103 votes

Why are there no "sleeper" planes?

There certainly are; it's called "Business Class" and you'll find such areas with seats that recline into what are essentially beds on most long-haul aircraft. However, you simply can't fit as many ...
  • 2,375
95 votes
Accepted

Why is the lower deck of the Airbus A380 curved like a single deck airplane?

The cabin interior is curved to accommodate, among other things, the brackets holding the upper deck floor beams. These brackets are a structural feature that transfers the weight of the upper deck ...
  • 17.9k
71 votes
Accepted

What is this white smoke like thing, seen inside the cabin before takeoff?

Direct answer Air conditioning causes a large drop in cabin temperature, air humidity present in the air condensates into water droplets. It is similar to mist, fog and clouds. If water droplets enter ...
  • 68.3k
62 votes
Accepted

Why are there no "sleeper" planes?

They just don't really fly them any more. All things considered history has a big impact on this. 13 hours is by comparison fairly short when it comes to long distance flying, historically speaking. ...
  • 97.1k
58 votes
Accepted

What prevents a passenger from opening the emergency door on his own will, mid-flight?

At cruising altitude there is between 4 and 8 tons of pressure acting on the inside of the door. There aren't too many passengers capable of exerting that much force on the handle (and even fewer ...
  • 14.6k
56 votes

Can cameras and LCD screens replace cabin windows?

Note that the windows are a safety feature: You need to see outside in case of emergency, e.g. to know which side of the plane is surrounded by flames, or how deep in the water you are. This is ...
  • 1,144
55 votes

Why are there no "sleeper" planes?

I have flown in sleeper class with British Airways flying overnight from Toronto to LHR. It was an expensive luxury which started out great, but when fully reclined the bed is not exactly flat and, ...
  • 4,806
47 votes
Accepted

Why does an airliner fuselage have a constant section over its length rather than a tear drop shape?

On the other hand, fuselage on an airliner is most of time bullet shaped. No, it is not. A “bullet shape” has a flat end, which is where most of the drag is generated (at subsonic speeds). But that ...
  • 54.8k
45 votes
Accepted

Can a commercial cargo aircraft be converted into a commercial passenger aircraft, and vice versa?

There are such a thing as "Quick Change" aircraft, allowing entire 'pallets' of chairs to be exchanged for cargo. Image courtesy of canalblog.com Image courtesy of airliner.net Nice film to show ...
43 votes

What does this black triangle placard on board an A320 denote?

If there is a problem on-board and the crew is unsure about the condition of the aircraft, the triangle indicates what window should be used to inspect flaps, slats or engines or look out for icing. ...
  • 8,762
41 votes
Accepted

What are these five indicators at the front of the 737 passenger cabin?

This is the forward Master Call Light Panel installed in the ceiling of the cabin. A second one is located aft. These panels exist on all large aircraft for the cabin crew members to be alerted ...
  • 68.3k
39 votes
Accepted

Why do lavatories in modern planes still have ash trays?

Because in the US (where Boeings are made) it's required by law. 14 CFR 25.853(g) says: (g) Regardless of whether smoking is allowed in any other part of the airplane, lavatories must have self-...
  • 70.7k
39 votes

Why is the lower deck of the Airbus A380 curved like a single deck airplane?

Consider this photo of the cross-section of the A380 and the illustration below. You can see the cargo deck on the bottom, the lower deck (where you sat) in the middle, and the upper deck on the top. ...
  • 8,258
38 votes

Why is the airflow in airline cabins downwards?

Temperature stratification is a vexing problem on lots of airliners. The big challenge is you need a distribution system that is effective when cooling (on the ground and at low altitude when the ...
  • 112k
37 votes

Can cameras and LCD screens replace cabin windows?

Problem #1: What gets displayed on the screen? While I'm aware of Emirates' recent 'virtual windows,' there is a big problem with this idea in general: what should actually be displayed there depends ...
  • 19.1k
36 votes
Accepted

Why don't airliners use noise cancelling?

First, some airliners do use it - the Bombardier Q400 uses a NVS (Noise and Vibration Suppression) system to reduce cabin noise. Basically, it uses devices called Active Tuned Vibration Absorbers (...
  • 99k
35 votes
Accepted

Why is the Airbus A320 permitted to carry 180 passengers, instead of the maximum 179 allowed?

See Page 9 of TCDS A.064 ANNEX - Airbus A318, A319, A320, A321 - Special Conditions TCDS A.064 ANNEX - Airbus A318, A319, A320, A321 - Special Conditions ...
34 votes
Accepted

Can cameras and LCD screens replace cabin windows?

Emirates Airlines have recently launched their new First Class with a similar concept. It is only available in First Class and I doubt it has much to do with the structural implications as of now, ...
33 votes
Accepted

What are the factors behind increasing aircraft window sizes?

In the early years of the jet age, which followed closely on the introduction of pressurized hulls, there was much fear of stresses specifically in the area of the window openings due to the loss of ...
  • 6,207
33 votes

Why don't pilots control window shades & seat recliners?

On the Boeing 787, the mechanical window shades have been replaced with glass panes which can be made more opaque or transparent by applying electric current to them. (source) The passengers can ...
  • 1,943
30 votes

What is the viability of stacking passengers in an airplane cabin?

I see several challenges with this design, both technological and not: Making that design safe enough will be difficult, the structure you add in the cabin would need to be strong enough to maintain ...
  • 50.9k
28 votes

Why don't pilots control window shades & seat recliners?

Adding to @Airsick's answer there's an important psychological component, which is the illusion of control. Passengers in an airplane have very little they have control of, they are told when they can ...
  • 50.9k
27 votes

Do airliner cabin filters trap viruses or other pathogens?

Modern airliners use HEPA filters to filter the air before re-circulation. This will remove almost all airborne pathogens like viruses: The overall risk of contracting a disease from an ill person ...
  • 49.6k
27 votes

Why is the airflow in airline cabins downwards?

Not at all. Cold air tends to go low and hot air high. If the cooled air flow were pumped in from the floor, then what we would have would be customers with cold feet and hot heads, making an already ...
  • 10.9k
26 votes
Accepted

Are cabin dividers used to "hide" the flex of the airplane?

Was my fellow passenger right? No. That photo is taken in a B777-300 (2 aisles, 4 seats in the centre and three at the sides, lavatories only behind the central rows, rows on the left side of the ...
  • 31.7k
26 votes

Do airliner cabin filters trap viruses or other pathogens?

IF the airliner has HEPA filtration yes, so pathogens floating in the air that happen to get drawn into the recric system would be trapped and not recirculated, so some of the total pathogen load in ...
  • 112k
25 votes
Accepted

Could the non-smoking sign still be turned off in modern airplanes?

It would appear that the aircraft you flew was D-AGWR, a A319 with MSN (Manufacturer Serial Number) 4285 delivered in April 2010 (hence fairly new). There is a switch at the bottom of the overhead ...
25 votes

Can a commercial cargo aircraft be converted into a commercial passenger aircraft, and vice versa?

It applies to helicopters too. When on holiday in the West Indies, one of the locations offered helicopter rides. If anyone booked one, they contacted the local freight helicopter company who put ...
  • 351
25 votes

What is the viability of stacking passengers in an airplane cabin?

The problems I can see with that design: Increased structural weight: all things remaining the same, you will have less payload availability for luggage/cargo. Cabin servicing you either add an ...
  • 31.7k

Only top scored, non community-wiki answers of a minimum length are eligible