Takeoff and Departure Operations Understanding Takeoff Speeds Flight Operations Briefing Notes Flight Operations Briefing Notes Takeoff and Departure Operations Understanding Takeoff Speeds I Introdu

Takeoff and Departure Operations Understanding Takeoff Speeds Flight Operations Briefing Notes Flight Operations Briefing Notes Takeoff and Departure Operations Understanding Takeoff Speeds I Introdu - Description

Takeoff speeds are a safety key element fo r t of an d en able pilot sit at ion l awareness and decisionmaking thi very dynami c si tuati n The use of erroneous takeoff speeds can lead to tail strikes highspeed rejected ta keoffs or initial climb w ID: 28094 Download Pdf

157K - views

Takeoff and Departure Operations Understanding Takeoff Speeds Flight Operations Briefing Notes Flight Operations Briefing Notes Takeoff and Departure Operations Understanding Takeoff Speeds I Introdu

Takeoff speeds are a safety key element fo r t of an d en able pilot sit at ion l awareness and decisionmaking thi very dynami c si tuati n The use of erroneous takeoff speeds can lead to tail strikes highspeed rejected ta keoffs or initial climb w

Similar presentations


Tags : Takeoff speeds are
Download Pdf

Takeoff and Departure Operations Understanding Takeoff Speeds Flight Operations Briefing Notes Flight Operations Briefing Notes Takeoff and Departure Operations Understanding Takeoff Speeds I Introdu




Download Pdf - The PPT/PDF document "Takeoff and Departure Operations Underst..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.



Presentation on theme: "Takeoff and Departure Operations Understanding Takeoff Speeds Flight Operations Briefing Notes Flight Operations Briefing Notes Takeoff and Departure Operations Understanding Takeoff Speeds I Introdu"— Presentation transcript:


Page 1
Takeoff and Departure Operations Understanding Takeoff Speeds Flight Operations Briefing Notes Flight Operations Briefing Notes Takeoff and Departure Operations Understanding Takeoff Speeds I Introduction ilot are u ed t calcu at in g t of speed s and, therefore, under stand the operational significance of V , V R, and V How r, ey are sligh ly less f miliar w t e definitions of V MU , V MCG, and V MCA. . Takeoff speeds are a safety key element fo r t of an d en able pilot sit at ion l awareness and decision-making thi very dynami c si tuati n. The use of erroneous takeoff

speeds can lead to tail strikes, high-speed rejected ta keoffs or initial climb with degraded performance. e object of t e f llow F ligh Operat ion Brief N s is prov ide, om an operat ion l perspect iv e, an ov erall rev ew of takeoff speeds, and of the factors that affect the calculation and use of V speeds. II Background Information is sect ion is prov ided as a t of speeds ref esh r. How r, addit on al in rmat ion is also av ailable in t e Airbu Get t Grips with Aircraft Performance” brochure. II.1 Control Speeds and associated Takeoff Speeds The efficiency of such aero dynami c surfaces as

the wi ngs (for l t), the rudder, the ailerons, and the elevators, depends on ad equate airflow speed. This airflow speed determines the minimum takeoff speeds. Page 1 of 8
Page 2
Takeoff and Departure Operations Understanding Takeoff Speeds Flight Operations Briefing Notes MCG (Velocity of Minimum Control on Ground) in g e of roll, it is of u most import an ce t k ow t e min mu m speed at w ich e aircraf w ill remain con rollable, in t e ev en of an en gin ilu re on grou is is becau e, in su ch a case, an d if t e t of is con in d, on ly e ru dder ill be able counteract the yaw

moment that i gene rated by asymmetric engine(s) thrust. Per regulations, the minimum sp eed at which an aircraft is defined to be “controllable (lateral excursion lower than 30 feet) after an engine failure on ground, is referred to as (Velocity of Minimum Control on Ground) MCG . MCG main ly depen s on Engi ne(s) thrust Pressure al ti tude. If a failure occurs before reaching MCG , the takeoff must be i terrupted to mai tai control of the aircraft. Note : Steering is not used during certificatio n flight tests. However, in real life operations, steering would be help ful in controlling the

aircraft. Figure 1 Ground Control after Engine Failure : Decision Speed is the maximum speed at which a rejected take off can be initiated, in the event of an emergen Addit on al in rmat ion on t is “Go/No-Go” decision can be found i the Flight Operations Briefing Note entitled: Rev siting the Stop or Go Decision ”. al so the mi ni mum speed at whi h a pi t can conti nue a takeoff after an engi ne ilu re. If an en gin ilu re is det ct ed af r V t e t of mu st be con in d. T is implies t at the aircraft must be controlla ble on ground. Therefore, V 1 is alw greater than V MCG Page 2 of 8


Page 3
Takeoff and Departure Operations Understanding Takeoff Speeds Flight Operations Briefing Notes MU (Velocity of Minimum Unstick) i achi eved by pi tchi ng the ai rcraft up to the maxi mum (tai on the runway, MU for aircraft that are are geomet rically limit ed) during the takeoff roll (Refer to Fi gure 2 below T e speed at w ich t e aircraf f rst lif of is . MU Therefore, lift-off is not possible prior to MU . Note : All Airbus aircraft types, with the exception of the A318, are geometrically- limited. Figure 2 MU Flight Test on an A330 : Rotation Speed The rotation speed

ensures that, in the case of an en gin ilu re, lif of is possible an d is reached at 35 feet at the l test . Note : Therefore, at 35 feet, the actual speed is usually greater than V . The rotati on of the ai rcraft begi ns at V , which makes lift-off possible, at the end of the maneuver. The V must be such that the l t-off speed i greater than V MU . Page 3 of 8
Page 4
Takeoff and Departure Operations Understanding Takeoff Speeds Flight Operations Briefing Notes MCA (Velocity of Minimum Control in the Air) The rudder is used to compensate for the yaw moment caused by thrust

asymmetry. ere is a min mu m speed at w ich f ll ru dder w ill be n cessary in order t f a constant headi g wi th l vel wi ngs. Figure 3 Sideslip Angle in a One Engine-out Condition To reduce sideslip, this speed can be reduce d even more, if the aircraft is banked on the live engine’s side. The lower the speed, the greater the necessary bank angle. The speed that corresponds to a 5-degree bank angle is defined, by re gul ti ons, as the mi ni mum control speed and is referred to as ( elocit of M mu m C rol in t e Air) MCA Figure 4 Roll Angle at VMCA : Takeoff Safety Speed is t e minimum speed

that needs to be mai tai ed up to accel rati on al ti tude, the event of an engine failure after F ligh at V ensures that the minimum required climb gradien is ach ev ed, an d t at t e aircraf is con rollable. V speed is always greater than V MCA an d f cilit at es con rol of t e aircraf in f ligh In an all-engines operative takeoff, +10 provides a better climb performance than V 2 (Refer to Figure 5 below). Page 4 of 8
Page 5
Takeoff and Departure Operations Understanding Takeoff Speeds Flight Operations Briefing Notes Figure 5 Climb Gradient Relative to Speed in a Specific Flaps’

Configuration If one engi ne i l st before reachi ng V t en t e in it ial climb is f ow at V . If thrust i l st at a speed between V and +10, then the current speed is main in ed, to ensure the most efficient climb speed. It is not necessary to increase pitch, i order to reduce the speed to V 2, when a higher speed has already been reached. II.2 Minimum Control Speeds with Derated Thrust “JAR/FAR: AMJ 25-13 / AC 25-13 (4)(b) Derated takeoff thrust, for an aeroplane, is a ta keoff thrust less than the maximum takeoff thrust, for which exists in the AFM a set of separate and independent takeoff

limitations and performance data that complies with all requirements of Part 25. A specif ic derat lev l correspon ds t t e basic maximum thrust th at is reduced by a corresponding percentage value. New minimum control speeds (V MCG, V MCA ) can then be est blish d. Reducing the minimum control speeds so metimes improves takeoff performance (hi her MTOW), when taki ng off on a short runway. Indeed, the 1 decision speed is the maximu m speed at w ich it is st ill possible t reject t e keof an d st op e aircraf in t e ru ay limit s. N rt less, V must be greater than V MCG , and the

“Accelerate-Stop Distance” is often the most constrai ni ng l ati n on a short runway. A redu ct ion in V MCG en permit s a redu ct ion in t e ASD f r a specif ic t of w igh and can improve takeoff performance when the MTOW (wi hout derate) i ASD/V MCG limit ed. Page 5 of 8
Page 6
Takeoff and Departure Operations Understanding Takeoff Speeds Flight Operations Briefing Notes For a derated takeoff, the ati ns, the procedures, and the performance data must be in clu ed in t e Aircraf F ligh M l ( F r each derat lev l, a specif ic RT OW chart can be defi ned for a each runway, order to

take into account such new limit at ion as min mu m con rol speeds. Note: The objective of flexible thrust differs from that of derated thrust. Both types of thrust cannot be used interchangeably. Flexible Thrust is a thrust reduction, designed to save engine life. This thrust is reduced to take advantage of the available runway length, when full thrust is not necessary (from a performance perspective), but take off speeds with full thrust still apply. III Operational and Human Factors Affecting Takeoff Speed Computation and Utilization The following factors are often observed wh en an aly in

g t of in w ich t of speeds were not respected. Two cases can be observed: III.1 Error in Takeoff Speed Computation: x Data, issued from a computerized system, is rarely ch allen ed. How r, in correct inputs may occur, and could result in inadequate takeoff speeds values. x In takeoff speed calculations, Zero Fuel Weight (ZFW) is sometimes mistaken for Gross Weigh ( W) T is is part icu arly t w en a last min e ch an ge occu rs in cargo loading, or when time pressure and workload are high. Therefore, calculated speeds w ill be mu ch low r t an ex pect ed, an d ill lead ilst ik es, eav aircraft”

sensation, and high -speed rejected takeoffs. x Takeoff speeds calculations are based on sp ecif ic con igu at ion An ch an ge in e paramet rs of t ese con igu at ion w ill in lidat e t of speeds. amples of su ch parameters include a runway change, a we t runway that becomes contaminated, or a takeoff from an i tersecti on. III.2 Error in Takeoff Speed Utilization: x When a last minute-change occurs, take off speeds are sometimes modified and crosschecked during pushback or taxi. During such phases of flight, the PF workload hi gh. As a resul the PF may not have sufficient time or resources to

perform efficient crosschecks. x If an incident occurs before V , the PNF’s attenti n may be focused on tryi ng to assess the situation and may forget the V announcement. Page 6 of 8
Page 7
Takeoff and Departure Operations Understanding Takeoff Speeds Flight Operations Briefing Notes x In the event of an engine fa re after takeoff, and i an attempt to cl b faster, there may be a tendency to set a pi tch atti tu de too high, if FD bars are not followed. The aircraft is then flown below V , and climb performance cannot be ensured, as illu st rat d in F gu re 5. IV Prevention Strategies

and Lines of Defense The following strategies help to preven t takeoff speed errors. Airlines should: x Define and use good CRM practices for ta keoff speed computation and crosscheck. x Conduct a takeoff bri fi ng that hi ghl hts takeoff speeds, slats/flaps configurations, an d igh depen in g on t e daily w at r con it ion At ion sh ou ld be paid t of speeds, part icu arly if t ey w re changed during taxi, in order to detect possible keystroke errors. x For aircraft that are not equipped with a V auto-cal ut: cl ose attenti n to the V st an dard callou sh ou ld be paid. x ph asiz e at on ce

airborn pilot sh ou ld alw f llow t e F ligh D rect or pit gu idan ce bar an d sh ou ld con ider u in g t e au pilot in t e ev en of an en gin ilu re. T is w ill con iderably redu ce t e f ligh crew w rk load du rin deman in g ligh ph ase sit at ion V Summary of Keypoints Takeoff speed calculation errors are ofte n due to a combination of two factors: x Error in parameter entry x Poor crosschecks by other crewmember. Prevention strategies should be developed to ensure efficient cro sschecks, particularly after last-minute changes (runway change, loadsheet modification…). VI Associated Flight

Operations Briefing Notes e llow ligh Operat ion Brief N s should be reviewed al ong wi th the above in rmat ion x Conducting Effectiv e Briefings x Prev enting Tailstrike at Takeoff x Rev siting the “Stop or Go” Decision x Prev enting Runw ay Excursions and Ov erruns at Takeoff Page 7 of 8
Page 8
Takeoff and Departure Operations Understanding Takeoff Speeds Flight Operations Briefing Notes VII Regulatory References x JAR/FAR 25.107 Subpart B – Takeoff Speeds VIII Airbus References The fol wi ng Ai rbus brochure provi es more performance-ori nted formati n concerning takeoff speeds:

x “Getti ng To Gri s wi th Ai rcraft Performance IX Additional Reading Material ample of events linked to takeoff speeds are av ailable in t e f llow docu men s: x Transportation Safety Board of Canada 2002 Air Investigation Reports – 14 June 2002 ( www. 2002 ) x National Transportation Safety Boar d – NTSB accident number: NYC91FA086 www. ) x Fl ht Safety Foundati – Accident prevention – May 1995 x Fl ht Safety Foundati – Accident prevention – May 1996 Note: These documents can be found on the Flight Safety Foundation website: www. is F is p o a s o F lig O er io B ief No t p id e a o er ew o

e lic le fl yi ng techni ques and best practi ces, operati nal and human fa ctors, suggested company preventi on strategi es and personal es-of-defense rel ted to major threats and hazards to fl ht operati ns safety. is F is in ed t en e t e r er f lig s a en es b it ll ed e e lic le la and the Ai rbus or ai rl e's operati nal documentati n; shoul any devi ati n appear between thi FOBN and the Ai rbus or ai rl e’s AFM / (M)MEL / FCOM / QRH / FCTM , t e la s ll p ev il a a ll t e in ia , is ed in w e o in p - in a ll m - o t ed a u e o is F s ll n m it c en o a a ex it ig in ex ia l e is ly ex

ed ll u es s ll c ed it A . ll lia ilit o r ilit f t e u e o t is F , t e c o t e d lic io a o transl ati n and for the updati ng and revi si on of any dupl ated versi n. Ai rbus Customer Servi es Flight O er atio ns Suppo and Line Assistance 1 R nd Poi Mauri Be nt - 31707 BLAGN C CED X F AN CE FOBN Re fe re nce : FLT_OP S – TOFF_DEP – SEQ 07 – REV 01 – AU 2004 Page 8 of 8