HANDLING THE BIG JETS SUMMARY Chapter 1: Introduction Three phases of flight which combine to make jet transport A/C entirely different from any other: T/O, Landing, Severe Wx flight HBJ - large, heavy, turbine engines, faster, higher! Terms: EPR - engine pressure ratio - max compressor delivery pressure to air intake pressure N 1 /N 2 - speed of the low-pressure compressor / speed of the high-pressure compressorTHP - SHP x propeller efficiency of a prop driven A/C SFC - lbs/hr per lb of thrust Gross performance - test A/C performance adjusted to be representative o f the minimum of the fleet Net Performance - gross performance adjusted downward to account for other errors such as flying technique Net Flight Path - engine out climb V 2 to enroute climb EAS - IAS corrected for PE and compressibility error - A/C is sensitive only to EAS T AS - TAS relative to undisturbed air - EAS corrected for density V R– Rotate: V MU + 5% or 10% depend ing on whether type is prone to tailstrike V 1 - decision speed - for engine failure on T/O can either continue the T/O or abort V 2 - T/O safety speed for engine failure on T/O V 3 - all engine screen speed ie. at 35ft on T/O (normally ~V2+10kts) V 4 - all engine initial climb speed (for initial noise abatement climb – achieved at ~300ft; Normally ~V2+15kt) V AT - target threshold speed V AT0 - threshold speed full flap/ V AT1 - 1 engine out / V AT2 - 2 engine out V TMAX - max threshold speed ~V AT +15 kts = unacceptable risk of overrun V NO - normal operating / V MO - maximum operating / V NE - never exceed V RA - rough air speed / V F - maximum flap speed V IMD - min drag speed / V IMP - min power speed (1.6-1.7 V s modern jets) Screen height - 35ft ft T/O, 30ft for landing Strength - proof - maximum load in normal operation ¬ +2.5G/-1G ultimate - ~ 1.5 x proofG < proof may bend / G> proof bend and remain bent / G>Ult may breakADC - air data computerTVSI - Instantaneous VSI - accelerometer gives advanc ed signal by sucking or blowing air into the VSI capsule Chapter 2: First Order Differences ! Size:Optimum size of A/C for - route/demand/speed/frequency/seat-mile cost ! Seat - mile costs generally decrease with increased A/C capacity - so use the largest capacity aircraft without decreasing the trip frequency 1
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EPR - engine pressure ratio - max compressor delivery pressure to air intake pressure N
1/N
2- speed of the low-pressure compressor / speed of the high-pressure compressor
THP - SHP x propeller efficiency of a prop driven A/C
SFC - lbs/hr per lb of thrust
Gross performance - test A/C performance adjusted to be representative of theminimum of the fleet
Net Performance - gross performance adjusted downward to account for other errors
such as flying technique
Net Flight Path - engine out climb V2 to enroute climbEAS - IAS corrected for PE and compressibility error - A/C is sensitive only to EASTAS - TAS relative to undisturbed air - EAS corrected for density
VR – Rotate:
V
MU + 5% or 10% depending on whether type is prone to tailstrike
V1- decision speed - for engine failure on T/O can either continue the T/O or abort
V2 - T/O safety speed for engine failure on T/O
V3 - all engine screen speed ie. at 35ft on T/O (normally ~V2+10kts)
V4 - all engine initial climb speed (for initial noise abatement climb – achieved at
~300ft; Normally ~V2+15kt)
VAT
- target threshold speed
VAT0 - threshold speed full flap/ VAT1 - 1 engine out / VAT2 - 2 engine outV
TMAX - max threshold speed ~V
AT +15 kts = unacceptable risk of overrun
V NO
- normal operating / VMO
- maximum operating / V NE
- never exceed
VRA
- rough air speed / VF- maximum flap speed
VIMD
- min drag speed / VIMP
- min power speed (1.6-1.7 Vs modern jets)
Screen height - 35ft ft T/O, 30ft for landing
Strength - proof - maximum load in normal operation ¬ +2.5G/-1Gultimate - ~ 1.5 x proof
G < proof may bend / G> proof bend and remain bent / G>Ult may break
ADC - air data computer
TVSI - Instantaneous VSI - accelerometer gives advanced signal by sucking or blowing air into the VSI capsule
Chapter 2: First Order Differences
! Size: Optimum size of A/C for - route/demand/speed/frequency/seat-mile cost
! Seat - mile costs generally decrease with increased A/C capacity - so use the
largest capacity aircraft without decreasing the trip frequency
! Speed: A/C should fly at the highest subsonic speed before compressibility drag
becomes excessive M0.8/M0.9 or supersonic speed sufficiently high for economic
advantages to offset drag penalties >M2.0
! Turbines: Only jets can produce the power required at high altitude and high speed -
propeller compressibility losses at high altitude and speed too great
! Piston engine = 2lb thrust / lb weight
!Jet engine = 4lb thrust / lb weight and improving! Jet engine more fuel but more economical overall higher propulsive
efficiency
! Jet at least 4 x more reliable
! Higher: Best operating for engine and the airframe
! Min drag ~ 1.4 Vs on older types; 1.6-1.7V
s on modern types = max endurance / Max
range ~ 1.3 VIMD
! As TAS increases with A/C altitude - maybe reducing EAS, but reducing drag increases
TAS
! Best SFC need 90% of maximum RPM, but thrust falls with altitude for given RPM
BUT want thrust = drag at 90% RPM = high altitude
! eg. at low altitude and low sped SFC increases because of poor jet performance at low %RPM if increase % RPM increase speed increasing drag / at lower speed at high altitude
stability problems and decreased SFC due to lower % RPM
! Best cruise speed = lower altitude
! Best range = higher altitude
! Low alt = %Thrust with !IAS due internal engine drag // Hi alt = overall lower trust but
!Thrust with !IAS due ram effect see fig 2.3 p19
Chapter 3: Consequences of Increased Size and Weight
! Increased momentum (M x V): Greater divergence if disturbed & more time req’d tocorrect flight path; so must anticipate more - projected flight path - must know the attitude
and power requirement for the next phase of flight and be prepared - must retrim for eachattitude or power change
! Powered Controls: Devices like set-back hinges, horn balance, trailing edge bal tabs
insufficient, so pure power operated controls - pilot signals the hydraulic actuators - if
manual is possible programme flight to avoid large rapid control applications and
turbulence
! Pitch control fail: CG change can be used fuel/pax, configure earlier, restrict flap changes
to reduce attitude changes in the flare. For degraded elev or stuck stab, want aft CoG for
ease of control
! Artificial feel: Power operated surfaces - no feedback - can use spring but these are onlyaccurate at one IAS; ‘q’ feel system uses dynamic pressure (# pV2) -senses static and pitot pressure and feed the control system; common for elevator is V2.2 and rudder V3.0;
! Failure of artificial feel: Overstress risk. Slow, smooth, small control changes - trim; do
not use the autopilot as it relies on the ‘q’ feel system; avoid turbulence. For degraded pitch
feel should move the CG FWD (! long stabil) so the A/C response is less for elevator
movements
! Roll control fail: Deg aileron or spoilers. Use power and other controls such as spoilers
rather than ailerons; for crosswinds > 15 kt may need an alternate
! Yaw control fail: Degraded rudder. Use asymmetric power changes, decreased VMCA
margin for T/O & increased VMCL
for landing so need higher IAS approaches; crosswind <
10kts touchdown with drift on, crosswind > 10kts use an alternate
! Large weight range: - typical weights max T/O - 335 000lb, land 234 000lb, payload 27-
55 000lb, fuel load 155 000lb, APS weight no fuel/payload 153 000lb; carries more fuel
than the APS weight; T/O - land weight differs by 141 000lb; a light weight T/O is possible
on two engines; for calculations at 155 000lb fuel need weight within 10 000lb ("Vs by~4kts)except for T/O and landing use within 5 000lb ("V
s by ~2kts)
! Large Ref speed changes: stall speed changes mostly with weight and configuration;
VS1
:VS2
~ square root of W1:W2; large variations of stall speeds, threshold speeds, and T/O
safety speeds
! Large CG range: - fuel from swept wing tanks, freight and PAX; stability increases with
fwd CG - stick forces are higher and controls are less responsive (Opposite for AFT CG);Flare at FWD CG requires increased forces; tendency to overtrim at AFT CG; AFT CG
landing must keep force on the nosewheel while spoilers and reverse thrust on A/C tend to
pitch A/C up
! Variable incidence tailplane:
! Reasons (4): Large CG range, Large IAS range, Large trim changes (LE & TEflaps), Reduced trim drag;
! Other advantages: Elevators always in neutral-available for full range at alltimes; Stall speeds are higher at FWD CG (by about 5kts) as extra weight
exerted by tailplane to balance A/C; in practice there is a small download on the
tailplane in the cruise; T/O setting of the tailplane is extremely important
otherwise may not have sufficient force to rotate the A/C
! Failures:
! Operating system failure - use backup tailplane system eg. electric
! Stuck stabiliser - A/C in trim at one speed , stay there as long as
possible, long fast final with less flap, use CoG to help controlmove fuel/pax FWD or AFT as required, both pilots to share the
forces
! Runaway - stop it ASAP
! Stalled Drive - may need to ease off the pitch force while still
trimming
! All flying tailplanes: Tail always effective, most efficient form of longitudinal control, esp
if aft section is hinged to alter camber at high AoA.
! Long wheel base: Need to go deep into corners prior to turning; nose gear is well behind
the pilots, pilots may be off the taxiway; bog the nosegear prior to the main gear because itsmore easily fixed; line up - need to put # the fuselage over the centreline then turn;
remember to completely straighten the nosewheel prior to stopping; landing - the main gear
is up to 30ft lower than the pilots and well AFT remember this fact NEVER land short.
L and S; too small = poor perf / too large = high drag
2. Aspect Ratio: Induced drag is inversely proportional to Aspect Ratio but need higher
structural strength to support a high aspect ratio. Ie ! AR but within reason
3. Sweep: Increasing sweep increases cruise Mach No due ! MCRIT & MCDR - reducedchordwise vector but increasing sweep increases tip stalling tendency and pitch up and poor oscilliatory stability (Dutch roll)
=> Increased Aspect Ratio and sweep results in a marked pitch up (stall) tendency
4. Taper Ratio: Ideally, root chord to tip chord 2.5 : 1 = elliptical loading. ! ratio = tip stall.5. Section: Roof top- lift over most of chord. Peaky lift is higher over the leading edge –
velocity falls in aft of chord to avoid supersonic probs- ! MCRIT
& MCDR
but ! drag at
lower speed
6. Twist and Chamber: Optimum distribution of lift across span. Washout to help reducetip stall, increase camber towards tip to allow higher CL
MAX => bal twist & camber for
lowest cruise drag against clean stall qualities.
7. Thickness/chord ratio: Structural need thick - strength and L/G fuel etc. Aerodynamicsneed thin (to allow hi speed, less sweep required for given Mach)
! Speed margins: piston/prop - V NO
/V NE
/VDF
- DF more demonstrated dive speed for
certification. A/C not likely to exceed these figures.
! Jet: VMO
/MMO
- maximum intentional speeds - normal strength/handling
! Flap failures: Partial fail: any flap is good except asymmetric; higher attitude. Completefail: % weight, avoid low wx, large LDR, long flat final, caution tail strike, max use of
spoilers & reverse, 4Eng – consider idling 2 for speed control
! Sweep: Sraight wing MCRIT
approximately M0.7. MCRIT
increased by thin wings and sweep
(decreases chordwise flow)
! Less lift at same incidence and IAS than straight wing so fly increased incidence
! CLmax
at much higher incidence so still safe
! Yawing effect increases roll more than straight wing as > movement of chordwise flow.
yaw markedly increases the effective aspect ratio of outboard wing decreases effective
! Dutch Roll: Oscillatory stability - combination of rolling/yawing. Roll much more
noticeable - little pitch disturbance
! Initial yaw is trigger then measure roll (bank angle against time)
mean time to reach # amplitude = degrees of stability
! Dutch roll worse at increased altitude or weight and lower speed (generally)
!Lateral stabil: Affected by dihedral & sweep
! Directional stabil: Affected by fin size & rudder effectiveness
! Oscillating stability always in conflict with directional stabil. Larger fin = more damping
= less Dutch roll tendency when disturbed, but fin too large = poor spiral stabil
(directional or lateral) to damp roll/yaw motion
! Correct with ailerons only - take your time (roll easier to see)
! Most A/C only slightly oscillatory unstable or protected by devices
! Spiral Stability:
! Tendency for A/C in a coordinated turn to return to wings level an release of the ailerons
NOT lateral stability = tendency for the A/C to return to wings level from a sideslip
when the ailerons released
! Spiral stabil % with $ fin area (opposite to dutch roll) so must accept a compromise ! As with dutch roll use the yaw damper to feedback to rudder so always need aileron to
maintain a turn - penalty s that must hold the aileron in the turn
! Spiral stability measured by the time taken to bank angle by # ! Most jet A/C are neutral
! Yaw and Roll Dampers
! The cause is wing sweep and lack of effective fin/rudder area
! If significant dutch roll - need yaw damper to prevent slip building up
! Yaw damper is a gyro system sensitive to changes in yaw and feeds input to rudder to
counteract the yaw
! Can have 1/2/3 yaw dampers depending on how oscillatory unstable the A/C is
! 2 Types - parallel the pilot feels the yaw through the pedals - off for T/O and landingo Series inputs direct to the rudders and the pilot feels nothing so OK to have
selected on for T/O and landing
! Roll dampers - can control dutch roll through ailerons, but more likely fitted for roll
damping in turbulence. Not normally required.
! Directional and Lateral trim:
! Trim the rudder first to maintain heading then the aileron - then autopilot on - then if the
auto pilot drops out there will be no transients. Check that a constant heading has beenmaintained
! Recommended to have copilot wind out the rudder trim on an asymmetric approaches so
in trim for the thrust reduction on the runway
! Stalling: ! Need to know the warnings, identification and survival capabilities
! Warning - buffet/stick shaker at ~ 10% above the EAS for the stall; shaker added if
buffet is insufficient warning
! Identification - something the pilot cannot miss/ stick pushers for the deep stall
aeroplanes
! Stall qualities - older aeroplanes had a requirement for a nose drop at the stall ie a
natural stall recovery
! Piston transport - good buffet warning and straight nose drop
! Turboprop - stick shakers and roll tendency with power on (slipstream)
! 1st generation Jets stall buffet and nose drop
! 2nd generation Jets - not good - devices needed for warning and qualities( this includes
highly developed wings or rear engines or T tails)- some pitch up, so need stability
augmentation (pushers)
! Super stall - rear fuselage engines with high T tail
o
Different pitching tendency as the stall develops 1) pitches up, 2) loss of tailplaneeffectiveness at the stall (normal A/C has a increased tailplane effect as the
tailplane is moved into clean air at the stall) these A/C have a pitch up at the stall,the tailplane moves into the wings wake losing the capability to pitch down( the
incidence remains negative though may slowly pitch down)
o Wing section changes to a leading edge peaky pressure distribution due to
increased suction at the nose
o Sweep – reduces the lift capability outboard and tips stall first = pitch up
so camber and twist and wing fences and leading edge breaker strips
o Fuselage also cause pitch up tendency
o Can have very flat attitude, but negative AoA due to high ROD
o Recovery - full forward elevator and hold it in and flaps at recommended position,steep nose down and rapidly increasing IAS, most of these A/C have stick shaker
and stick pusher
! Factors affecting the stall:
! Wing always stalls at the same incidence - stall occurs at a relatively constant EAS but
IAS $ at higher altitude due to compressibility and instrument and PE with $ altitude
! Also stall EAS increase slightly due to Mach effect on wing
! Stall speed varies with effective weight ie. ‘g’ 63 deg coordinated turn = 2.25 g = 50%
increase in stall speed (!G = stall increase factor)
! Stick shakers:
! For warning could be tactile aural or visual
! Stick knockers added sometimes for aural ! Sensors measure incidence. Can be stagnation point vane, px differential or incidence
sensing vane; Motor with out of balance weight bolted to the column, 10-30 cps so its
unmistakable not like turbulence.
! Sick Pushers:
! Statistics - failing to operate when req’d 1 in 10 mil, operating when not req’d 1 in 10 mil
! Clear ID of stall by sharp nose down of column and adequate nose down pitch by A/C
! Never operates prior to A/C reaching CL max
! 80lb push - not high enough to prevent rotation.
! Some cutout above 250 knots as runaway will exceed max G of A/C
! Exerts a force not a specific elevator angle
! Designs - autoignition, stick shaker, stick pusher all sense incidence , some A/C combine
one sensor on 2 sides of the fuselage also senses rate of change of incidence. Biased to not
push when req’d vice push when not req’d (2 sensors per side; failure light = system inop)
! Speed Stability:
! Behaviour of A/C speed after a speed disturbance ie stable = increase speed = increase
drag = decrease speed
! Note: Jet much flatter drag curve 1.3VS slower than V
IMD(sometimes) ie. speed decrease =
drag increase = speed decrease " back end of the drag curve
! Also - piston /prop power is constant with small speed changes, but jet thrust is constant.
! So jet has poorer speed stability than Piston/Prop due to
1) drag curve - approach speeds in the neutral unstable region2) No stabilising thrust changes with speed
! Must monitor IAS and trends carefully
! So future - speed stability augmentation/ Auto throttle
! Spoilers: Provide up to # rolling power
! 6 Reasons (4 roll, 2 lift):
1. Size: as much wing area as possible needed for the flaps
2. Twist: large ailerons on thin wings twists the wings too much = aileron reversal
3. Effectiveness: ailerons loose effectiveness at high Mnos and cause increase yaw4. Roll with yaw: swept wing = large roll with yaw so need increase aileron control
5. Drag: need high drag devices anyway
6. Runway: need to dump lift after landing
! Roll control - spoilers open on up aileron increasing the drag and decreasing the lift =
wing drops
!When already extended as speedbrakes; Non-differential spoilers - extend on one side but don’t retract on the other for rolls; Differential spoilers extend on one side and partially retract on the other for roll
! Blowback: Partial retraction under hi load/speed
! Failures: OK if asymmetric. Usually fitted in pairs, so may only lose # usage. Use
appropriate crosswind runway
! Jet Upset:
! High M (usually >MMO
& near MDF
), spoiler blowback. Also ailerons poor due twist/M
effect" little/no roll control
! Sideslip control reversal = yaw left, roll right as wing advances into compressibility effect
& drag rises, but now zero roll control to correct!
! Can result in high nose down att & hi bank " MUST slow down ! Fixes: Restrict spoiler max angle to below blowback angle or reduce M
MO/M
DF to provide
compressibility margin
Chapter 6: FLYING HIGHER
! High mach number stability:
! Shock wave: Upsets lift distribution chordwise and causes a rearward shift of centre of lift
! Swept wing: shock wave at (thick) root end first - loss of lift forward
! Loss of downwash over tail
! Mach Tuck : So pitch nose down and becomes unstable as mach number increases
! As mach number increases through M0.85 need to hold back stick rather than forward
! On some a/c, stabil returns briefly as lower shockwave moves aft to align with upper s/w
! Directional Controllability: Reverse rolling moment due to side slip ie. right udder causes
left wing acceleration into compressibility = reduced lift
! Lateral Directional: Reduced aileron effect at high mach numbers $control forces, jack
stalling, spoiler blowback
! Longitudinal Directional: Reduced elevator effectiveness for given deflection angle
large errors - most air data computers (ACDS) ensure
an over-reading Mach meter at MMO
to MDF
! Note: leave the rudder alone at high Mach numbers Avoid flight above MMO
! Mach trimmers: Stability augmentation @ high Mach numbers -compensates for
longitudinal instability
! Dependant on MNo feeds signal to elevator so stability remains positive
! Result is stable a/c up to MDF ie. needs increasing push force as MNo increases ! Only operate above normal max cruise MNo (most times)
! U/S trimmer - keep your speed below MMO
! Trimmer runaway - approved drill
! Always monitor activity of the trimmer in normal flight
! Emergency Descent:
! Fly high less O2 and cabin pressure 43 000ft = 15 seconds consciousness on average
! Must initiate descent immediately
! Don’t trim fully otherwise there will be a too higher pull force coming out
! NB: Safety altitude may be above 10 000ft (use 15 000ft generally)
!May want to descend LG up so highest ROD at high altitude without requirement toslow down for LG extension
! 1 pilot descend, 1 pilot gets on O2 then hand over
! High Drag Devices
! No increase in drag when flight idle - difficult to slow down/descend quickly
! Devices for: rapid descent; approach; after landing and abort
! Devices: spoilers and LG; reverse thrust; parachute; flap beyond the landing
configuration
! Spoilers - OK up to MDF
/VDF
but they do blow back, no stall quality changes (but does
$stall speed), no pitch changes (or small pitch up); Generally don’t use with flap – highsink rate, buffet
! LG - take care on the extension and the retraction = different speed limitations ! Flaps - keep thrust and speed up - don’t take thrust out too early
! Flapless - drag very low - use two engines symmetric power and other two at flight idle -
easier to control IAS
! High Altitude: Four penalties
1. Reduced Damping: # pV2 (=q)+ area + incidence; at constant ‘q’ as altitude increases
velocity increases reducing the incidence therefore decreased damping.
2. Reduced Stability - Spiral stability (which opposes oscillatory stability) improves withincreased altitude and oscillatory stability decreases with increased altitude
! Be gentle with aeroplane at high altitude - control it smoothly
! 5 stability modes:
! Stick-free long stabil (pitch) ! Stick-free lateral stabil (roll)
! Directional stabil (yaw)
! Spiral stabil (spiral dive recovery tendency)
! Oscilliatory stabil (Dutch roll tendency)
3. Restricted Maneuver - buffet speeds increase with ‘g’ decreasing the maneuver marginsespecially above F300; as Mno reduces the VMO/VDF values. Also manoeuvre ceiling
! 140kts = 233 ft/sec - so rehearse the abort drill prior to T/O - keep it straight on landing
and persist with reverse and modulate the braking until very slow ie taxi speed
! Tyres are also speed limited
! Brake temperatures: Heavy weight abort; may be close to 900 deg C; just taxiing raises
the temperature possibly sufficient to compromise the abort performance - possiblywelded on
!Always adhere to the brake cooling procedures
! Fusible plugs fitted to the rims deflate the tyre prior to its bursting
! Plugs only work due to over pressures from excessive braking not due to excessive
carcass temperatures as in prolonged high weight taxi
! Following abort use only light brake pressure only
! Following landing - chock as soon as possible and release the brakes
! Known hot brakes = after T/O leave LG down for up to 20min to cool
o After landing: If excessive, evac a/c & prepare for brake fire
o If not excessive, slow taxi, chock a/c
o Rejected T/O: Hold in suitable location for rec cooling time before next T/O
! Mishandled Rotations
! Need to rotate correctly or may not leave the ground - ground stall ! T/O distance greatly influence by the rotation speed, rotation rate, and the rotate attitude
! Early high rotations cause increased drag and increased ground run
! Late low rotations cause increased ground runs
! Some A/C all engine T/O can be more limiting than the engine out T/O for obstacles due
to increased IAS
! No snatch rotations - VR to V
LOF to V
3 etc
! Heavy weight = slower rotation rate not different attitude
! Reverse Thrust
! Reverse flow path is ~45 degrees from ahead and ~ 50% efficiency loss
! Reverse in flight - OK but buffet
! Problems in crosswind landing/abort - go to idle reverse and use asymmetric braking
! Use reverse thrust ASAP on landing as more efficient at the higher IASs
! Must hold the A/C on the runway
! Unlike the propeller where idle reverse = 60% of full reverse, jets have no good reverse
until full reverse - so don’t cancel it too early - leave it until 100% certain
! ~50kt in headwind engine exhaust towards the intake and visibility problems
! Abort at V1 need to go to full reverse ASAP and held to a complete stop
! Engine out case - maximum symmetrical full reverse then the other if held on the rudder
and the nose wheel steering- if need asymmetric braking idle reverse asymmetric engine
! Aquaplaning
!Complete dynamic aquaplaning = icy runway ! Dynamic - standing water lifts tyre off the runway - 9" p
! Viscous - thin film water (damp runway) and smooth surface eg. rubber deposits - well
below 9" p (7.7" p)
! Rubber reversion - skid and water = steam = reverted rubber delaying water dispersal
! All three types can occur in one landing run
! Tandem bogies tend to reduce the aquaplaning hazard of the rear wheels
! Radar does not see dry hail and there is no difference between wet hail and rain
! Avoid echoes by 15nm at reduced airspeed and 20 nm when above F300
! Avoid especially the scalloped edges or hooked fingers
!Flight Techniques ! No T/O or landings in severe turbulence
! Flight Plan around predicted areas
! Avoid turbulence airborne
! If committed to weather fly correct technique (can turn back)
o Harness on, strap in the PAX and the cabin staff
o Don’t climb over the storm
o Check your terrain clearance ; use the weather radar; believe and use the flight
instruments; use the deicing; turn off the static radios; full flight deck lights; fly at
rough air speed and use the correct power; autopilot on but with no locks
! Be prepared for it
! Fly attitude at rough air speed don’t chase with power; Leave pitch trim alone ! Spin - high rate of turn + fairly low airspeed - hard opposite rudder, forward column and
centre the ailerons
! Spiral Dive - high rate of turn and rapidly increasing airspeed - use the ailerons
Chapter 9: THE VERY BIG JET - ~700 000LB (B747)
! Can demonstrate 0.97 True Mno and no requirement for Mach trimmers or yaw dampers
! Low workload and good stability and control especially for T/O and landing
! Initially difficult to judge clearance on final and at flare height due to higher pilots eye level
! Easy to fly, light to handle, responsive and manoeuvrable ! Dimensions ~200 ft wide, 230ft long, 32’/63’high 36 ft wheel clearance and 90 ft to rear
LG
! MTOW 710 000 lb MLW 564 000lb C of G 15-32% MAC
! VMO
330 kt below 8 000ft for birds and the windscreen
! VRA
- rough airspeed = 280 kt APS weight (no crew, fuel or payload) 360 000 lb
! Fuel weight max 315 000 lb LG 270 kt extension, 320 kt max
! V2 133-170 kt, V
ATO 118-148 kt max 45 000 ft LCN 77.5/83.0 flexible
! Flight Deck
! Horizontal glareshield for a horizontal reference ! Reference eye position indicator - to ensure adequate downwards vision on approach
! Instrument panel 16 deg canted from vertical
! Flight Controls
! Fully hydraulic, LE flaps pneumatic - all have alternate power
! LG hydraulic with free fall backup
! Four hydraulic systems each has EDP and ADP (air driven pump- off engine bleed air)
loss of engine dose not equal loss of hydraulic still have ADP off bleed air from the
! Crosswind landing - while waiting for the aircraft to land push off the drift with rudder
! Full reverse to 90 kt then reducing to not above 50% N1 below 50kt
! Note: for T/O and approach takes approx 30 seconds from 1 deg to 5 deg flap
! Abnormal/Double Failures
! No real problems - minimum asymmetric control speed for the go-round is 142 kt
!Can still achieve 200 ft/min ROC double asymmetric at 10-20 deg flap at 470 000lb
! Comfortable go-round from min 300 ft
! If above 470 000 lb OK since can achieve a cleaner configuration in 200 ft altitude loss
! Two in reverse on the runway is fine in dry conditions
! Partial Flap
! Fly approach VREF
+ 20 for or VREF
+ 40 for double flap failure
! May have to disable the stick shaker
! Hydraulic Failures
! #1, #2 systems out gives 1/2 pitch control VREF
+ 20 kt is good
! Side Window Landings - Use the left hand edge of the runway to line up on approach
! Miscellaneous Items
! Buffet boundaries - most limiting is at high weights and high altitudes ! Half main gear retracted landings - can land with 2 wing gear and 1 body gear but not 2
body and 1 wing gear since the wing LG is in front of the body LG - minimum weight,maintain lateral conrol
! Can land no wing gear (ie retract the serviceable wing gear)
! Can land body gear only also
! Special Systems
! Attitude Warning - set to operate at 11 deg body angle at low rate of pitch change and 6
deg body angle at high rates of pitch change (>7deg/sec) and to stop tail strike at 13 deg body angle
! Throttle Bar - to prevent rapid reversals at high altitudes – raises idle setting
! Flap loading relief - limits the maximum speed for 30 deg flap, flaps don’t run below 25
deg until below 170 kt regardless of the flap lever, Flaps raise from 30 to 25 deg whenIAS above 170 kt regardless of the flap lever
! Workload
! Command / lookout / flight path control / engineering / navigation / communication
! Command, lookout, and comms are the same in any aircraft, the rest are very easy 747
! Ferry
! 2 engine out VMCG
suitable for 3 engine ferry T/O
! Full thrust on the 3rd engine by 110 kt MTOW 560 000lb
! Fifth Pod Ferry between fuselage and #2 approved