11/25/88 AC 00-54 Appendix 1
2.4.4 FOLLOW ESTABLISHED STANDARD shears that proved to be most deadly OPERATING TECHNIQUES are those which caught crews by surprise.
In an effort to aid crews with the early recognition of a windshear en- Crews should be aware of normal verti- Care formulateres were series of recommendations under the general cal windshear induced deviations are more flight path indications so that On takeoff, rate, heading niques (SOT's). of Standard Operating These SOT's fall into Tech- would readily recognized. include attitude, on approach, climb this two general headings of crew awareness and airspeed buildup.
and crew coordination. airspeed, attitude, descent rate and throttle position provide valuable in- The need for emphasis on SOT's came formation. Awareness of these indicafrom recognition that in most takeoff tions assures that flight path degradation is recognized as soon as pospitch attitude was reduced below the sible.
attitude that would maintain level flight. This was done when the air- During takeoff and approach, be alert plane was already descending toward for airspeed fluctuations. Such flucthe ground tuations may be the first indication flight path awareness on the part of of windshear. Control column forces the crews involved. This lack of significantly different than those exwas also observed during pected during a normal takeoff or piloted simulator studies of windshear go-around may result if airspeed is encounters. Traditional training pro- below target or airspeed buildup is grams and routine flying may not have low during rotation and liftoff. Verreinforced proper flight path control tical flight path displays should be for altitude loss. used to crosscheck flight director commands.
focus when dealing with During takeoff while at relatively low ADHERENCE TO AIRSPEED MUST BE MODIFIED altitude (below 1000 feet), the SOT':
IN FAVOR OF MAINTAINING FLIGHT PATH BY equire awareness and use of norma CONTROLLING PITCH ATTITUDE. climbout pitch attitude and less em- The SOT's that follow emphasize flight Rhow the all engine initial climb all-engine initial climb path and pitch attitude for operations pitch attitude. Rotate at the normal near the ground. Following SOT's re- rotation rate to this attitude for all sults in better crew performance dur- takeoffs. Minimize pitch attitude reing day-to-day operations, as well as ductions in response to low airspeed case an ordination ding viest until terrain and obstruction clearance is assured.
for timely windshear recognition, par- On approach, avoid large thrust reducticularly at night or in marginal tions or trim changes in response to weather conditions. airspeed increases as an airspeed decrease follow.
o Crew Awareness monitor vertical flight path instruments, such as vertical speed, altime- It is important for crews to remain ters and glideslope displacement.
alert for any change in conditions, addition, comparison of groundspeed remembering that windshear can be and airspeed indications can provide quick to form and to dissipate. The additional information Page 43
Appendix 1 windshear recognition. When potential asses judgment to determine the sarent assessing the situation for windshear exists, achieve a stabilized approach no later than 1,000 course of action.
feet AGL.
• Crew Coordination High workload and distractions in the approach phase, particularly in mar- The PF should focus attention on flyginal weather, attention ing the airplane. In a windshear eninstruments provide counter, appropriate action should be early recognition of flight path de- taken in response to callouts.
terioration. Additionally, application of thrust on approach may The PNF should focus attention on airmask a decreasing airspeed trend. speed, vertical speed, altitude, pitch attitude,,& any sionificant deviations glidepath deviation and Crews should be prepared to execute thrust.
the recommended recovery procedure im- from normal indications are detected, mediately if deviations from target the PNF should immediately call out conditions in excess of the following the deviation. Callouts in the cockoccur: pit should be standardized and easy to understand to ensure timely recogni- Takeoff/Approach tion.
1) +15 knots indicated airspeed EXAMPLE:
2) +500 FPM vertical speed low. " decreasing--glideslope "Vertical speed 1200 down--airspeed one dot
3) +5° pitch attitude Approach STANDARD OPERATING TECHNIQUES SUMMARY
1) +l dot glideslope displacement • Takeoff
2) Unusual throttle position for a significant period of time. o Know normal attitudes, climb rates, airspeed build-uP initial
• Know/use ail-engine These values should be considered as climb attitude.
guidelines only. • Make continuous rotation at certain in- normal rate.
significant • Crosscheck flight director cominitiate recover me ore necessary the recovery before any of o Minimize pitch attitude reduc- mands.
are exceeded. tions.
situations may exist where brief ex- • Monitor vertical flight path particularly in airspeed, instruments, call out deviafrom known or anticipated tions (PNF).
local wind effects may not be an indi- o Know recovery decision guidesignificant lines.
pilot flying (PF) is responsible for Page 44
Appendix 1 o Approach initial target pitch attitude for both takeoff and approach. Additional o Know normal attitudes, descent vantages of 15 initial target pitch rates airspeeds, throttle attitude are that it is easily reosition. called in emergency situations and it
• Crosscheck flight director com- is prominently displayed on attitude mands. director indicators.
Avoid large thrust reductions.
Monitor vertical flight path Note: 1) L-1011 target attitudes:
instruments, call out devia- Takeoff = 17.5° tions (PNF). Approach = 15° o Know recovery decision guidelines. 2) Operators lated target pitch attitudes such as all-engine attitude
2.4.5 WINDSHEAR RECOVERY TECHNIQUE takeoffs go-arounds may use these at- The primary recovery technique objec- titudes in place of the rective is to keep the airplane flying as ommended initial target relong as possible in hope of exiting covery attitude.
the shear. A wide variety of techniques were considered to establish While other more complex techniques the one best meeting this objective. may make slightly better use of air- The best results were achieved by plane performance, these techniques do itching toward an initial target at not meet simplicity and ease of recall titude while using necessary thrust. requirements. Evaluations showed that Several factors were considered in the recommended technique provides a developing this technique. simple, effective means of recovering from a windshear encounter.
Studies show windshear encounters occur infrequently and that only a few A detailed discussion of the recomsuccessful seconds are recovery situations available to initiate a Additionally, Recovery both recovery during takeoff technique during high stress pilot and during approach is disinstrument scan typically becomes very cussed together in the following seclimited--in extreme cases, to only one tion since the technique for both sitinstrument. Lastly, recovery skills uations is identical. The recovery will not be exercised on a day-to-day technique for encounters during takebasis. These factors dictated that off on runway is presented later.
the recovery technique must not only be effective, but simple, easily re- 2.4.5.1/3 ENCOUNTER DURING TAKEOFF - called, and have general applicability. AFTER LIFTOFF and Extensive analysis and pilot evalua- ENCOUNTER ON APPROACH conducted. Al though range of recovery attitudes (including Windshear recognition is crucial to and the range of all-engine ini- making a timely recovery decision.
tial climb attitudes) provides good The recommended recovery procedure recovery capability for a wide variety should be initiated any time the of windshears, 15 was chosen as the flight path is threatened below 1000 Page 45
11/25/88 AC 00-54 Appendix 1 feet AGL on takeoff or approach flight required to avoid ground contact.
guidelines unacceptable When airplane safety has been ensured, path degradation are repeated below: adjust thrust to maintain engine parameters within specified limits.
o Takeoff/Approach
• PITCH
1) +15 knots indicated airspeed The pitch control technique for re-
2) +500 FPM vertical speed covery, stose a windshear encounter or on approach is as
3) +5° pitch attitude follows:
o Approach o At a normal pitch rate, increase or decrease pitch atti-
1) +l dot glideslope displacement tude as necessary toward an initial target attitude of
2) Unusual throttle position for a director Should be turned off autopilot/flight significant period of time.
by the PNF unless specifically again. these should be considered as designed for operations in guidelines since exact criteria cannot windshear, or unless using a e established. In every case, it is pitch selectable flight direche responsibility of the pilot flying tor with desired attitude comto assess the situation and use sound manded.
judgement in determining the safest course of action. In certain in- • Always respect stick shaker.
stances where significant rates of Use intermittent stick shaker change occur, it may be necessary to as the upper pitch limit. In a initiate recovery before any of the secure sow 15 pitch atten day severe above are exceeded.
If windshear inadvertently o If attitude has been limited to immediately initiate the rec- less than 15° increase to stop attitude stick ert tettenue to land! as soon as stick shaker stops.
(However, if on approach and an inperformance shear is encoun- • If vertical flight path or altered, a normal go-around, rather than titude loss is still unaccepta the recovery maneuver, may be accom- ble after reaching 15' › Turther increase pitch attitude smoothly in small increments.
recovery from a windshear encounter after liftoff or o Control pitch in a smooth, during approach is the same for both steady manner (in approximately cases. This technique is described as 2 degree increments) to avoid follows: excessive overshoot/undershoot of desired attitude.
• THRUST o Once the airplane is climbing Aggressively apply necessary thrust to and ground contact is no longer ensure adequate airplane performance. an immediate concern, airspeed Disengage the autothrottle if neces- should be increased by cautious sary. Avoid engine overboost unless reductions in pitch attitude.
Appendix 1
• CONFIGURATION for windshear recovery.
Such systems must be disre- Maintain flap and gear position until garded if recovery is reterrain clearance is assured. AT- ouired and, time permitting, though a small performance increase is switched off by the PNF.
available after landing gear retraction, initial performance degradation Use of autopilot control wheel steermay occur when landing gear doors open ing (CWS) has not been fully evaluated for retraction. While extending flaps for its effectiveness in a windshear during a recovery after liftoff may encounter. One consideration regardresult in a performance benefit, it is ing CWS is that it is usually a single not a recommended technique because: channel autopilot mode and as such has authority.
1) Accidentally retracting flaps case, if CWS is used during a wind- (the usual direction of move- encounter, should be ment) has a large adverse im- discontinued if it produces difficulty pact on performance. in achieving the desired attitude.
2) If landing gear retraction had been initiated prior to recognition of the encounter, extending flaps beyond a takeoff rap setting might result in a continuous warning horn which distracts the crew.
ADDITIONAL CONSIDERATIONS Some flight directors are equipped selectable pitch If normal procedures this feature, the selectable pitch attitude mode may be effectively used in a windshear encounter provided the selected attitude is within the acceptable range: However, if an attitude other than the selected attitude becomes necessary, the flight director If autopilot/flight director systems should be disregarded, and time perspecifically designed for operation in mitting, switched off by the PNF.
windshear are engaged during approach, they should be used during the re- Avoid stabilizer trim changes in recovery maneuver. These systems may sponse to short term windshear-proaid in recovery from an inadvertent duced airspeed/stick force changes.
windshear encounter However, due to However, stabilizer trim should be limited time available to recognize used to trim out stick force due to and respond, do not engage the auto- thrust application.
pilot or autothrottle if these systems were not engaged prior to recovery. hroughout recovery the PNF should all out vertical flight path devia Totator sir sprople for example, for operation in windshear may command a pitch attitude "sinking 500, 300, etc." altitude 200, climbing change to follow target air- 400, altitude speeds or a fixed pitch attitude regardless of flight Operators of airplanes requiring a degradation. flight engineer may incorporate the may be in conflict second officer into the callout with the proper procedures process.
Appendix 1 Racist changing winds may cause rapid 2) Altitude at which shear was enexcursions pitch countered little or no pilot input as well as varying the attitude for stick shaker 3) Location of shear with respect to activation. runway in use As soon as possible, report the en- 4) Airplane type counter to the following may not have the performance 5) Use the term PIREP to encourage rebroadcast of the report to other windshear encounter. aircraft increasing in intensity must be aware that their timely. ac- dangerous. controllers Critical remarks are also helpful in establishing windshear ...maximum thrust required", severrity"...al- le.g• may prevent a pending disas- most contacted terrain", etc.).
ter--SECONDS ilot report for windshear encounter. EXAMPLE:
nould contain the following informa tion: iSan Francisco Tower, PIREP, Flight 126 encountered windshear on final
1) Maximum loss or gain of airspeed loss of 20 knots at 300 feet approaching middle marker runway 27 right, Douglas MD-80.
After Liftoff/On Approach Windshear Recovery Technique
• THRUST
• Apply necessary thrust
• PITCH
• Adjust toward 15°
• Increase beyond 15° if required to ensure acceptable flight path
• Always respect stick shaker
• CONFIGURATION
• Maintain existing configuration Page 48
Appendix 1
2.4.5.2 ENCOUNTER DURING TAKEOFF - The go/no-go criteria based on engine ON RUNWAY failure decision speed (V]) may not be valid for windshear conditions Recognition of windshear is difficult since groundspeed can be much higher during takeoff roll since airspeed is than airspeed (Figure 27). It therechanging rapidly. In addition to fore may not be possible to stop the visual clues described previously, un- airplane on the runway during a reusual airspeed fluctuations, slow or jected takeoff. The ability to lift erratic airspeed build-up may be indi- off is a function of airspeed; the cations of a windshear encounter. ability to stop is largely a function of ground speed.
Indicated Microburst Airspeed Reaches V1 V. = 130 kt Insufficient Stopping Distance Remains!
A/S = 80 kt AS = 120 k1 AS = 130 k1 Runway G/S = 80 kt G/S = 130 kt G'S = 170 kt Normal V, Distance Figure 27. Windshear effects on go/no-go decision point. Vy decision speed may not be attained until insufficient runway remains to abort takeoff.
Appendix 1 Prior to Vi NOT sufficient to offset the effects Overboost however, The takeoff should be rejected if un- of an inadvertent windshear enacceptable airspeed variations occur counter. Proper pitch attitude conbelow indicated V1 and the pilot trol is the most important factor in decides that there is sufficient run- recovery from windshear.
way remaining to stop the airplane.
• PITCH After Y1 When Vp is reached, rotate at normal toward 15° pitch attitude.
The takeoff must be continued if V1 severe windshear encounters, has been reached. VR might not be reached and the reject the takeoff may
• THRUST If this is the case, rotation must be initiated no later than 2,000 Aggressively apply necessary thrust to feet from the end of the usable ensure adequate airplane performance. face (Figure 28).
Avoid engine overboost unless sary to ensure airplane safety. Note: Transport category airplanes airplane safety has been ensured, ad- typically can lift off 5 to 10 just thrust to maintain engine param- knots prior to VRIiFt (except eters within specified limits. 727, which cannot Off prior to VR).
Microburst Approximately 2000 ft Required To Rotate and Lift off!
- Attempt To Stop Results in Overrun Runway May Be Less Than Vp F Indicated Airspeed - 2000 ft• Figure 28. Windshear effects on rotation decision. Windshear effects may force rotation at speeds below Vp. Rotation should begin no later than 2000 ft from runway departure end.
Appendix 1 Pitch attitude and rotation rate in the available runway Liftoff Re- Once airshould not be restricted to avoid aft borne, follow the After body contact since all available pitch covery Technique discussed earlier.
attitude may be required to lift off Takeoff (On Runway) Recovery Technique
• THRUST
• Apply necessary thrust
• PITCH
• Rotate toward 15° (no later than 2000 ft remaining)
• Increase beyond 15° if required to lift off Note: After liftoff follow after liftoff recovery technique Page 51
Appendix 1 The runway remaining during takeoff Another indication of runway remaining can be identified on runways having may be the runway lighting. FAA/ICAO appropriate marking and lighting. precision approach runways (Figure 29) While the markings discussed are usu- ally to assist landing aircraft, they rather than white for the last 2,000 lights which can also be used to determine runway feet of runway when viewed in the remaining during a takeoff. takeoff direction. In addition, centerline lighting can be used to iden- Figure 29 illustrates the markings and ify the amount of runway remaining lighting typical of FAA and ICAO pre- The crew in an airplane taking of cision approach runways. For an air- from left to right in the figure would plane departing from left to right in see white centerline lights until the figure, the first pair of single 3,000 feet from the end of the runway hash marks on either side of the cen- (1,000 feet until rotation must take terline indicates 3,000 feet of runway place). From 3,000 feet to the 1,000 remaining (i.e. 1,000 feet until rota- feet remaining point the centerline tion must be initiated). As takeoff lights alternate white and red. The continues, the 2,000 feet remaining centerline lights are all red for the point is denoted by the first pair of last 1,000 feet of runway. A line of double hash marks encountered. Note red lights perpendicular to the runway that the spacing of all hash marks is indicate the end of usable runway surin 500 foot intervals from the depar- face.
ture end threshold.
Centerline and Edge Lighting
• White Nighttime - Approximate Feet Remaining • Red 3000 2000 1000 • Yellow
• • • • • ..•.o ...
Daytime - Approximate Feet Remaining Figure 29. FAA ICAO precision approach runway markings and lighting.
Appendix 1 Figure 30 illustrates the markings on the runway threshold pilot _ For runways an FAA non-precision approach runway. with these markings, judgement The main indicator of distance remain- and/or familiarity with specific feaing on these runways is the fixed dis- tures along the runway are required to tance markings on either side of cen- estimate the 2,000 feet remaining terline approximately 1,000 feet from point.
Centerline and Eage Lighting O White
•Red Approximate Feet Remaining 1000
• • 0070 Figure 30. FAA nonprecision approach runway markings and lighting.
11/25/88 AC 00-54 Appendix 1 Runway markings and lighting on an centerline at intervals of approxi- ICAO non-precision runway are shown in mately 500 feet (150 meters) starting Figure 31. This figure represents the from the runway threshold. Fixed disoptimum configuration that might ap- tance markers may also be present appear. Most ICAO non-precision ap- proximately 1,000 feet (300 meters) proach runways would include some, but from the threshold. In addition, runnot necessarily all of these features. way edge lights may be color coded similar to precision approach runways ICAO non-precision runways have single with yellow rather than white lights hash marks on either side of runway for approximately the last 2,000 feet (600 meters) of the runway.
Centerline and Edge Lighting O White Nighttime - Approximate Feet Remaining • Red .......... • Yellow
• • • • • • 3000 2000 1000 Daytime - Approximate Feet Remaining Figure 31. ICAO nonprecision approach runway markings and lighting.