Limitations Flashcards
MTOW/MLW
3900lbs
MRW (Max ramp wgt)
3916lbs
Max baggage compartment
200lbs
VNE
194IAS
VNO
154IAS
VA
132IAS
VFE
20˚ : 120IAS
Full (35˚) : 110IAS
VLE
140IAS
VLO
112IAS
Manual: 100IAS
VMCA
65IAS
Vs
70IAS
60IAS (gear and flap)
Turbulent air op speed (3800lbs)
135IAS
VX
VXSE
71IAS
85IAS
VY
VYSE
85KIAS
VTOSS
75KIAS
VTOSS cannot be less than Vs1.2 or VMCA1.1
VREF
Normal 75KIAS
Flapless 80KIAS
SE Appr Spd
85KIAS
Max XWC
25KIAS
Max TO/LD TWC
10KIAS
Power TO and max continuous
Full throttle 2700RPM
Cruise 24” 2700RPM
Oil temp
245˚F
Oil px min - max
25 - 100 PSI
Fuel px min-max
0.5 - 8 PSI
CHT
500˚F
Cylinder head temp
Useable fuel
100US Gal
600lbs
51.5/4/30 (useable. Minus 1.5 for useable fuel)
Gyro suction normal range
4.3 - 5.9”
MAP normal range?
15 - 29.6”
Prop diameter and cut off range
76” and 74” cut off
Magneto drop allowance
175RPM
Magneto max difference between 1 and 2
50RPM
ZFM
3500lbs
Tyre px
38 PSI
Max slip duration
30 secs
Max gear retraction time
30 secs
To rest select the gear in down position
CoG reference datum?
129.37”
Emergency (OEI) enroute climb speed
85kts
Emergency descent
140kts
Emergency manoeuvre final approach speed (flaps DOWN)
90kts
Intentional OEI Vsse
71kts
Intentional OEI max glide range
95kts
2 major factors that govern OEI
Airspeed
Directional control
Battery and amp used in BE76
24v and 15.5A/hr current
Alternator voltage and amp?
28V and 55A/hr
AVGAS used?
100LL blue or 100 green
Type of oil used?
80W
Min - max oil required?
6-8 quarts
Min fuel required in each wing before TO?
9US G
Max alternator load capacity and at what RPM?
80% at 2300RPM
Turbulence category max weight
Light 15,500lbs (7,000Kg)
Med ≤ 300,000lbs
heavy ≥ 300,000lbs
Describe counter rotating prop
A prop on 1 shaft rotates in one direction while prop on other shaft rotates in the opposite direction
Describe contra-rotating props
When 2 props on one shaft rotate in opposite directions
What is VTOSS?
A speed greater than VMCA with a safety factor added to it.
Typical ice protection system for a twin
Carb heat
Ice boots
Anti ice and de ice systems
What is meant by drift down?
The AC is not able to climb or maintain an ALT (i.e. in event of OEI) and so the AC starts to descend. This descent is drift down.
What system(s) prevent inadvertently raising of the UC?
- Safety retraction switch - a safety px switch is fitted to the pitot system to detect impact (dynamic) air. When impact air is below 59-63kts the hydraulic pump circuit is deactivated.
- Weight on wheels (not on BE76).
Following OEI one engine flies in front of the other in S and L flight. Which eng is the front/leading engine and why?
The dead engine as the AC is side slipping to keep a straight line due to the yaw towards the live engine.
Define crit speed?
The min speed that needs to be achieved to maintain directional control of the AC
With OEI, how will apply 5˚ AOB towards live engine effect ROC? Why?
As lift no longer balances weight, as lift is tilted 5˚ and TR is now tilted, either more AOA and/or increase in speed is required to maintain level.
With regard TODA what percentage of HWC is taken into account?
50%
On light twin-eng AC fitted with normally aspirated engines how does increase in ALT affect crit speed (assume ISA temp and lapse rate), explain?
Decreases crit speed as higher ALT less dense air less engine perf thus less rudder effectiveness required to control the AC.
How many log books does a twin eng AC fitted with VP props req?
5
1 for fuselage
1 for prop
1 for engine
What is mean by amp/hr?
The current (amp) that can be sustained in an hour
An AC is fitted with a 24v batt, what is a typical Alt volt output?
28v
Alternator is always higher than the batt.
Definite service ceiling
The maximum alt an AC can climb to whilst sustaining a min of 50ft/min climb.
Definite absolute ceiling
The maximum ALT an AC given its configuration and performance on the day.
Why is correct synchronisation of props of twin desirable?
To prevent beat frequency and asymmetric thrust.
What is the recommended min height for a simulated OEI on a ME single pilot airplane?
300AGL
What is the min height for complete engine shut down on piston or turbo prop below ≤5700kg?
3000ft AGL
What is the ICAO wake turbulence min spacing, NM and time, for a light twin eng AC following a heavy AC on final appr?
3mins, 6nm
How will the centrifugal prop twist tend to affect the blade angle?
Fine the prop as centrifugal will always push the forces outwards. That’s why need springs to help keep the blade coarse.
What does the red light of the landing gear indicate?
That the gear is in transit or in an intermediate position.
Min-max positive and negative load factors for the BE76?
+3.8G (flaps UP)
+2 (flaps DOWN)
-1.52G
Describe the heating system fitted in the BE76.
Janitrol combustion air heater.
Located at the right side nose compartment the heated air is for cabin heat and defrost.
What is the published fuel consumption of the AC heater unit and from which tank is the fuel drawn?
2/3 US G from right tank
After start up, what is the min rise in oil pressure (PSI) and within how many secs?
25PSI (idle min) and 30 secs
How is the UC retracted?
The hydraulic pressure extends an actuator (pressurises) that pushes on the gear and frame causing the gear to retract. Once the gear is in the gear well the actuator is re-pressurised and thus locking the gear into place. As the gear stow flaps close the landing gear is fully locked in a vacuum and the red light in the cockpit goes out.
How is the UC locked down.
The depressurisation of the actuator (causing it to shorten) extends the gear.
The gear is also helped down by a spring and gravity. Once the gear and elbow is fully pivoted (locked) the green lights in the cockpit will illuminate.
What is the aft CoG (with landing gear extended) at MAUW?
117.5” aft of the datum
What is the max fwd CoG (with landing gear extended) at 3400lbs?
110.6” aft of the datum.
What are the flap setting in degrees?
10˚, 20˚, 35˚
At what flap setting (in degrees) will the gear warning horn sound regardless of throttle setting if the landing gear is not down and locked?
If the flaps are set more than 16˚
In what gear and flap config will the left wing stall vane trigger an alert?
Less than 16˚ flap regardless of landing gear config.
In what gear and flap config will the right stall vane trigger an alert?
More than 16˚ flaps select regardless of gear config.
Which engine cylinders are connected to the engine priming system?
1,2,4
UC extension failure, what is your first action?
Recycle the gear.
Check cct breaker
Nav light out (day only)
What is the UC emergency procedure?
Manual gear extension.
Cct breaker OFF/pull out UC select down Airspeed < 100kts Open the emergency extension valve UC cct breaker IN 3 greens
How do you cross feed fuel to the right engine?
Select right fuel cock to cross feed.
During power check (engine testing/run up checks) the props are moved aft to check what?
That the CSU is working therefore you should see:
RPM drop
oil pressure remain green and
no vibrations/surging
During power checks (engine testing/run up checks) when the props are checked, what indication might we expect to see?
RPM drop
Why do we keep carb heat usage on the ground to a min?
Potential overheating
It takes power from the engine
It eats at fuel
It causes the carburettor tunnel to become hot and thus when turned cold again, the tunnel could form ice especially on a cold day and moist day.
What are the nose and main wheel pressures?
38PSI
How is the alt static source accessed?
To use the alt static source, the lever is on the pilot’s door
Why is the alt static source needed?
In case there is a blockage/obstruction of the static ports.
On BE76 there are 2 flush ports on either side on the upper fuselage
During power checks (engine run up/run up checks), at what RPM are magnetos tested?
2200RPM
By putting the electrical system under stress (load) the system is more likely to fail in this configuration if there is a fault in it.
Why do we set props to 1500rpm before feathering?
To prevent prop stress as don’t want to be suddenly feathering a prop from high speed.
But don’t want the RPM to be so low that the props feather
With regard to landing gear, after how many seconds of continuous hydraulic pump operation will the time-delay disconnect the pump motor from it’s electrical supply?
30secs
Reset by recycling landing gear lever
Describe prop fine pitch latching system.
As the props are rotating at high speed, the centrifugal forces throws the latches out. As the prop slows and centrifugal forces lessen the latches drop into place and lock the props into fine position.
What are the devices fitted between the battery bus bar and main left and right bus bars?
Mutual or bus ties
What is the blade angle in fully feathered position?
81˚ from 30” station.
What 4 main factors will affect SE climb perf?
Airspeed
AC config (dirty/clean)
Weight
Weather
Are the air pumps for air driven gyro instruments pressure or suction (vacuum) pumps?
Instrument pressure pumps
Note: BCFT BE76 electrical driven gyro, therefore we have no pressure pumps in our AC.
What is the gases produced by the lead acid battery when it’s being charged?
Sulphuric acid fumes
How is the eng oil pressure boosted to operate the VP/CSU prop system?
Supplementary (auxiliary) pump (within CSU)
Which engine instrument (if fitted) would give the most accurate indication of correct mixture leaning?
Fuel gauge, not fitted on our BE76.
As not fitted, POH normal ops advises to use CHT to indicate correct leaning for cruise or power.
What 3 main effects are produced by the lowering of flaps?
Attitude - nose down
Airspeed decrease
Stall speed decrease
Where is the CoG reference datum?
129.37” fwd of centre of wing spar jack point
What is the structural life in hours, of the wing?
20,000 flight hours
Where is the leading edge MAC?
99.08” aft of the datum
How are the alternators driven?
By engine after the RPM reaches 1200-1400RPM
VMCA is 65kts, what is VTOSS?
VTOSS = VMCA *1.1
= 72kts however in POH VTOSS is 75kts.
BCFT SOPs VTOSS = 85kts
If the thermal cut out fitted to the Janitrol heater trips out, can it be reset in flight?
No
How is the alt static source operated?
The lever on the side door pilot’s side.
What performance cat is BE76?
B (light)
Where is the cabin air blower located?
The cabin blowers are above each front seat.
The fresh air vent is in the back of the AC and the vent is the scoop at the tail.
How is the temp of the eng oil controlled?
Air cooled
Via piping and thermostat controlled. Don’t want oil to be too cold as high viscosity causes faster wear and tear
What type of props does the BE76 have?
Hartzell 2 blade counter rotating
After shut down the props remain in coarse position, what has occurred and why?
High oil pressure has remained in the system thus indicating a CSU fault
Following engine failure when will max drag on a VP prop occur?
Windmilling prop
When will the effects of asymmetric flight be most prominent?
When low speed and high AOA
I.e. TO and LDG
Describe the CSU and how the props are coarsed/fined.
At high RPM the flyweights are thrown out by the centrifugal force. As this occurs the spring is wound upwards lifting the landing valve and allowing the oil in the CSU drain out. With low oil pressure the props then fine.
At low RPM the flyweights close inwards and the spring unwinds moving the landing valve downwards and allowing oil to enter the CSU. This added oil is used to push the props to coarse.
MAC length?
57.65” aft of datum
What condition is flight prohibited?
Icing conditions
What qty does the yellow arc indicate on the fuel gauge?
Empty to 9US G.
TO is not recommended when either fuel gauge is in the yellow arc.
How is fuel qty measured?
Float operated sensors in each wing tank.
What type of electrical sys is the AC?
Single wire ground return type where the AC is the ground return.
Where is the battery box?
Aft underside of fuselage.
There are also 2 vents under the box. One to let air in to vent the box and one to expel the battery fume.
If an RPM of 2500 is selected and the AC put into a dive how will prop pitch angle be affected?
In VP the pitch angle increases to maintain the AOA.
Pitch angle will go in the direction of relative air flow (RAF).
Note: In a fixed prop the pitch angle remains constant while the AOA changes.
What action MUST you take in retain control of the AC in the event of OEI below VMCA?
Any action that will give you rudder authority so….
DECREASE (IDLE) POWER
As its the live engine that is giving you asymmetric flight. By shutting down thrust of the live engine you no longer have an uncontrollable AC.
What kind of engine does the BE76 have?
2x Lycoming 180HP 2700RPM direct driven 4 cylinder horizontally opposed
What is meant by the term ‘Blue line speed’?
VYSE
Also for the Duchess: VY, VXSE
What red radials are on the ASI and what does it indicate?
VMCA and VNE
Define critical speed
Min speed you can fly in a given configuration to maintain directional control of the aircraft
With regard to LDR what percentage of HWC should be used?
In POH the example used is all of HWC however EU-Ops subpart H states LDG must be made by 70% of declared LDA.
In BCFT SOPs 0% HWC is used.
How will centrifugal prop twist tend to affect the blade angle?
Fine it as centrifugal force tends outwards.
In the event of prop over speed what is the best course of action?
Coarse prop and slow down.
Which systems were electrically driven?
Nav, comms, G1000 glass cockpit, window and cabin heat
How would you know the battery was charging
No ALT light, load on ammeters
How long would the battery last?
30 mins
You have lost both alternators, how long would the battery last and what would you do?
30 mins, land ASAP and reduce any unnecessary electrical items e.g. heating
What is the back up instrument in the Duchess if there is an electrical failure?
G500 and is powered on a separate battery that can last up to 2hrs.
What uses the most battery power, transmit or receive?
Transmit
