737 Tech Questions Flashcards
Seats on 737-800
189
Seats on 737-8200
197
Type of engines on 737 800/8200
- 800 = CFM 56 7B (27,300 lbs of thrust)
- 8200 = CFM LEAP 1B (29,300lbs of thrust)
Pressurisation of cabin
Between 6-8000ft (11-12psi)
Difference between FMS and FMC
FMS - Manages aircraft route navigation and performance to achieve optimum results. Combines data from various aircraft systems which are fed into the FMC
FMC - Inputs are fed into the centralised computer. Uses a large database to allow routes to programmed and fed into the system.
What are winglets
Reduces induced drag by dispersing the spanwise flow from the upper and lower surfaces of the wing at different points. Prevents intermixing of the airflows and therefore reduce induced drag vortices.
Benefits of winglets
- Lower drag and therefore reducing fuel burn. Improve cruise mileage up to 6%
- Lower carbon emissions, more environmentally friendly
- Better climb performance, lower takeoff power required
- Also a source of advertisement
What is the fuel capacity of 737-800
20,000kgs 26,000lts
Range of 737-800
3000nm
What is FMA, location and explain the modes?
Indicates what system is controlling the aircraft and what mode is operational.
Located on the top of both the captain and fo PFD.
3 columns 2 rows.
Left = A/t mode
Centre = Roll
Right = Pitch
Operational = Green White = Armed
Ice protection systems on 737-800
Window heat - Electrically heated
Wing anti ice - Provides protection for the 3 inboard leading edge slat using bleed air.
Engine anti-ice - Bleed air heats the engine cowling to prevent ice build up flaking off and going in the engine.
Icing detection system - Light illuminates in flight deck to indicate ice build up
Probe heat - Electrically heated to prevent icing on the pitots
Can the 737 fly in icing conditions
In light and moderate conditions. If safe to do so.
Not in severe.
Max mach number on 737-800
Mach 0.82
Cruise speed of 737-800
0.78-0.8
Absolute ceiling
41000ft
Vne
480-490kts
MTOW
172,475lbs
How many exits on 737-800
8
Bypass ratio of CFM 56 7B
5:1
20% go through the engine 80 % bypasses
Bypass ratio of CFM LEAP 1B
9:1
Max thrust 29,300
737 8200 (MAX) differences
Quieter due to new engines
12% more fuel efficient and 7% reduction in operating costs
Fly by wire spoiler system - improves stopping distances and reduces weight
Reshaped tail cone - 1% less fuel burn
Cockpit is more refined and less cluttered with latest avionics and larger LCD screens
New electronic bleed system - increased optimisation of the cabin pressure and ice protection system giving better fuel burn. Regulates it better than all or nothing.
Thrust line changed - moved forwards and up to accommodate bigger fan diameter. All handling differences have been tuned out by the flight control system feel.
Boomerang winglets - Lower winglet aerofoil creates lift forward and away from fuselage which increases the efficiency of the wing and further reduces fuel costs.
197 seats, less galley space, new emergency exit and toilets moved back.
Electrical system 737-800
Primary electrical power is provided by two integrated drive generators (IDGs) which are rated at 90Kva and supply 3 phase, 115 volt, 400 Hz AC
Battery - 36 amp hour 24-volt, nikel cadium battery and provides 30 mins
Auxiliary battery - reserve battery which is normally isolated unless the main battery is powering the standby system. Auxiliary plus main battery = 60 mins.
Sweep angle 737-800
25*
Angle relative to the root chord.
Advantages of a swept wing
More laterall stability
Higher speeds = higher Mcrit, low drag at high speeds = better fuel economy
Delays airflow going supersonic reduces shockwave drag.
Disadvantages of swept wing.
Poor lift qualities
Higher stall speed
Speed instability
Stalls at wing tips first.
