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V speeds

January 26, 2023

In aviation, V-speeds are standard terms used to define airspeeds important or useful to the operation of all aircraft.[1] These speeds are derived from data obtained by aircraft designers and manufacturers during flight testing for aircraft type-certification. Using them is considered a best practice to maximize aviation safety, aircraft performance, or both.[2]

A single-engined Cessna 150L's airspeed indicator indicating its V-speeds in knots

The actual speeds represented by these designators are specific to a particular model of aircraft. They are expressed by the aircraft's indicated airspeed (and not by, for example, the ground speed), so that pilots may use them directly, without having to apply correction factors, as aircraft instruments also show indicated airspeed.

In general aviation aircraft, the most commonly used and most safety-critical airspeeds are displayed as color-coded arcs and lines located on the face of an aircraft's airspeed indicator. The lower ends of the white arc and the green arc are the stalling speed with wing flaps in landing configuration, and stalling speed with wing flaps retracted, respectively. These are the stalling speeds for the aircraft at its maximum weight.[3][4] The yellow band is the range in which the aircraft may be operated in smooth air, and then only with caution to avoid abrupt control movement. The red line is the VNE, the never-exceed speed.

Proper display of V-speeds is an airworthiness requirement for type-certificated aircraft in most countries.[5][6]

Regulations

The most common V-speeds are often defined by a particular government's aviation regulations. In the United States, these are defined in title 14 of the United States Code of Federal Regulations, known as the Federal Aviation Regulations (FARs).[7] In Canada, the regulatory body, Transport Canada, defines 26 commonly used V-speeds in their Aeronautical Information Manual.[8] V-speed definitions in FAR 23, 25 and equivalent are for designing and certification of airplanes, not for their operational use. The descriptions below are for use by pilots.

Regulatory V-speeds

These V-speeds are defined by regulations. They are typically defined with constraints such as weight, configuration, or phases of flight. Some of these constraints have been omitted to simplify the description.

V-speed designator Description
V1 The speed beyond which takeoff should no longer be aborted. (See V1 definitions below)[7][8][9]
V2 Takeoff safety speed. The speed at which the aircraft may safely climb with one engine inoperative.[7][8][9]
V2min Minimum takeoff safety speed.[7][8][9]
V3 Flap retraction speed.[8][9]
V4 Steady initial climb speed. The all engines operating take-off climb speed used to the point where acceleration to flap retraction speed is initiated. Should be attained by a gross height of 400 ft (120 m).[10]
VA Design maneuvering speed. This is the speed above which it is unwise to make full application of any single flight control (or "pull to the stops") as it may generate a force greater than the aircraft's structural limitations.[7][8][9][11]
Vat Indicated airspeed at threshold, which is usually equal to the stall speed VS0 multiplied by 1.3 or stall speed VS1g multiplied by 1.23 in the landing configuration at the maximum certificated landing mass, though some manufacturers apply different criteria. If both VS0 and VS1g are available, the higher resulting Vat shall be applied.[12] Also called "approach speed". Also known as Vth[13][14]

Davies defines Vat and Vref as equivalent.[15]

VB Design speed for maximum gust intensity.[7][8][9]
VC Design cruise speed, used to show compliance with gust intensity loading.[16]
Vcef See V1; generally used in documentation of military aircraft performance. Denotes "critical engine failure" speed as the speed during takeoff where the same distance would be required to either continue the takeoff or abort to a stop.[17]
VD Design diving speed, the highest speed planned to be achieved in testing.[7][8][9]
VDF Demonstrated flight diving speed, the highest actual speed achieved in testing.[7][8][9]
VEF The speed at which the critical engine is assumed to fail during takeoff.[7]
VF Designed flap speed.[7][8][9]
VFC Maximum speed for stability characteristics.[7][9]
VFE Maximum flap extended speed.[7][8][9]
VFTO Final takeoff speed.[7]
VH Maximum speed in level flight at maximum continuous power.[7][8][9]
VLE Maximum landing gear extended speed. This is the maximum speed at which a retractable gear aircraft should be flown with the landing gear extended.[7][8][9][18]
VLO Maximum landing gear operating speed. This is the maximum speed at which the landing gear on a retractable gear aircraft should be extended or retracted.[7][9][18]
VLOF Lift-off speed.[7][9]
VMC Minimum control speed. The minimum speed at which the aircraft is still controllable with the critical engine inoperative.[7] Like the stall speed, there are several important variables that are used in this determination. Refer to the minimum control speed article for a thorough explanation. VMC is sometimes further refined into more discrete V-speeds e.g. VMCA,VMCG.
VMCA Minimum control speed air. The minimum speed that the aircraft is still controllable with the critical engine inoperative[19] while the aircraft is airborne. VMCA is sometimes simply referred to as VMC.
VMCG Minimum control speed ground. The minimum speed that the aircraft is still controllable with the critical engine inoperative[19] while the aircraft is on the ground.
VMCL Minimum control speed in the landing configuration with one engine inoperative.[9][19]
VMO Maximum operating limit speed.[7][8][9] Exceeding VMO may trigger an overspeed alarm.[20]
VMU Minimum unstick speed.[7][8][9]
VNE Never exceed speed.[7][8][9][21] In a helicopter, this is chosen to prevent retreating blade stall and prevent the advancing blade from going supersonic.
VNO Maximum structural cruising speed or maximum speed for normal operations. Speed at which exceeding the limit load factor may cause permanent deformation of the aircraft structure.[7][8][9][22]
VO Maximum operating maneuvering speed.[23]
VR Rotation speed. The speed at which the pilot begins to apply control inputs to cause the aircraft nose to pitch up, after which it will leave the ground.[7][24][Note 1]
Vrot Used instead of VR (in discussions of the takeoff performance of military aircraft) to denote rotation speed in conjunction with the term Vref (refusal speed).[17]
VRef Landing reference speed or threshold crossing speed.[7][8][9] Must be at least 1.3 VS0. Must be at least VMC for reciprocating-engine aircraft, or 1.05 VMC for commuter category aircraft.[25]

In discussions of the takeoff performance of military aircraft, the term Vref stands for refusal speed. Refusal speed is the maximum speed during takeoff from which the air vehicle can stop within the available remaining runway length for a specified altitude, weight, and configuration.[17] Incorrectly, or as an abbreviation, some documentation refers to Vref and/or Vrot speeds as "Vr."[26]

VS Stall speed or minimum steady flight speed for which the aircraft is still controllable.[7][8][9]
VS0 Stall speed or minimum flight speed in landing configuration.[7][8][9]
VS1 Stall speed or minimum steady flight speed for which the aircraft is still controllable in a specific configuration.[7][8]
VSR Reference stall speed.[7]
VSR0 Reference stall speed in landing configuration.[7]
VSR1 Reference stall speed in a specific configuration.[7]
VSW Speed at which the stall warning will occur.[7]
VTOSS Category A rotorcraft takeoff safety speed.[7][21]
VX Speed that will allow for best angle of climb.[7][8]
VY Speed that will allow for the best rate of climb.[7][8]

Other V-speeds

Some of these V-speeds are specific to particular types of aircraft and are not defined by regulations.

V-speed designator Description
VAPP Approach speed. Speed used during final approach with landing flap set.[27] VREF plus safety increment,[28][29][30] typically minimum 5 knots,[31] and maximum 15 knots[27] to avoid exceeding flap limiting speeds. Typically it is calculated as half the headwind component plus the gust factor.[27] The purpose is to ensure that turbulence or gusts will not result in the airplane flying below VREF at any point on the approach.[27] Also known as VFLY.
VBE Best endurance speed – the speed that gives the greatest airborne time for fuel consumed.[citation needed]
VBG Best power-off glide speed – the speed that provides maximum lift-to-drag ratio and thus the greatest gliding distance available.
VBR Best range speed – the speed that gives the greatest range for fuel consumed – often identical to Vmd.[32]
VFS Final segment of a departure with one powerplant failed.[33]
Vimd Minimum drag[34]
Vimp Minimum power[34]
VLLO Maximum landing light operating speed – for aircraft with retractable landing lights.[9]
VLS Lowest selectable speed[35]
Vmbe Maximum brake energy speed[34][36]
Vmd Minimum drag (per lift) – often identical to VBR.[32][36] (alternatively same as Vimd[37])
Vmin Minimum speed for instrument flight (IFR) for helicopters[21]
Vmp Minimum power[36]
Vms Minimum sink speed at median wing loading – the speed at which the minimum descent rate is obtained. In modern gliders, Vms and Vmc have evolved to the same value.[38]
Vp Aquaplaning speed[36]
VPD Maximum speed at which whole-aircraft parachute deployment has been demonstrated[39]
Vra Rough air speed (turbulence penetration speed).[9]
VSL Stall speed in a specific configuration[9][36]
Vs1g Stall speed at 1g load factor[40]
Vsse Safe single-engine speed[41]
Vt Threshold speed[36]
VTD Touchdown speed[42]
VTGT Target speed[citation needed]
VTO Take-off speed. (see also VLOF)[43]
Vtocs Take-off climbout speed (helicopters)[21]
Vtos Minimum speed for a positive rate of climb with one engine inoperative[36]
Vtmax Max threshold speed[36][44]
Vwo Maximum window or canopy open operating speed[45]
VXSE Best angle of climb speed with a single operating engine in a light, twin-engine aircraft – the speed that provides the most altitude gain per unit of horizontal distance following an engine failure, while maintaining a small bank angle that should be presented with the engine-out climb performance data.[41]
VYSE Best rate of climb speed with a single operating engine in a light, twin-engine aircraft – the speed that provides the most altitude gain per unit of time following an engine failure, while maintaining a small bank angle that should be presented with the engine-out climb performance data.[18][41]
VZF Minimum zero flaps speed[46]
VZRC Zero rate of climb speed. The aircraft is at sufficiently low speed on the "back of the drag curve" that it cannot climb, accelerate, or turn, so must reduce drag.[36] The aircraft cannot be recovered without loss of height.[15]: 144–145 

Mach numbers

Whenever a limiting speed is expressed by a Mach number, it is expressed relative to the local speed of sound, e.g. VMO: Maximum operating speed, MMO: Maximum operating Mach number.[7][8]

V1 definitions

V1 is the critical engine failure recognition speed or takeoff decision speed. It is the speed above which the takeoff will continue even if an engine fails or another problem occurs, such as a blown tire.[9] The speed will vary among aircraft types and varies according to factors such as aircraft weight, runway length, wing flap setting, engine thrust used and runway surface contamination, thus it must be determined by the pilot before takeoff. Aborting a takeoff after V1 is strongly discouraged because the aircraft may not be able to stop before the end of the runway, thus suffering a runway overrun.[47]

V1 is defined differently in different jurisdictions, and definitions change over time as aircraft regulations are amended.

  • The US Federal Aviation Administration defines it as: "the maximum speed in the takeoff at which the pilot must take the first action (e.g., apply brakes, reduce thrust, deploy speed brakes) to stop the airplane within the accelerate-stop distance. V1 also means the minimum speed in the takeoff, following a failure of the critical engine at VEF, at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance."[7] V1 thus includes reaction time.[24] In addition to this reaction time, a safety margin equivalent to 2 seconds at V1 is added to the accelerate-stop distance.[48][49]
  • Transport Canada defines it as: "Critical engine failure recognition speed" and adds: "This definition is not restrictive. An operator may adopt any other definition outlined in the aircraft flight manual (AFM) of TC type-approved aircraft as long as such definition does not compromise operational safety of the aircraft."[8]

See also

Notes

  1. ^ However most pilots often call out "rotate," instead of VR and Vrot. The "rotate" command has the same meaning of VR and Vrot.

References

  1. ^ Love, Michael C. (2005). "2". Better Takeoffs & Landings. Mc-Graw Hill. pp. 13–15. ISBN 0-07-038805-9. Retrieved 7 May 2008.
  2. ^ Craig, Paul A. (2004). "1". Multiengine Flying (3rd ed.). McGraw Hill. pp. 3–6. ISBN 0-07-142139-4. Retrieved 7 May 2008.
  3. ^ Federal Aviation Administration (July 2008). . Archived from the original on 29 September 2006. Retrieved 1 August 2008.
  4. ^ (PDF). FAA. Archived from the original (PDF) on 3 September 2013. Retrieved 29 January 2010.
  5. ^ (PDF). FAA. Archived from the original (PDF) on 3 September 2013. Retrieved 29 January 2010.
  6. ^ Federal Aviation Administration (July 2008). . Archived from the original on 29 September 2006. Retrieved 1 August 2008.
  7. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj "Title 14 - Aeronautics and Space; Chapter I - Federal Aviation Administration, Subchapter A - Definitions and General Requirements; Part 1 - Definitions and Abbreviations; § 1.2 Abbreviations and symbols". ecfr.gov. Federal Register. Retrieved 13 October 2022.
  8. ^ a b c d e f g h i j k l m n o p q r s t u v w x y Transport Canada (October 2012). "Aeronautical Information Manual GEN – 1.0 GENERAL INFORMATION" (PDF). Retrieved 1 January 2013.
  9. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa Peppler, I.L.: From The Ground Up, page 327. Aviation Publishers Co. Limited, Ottawa Ontario, Twenty Seventh Revised Edition, 1996. ISBN 0-9690054-9-0
  10. ^ (PDF). Civil Aviation Authority (United Kingdom). 2006. pp. Section 4–MRJT1 Page 3. ISBN 0-11-790653-0. Archived from the original (PDF) on 14 November 2009. Retrieved 9 December 2009.
  11. ^ FAA Advisory Circular 23-19A Airframe Guide for Certification of Part 23 Airplanes, Section 48 (p.27) Retrieved 2012-01-06
  12. ^ PANS-OPS, Volume I, Part I, Section 4, Chapter 1, 1.3.3
  13. ^ Aircraft Noise Abatement: Hearings Before the Subcommittee on Aeronautics and Space Technology of the Committee on Science and Astronautics, U.S. House of Representatives, Ninety-third Congress, Second Session, July 24, 25, 1974, page 593.
  14. ^ Aerodrome Design Manual, Part 2, Taxiways, Aprons and Holding Bays. Fourth Edition, 2005. ICAO Doc 9157 AN/901. Page 1-34. https://skybrary.aero/bookshelf/books/3090.pdf
  15. ^ a b Davies, David P. (1971). Handling the Big Jets: An Explanation of the Significant Differences in Flying Qualities Between Jet Transport Aeroplanes and Piston Engined Transport Aeroplanes, Together with Some Other Aspects of Jet Transport Handling (3rd ed.). Air Registration Board. ISBN 0903083019.
  16. ^ FAR Part 23.335
  17. ^ a b c MIL-STD-3013A Department of Defense Standard Practice: Glossary of definitions, ground rules, and mission profiles to define air vehicle performance capability. 9 September 2008. Page 21.
  18. ^ a b c Pilot's Encyclopedia of Aeronautical Knowledge. Federal Aviation Administration. 2007. pp. G–16. ISBN 978-1-60239-034-8. Retrieved 12 May 2008.
  19. ^ a b c Federal Aviation Administration. (February 2009). . Archived from the original on 4 October 2010. Retrieved 16 February 2009.
  20. ^ Administration, Federal Aviation (2017). Airplane Flying Handbook: FAA-H-8083-3B. Skyhorse Publishing, Inc. pp. 15–9. ISBN 9781510712843. Retrieved 3 October 2017.
  21. ^ a b c d Bell Helicopter Textron: Bell Model 212 Rotorcraft Flight Manual, page II. Bell Helicopters Textron Publishers, Fort Worth, Texas, Revision 3, 1 May 1998. BHT-212IFR-FM-1
  22. ^ Pilot's Handbook of Aeronautical Knowledge: FAA-H-8083-25B. Federal Aviation Administration (FAA). 25 September 2016. Retrieved 6 June 2022.
  23. ^ USA 14 CFR §23.1507 Retrieved 2012-01-06
  24. ^ a b "Code of Federal Regulations. Title 14 Chapter I Subchapter C Part 25 Subpart B Performance, Section 25.107 Takeoff speeds". ecfr.gov. Federal Register. Retrieved 12 October 2022.
  25. ^ "Code of Federal Regulations 23.73" (PDF). Retrieved 27 June 2022.
  26. ^ TPUB INTERMEDIATE FLIGHT PREPARATION WORKBOOK APPENDIX A
  27. ^ a b c d Brenner, Thiago Lopes (15 May 2021). Aircraft Performance Weight and Balance. Thiago Lopes Brenner. p. 245. ISBN 979-8-5678-1522-9. Retrieved 26 October 2022.
  28. ^ Void, Joyce D. (1990). Aircraft Performance: Flying Training. Department of the Air Force, Headquarters US Air Force. p. 99. Retrieved 26 October 2022.
  29. ^ Flying Magazine. August 1985. p. 76. Retrieved 26 October 2022.
  30. ^ Gunston, Bill (1988). Airbus. Osprey. p. 60. ISBN 978-0-85045-820-6. Retrieved 26 October 2022.
  31. ^ Aircraft Accident Report: Runway Overrun During Landing. viii: U.S. Government. 12 April 2007. Retrieved 26 October 2022.
  32. ^ a b Brandon, John (October 2008). . FlySafe.raa.asn.au. Archived from the original on 1 November 2008.
  33. ^ airplanedriver.net. "Cessna Citation". Retrieved 14 February 2009.
  34. ^ a b c Bristow, Gary (22 April 2002). Ace the Technical Pilot Interview. ISBN 9780071396097. Retrieved 20 January 2009.
  35. ^ Castaigns, Philippe; De-Baudus, Lorraine (July 2017). (PDF). skybrary.aero. Archived from the original (PDF) on 24 August 2021. Retrieved 4 March 2022.
  36. ^ a b c d e f g h i Croucher, Phil (2007). Canadian Professional Pilot Studies. ISBN 9780968192894. Retrieved 20 January 2009.
  37. ^ "Transportation Safety Board of Canada – A05W0109". 27 July 2006. Retrieved 26 March 2010.
  38. ^ "Wills Wing Hang Glider Mfg". 25 September 2014. Retrieved 31 May 2016.
  39. ^ "SR20 Pilot's Operating Handbook". Cirrus Design. 2004: 8. {{cite journal}}: Cite journal requires |journal= (help)
  40. ^ "Performance. ATPL ground training series". CAE OXFORD AVIATION ACADEMY. 2016: 15. {{cite journal}}: Cite journal requires |journal= (help)
  41. ^ a b c Flight Sim Aviation (2009). "Aviation Rules of Thumb – V-Speeds Abbreviations List". Retrieved 19 January 2009.
  42. ^ E.G. Tulapurkara, Chapter 10 Performance analysis VI – Take-off and landing, retrieved 18 November 2015
  43. ^ "C-130 Takeoff and Landing Data Card" (PDF). Elite Electronic Engineering, Inc. (PDF) from the original on 19 August 2018. Retrieved 18 August 2018.
  44. ^ "VTMAX". The Free Dictionary. 2009. Retrieved 19 January 2009.
  45. ^ Blue Ridge Air Works (n.d.). . Archived from the original on 5 July 2008. Retrieved 13 February 2009.
  46. ^ "Speeds: Various Aviation Authorities" (PDF). sdmiramar.edu. Retrieved 4 March 2022.
  47. ^ (PDF). Federal Aviation Administration. p. 3. Archived from the original (PDF) on 4 March 2016. Retrieved 18 June 2015. V1. [...](1) The maximum speed by which a rejected takeoff must be initiated to assure that a safe stop can be completed within the remaining runway, or runway and stopway;
  48. ^ "Code of Federal Regulations. Title 14 Chapter I Subchapter C Part 25 Subpart B Performance, Section 25.109 Accelerate-stop distance". ecfr.gov. Federal Register. Retrieved 12 October 2022.
  49. ^ Albright, James (November 2014). "Aircraft Performance: Certification versus the real world" (PDF). Business & Commercial Aviation: 46–52. Retrieved 12 October 2022.

Further reading

  • Getting to grips with aircraft performance (PDF). Flight Operations Support & Line Assistance. Airbus Customer Services. January 2002.

January 26, 2023
speeds, aviation, speeds, standard, terms, used, define, airspeeds, important, useful, operation, aircraft, these, speeds, derived, from, data, obtained, aircraft, designers, manufacturers, during, flight, testing, aircraft, type, certification, using, them, c. In aviation V speeds are standard terms used to define airspeeds important or useful to the operation of all aircraft 1 These speeds are derived from data obtained by aircraft designers and manufacturers during flight testing for aircraft type certification Using them is considered a best practice to maximize aviation safety aircraft performance or both 2 A single engined Cessna 150L s airspeed indicator indicating its V speeds in knots The actual speeds represented by these designators are specific to a particular model of aircraft They are expressed by the aircraft s indicated airspeed and not by for example the ground speed so that pilots may use them directly without having to apply correction factors as aircraft instruments also show indicated airspeed In general aviation aircraft the most commonly used and most safety critical airspeeds are displayed as color coded arcs and lines located on the face of an aircraft s airspeed indicator The lower ends of the white arc and the green arc are the stalling speed with wing flaps in landing configuration and stalling speed with wing flaps retracted respectively These are the stalling speeds for the aircraft at its maximum weight 3 4 The yellow band is the range in which the aircraft may be operated in smooth air and then only with caution to avoid abrupt control movement The red line is the VNE the never exceed speed Proper display of V speeds is an airworthiness requirement for type certificated aircraft in most countries 5 6 Contents 1 Regulations 2 Regulatory V speeds 3 Other V speeds 4 Mach numbers 5 V1 definitions 6 See also 7 Notes 8 References 9 Further readingRegulations EditThe most common V speeds are often defined by a particular government s aviation regulations In the United States these are defined in title 14 of the United States Code of Federal Regulations known as the Federal Aviation Regulations FARs 7 In Canada the regulatory body Transport Canada defines 26 commonly used V speeds in their Aeronautical Information Manual 8 V speed definitions in FAR 23 25 and equivalent are for designing and certification of airplanes not for their operational use The descriptions below are for use by pilots Regulatory V speeds EditThese V speeds are defined by regulations They are typically defined with constraints such as weight configuration or phases of flight Some of these constraints have been omitted to simplify the description V speed designator DescriptionV1 The speed beyond which takeoff should no longer be aborted See V1 definitions below 7 8 9 V2 Takeoff safety speed The speed at which the aircraft may safely climb with one engine inoperative 7 8 9 V2min Minimum takeoff safety speed 7 8 9 V3 Flap retraction speed 8 9 V4 Steady initial climb speed The all engines operating take off climb speed used to the point where acceleration to flap retraction speed is initiated Should be attained by a gross height of 400 ft 120 m 10 VA Design maneuvering speed This is the speed above which it is unwise to make full application of any single flight control or pull to the stops as it may generate a force greater than the aircraft s structural limitations 7 8 9 11 Vat Indicated airspeed at threshold which is usually equal to the stall speed VS0 multiplied by 1 3 or stall speed VS1g multiplied by 1 23 in the landing configuration at the maximum certificated landing mass though some manufacturers apply different criteria If both VS0 and VS1g are available the higher resulting Vat shall be applied 12 Also called approach speed Also known as Vth 13 14 Davies defines Vat and Vref as equivalent 15 VB Design speed for maximum gust intensity 7 8 9 VC Design cruise speed used to show compliance with gust intensity loading 16 Vcef See V1 generally used in documentation of military aircraft performance Denotes critical engine failure speed as the speed during takeoff where the same distance would be required to either continue the takeoff or abort to a stop 17 VD Design diving speed the highest speed planned to be achieved in testing 7 8 9 VDF Demonstrated flight diving speed the highest actual speed achieved in testing 7 8 9 VEF The speed at which the critical engine is assumed to fail during takeoff 7 VF Designed flap speed 7 8 9 VFC Maximum speed for stability characteristics 7 9 VFE Maximum flap extended speed 7 8 9 VFTO Final takeoff speed 7 VH Maximum speed in level flight at maximum continuous power 7 8 9 VLE Maximum landing gear extended speed This is the maximum speed at which a retractable gear aircraft should be flown with the landing gear extended 7 8 9 18 VLO Maximum landing gear operating speed This is the maximum speed at which the landing gear on a retractable gear aircraft should be extended or retracted 7 9 18 VLOF Lift off speed 7 9 VMC Minimum control speed The minimum speed at which the aircraft is still controllable with the critical engine inoperative 7 Like the stall speed there are several important variables that are used in this determination Refer to the minimum control speed article for a thorough explanation VMC is sometimes further refined into more discrete V speeds e g VMCA VMCG VMCA Minimum control speed air The minimum speed that the aircraft is still controllable with the critical engine inoperative 19 while the aircraft is airborne VMCA is sometimes simply referred to as VMC VMCG Minimum control speed ground The minimum speed that the aircraft is still controllable with the critical engine inoperative 19 while the aircraft is on the ground VMCL Minimum control speed in the landing configuration with one engine inoperative 9 19 VMO Maximum operating limit speed 7 8 9 Exceeding VMO may trigger an overspeed alarm 20 VMU Minimum unstick speed 7 8 9 VNE Never exceed speed 7 8 9 21 In a helicopter this is chosen to prevent retreating blade stall and prevent the advancing blade from going supersonic VNO Maximum structural cruising speed or maximum speed for normal operations Speed at which exceeding the limit load factor may cause permanent deformation of the aircraft structure 7 8 9 22 VO Maximum operating maneuvering speed 23 VR Rotation speed The speed at which the pilot begins to apply control inputs to cause the aircraft nose to pitch up after which it will leave the ground 7 24 Note 1 Vrot Used instead of VR in discussions of the takeoff performance of military aircraft to denote rotation speed in conjunction with the term Vref refusal speed 17 VRef Landing reference speed or threshold crossing speed 7 8 9 Must be at least 1 3 VS0 Must be at least VMC for reciprocating engine aircraft or 1 05 VMC for commuter category aircraft 25 In discussions of the takeoff performance of military aircraft the term Vref stands for refusal speed Refusal speed is the maximum speed during takeoff from which the air vehicle can stop within the available remaining runway length for a specified altitude weight and configuration 17 Incorrectly or as an abbreviation some documentation refers to Vref and or Vrot speeds as Vr 26 VS Stall speed or minimum steady flight speed for which the aircraft is still controllable 7 8 9 VS0 Stall speed or minimum flight speed in landing configuration 7 8 9 VS1 Stall speed or minimum steady flight speed for which the aircraft is still controllable in a specific configuration 7 8 VSR Reference stall speed 7 VSR0 Reference stall speed in landing configuration 7 VSR1 Reference stall speed in a specific configuration 7 VSW Speed at which the stall warning will occur 7 VTOSS Category A rotorcraft takeoff safety speed 7 21 VX Speed that will allow for best angle of climb 7 8 VY Speed that will allow for the best rate of climb 7 8 Other V speeds EditSome of these V speeds are specific to particular types of aircraft and are not defined by regulations V speed designator DescriptionVAPP Approach speed Speed used during final approach with landing flap set 27 VREF plus safety increment 28 29 30 typically minimum 5 knots 31 and maximum 15 knots 27 to avoid exceeding flap limiting speeds Typically it is calculated as half the headwind component plus the gust factor 27 The purpose is to ensure that turbulence or gusts will not result in the airplane flying below VREF at any point on the approach 27 Also known as VFLY VBE Best endurance speed the speed that gives the greatest airborne time for fuel consumed citation needed VBG Best power off glide speed the speed that provides maximum lift to drag ratio and thus the greatest gliding distance available VBR Best range speed the speed that gives the greatest range for fuel consumed often identical to Vmd 32 VFS Final segment of a departure with one powerplant failed 33 Vimd Minimum drag 34 Vimp Minimum power 34 VLLO Maximum landing light operating speed for aircraft with retractable landing lights 9 VLS Lowest selectable speed 35 Vmbe Maximum brake energy speed 34 36 Vmd Minimum drag per lift often identical to VBR 32 36 alternatively same as Vimd 37 Vmin Minimum speed for instrument flight IFR for helicopters 21 Vmp Minimum power 36 Vms Minimum sink speed at median wing loading the speed at which the minimum descent rate is obtained In modern gliders Vms and Vmc have evolved to the same value 38 Vp Aquaplaning speed 36 VPD Maximum speed at which whole aircraft parachute deployment has been demonstrated 39 Vra Rough air speed turbulence penetration speed 9 VSL Stall speed in a specific configuration 9 36 Vs1g Stall speed at 1g load factor 40 Vsse Safe single engine speed 41 Vt Threshold speed 36 VTD Touchdown speed 42 VTGT Target speed citation needed VTO Take off speed see also VLOF 43 Vtocs Take off climbout speed helicopters 21 Vtos Minimum speed for a positive rate of climb with one engine inoperative 36 Vtmax Max threshold speed 36 44 Vwo Maximum window or canopy open operating speed 45 VXSE Best angle of climb speed with a single operating engine in a light twin engine aircraft the speed that provides the most altitude gain per unit of horizontal distance following an engine failure while maintaining a small bank angle that should be presented with the engine out climb performance data 41 VYSE Best rate of climb speed with a single operating engine in a light twin engine aircraft the speed that provides the most altitude gain per unit of time following an engine failure while maintaining a small bank angle that should be presented with the engine out climb performance data 18 41 VZF Minimum zero flaps speed 46 VZRC Zero rate of climb speed The aircraft is at sufficiently low speed on the back of the drag curve that it cannot climb accelerate or turn so must reduce drag 36 The aircraft cannot be recovered without loss of height 15 144 145 Mach numbers EditWhenever a limiting speed is expressed by a Mach number it is expressed relative to the local speed of sound e g VMO Maximum operating speed MMO Maximum operating Mach number 7 8 V1 definitions EditV1 is the critical engine failure recognition speed or takeoff decision speed It is the speed above which the takeoff will continue even if an engine fails or another problem occurs such as a blown tire 9 The speed will vary among aircraft types and varies according to factors such as aircraft weight runway length wing flap setting engine thrust used and runway surface contamination thus it must be determined by the pilot before takeoff Aborting a takeoff after V1 is strongly discouraged because the aircraft may not be able to stop before the end of the runway thus suffering a runway overrun 47 V1 is defined differently in different jurisdictions and definitions change over time as aircraft regulations are amended The US Federal Aviation Administration defines it as the maximum speed in the takeoff at which the pilot must take the first action e g apply brakes reduce thrust deploy speed brakes to stop the airplane within the accelerate stop distance V1 also means the minimum speed in the takeoff following a failure of the critical engine at VEF at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance 7 V1 thus includes reaction time 24 In addition to this reaction time a safety margin equivalent to 2 seconds at V1 is added to the accelerate stop distance 48 49 Transport Canada defines it as Critical engine failure recognition speed and adds This definition is not restrictive An operator may adopt any other definition outlined in the aircraft flight manual AFM of TC type approved aircraft as long as such definition does not compromise operational safety of the aircraft 8 See also EditICAO recommendations on use of the International System of Units Balanced field takeoffNotes Edit However most pilots often call out rotate instead of VR and Vrot The rotate command has the same meaning of VR and Vrot References Edit Love Michael C 2005 2 Better Takeoffs amp Landings Mc Graw Hill pp 13 15 ISBN 0 07 038805 9 Retrieved 7 May 2008 Craig Paul A 2004 1 Multiengine Flying 3rd ed McGraw Hill pp 3 6 ISBN 0 07 142139 4 Retrieved 7 May 2008 Federal Aviation Administration July 2008 Title 14 Aeronautics and Space PART 23 AIRWORTHINESS STANDARDS NORMAL UTILITY ACROBATIC AND COMMUTER CATEGORY AIRPLANES Subpart G Operating Limitations and Information Markings And Placards Part 23 23 1545 Archived from the original on 29 September 2006 Retrieved 1 August 2008 Pilot s Handbook of Aeronautical Knowledge Chapter 7 PDF FAA Archived from the original PDF on 3 September 2013 Retrieved 29 January 2010 Pilot s Handbook of Aeronautical Knowledge Chapter 8 PDF FAA Archived from the original PDF on 3 September 2013 Retrieved 29 January 2010 Federal Aviation Administration July 2008 Title 14 Aeronautics and Space PART 25 AIRWORTHINESS STANDARDS TRANSPORT CATEGORY AIRPLANES Subpart G Operating Limitations and Information Airplane Flight Manual Part 25 25 1583 Archived from the original on 29 September 2006 Retrieved 1 August 2008 a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj Title 14 Aeronautics and Space Chapter I Federal Aviation Administration Subchapter A Definitions and General Requirements Part 1 Definitions and Abbreviations 1 2 Abbreviations and symbols ecfr gov Federal Register Retrieved 13 October 2022 a b c d e f g h i j k l m n o p q r s t u v w x y Transport Canada October 2012 Aeronautical Information Manual GEN 1 0 GENERAL INFORMATION PDF Retrieved 1 January 2013 a b c d e f g h i j k l m n o p q r s t u v w x y z aa Peppler I L From The Ground Up page 327 Aviation Publishers Co Limited Ottawa Ontario Twenty Seventh Revised Edition 1996 ISBN 0 9690054 9 0 CAP 698 Civil Aviation Authority JAR FCL Examinations Aeroplane Performance Manual PDF Civil Aviation Authority United Kingdom 2006 pp Section 4 MRJT1 Page 3 ISBN 0 11 790653 0 Archived from the original PDF on 14 November 2009 Retrieved 9 December 2009 FAA Advisory Circular 23 19A Airframe Guide for Certification of Part 23 Airplanes Section 48 p 27 Retrieved 2012 01 06 PANS OPS Volume I Part I Section 4 Chapter 1 1 3 3 Aircraft Noise Abatement Hearings Before the Subcommittee on Aeronautics and Space Technology of the Committee on Science and Astronautics U S House of Representatives Ninety third Congress Second Session July 24 25 1974 page 593 Aerodrome Design Manual Part 2 Taxiways Aprons and Holding Bays Fourth Edition 2005 ICAO Doc 9157 AN 901 Page 1 34 https skybrary aero bookshelf books 3090 pdf a b Davies David P 1971 Handling the Big Jets An Explanation of the Significant Differences in Flying Qualities Between Jet Transport Aeroplanes and Piston Engined Transport Aeroplanes Together with Some Other Aspects of Jet Transport Handling 3rd ed Air Registration Board ISBN 0903083019 FAR Part 23 335 a b c MIL STD 3013A Department of Defense Standard Practice Glossary of definitions ground rules and mission profiles to define air vehicle performance capability 9 September 2008 Page 21 a b c Pilot s Encyclopedia of Aeronautical Knowledge Federal Aviation Administration 2007 pp G 16 ISBN 978 1 60239 034 8 Retrieved 12 May 2008 a b c Federal Aviation Administration February 2009 Title 14 Aeronautics and Space PART 25 AIRWORTHINESS STANDARDS TRANSPORT CATEGORY AIRPLANES Subpart B Flight Controllability and Maneuverability 25 149 Minimum control speed Archived from the original on 4 October 2010 Retrieved 16 February 2009 Administration Federal Aviation 2017 Airplane Flying Handbook FAA H 8083 3B Skyhorse Publishing Inc pp 15 9 ISBN 9781510712843 Retrieved 3 October 2017 a b c d Bell Helicopter Textron Bell Model 212 Rotorcraft Flight Manual page II Bell Helicopters Textron Publishers Fort Worth Texas Revision 3 1 May 1998 BHT 212IFR FM 1 Pilot s Handbook of Aeronautical Knowledge FAA H 8083 25B Federal Aviation Administration FAA 25 September 2016 Retrieved 6 June 2022 USA 14 CFR 23 1507 Retrieved 2012 01 06 a b Code of Federal Regulations Title 14 Chapter I Subchapter C Part 25 Subpart B Performance Section 25 107 Takeoff speeds ecfr gov Federal Register Retrieved 12 October 2022 Code of Federal Regulations 23 73 PDF Retrieved 27 June 2022 TPUB INTERMEDIATE FLIGHT PREPARATION WORKBOOK APPENDIX A a b c d Brenner Thiago Lopes 15 May 2021 Aircraft Performance Weight and Balance Thiago Lopes Brenner p 245 ISBN 979 8 5678 1522 9 Retrieved 26 October 2022 Void Joyce D 1990 Aircraft Performance Flying Training Department of the Air Force Headquarters US Air Force p 99 Retrieved 26 October 2022 Flying Magazine August 1985 p 76 Retrieved 26 October 2022 Gunston Bill 1988 Airbus Osprey p 60 ISBN 978 0 85045 820 6 Retrieved 26 October 2022 Aircraft Accident Report Runway Overrun During Landing viii U S Government 12 April 2007 Retrieved 26 October 2022 a b Brandon John October 2008 Flight Theory Airspeed and the properties of air FlySafe raa asn au Archived from the original on 1 November 2008 airplanedriver net Cessna Citation Retrieved 14 February 2009 a b c Bristow Gary 22 April 2002 Ace the Technical Pilot Interview ISBN 9780071396097 Retrieved 20 January 2009 Castaigns Philippe De Baudus Lorraine July 2017 Procedures PDF skybrary aero Archived from the original PDF on 24 August 2021 Retrieved 4 March 2022 a b c d e f g h i Croucher Phil 2007 Canadian Professional Pilot Studies ISBN 9780968192894 Retrieved 20 January 2009 Transportation Safety Board of Canada A05W0109 27 July 2006 Retrieved 26 March 2010 Wills Wing Hang Glider Mfg 25 September 2014 Retrieved 31 May 2016 SR20 Pilot s Operating Handbook Cirrus Design 2004 8 a href Template Cite journal html title Template Cite journal cite journal a Cite journal requires journal help Performance ATPL ground training series CAE OXFORD AVIATION ACADEMY 2016 15 a href Template Cite journal html title Template Cite journal cite journal a Cite journal requires journal help a b c Flight Sim Aviation 2009 Aviation Rules of Thumb V Speeds Abbreviations List Retrieved 19 January 2009 E G Tulapurkara Chapter 10 Performance analysis VI Take off and landing retrieved 18 November 2015 C 130 Takeoff and Landing Data Card PDF Elite Electronic Engineering Inc Archived PDF from the original on 19 August 2018 Retrieved 18 August 2018 VTMAX The Free Dictionary 2009 Retrieved 19 January 2009 Blue Ridge Air Works n d Cessna 152 4843H General Info Archived from the original on 5 July 2008 Retrieved 13 February 2009 Speeds Various Aviation Authorities PDF sdmiramar edu Retrieved 4 March 2022 Takeoff Safety Training Aid PDF Federal Aviation Administration p 3 Archived from the original PDF on 4 March 2016 Retrieved 18 June 2015 V1 1 The maximum speed by which a rejected takeoff must be initiated to assure that a safe stop can be completed within the remaining runway or runway and stopway Code of Federal Regulations Title 14 Chapter I Subchapter C Part 25 Subpart B Performance Section 25 109 Accelerate stop distance ecfr gov Federal Register Retrieved 12 October 2022 Albright James November 2014 Aircraft Performance Certification versus the real world PDF Business amp Commercial Aviation 46 52 Retrieved 12 October 2022 Further reading EditGetting to grips with aircraft performance PDF Flight Operations Support amp Line Assistance Airbus Customer Services January 2002 Retrieved from https en wikipedia org w index php title V speeds amp oldid 1128388236, wikipedia, wiki, book, books, library,

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