CFM International LEAP

LEAP
Mockup of a LEAP-X, the early code name of the engine
Type Turbofan
National origin France/United States
Manufacturer CFM International
First run 4 September 2013[1]
Major applications Airbus A320neo family
Boeing 737 MAX
Comac C919
Number built 2,516 (June 2019)[i]
Developed from CFM International CFM56
General Electric GEnx

The CFM International LEAP ("Leading Edge Aviation Propulsion") is a high-bypass turbofan engine produced by CFM International, a 50–50 joint venture between American GE Aerospace and French Safran Aircraft Engines. It is the successor of the CFM56 and competes with the Pratt & Whitney PW1000G to power narrow-body aircraft.

Design

The LEAP's basic architecture includes a scaled-down version of Safran's low-pressure turbine used on the GEnx engine. The fan has flexible blades manufactured by a resin transfer molding process, which are designed to untwist as the fan's rotational speed increases. While the LEAP is designed to operate at a higher pressure than the CFM56 (which is partly why it is more efficient), CFM plans to set the operating pressure lower than the maximum to maximize the engine's service life and reliability.[6] Currently proposed for the LEAP is a greater use of composite materials, a blisk fan in the compressor, a second-generation Twin Annular Pre-mixing Swirler (TAPS II) combustor, and a bypass ratio around 10–11:1.

The high-pressure (HP) compressor operates at up to a 22:1 compression ratio, which is roughly double the corresponding value for the CFM56's HP compressor.[7]

CFM uses ceramic matrix composites (CMC) to build the turbine shrouds.[8] These technological advances are projected to produce 16% lower fuel consumption.[9][10] Reliability is also supported by use of an eductor-based oil cooling system similar to that of the GEnx, featuring coolers mounted on the inner lining of the fan duct. According to Aviation Week's article, "The eductor device produces a venturi effect, which ensures a positive pressure to keep oil in the lower internal sump."[6] The engine has some of the first FAA-approved 3D-printed components.[11]

The LEAP-1C for the Chinese-built Comac C919 reportedly lacks many of the improvements of the other LEAP models over concerns that the technology could be stolen and put into the CJ-1000A engine being developed by another state-owned manufacturer, the Aero Engine Corporation of China. Experts believe that the LEAP-1C is actually an upgraded version of the prior-generation CFM56.[12] Compared to the similarly sized LEAP-1A, the -1C is heavier and produces less thrust.[13]

Development

18 blade fan

The LEAP[14] incorporates technologies that CFM developed as part of the LEAP56 technology acquisition program, which CFM launched in 2005.[15] The engine was officially launched as LEAP-X on 13 July 2008.[9] It is intended to be a successor to the CFM56.

In 2009, COMAC selected the LEAP engine for the C919.[16] The aircraft was due to begin testing in 2016.[17] In total, 28 test engines will be used by CFM to achieve engine certification, and 32 others will be used by Airbus, Boeing and COMAC for aircraft certification and test programs.[1][18] The first engine entering the test program reached and sustained 33,000 lbf (150 kN) of thrust, required to satisfy the highest rating for the Airbus A321neo. The same engine ultimately reached 35,000 lbf (160 kN) of thrust in test runs.[6]

The LEAP-1A was tested on GE's 747-400 flying test platform.[19]

CFM carried out the first test flight of a LEAP-1C in Victorville, California, with the engine mounted on the company's Boeing 747 flying testbed aircraft on 6 October 2014. The -1C version features a thrust reverser equipped with a one-piece O-ring replacing a two-piece door. The thrust reverser is deployed by the O-ring sliding aft, reducing the drag that was induced by the older design and improving efficiency.[20]

In April 2015, it was reported that the LEAP-1B was suffering up to a 5% shortfall on its promised reduction in fuel consumption.[21]

It obtained its 180-minute ETOPS approval from the U.S. Federal Aviation Administration and the European Aviation Safety Agency on 19 June 2017.[22]

Orders

On 20 July 2011, American Airlines announced that it planned to purchase 100 Boeing 737 aircraft featuring the LEAP-1B engine.[23] The project was approved by Boeing on 30 August 2011, as the Boeing 737 MAX.[24][25] Southwest Airlines is the launch customer of the 737 MAX with a firm order of 150 aircraft.[26]

The list price is US$14.5 million[27] for a LEAP-1A, and US$14.5 million for a LEAP-1B.[28]

CFM International offers rate-per-flight-hour support agreements (also known as "power by the hour" agreements) for the engine. For a LEAP-1A engine, costs are around US$3,039 per engine, per day, compared to US$1,852 per engine, per day for the prior-generation CFM56.[29]

In 2016, CFM booked 1,801 orders, and the LEAP backlog stood at more than 12,200, worth more than US$170 billion at list price.[2]

By July 2018, the LEAP had an eight-year backlog with 16,300 sales. At that time, more LEAPs were produced in the five years it was on sale than CFM56s in 25 years.[3] It is the second-most ordered jet engine behind the 44-year-old CFM56,[30] which achieved 35,500 orders.[3] Also, on the A320neo, where the engine competes head-to-head with the Pratt & Whitney PW1000G, the LEAP had captured a 59% market share in July 2018. By comparison, the CFM56 had a 60% share of the prior-generation A320ceo market.[30][31]

In 2020, GE Aviation reported that CFM had lost 1,900 orders for LEAP engines worth US$13.9 billion (US$7.3 million each), reducing the backlog value to US$259 billion. More than 1,000 cancellations came from Boeing 737 MAX orders being canceled among the Boeing 737 MAX groundings, while the remainder came from the impact of the COVID-19 pandemic on aviation.[32]

Production

side view with cutaways

In 2016, the engine was introduced in August on the Airbus A320neo with Pegasus Airlines and CFM delivered 77 LEAP.[2] With the 737 MAX introduction, CFM delivered 257 LEAPs in the first three quarters of 2017, including 110 in the third: 49 to Airbus and 61 to Boeing, and targets 450 in the year.[33] CFM was to produce 1,200 engines in 2018, 1,900 in 2019, and 2,100 in 2020.[34] This is compared to the 1,700 CFM56 produced in 2016.[35]

To cope with the demand, CFM is duplicating supply sources on 80% of parts and even subdivide assembly sites, already shared between GE and Safran.[36] GE assembles its production in Lafayette, Indiana, US in addition to its previous Durham, North Carolina, US facility.[36] As more than 75% of the engine comes from suppliers, critical parts suppliers pass “run-rate stress tests” lasting two to 12 weeks.[36] Pratt & Whitney acknowledges a production ramp-up bottleneck on its rival PW1100G geared turbofan including a critical shortage of the unique aluminium-titanium fan blade, hitting the Airbus A320neo and the Bombardier CSeries deliveries.[36] Safran assembles its production in Villaroche, France, Safran and GE each assemble half of the annual volume.[37] Mecachrome plan to produce 120,000–130,000 LEAP turbine blades in 2018 up from 50,000 in 2017.[38]

In mid-June 2018, deliveries remained four to five weeks behind schedule, down from six, and should catch up in the fourth quarter as the quality variation of castings and forgings improves.[3] The production has no single manufacturing choke point by selecting multiple suppliers for every critical part.[3]

From 460 in 2017, 1,100 LEAPs should be built in 2018, along with 1,050 CFM56s, as it encountered unexpected sales, to pass the record production of 1,900 engines in 2017.[3] It will stay at over 2,000 engines per year as 1,800 LEAPs should be produced in 2019, while CFM56 production will drop, then 2,000 in 2020.[3] In 2018, 1,118 engines were delivered.[4]

Over the first half of 2019, CFM revenues were up by 23% to €5.9 billion with 1,119 engine deliveries; declining sales of CFM56 (258 sold), more than offset by LEAP (861 sold).[5] Recurring operating income rose by 34% to €1.2 billion, but was reduced by €107 million (US$118 million) due to the negative margins and initial costs of LEAP production, before a positive contribution expected in the second half.[5] Revenues should grow by 15% in 2019 but free cash flow depends on the return to service of the grounded 737 MAX.[5]

In 2019, LEAP production rose to 1,736 engines, and orders and commitments reached 1,968 amid the 737 MAX groundings, compared with 3,211 for 2018, for a stable backlog of 15,614 (compared to 15,620).[39] CFM expects to produce 1,400 LEAP engines in 2020, including an average of 10 weekly LEAP-1Bs for the Boeing 737 Max.[39] By March 2022, CFM intended to output 2,000 engines in 2023, up from 845 deliveries in 2021.[40] In 2023, CFM booked over 2,500 orders, resulting in a backlog of 10,675, delivered 1,570 Leap engines, up by 38% from 1,136 in 2022, and was expecting 20-25% more deliveries for 2024.[41]

The troubled introduction of the Pratt & Whitney PW1100G on the A320neo has motivated customers to choose LEAP engines. LEAP market share rose from 55% to 60% in 2016, but orders for 1,523 aircraft (29%) had not specified which engine would be chosen.[42] From January through early August 2017, 39 PW1100G engines versus 396 CFM LEAP engines were chosen.[42] By 2024, the LEAP was selected for 75% of the A320neo orders.[41] As an example of PW1100G reliability issues, 9% of LEAP-powered A320neos were out of service for at least one week in July 2017, compared with 46% of those using the PW1100G.[42]

Operations

The Boeing 737 MAX LEAP-1B started revenue service in May 2017 with Malindo Air with 8 hours of daily operation, while the A320neo LEAP-1A surpassed 10 hours per day by July. Safran discovered a production quality defect on LEAP-1B low-pressure turbine disks during assembly for possibly 30 engines, and CFM is working to minimize flight-test and customer-delivery disruptions.[43]

In early October 2017, an exhaust gas temperature shift was noticed during a flight and a CMC shroud coating in the HP turbine was seen flaking off in a borescope inspection, creating a leaking gap: eight in-service engines are seeing their coating replaced.[44] Safran provisioned €50 million (US$58 million) to troubleshoot in-service engines, including potentially LEAP-1Bs.[33] Forty LEAP-1A were replaced and the part should be replaced in over 500 in-service engines, while shipments are four weeks behind schedule.[45] Deliveries with the permanent CMC environmental-barrier coating fix began in June.[46]

On 26 March 2019, due to the Boeing 737 MAX groundings, Southwest Airlines flight 8701 (737 MAX 8) took off from Orlando International Airport for a ferry flight to storage without passengers, but soon after problems with one of the engines caused an emergency landing at the same airport. Southwest then inspected 12 LEAP engines, and two other airlines also inspected their engines.[47] CFM recommended replacing the fuel nozzles more often due to coking, a carbon buildup.[48]

Applications

CFM International LEAP variants[49]
Model Application Thrust range Introduction
-1A Airbus A320neo family 24,500–35,000 lbf (109–156 kN) 2 August 2016[50]
-1B Boeing 737 MAX 23,000–29,000 lbf (100–130 kN) 22 May 2017[51]
-1C Comac C919 27,980–30,000 lbf (124.5–133.4 kN) 28 May 2023[52]

Specifications

Model LEAP-1A[13] LEAP-1B[53] LEAP-1C[13]
Configuration Twin-spool, high bypass turbofan
Compressor 1 fan, 10-stage HP, 3-stage LP[54]
Combustor TAPS II (Twin-Annular, Pre-mixing Swirler second-generation)[49]
Turbine[55] 2-stage HP, 7-stage LP 2-stage HP, 5-stage LP 2-stage HP, 7-stage LP
Overall pressure ratio 40:1[54] (50:1 at top of climb)
TSFC at cruise 0.51 lb/lbf/h (14.4 g/kN/s)[56] 0.53 lb/lbf/h (15.0 g/kN/s)[56] 0.51 lb/lbf/h (14.4 g/kN/s)[57]
Fan diameter[54] 78 in (198 cm) 69.4 in (176 cm) 77 in (196 cm)[58]
Bypass ratio[54] 11:1 9:1 11:1
Length 3.328 m (131.0 in)[a] 3.147 m (123.9 in) 4.505 m (177.4 in)[b]
Max. width 2.543 m (100.1 in) 2.421 m (95.3 in) 2.659 m (104.7 in)
Max. height 2.362 m (93.0 in) 2.256 m (88.8 in) 2.714 m (106.9 in)
Max. weight 3,153 kg (6,951 lb) (Wet) 2,780 kg (6,130 lb) (Dry) 3,935 kg (8,675 lb) (Wet)
Max. take-off thrust 143.05 kN (32,160 lbf) 130.41 kN (29,320 lbf) 137.14 kN (30,830 lbf)
Max. continuous thrust 140.96 kN (31,690 lbf) 127.62 kN (28,690 lbf) 133.22 kN (29,950 lbf)
Max. rpm HP: 19,391
LP: 3,894		 HP: 20,171
LP: 4,586		 HP: 19,391
LP: 3,894
  1. ^ fan case forward flange to turbine rear frame aft flange
  2. ^ fan cowl hinge beam front to centre vent tube end
Thrust ratings[13][53]
Variant Take-off Max. continuous Application
-1A23 106.80 kN (24,010 lbf) 104.58 kN (23,510 lbf) A319neo
-1A24 106.80 kN (24,010 lbf) 106.76 kN (24,000 lbf) A319neo, A320neo
-1A26 120.64 kN (27,120 lbf) 118.68 kN (26,680 lbf) A319neo, A320neo
-1A29 130.29 kN (29,290 lbf) 118.68 kN (26,680 lbf) A320neo
-1A30 143.05 kN (32,160 lbf) 140.96 kN (31,690 lbf) A321neo
-1A32
-1A33
-1A35A
-1B25 119.15 kN (26,790 lbf) 115.47 kN (25,960 lbf) 737 MAX 8
-1B27 124.71 kN (28,040 lbf) 121.31 kN (27,270 lbf) 737 MAX 8, 737 MAX 9
-1B28 130.41 kN (29,320 lbf) 127.62 kN (28,690 lbf) 737 MAX 8, 737 MAX 9
-1C28 129.98 kN (29,220 lbf) 127.93 kN (28,760 lbf) C919
-1C30 137.14 kN (30,830 lbf) 133.22 kN (29,950 lbf) C919

See also

Related development

Comparable engines

Related lists

Notes

  1. ^ 77 delivered in 2016,[2] 460 in 2017,[3] 1,118 in 2018,[4] 861 in H1 2019.[5]

References

  1. ^ a b "CFM launches a new era as first LEAP engine begins ground testing". CFM International. 6 September 2013. Archived from the original on 20 June 2015. Retrieved 7 September 2013.
  2. ^ a b c "2016 CFM orders surpass 2,600 engines" (Press release). CFM International. 14 February 2017. Archived from the original on 10 December 2019. Retrieved 15 February 2017.
  3. ^ a b c d e f g Chris Kjelgaard (4 July 2018). "CFM Confident Leap Production Can Catch Up Soon". AIN online. Archived from the original on 5 July 2018. Retrieved 5 July 2018.
  4. ^ a b Jon Hemmerdinger (1 February 2019). "MID SUPPLY CHAIN RECOVERY CFM's Leap deliveries doubled in 2018 amid supply chain recovery". Flightglobal. Archived from the original on 26 October 2019. Retrieved 26 October 2019.
  5. ^ a b c d David Kaminski-Morrow (5 September 2019). "Leap production edges towards positive contribution". Flightglobal. Archived from the original on 5 September 2019. Retrieved 5 September 2019.
  6. ^ a b c Guy Norris (28 October 2013). "Smooth Start To Fast-Paced Leap-1A Test Program". Archived from the original on 28 September 2018. Retrieved 5 July 2018. "Pressure testing". Aviation Week & Space Technology. p. 43. Archived from the original on 5 July 2018. Retrieved 5 July 2018.
  7. ^ Chandler, Jerome Greer (18 May 2017). "Taking the LEAP: CFM's successor to the fabulous 56". Aviation Pros. Retrieved 1 March 2022.
  8. ^ Guy Norris (13 April 2015). "Pratt Targets Hot, Rotating Blade Use Of CMCs". Archived from the original on 28 September 2018. Retrieved 5 July 2018. "Hot blades" (PDF). Aviation Week & Space Technology. 27 April 2015. p. 55. Archived (PDF) from the original on 5 July 2018. Retrieved 5 July 2018.
  9. ^ a b "CFM Unveils New LEAP-X Engine" (Press release). CFM International. 13 July 2008. Archived from the original on 5 July 2018. Retrieved 5 July 2018.
  10. ^ "New engines: flurry of activity despite downturn". Flightglobal. 6 October 2009. Archived from the original on 9 May 2018. Retrieved 5 July 2018.
  11. ^ Tomas Kellner (14 April 2015). "The FAA Cleared the First 3D Printed Part to Fly in a Commercial Jet Engine from GE". GE. Archived from the original on 29 June 2017. Retrieved 22 April 2015.
  12. ^ Bogaisky, Jeremy (20 September 2022). "China Preps To Launch Its First Big Passenger Jet. It's No Threat To Boeing Or Airbus—Yet". Forbes. Retrieved 26 April 2024.
  13. ^ a b c d "Type Certificate data sheet for LEAP-1A & LEAP-1C Series Engines" (PDF). EASA. 30 May 2018. Archived from the original (PDF) on 13 October 2018. Retrieved 12 October 2018.
  14. ^ "LEAP Turbofan Engine, History". Archived from the original on 3 September 2018. Retrieved 16 August 2012.
  15. ^ "CFM Laying the Technology Foundation for the Future" (Press release). 13 June 2005. Archived from the original on 29 October 2009.. CFM International
  16. ^ "CFM International to provide engines for COMAC's C919". flightglobal. 21 December 2009. Archived from the original on 15 November 2019. Retrieved 15 July 2018.
  17. ^ "CFM to finish Leap core testing by mid-May". flightglobal. 28 April 2010. Archived from the original on 3 September 2014. Retrieved 15 July 2018.
  18. ^ david kaminski morrow (22 April 2015). "First Leap-powered A320neo moved to flight-test team". flightglobal. Archived from the original on 25 April 2015. Retrieved 22 April 2015.
  19. ^ Guy Norris (20 November 2015). "CFM Lifts Veil On Leap Engine Test Details". Aviation Week & Space Technology. Archived from the original on 11 February 2019. Retrieved 12 December 2018.
  20. ^ Guy Norris (13 October 2014). "CFM Marks 40th Anniversary With Leap-1 Flight Test". Aviation Week & Space Technology. p. 40. Archived from the original on 30 November 2014. Retrieved 12 December 2018.
  21. ^ "Engine problems aren't Propulsion South Carolina's problem". Archived from the original on 24 April 2015. Retrieved 20 April 2015.
  22. ^ "LEAP engines awarded 180-minute ETOPS certification" (Press release). CFM International. 21 June 2017. Archived from the original on 22 May 2018. Retrieved 21 June 2017.
  23. ^ "Boeing and American Airlines Agree on Order for up to 300 Airplanes – Jul 20, 2011". Boeing.mediaroom.com. 20 July 2011. Archived from the original on 9 September 2011. Retrieved 31 May 2013.
  24. ^ Boeing Confirms Duopoly With Airbus Announcing Re-Engining Of 737 Archived 5 March 2016 at the Wayback Machine. Forbes
  25. ^ Boeing rendering illustrates major changes to 737NE Archived 16 October 2014 at the Wayback Machine. flightglobal.com
  26. ^ "Southwest Airlines Will Become Launch Customer for the New Boeing 737 Max Aircraft – Southwest Airlines Newsroom". Swamedia.com. 13 December 2011. Archived from the original on 15 October 2014. Retrieved 31 May 2013.
  27. ^ Alan Dron (30 March 2018). "Lion Group completes $5.5 billion LEAP-1A purchase". Aviation Week Network. Archived from the original on 31 March 2018. Retrieved 31 March 2018.
  28. ^ "ALC finalizes $348 million CFM LEAP-1B engine order" (Press release). CFM. 8 August 2017. Archived from the original on 16 September 2017. Retrieved 15 September 2017.
  29. ^ "Zhejiang Loong Air signs RPFH agreement for CFM56-5B engines". Aviation News Ltd. 15 June 2015. Archived from the original on 23 September 2015. Retrieved 16 June 2015.
  30. ^ a b Stephen Trimble (15 July 2018). "CFM looks to another Leap forward at Farnborough". Flightglobal. Archived from the original on 15 July 2018. Retrieved 15 July 2018.
  31. ^ "GE/CFM in "lockstep" with Boeing on NMA". Leeham News. 22 March 2018. Archived from the original on 10 December 2019. Retrieved 22 March 2018.
  32. ^ Jon Hemmerdinger (27 April 2021). "GE Aviation lost 1,900 Leap orders in 12 months". Flightglobal. Archived from the original on 28 April 2021. Retrieved 28 April 2021.
  33. ^ a b Sean Broderick (31 October 2017). "Safran Reveals Leap Turbine Shroud Coating Issue Issue". Aviation Week Network. Archived from the original on 31 October 2017. Retrieved 31 October 2017.
  34. ^ Stephen Trimble (19 June 2017). "GE ups production target to meet Boeing and Airbus demand". Flight Global. Archived from the original on 19 June 2017. Retrieved 19 June 2017.
  35. ^ Max Kingsley-Jones (15 November 2016). "CFM quietly confident on Leap production ramp-up". Flight Global. Archived from the original on 15 November 2016. Retrieved 15 November 2016.
  36. ^ a b c d "New GE plant highlights CFM ramp-up strategy on Leap". Flight Global. 16 November 2016. Archived from the original on 17 November 2016. Retrieved 17 November 2016.
  37. ^ "CFM confirms initial LEAP-1A and LEAP-1B assembly allocation". MRO Network. 15 December 2016. Archived from the original on 25 December 2017. Retrieved 24 December 2017.
  38. ^ Thierry Dubois (15 March 2018). "Leap Engine Deliveries To Airbus Still Challenging". Aviation Week & Space Technology. Archived from the original on 23 March 2018. Retrieved 23 March 2018.
  39. ^ a b David Kaminski-Morrow (27 February 2020). "CFM to build 10 737 Max engines weekly for 2020". Flightglobal. Archived from the original on 26 January 2022. Retrieved 27 February 2020.
  40. ^ Jon Hemmerdinger (11 March 2022). "GE Aviation confident in ability to double Leap output by 2023". FlightGlobal.
  41. ^ a b Dominic Perry (18 February 2024). "Leap sales 'not threatened' by GTF Advantage performance gain, says Safran chief". FlightGlobal.
  42. ^ a b c Rick Clough (22 August 2017). "Pratt's $10 Billion Jet Engine Lags GE by 10-to-1 on New Orders". Bloomberg. Archived from the original on 23 August 2017. Retrieved 23 August 2017.
  43. ^ Sean Broderick (31 August 2017). "Issues With Newest Engines Provide Early MRO-Proving Opportunities". Aviation Week Network. Archived from the original on 20 September 2017. Retrieved 20 September 2017.
  44. ^ Stephen Trimble (30 October 2017). "CFM reviews fleet after finding Leap-1A durability issue". Flightglobal. Archived from the original on 30 October 2017. Retrieved 30 October 2017.
  45. ^ Rick Clough and Julie Johnsson (5 March 2018). "Fix for New Boeing, Airbus Planes". Bloomberg. Archived from the original on 6 March 2018. Retrieved 6 March 2018.
  46. ^ Chris Kjelgaard (17 July 2018). "CFM Fixes Leap Turbine Shroud Coatings". AIN online. Archived from the original on 17 July 2018. Retrieved 17 July 2018.
  47. ^ Schlangenstein, Mary; Clough, Rick; Levin, Alan (17 April 2019). "Airlines to Conduct Engine Checks on Grounded Boeing Max". Bloomberg News. Archived from the original on 18 April 2019. Retrieved 4 May 2019.
  48. ^ Broderick, Sean (18 April 2019). "CFM Monitoring Leap Fleet For Issue Linked To Southwest Engine Failure". Aviation Week Network. Archived from the original on 5 May 2019. Retrieved 5 May 2019.
  49. ^ a b "The Leap Engine". CFM International. Archived from the original on 3 September 2018. Retrieved 14 November 2016.
  50. ^ "Pegasus starts flying Leap-1A-powered A320neo". Flight Global. 2 August 2016. Archived from the original on 26 June 2018. Retrieved 3 August 2016.
  51. ^ "Malindo operates world's first 737 Max flight". Flight Global. 22 May 2017. Archived from the original on 13 November 2018. Retrieved 22 May 2017.
  52. ^ Alfred Chua (28 May 2023). "'A new beginning': Comac C919 enters commercial service". Flight Global.
  53. ^ a b "Type Certificate data sheet for LEAP-1B Series Engines" (PDF). EASA. 16 June 2017. Archived from the original (PDF) on 4 April 2018. Retrieved 4 April 2018.
  54. ^ a b c d "LEAP overview" (PDF). CFM International. June 2017. Archived (PDF) from the original on 4 April 2018. Retrieved 4 April 2018.
  55. ^ "Comparing the new technology Narrow-body engines: GTF vs LEAP maintenance costs". Airinsight. 9 November 2011. Archived from the original on 18 April 2015. Retrieved 31 May 2013.
  56. ^ a b Vladimir Karnozov (19 August 2019). "Aviadvigatel Mulls Higher-thrust PD-14s To Replace PS-90A". AIN Online. Archived from the original on 16 May 2021. Retrieved 16 May 2021.
  57. ^ Fomin, Andrey (December 2011). "PD-14: New generation engine for MC-21". Take-off. pp. 20–21. Archived from the original on 26 January 2022. Retrieved 7 August 2019.
  58. ^ "LEAP-1C: integrated propulsion system for the Comac C919". Safran Aircraft Engines. June 2015. Archived from the original on 21 April 2017. Retrieved 4 April 2018.
Wikimedia Commons has media related to CFM International LEAP.