[Sarmishtha]

Yes, indeed they are fast with reasonable enough fuel efficiency, of course it is relative. I remember that we had completed our Kolkata to Guwahati flight with Vistara in about 50 minutes!

[silversteed]

Originally Posted by createrkid

I've always seen a couple of airplanes flying low at night in circles and I've always wondered, what do they actually do? Do they train newbies in an empty plane? Do they conduct maintenance checks? I'm attaching a picture, does any Guru have an analysis into this? I'd really appreciate it

Thanks again,
Zo.

SG9111 and 6E8008 - Spice Jet and Indigo respectively use these flight numbers for their training flights.

As Jeroen rightly mentioned, most European cities do not allow flight ops at night due to noise abatement issues, but we in India don't care about these things. It gets quite loud during some of the passes, loud enough to wake kids up.

[saket77]

A lot of places where noise abatement procedures are followed, the pilot is supposed to turn down the throttle once the aircraft is airborne. They are allowed to throttle up only after the city limits. The procedures also involve designing flight paths with minimum impact to residential areas near the airports/ cities.

[itwasntme]

Originally Posted by silversteed

As Jeroen rightly mentioned, most European cities do not allow flight ops at night due to noise abatement issues, but we in India don't care about these things. It gets quite loud during some of the passes, loud enough to wake kids up.

Can sympathize with your dilemma but to say 'we in India don't care' is a sweeping, simplistic and unfair generalization. Having earlier worked extensively in the IN airports sector, I can tell you there is serious emphasis on noise abatement to the extent practical/possible.

AAI (where relevant), and PPP operators self monitor 24x7 as part of their EHS programs, and are also audited by the DGCA. IGIA Delhi (DIAL), which borders Pushpanjali, Samalkha, Bijwasan / Vasant Kunj / Dwarka residential areas has specifically implemented extensive noise abatement procedures which has somewhat reduced the suffering caused to such residents.

CSIA (MIAL) is less impacted but are no less vigilant. Some links below:

https://timesofindia.indiatimes.com/...w/69604706.cms
https://aim-india.aai.aero/sites/def...S_2018_116.pdf
https://www.newdelhiairport.in/pdf/D...eets-Noise.pdf
https://www.csmia.aero/environment-c...ompliance.aspx
https://www.hindustantimes.com/india...6DqwqMnBJ.html

Airports are also in sync with all airlines, for example, older noisier aircraft have been banned (e.g. B727) adoption of continuous descent profiles etc.

[Jeroen]

Originally Posted by saket77

A lot of places where noise abatement procedures are followed, the pilot is supposed to turn down the throttle once the aircraft is airborne. They are allowed to throttle up only after the city limits. The procedures also involve designing flight paths with minimum impact to residential areas near the airports/ cities.

On these noise abatement and departure procedures: I can not possible cover it all, as it is way to complex and in all honesty I don’t know all the details, but here some basics on how things work in general.

On your typical commercial airport there are so called SID, Standard Instrument Departures. For each runway there is a unique SID chart. The chart will tell the pilot exactly how to fly, at what minimum (sometimes maximum), various headings etc.

Below such a SID chart for one of the Amsterdam runway., in this case RWY06 (06 means its orientation is roughly 60 degrees magnetic)



You can find a lot of these sort of stuff on line these days.

Have a look at this:
https://www.lvnl.nl/eaip/2019-08-01-...HAM-en-GB.html

if you would read thought this you will find that for Amsterdam noise abatement is build into their published SID charts. But there are other considerations for a pilot as well. For instance obstacles clearance is a hugely important factor and keeping to the published altitudes will ensure so. Sometimes there are maximum altitudes for certain segments in the SID. That is usually so as not to interfere with other higher departure or arrival routes/traffic.

There is a similar system for the arrival routes, called STAR, Standard Arrival Route. All SIDS and STARS are pre-loaded in the Flight Management System. So the pilot choses his/her SID, based on what ATC tell him/her. That whole route will be displayed on the navigation display and the plane with the autopilot and auto throttle on will follow the SID, keeping to the correct altitudes and speeds.

SIDS are usually categorised in three main type. There are those where the whole SIDS is available and the pilot either handles, or has George his friendly auto pilot do for him. There are also Vector SIDs. These define specific points where ATC will tell you exactly which heading, altitude and speed you must proceed. And the third type is a hybrid, mix of the previous two.

The pilot version is typically the easiest to fly. Because once you have the relevant clearance and get your take off clearance you would just fly the SID and you don’t need to talk to ATC anymore.

Although noise abatement can be build into the SID (and or STAR) there might be other, further procedures in place as well. Pilots need to verify what airport specific stuff they might need to adhere too. Lots of sources are available and most carriers have flight planning departments that crank out all the relevant details. The pilots just need to verify and familiarise themselves prior to the flight.

Me, being a one-man air crew, non commercial, I would have to figure it all out by myself. Part of the flight planning and I always thought it was a lot of fun.

Just because an airport has Published SID/STARS does not mean they get used all the time. When traffic is low, ATC might allow/advise you to fly a more direct route.

Jeroen

[Jeroen]

Just some more information about take offs. Irrespective of procedures, noise abatement and such, every plane has a certain take-off profile.

I have found this little diagram in one of my old Boeing 747-400 Flight Crew Training manual.



Typically planes after leaving the runway will pitch up sharply and proceed on runway heading till at least 500 feet AGL (Above Ground Level). At this point of time the flaps are still in their take off position and engines are running at take off thrust. The landing gear is retracted as soon as “positive rate of climb” is established. This reduces drag considerably! (Although during the actual retraction of the gear, drag might increase as the doors need to open before the gear can be retracted)

The pilots will have determined (or by company procedure) a so called acceleration height. For instance on the 747-400 this is very often about 1000 feet AGL. At that point thrust tends to be reduced somewhat to (economy climb speed), vertical climb speed reduces and the flaps are being retracted in accordance with the flap/speed schedule. (Speed determines the next flap setting.)

So the aircraft climbs, on a usually slightly shallower angle, but it is still accelerating, flaps are retracted as the subsequent speeds are reached. This reduces drag further and helps acceleration.

Depending on airspace there might be (air) speed restrictions in place as well. In many parts of for instance the USA and Europe below 10.000 feet, your speed needs to be below 250 knots.

So for a given SID procedure, the pilots will also check if it complies with their standard take off profile.

Contrary to what many people thinks, the autopilot can not do the take off. It is always the pilots who perform the actual take off. They are likely to use the auto-throttle system though. As soon as the gear is stowed, many company procedures call for the auto pilot to be engaged. The auto pilot in combination with the auto throttle will fly this profile, within a SID, all by themselves. Flap retraction is as far as I am aware, always manual by the pilot.

This diagram shows two different profiles, one for a straight runway heading departure. The other one is for a close in turn after take off. They might come with different acceleration heights.

Usually close turn in after take off are due to obstacle clearance. Eg. a mountain in front of the runway. So you want to turn as early as possible, you want to get a good vertical speed and you don’t want to change the aircraft configuration during such close to the ground manoeuvres (so no flap retraction).

Although noise abatement procedures are extremely relevant, no pilot will or should ever compromise safety for these.

If you want some more detail, have a look at this training video. The author is a former British Airways (training) 747-400 Captain. He is a very active member on the PSX - 747 400 simulation group and produces these sort of video’s:

https://www.youtube.com/watch?v=Zd0e...ature=youtu.be

Enjoy

Jeroen

[McLaren Rulez]

Originally Posted by Jeroen

Pretty scary story:

http://avherald.com/h?article=48b217ed&opt=0

Jeroen

Mentour Pilot did a video on this incident

https://www.youtube.com/watch?v=o-IuOnDBoGA

[TSIboy]

Originally Posted by McLaren Rulez

Mentour Pilot did a video on this incident

Does anyone know where to find the CVR clips of this flight? or is it not in public domain?

From the incident report:

The first officer asked PIC at time 1:38:06 UTC “do you know where it is” and PIC mentions that “just going blindly”, thereafter autopilot disconnect noise is recorded and the bank angle alert is also heard and subsequently the aircraft lands on the runway.

No comments!

[McLaren Rulez]

A beautiful video of what's on a flight deck in a modern airliner. Great narration too - this is one of my favorite channels!

https://www.youtube.com/watch?v=TYJ8uoJ7DAk

[arijitkanrar]

Originally Posted by McLaren Rulez

A beautiful video of what's on a flight deck in a modern airliner. Great narration too - this is one of my favorite channels!

Off topic, but Animagraffs is one of best Youtube channels. They have more videos on many things. You can spend hours going through its contents. Very interesting.

Linking a few more of their videos that are relevant to the topic of the thread.

How an Airliner works

https://www.youtube.com/watch?v=NZLbTuBDhJg

How a Jet engine works

https://www.youtube.com/watch?v=L24Wf0VlTE0