[Jeroen]

Originally Posted by Guite

Aviation fuel is probably cheap in the middle east, just like other petroleum products. So would an airline fill up excess fuel flying out of, say, Dubai? Would it make economic sense to carry extra cheaper fuel for a flight which last 4 to 8 hours?

It really depends on the price difference obviously. But for instance in Europe prices can vary from country to country and they are all short hops in essence. You would also think that big carriers should be able to demand best global prices from fuel suppliers irrespective of where they get their fuel.

Jeroen

[pgsagar]

I have a question which may appear silly. We see aircrafts taxi out slowly before take-off. They crawl very slowly and sometimes stop at the end of the runway for several minutes, waiting for clearances. Now, if it's night and if an aircraft is waiting for say 5 minutes, isn't there a risk of a snake crawling out of runway grass and entwining itself to landing gear? Now, if it does, then what happens after the plane lifts off and the gear retracts? Before the temperature drops to below freezing, can the snake make its way into the aircraft cabin or other inaccessible areas like panels and sections holding vital electronics? I'm sure such incidents must have occurred somewhere.

[libranof1987]

Originally Posted by smartcat

Check this -> Air India plans to launch Boeing 777 flights on Delhi - Chennai sector

Actually; there are a bunch of such flights.

Eg. when I flew to Chicago on a AI 777 plane, my flight was DEL - ORD but the flight originally come from Hyderabad.

There were a few HYD passengers who got off at DEL.

Similarly, there are a few late night BLR-DEL flights on a 777 where the domestic leg is a part of a larger international segment.

This way, I guess carriers get to have two international destinations from two locations (DEL, BLR/HYD) and also, utilize the domestic segment for those who want to fly between these two cities.

Originally Posted by pgsagar

I have a question which may appear silly. We see aircrafts taxi out slowly before take-off. They crawl very slowly and sometimes stop at the end of the runway for several minutes, waiting for clearances. Now, if it's night and if an aircraft is waiting for say 5 minutes, isn't there a risk of a snake crawling out of runway grass and entwining itself to landing gear? Now, if it does, then what happens after the plane lifts off and the gear retracts? Before the temperature drops to below freezing, can the snake make its way into the aircraft cabin or other inaccessible areas like panels and sections holding vital electronics? I'm sure such incidents must have occurred somewhere.

The way this thread started, I thought, for sure, this is about what just happened at SFO!

Don't you think whatever animals there are would be put off by the noise?

[akshaymahajan]

Originally Posted by pgsagar

I'm sure such incidents must have occurred somewhere.

You mean like these?

http://www.newscrunch.in/2017/05/gia...-say-officials

http://www.dailymail.co.uk/news/arti...-30-000ft.html


And when one decided to fly economy

http://www.bbc.co.uk/newsbeat/articl...ake-on-a-plane

[Jeroen]

Originally Posted by pgsagar

I have a question which may appear silly. We see aircrafts taxi out slowly before take-off. They crawl very slowly and sometimes stop at the end of the runway for several minutes, waiting for clearances. Now, if it's night and if an aircraft is waiting for say 5 minutes, isn't there a risk of a snake crawling out of runway grass and entwining itself to landing gear? Now, if it does, then what happens after the plane lifts off and the gear retracts? Before the temperature drops to below freezing, can the snake make its way into the aircraft cabin or other inaccessible areas like panels and sections holding vital electronics? I'm sure such incidents must have occurred somewhere.

On all commercial liners I'm familiar with the gear wells are not pressurised. So at altitude it will die because of hypoxia and or hypothermia. So even it survived or early during the climb it will not be able to get into the pressurised cabin. But depending on the plane might wriggle into adjacent unpressurised areas.

Some amazing human survival stories

https://en.m.wikipedia.org/wiki/List...owaway_flights

Jeroen

[pgsagar]

Originally Posted by libranof1987

The way this thread started, I thought, for sure, this is about what just happened at SFO!

Don't you think whatever animals there are would be put off by the noise?

My apologies. Funny, how I always forget Google. I googled AFTER posting and did come across several such occurrences. SFO, and one case where a Scorpion came aboard. Now that's scary. Undergrowth near tarmac teems with these creatures. Last thing we want to see happen is a plane turning into Noah's Ark. What if a snake survives and enters sections holding critical cables and shorts them out by straining in its coil. Wouldn't it force a plane to emergency-land?

[V.Narayan]

Originally Posted by pgsagar

Now, if it does, then what happens after the plane lifts off and the gear retracts? Before the temperature drops to below freezing, can the snake make its way into the aircraft cabin or other inaccessible areas like panels and sections holding vital electronics?

One should never say never but the likelihood is very very low. The pressurized compartment where the passengers & pilots sit is by definition sealed away from the non-pressurized sections of an aircraft - here sealed means sealed as air will fizz away even through a hole 0.1mm in diameter. Theoretically a snake or a rat or other energetic creature could climb up through the door you use but not through the landing gear well. Possibly the second part of my answer offers little comfort but what is life without an ounce of uncertainty. Where the avionics bays go it is unusual for the bay(s) to have a hole big enough to let in a small animal.

On a lighter note a follow up question could be - can a snake crawl up the lavatory orifice. I could tell you but it might take the fun away.

[Thad E Ginathom]

Originally Posted by V.Narayan

On a lighter note a follow up question could be - can a snake crawl up the lavatory orifice. I could tell you but it might take the fun away.

I wouldn't like to be a snake in a toilet when someone presses the vacuum "flush" button!

[honeybee]

Originally Posted by Thad E Ginathom

I wouldn't like to be a snake in a toilet when someone presses the vacuum "flush" button!

And I wouldn't like to be in a toiket in which a snake is hiding!

So if the pressurized compartment for the passengers and pilots is completely insulated from the non pressurized compartment for the landing gear, we can eliminate the possibility of any animal or reptile from entering that way.

How about the luggage area for live animals? I suppose the cargo too must be stored in a pressurized compartment?

[Jeroen]

Originally Posted by pgsagar

What if a snake survives and enters sections holding critical cables and shorts them out by straining in its coil. Wouldn't it force a plane to emergency-land?

The changes of a snake getting anywhere from the wheel well are remote at best. Even so, anything considered critical tends to be duplicated if not trippled on planes. So electric cables carrying for instance signals to the various control components such as rudders, engines are always redundant as a minimum. Also, there are very strict requirements on how close cables carrying redundancy signals can be to one antoher. So typically there are very far, physically, apart.

So, whilst you can never rule it out completely, an emergency landing due to a snake doing whatever is unlikely. The biggest danger with snakes is probably if they are in the cabin and bite somebody. Then you might have to land very quickly. Very often that will be reported in the press as an emergency landing. But it's just a regular landing for the pilots, but an unplanned destination.

Jeroen

[V.Narayan]

Originally Posted by honeybee

And I wouldn't like to be in a toiket in which a snake is hiding!

Chances of that happening on a train in Indian Railways is probably many many many times higher.

So if the pressurized compartment for the passengers and pilots is completely insulated from the non pressurized compartment for the landing gear, we can eliminate the possibility of any animal or reptile from entering that way.

For all practical purposes yes.

How about the luggage area for live animals? I suppose the cargo too must be stored in a pressurized compartment?

The area in the cargo hold where the animals are kept is also pressurized and heated. There are pressure blow doors to equalize pressure between the passenger cabin above and cargo hold below in case of accidental de-pressurization in either. With pressurization normally maintained in both zones the doors remain shut.

Suggested viewing - the movie 'Snakes on a Plane'

[honeybee]

Here is a question that is pretty simple, actually. When an aircraft is descending, as in landing, at what height does the undercarriage extend / open? Also what is the sequence of activities when descending - first the wheels are out and then the flaps?

That will help me make sense of the various noises that I hear on the final approach. I can already distinguish some of them, like the pilot announcing the approach or the flight crew giving instructions, but there are several other noises I would like to understand better.

[benu9714]

"what is the sequence of activities when descending - first the wheels are out and then the flaps"

No, first the flaps, in gradually increasing mode, and later the wheels.

[Jeroen]

Originally Posted by benu9714

"what is the sequence of activities when descending - first the wheels are out and then the flaps"

No, first the flaps, in gradually increasing mode, and later the wheels.

On most plane the last one or two notches of flaps will be given on final.

So on a 747 the typical sequence would be to deploy flaps gradually, whilst slowing down, in steps till flaps 20. With flaps 20 the wheels are lowered and on final the flaps are further to deployed to 25 or 30.

Other sequence are possible with other types of planes and or procedures.

Jeroen

[phamilyman]

Originally Posted by Jeroen

It really depends on the price difference obviously. But for instance in Europe prices can vary from country to country and they are all short hops in essence. You would also think that big carriers should be able to demand best global prices from fuel suppliers irrespective of where they get their fuel.

Jeroen

Not really. Atleast Indian refiners won't bother about any of the global heavyweights because their primary customers are indian carriers. Maybe reliance might have some such relationships, but I would really doubt that. Atleast in India, the business is regulated enough that the price would be set as per Indian taxes, and per airport approved charges, leaving little leeway.

@Guite: Yes that happens. No first hand information, but from friends in multiple airports. Maybe you could search up forums like pprune.