75
votes
Accepted
Why is the 787 tail cone made out of titanium?
Whenever you see titanium being used on aircraft, look for heat sources. The metallic alternative aluminum is usually lighter and much cheaper.
In most commercial aircraft the APU (Auxiliary Power ...
- 4,292
74
votes
Accepted
Why did my flight leave the gear down for the first 10 minutes of flight?
It could be that the Wheel Well Fire Detection System was inoperative.
According to the B-787 "Master Minimum Equipment List" (as shown from this website, in pertinent part) the Wheel Well ...
- 32.3k
32
votes
Accepted
Why do flight attendants on the 787 lock the dimmable windows at different phases of the flight?
On long-haul flights, most passengers will want to sleep, often including when the aircraft is flying through daylight. It's especially common on East-West long-haul flights for lots of people to want ...
- 19.3k
28
votes
Accepted
Why does the Boeing 787 have fewer cockpit windows?
It is because of the carbon fibre. This is the same reason that the 787 has bigger passenger windows. Here you can find a link explaining the polarized windows on the 787. Because of its higher ...
- 873
27
votes
Could an airliner with only one functioning engine recover from a stall?
Yes, but the challenge is managing the asymmetric thrust effects when applying power during the stall recovery.
Pilots are trained in the sim for two stall (actually, just stick shaker onset) ...
- 125k
24
votes
Accepted
What is the purpose of the 787 engines extending on landing?
Those are the thrust reversers, which cause the engines to produce thrust "backwards" to help slow the aircraft during the landing.
You can see a close-up video of 787 thrust reversers in operation, ...
- 8,287
23
votes
Would the wings of a Boeing 787 be snapped off in the same turbulence in which a DC-8 lost an engine and parts of a wing?
It's very likely that the 787 would have less problems with turbulence than the DC-8 did.
The wings of the Boeing 787 are more flexible than the DC-8, and that flexibility will damp the immediate ...
- 81.7k
23
votes
Could an airliner with only one functioning engine recover from a stall?
A stall recovery doesn't require engines (although they help, especially if altitude is an issue). To recover from a stall, you need to lower the angle of attack. You can do this by lowering the nose ...
- 36k
22
votes
Accepted
Does the Boeing B787 have safety issues with its battery and windshield?
The 787 is among the safest airliners currently flying. At the time of writing, it has been involved in zero hull loss incidents and there have been zero fatalities due to incidents.
While you can ...
- 31.1k
21
votes
How can a two-engine B787 create three contrails?
Contrails are created due to variances in the pressure of the air, coupled with the amount of moisture in that air. When the 2 engines of the B787 blast their exhaust out, the high pressure of the ...
- 227
20
votes
How can a two-engine B787 create three contrails?
Fascinating question. Not being an expert in contrail aerodynamics I'm forced to speculate, but I'm guessing the apparent three trails is caused by the spreading of the trails by wingtip vortexes.
I ...
- 1,043
20
votes
Could an airliner with only one functioning engine recover from a stall?
With enough height, any aircraft can recover from a stall without any engine power required. In fact, for under-wing engined aircraft like the 787, it is sometimes necessary to reduce the thrust, ...
- 14k
18
votes
Why does the Boeing 787 have fewer cockpit windows?
The rules on visibility from the cockpit have been updated.
There are rules and regulations imposed on the view from the cockpit, for very good reasons - collision avoidance for instance. During ...
- 61.2k
18
votes
Accepted
What are these paint patches on this 787-8?
They are fixed spots where the surface paint has peeled off. Both Boeing and Airbus have been having this issue with their newer models.
Manufacturers are stressing that this is simply a cosmetic ...
- 26.7k
16
votes
What is an "all-electric APU"?
Usually an APU provides electricity and bleed-air, just like the aircraft engines do. An all-electric APU only provides electricity. This can be done in the Boeing 787 because of the bleedless ...
- 669
16
votes
Why do flight attendants on the 787 lock the dimmable windows at different phases of the flight?
For takeoff and landing, @bianfable pointed out the answer. For longer flights across timezones, they set them to dark in order to not disturb passengers who would like to sleep.
And yes, I ...
- 391
14
votes
Accepted
Why does the boeing 747-8 have less wing flex than the 787?
The reason is twofold: The materials used and the high aspect ratio.
The 747-8 primarily uses advance aluminum alloys, while the 787 uses carbon composites.
The carbon composites flex more compared ...
- 99.9k
12
votes
Why did the Boeing 787 switch back to separate IRS systems?
There were also other practical end use issues as well. Having worked in the manufacturing and repair of theses fault tolerant units, one of the benefits was supposed to be the ability to plan ...
- 121
12
votes
United’s 787-9 upgrade
This is not at all uncommon in car engines, and optimization can be done in jet engines also.
For longevity and safety reasons engines are not ran to their full capacity (except in drag race cars), ...
- 26.7k
11
votes
Accepted
What components of the Boeing 787 are made out of titanium?
The Boeing 787 is special due to its high count of composite parts. When aluminium comes in contact with graphite fiber, contact corrosion will damage the aluminium whereas titanium will be unaffected ...
- 228k
11
votes
Which commercial aircraft can perform a parallel engine start?
The main reason behind this capability is that the Boeing 787 starts its engines entirely on electrical power generated by the APU's VFSG (Variable Frequency Starter Generators) vs relying on APU ...
- 1,681
11
votes
Accepted
Who is the owner of the world's only private Boeing 787 Dreamliner?
The registration number of this aircraft is well visible in the video: 2-DEER.
According to Planespotters, this B787 was first leased by Jet Aviation Flight Services from 2014 to 2016. During this ...
- 10.7k
10
votes
Accepted
How long would it take the Boeing 787 to go around the world?
If you departed from an airport near the equator and flew around the world with an average ground speed of 480 knots it would take about 45 hours plus the time needed for 2 fuel stops.
Great Circle ...
- 37.3k
10
votes
Is there any difference between the Boeing 787 and the 737 MAX?
The main difference is size and purpose. Despite being larger than most 737 variants, the 737-MAX is still a smaller, short haul plane. It carries 180 passengers to the 787's 280, has a range of 3630 ...
- 2,723
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