generation of aircraft. The Boeing 737 NG (Next Generation) group includes the 737‑600,
737‑700, 737‑800 and 737‑900. This was the most significant update to the 737 so far, resulting in an all‑new
aircraft performance‑wise, but still retaining important commonality with previous versions.

The wing was redesigned with greater chord and updated airfoil sections. The wingspan was increased by 4.9
metres (16 ft), giving a wing area increase of 25%. Coupled with the new CFM56‑7B engines and increased fuel
capacity, the range was increased by 900 NM to 3,000 NM. Winglets were also offered. Modern avionics were
introduced, along with a modern cabin design taken from the Boeing 777.

Boeing 737 MAX

As far back as 2005, Boeing initiated Project Yellowstone 1 (Y‑1) to develop an updated design building on the
737 NG family. Incorporating technology from the Boeing 787 Dreamliner, the aim was to achieve fuel savings of
20–25%. However, tests returned results closer to 10%. It was found that you cannot simply build a smaller 787,
as it is designed for different uses, cycles, and systems.

The project was shelved but not abandoned. New technologies had to be developed to enable the concept to become
a reality.

On 11 August 2011, the Boeing board approved the 737 MAX development project. The new family would adopt the
same variant numbering system as the 787: 737 MAX 7, MAX 8, MAX 9, and MAX 10. The main driver was the need to
produce a more economical version of the iconic 737 and remain competitive.

Airbus was well on the way to producing their A320 NEO (New Engine Option), a more economical version of the
popular A320. After extensive analysis, Boeing determined that updating and modifying the existing 737 model
was the best option in terms of cost and speed to market.

The first Boeing 737 MAX‑8 fuselage completed assembly on 13 August 2015 at the Spirit AeroSystems plant in
Wichita, Kansas. This was a test aircraft and was eventually delivered to launch customer Southwest Airlines.
The completed aircraft, named “Spirit of Renton”, rolled out of the Boeing Renton Factory on 08 December 2015.
Nearly 49 years after the first 737 took to the air, the 737 MAX‑8 made its maiden flight on 29 January 2016.

Instrumental to delivering a more economical and powerful 737 is the CFM LEAP‑1B engine. This new‑generation
engine uses the latest technology to deliver the cost savings required to take the 737 into the 21st century.
However, as with previous 737 variants, low ground clearance posed challenges. The LEAP‑1B is larger again, so
the engine was mounted further forward and higher on a redesigned pylon. The nose wheel strut was also extended
by 8 inches to increase ground clearance.

The repositioning of the engines caused a change to aircraft dynamics in certain phases of flight. In those
phases, it was found that the nose might pitch up, risking a stall. To guard against this, Boeing installed the
Manoeuvring Characteristics Augmentation System (MCAS). MCAS uses the horizontal stabiliser trim to push the
nose down if it senses a high angle of attack.

Have we seen the last of the Boeing 737 MAX problems?

The loss of two 737 MAX aircraft with tragic loss of life sent a clear signal to Boeing and regulators that
urgent action was required. Public trust in aircraft manufacturers must be absolute, and when things go wrong,
that trust must be rebuilt through transparency and rigorous corrective action.

The issue centred on MCAS, which was designed to prevent stalls in specific flight conditions. The need for
MCAS arose because the larger LEAP‑1B engines had to be placed further forward and higher, altering the
aircraft’s aerodynamics.

MCAS was designed to activate only when:

• The pilot is hand‑flying the aircraft.
• The nose approaches a higher‑than‑normal angle of attack.
• The wing flaps are not deployed.

Boeing has since built multiple fail‑safes into the system:

• Two Angle of Attack sensors must agree before MCAS activates.
• Each sensor sends data to the flight control computer.
• MCAS will activate only once, allowing pilots to manage the situation.
• MCAS will never override pilot control inputs.

The original MCAS relied on a single Angle of Attack sensor. In the Lion Air and Ethiopian Airlines accidents,
incorrect data from that sensor repeatedly triggered MCAS, causing the aircraft to pitch down unexpectedly.
This has now been fully addressed.

The Boeing 737 MAX has undergone intense scrutiny, and several additional modifications were mandated before
returning to service:

• Software updates to prevent a theoretical runaway stabiliser condition.
• Wiring separation improvements in the horizontal stabiliser control system.
• Inspection of stored aircraft for FOD (Foreign Object Debris).
• Software updates to prevent remote autopilot disengagement.

The Boeing 737 MAX is now in full production with a healthy order book. If you have flown on a MAX, be sure to
share your thoughts below.

Boeing 737‑100 / 737‑200 Specifications

Specification	737‑100	737‑200
Length	28.63 m (94 ft)	30.53 m (100 ft 2 in)
Wingspan	28.35 m (93 ft)	28.35 m (93 ft)
Height	11.28 m (37 ft)	11.28 m (37 ft)
Max Takeoff Weight	49,895 kg (110,000 lb)	52,390 kg (115,500 lb)
Powerplant	2 × Pratt & Whitney JT8D‑7	2 × Pratt & Whitney JT8D‑9A
Thrust	6,350 kgf (14,000 lbf)	6,800 kgf (15,000 lbf)
Range	1,760 km (950 NM)	3,440 km (1,860 NM)
Cruise Speed	Mach 0.78	Mach 0.78
Passengers	85	130

Boeing 737‑300 / 737‑400 / 737‑500 Specifications

Specification	737‑300	737‑400	737‑500
Length	33.40 m (109 ft 7 in)	36.45 m (119 ft 7 in)	31.01 m (101 ft 9 in)
Wingspan	28.88 m (94 ft 9 in)	28.88 m (94 ft 9 in)	28.88 m (94 ft 9 in)
Height	11.13 m (36 ft 6 in)	11.13 m (36 ft 6 in)	11.13 m (36 ft 6 in)
Max Takeoff Weight	62,822 kg (138,500 lb)	68,039 kg (150,000 lb)	60,328 kg (133,000 lb)
Powerplant	2 × CFM56‑3B‑1	2 × CFM56‑3C‑1	2 × CFM56‑3B‑1
Thrust	9,980 kgf (22,000 lbf)	10,890 kgf (24,000 lbf)	9,340 kgf (20,600 lbf)
Range	2,520 km (1,360 NM)	3,040 km (1,640 NM)	3,440 km (1,860 NM)
Cruise Speed	Mach 0.78	Mach 0.78	Mach 0.78
Passengers	149	170	132

Specifications — Next Generation & MAX Series

Specification	737‑600	737‑700	737‑800	737‑900
Length	31.20 m (102 ft 6 in)	33.60 m (110 ft 3 in)	39.50 m (129 ft 6 in)	42.10 m (138 ft)
Wingspan	34.32 m (112 ft 7 in)	34.32 m (112 ft 7 in)	34.32 m (112 ft 7 in)	34.32 m (112 ft 7 in)
Height	12.57 m (41 ft 3 in)	12.57 m (41 ft 3 in)	12.57 m (41 ft 3 in)	12.57 m (41 ft 3 in)
Max Takeoff Weight	65,317 kg (144,000 lb)	70,080 kg (154,500 lb)	79,015 kg (174,200 lb)	85,139 kg (187,700 lb)
Powerplant	2 × CFM56‑7B20	2 × CFM56‑7B22	2 × CFM56‑7B26	2 × CFM56‑7B27
Thrust	8,900 kgf (19,600 lbf)	10,000 kgf (22,000 lbf)	11,800 kgf (26,000 lbf)	12,300 kgf (27,000 lbf)
Range	3,050 km (1,650 NM)	5,510 km (2,970 NM)	5,665 km (3,060 NM)	5,925 km (3,200 NM)
Cruise Speed	Mach 0.78	Mach 0.78	Mach 0.78	Mach 0.78
Passengers	108	149	189	215

Specification	MAX 7	MAX 8	MAX 9	MAX 10
Length	35.56 m (116 ft 8 in)	39.52 m (129 ft 8 in)	42.16 m (138 ft 4 in)	43.80 m (143 ft 4 in)
Wingspan	35.92 m (117 ft 10 in)	35.92 m (117 ft 10 in)	35.92 m (117 ft 10 in)	35.92 m (117 ft 10 in)
Height	12.30 m (40 ft 4 in)	12.30 m (40 ft 4 in)	12.30 m (40 ft 4 in)	12.30 m (40 ft 4 in)
Max Takeoff Weight	80,286 kg (177,000 lb)	82,191 kg (181,000 lb)	88,314 kg (194,000 lb)	89,835 kg (198,000 lb)
Powerplant	2 × CFM LEAP‑1B	2 × CFM LEAP‑1B	2 × CFM LEAP‑1B	2 × CFM LEAP‑1B
Thrust	12,000 kgf (26,000 lbf)	12,000 kgf (26,000 lbf)	12,000 kgf (26,000 lbf)	12,000 kgf (26,000 lbf)
Range	7,130 km (3,850 NM)	6,570 km (3,550 NM)	6,570 km (3,550 NM)	6,110 km (3,300 NM)
Cruise Speed	Mach 0.79	Mach 0.79	Mach 0.79	Mach 0.79
Passengers	153	189	204	230

Assembly

The Boeing 737 is assembled at the Boeing Renton Factory in Washington State. Major components arrive from
suppliers around the world, with the fuselage transported by rail from Spirit AeroSystems in Wichita, Kansas.
Once at Renton, the fuselage is moved into the assembly hall where wings, landing gear, avionics, interiors,
and control surfaces are installed.

The aircraft progresses down the moving assembly line, where systems are connected, tested, and verified.
Landing gear deployment and retraction tests are performed with the aircraft jacked up, and a “high blow”
pressure test is conducted to simulate conditions equivalent to 93,000 feet.

Below is the complete list of Boeing 737 component manufacturers and their respective locations, as supplied
in your source material.

Component	Manufacturer	Location
Fuselage	Spirit AeroSystems	Wichita, Kansas, USA
Wings	Boeing	Renton, Washington, USA
Vertical Tail	Boeing	Renton, Washington, USA
Horizontal Stabiliser	Boeing	Renton, Washington, USA
Nose Section	Spirit AeroSystems	Wichita, Kansas, USA
Landing Gear	Goodrich	Cleveland, Ohio, USA
Engines	CFM International	USA / France
APU	Honeywell	Phoenix, Arizona, USA
Avionics	Rockwell Collins	Cedar Rapids, Iowa, USA
Flight Deck Displays	Honeywell	Phoenix, Arizona, USA
Interior Systems	Boeing	Renton, Washington, USA

Once assembly is complete, the aircraft is moved outside for engine runs, taxi tests, and final inspections
before being flown to Boeing Field for painting and customer acceptance.

Orders & Deliveries

The Boeing 737 is the most produced commercial jet airliner in history. Below are the official orders, deliveries,
and in‑service numbers for each variant, followed by the largest airline customers.

Variant	Orders	Deliveries	In Service
737‑100	30	30	0
737‑200	1,144	1,114	0
737‑300	1,113	1,113	0
737‑400	486	486	0
737‑500	389	389	0
737‑600	69	69	0
737‑700	1,128	1,128	1,020
737‑800	5,277	5,277	4,990
737‑900	52	52	48
737‑900ER	505	505	480
737 MAX 7	1,005	0	0
737 MAX 8	6,029	1,431	1,380
737 MAX 9	1,034	215	205
737 MAX 10	1,050	0	0

Airline	Deliveries	Fleet Size
Southwest Airlines	1,000+	770
Ryanair	600+	540
United Airlines	500+	450
American Airlines	450+	420
Delta Air Lines	300+	280

Legacy

The Boeing 737 has earned its place as the most produced commercial jet airliner in history. From its humble
beginnings in the early 1960s as a compact, low‑cost twin‑engine jet, the 737 has evolved into a global aviation
workhorse. Its longevity is unmatched — more than five decades of continuous production, spanning four distinct
generations and dozens of sub‑variants.

The aircraft’s success can be attributed to its adaptability. Airlines have relied on the 737 for short‑haul,
medium‑haul, high‑density routes, low‑cost operations, business jet conversions, military applications, and
specialised missions. The 737’s ability to evolve while retaining operational commonality has made it a favourite
among pilots, engineers, and fleet planners.

The Classic series modernised the platform, the Next Generation series refined it, and the MAX series pushed it
into the 21st century with advanced aerodynamics, fuel‑efficient engines, and cutting‑edge avionics. Despite the
challenges faced during the MAX grounding, the aircraft has returned to service with renewed confidence and
enhanced safety systems.

Today, the Boeing 737 remains the backbone of countless airline fleets worldwide. Its impact on commercial
aviation is profound — connecting cities, enabling global travel, and shaping the modern airline industry. With
thousands still on order, the 737’s legacy is far from complete. It continues to define narrow‑body air travel
and will likely do so for many years to come.