[deecee]

I know there have been some threads on aircraft flying low, but none have answered the question I am going to ask.

Is there anyone on the forum who can tell me why the passenger jets seem to fly lower when we have lovely hot or even nice weather. We see a lot of the flights going over our area which seem to be coming out of Manchester. Is it because of air pressure or something like that ?
It's not a critisism because we enjoy looking at them and imagining the destinations.

[Jabberwocky]

Its the same here where I live in north Leicestershire. We get the traffic from East Midlands powering down after they take off right over the house.
Noisy buggers.
The ones that seem to be passing over head to some other airport seem to be almost at rooftop height too.

[KenH]

Originally Posted by deecee

I know there have been some threads on aircraft flying low, but none have answered the question I am going to ask.

Is there anyone on the forum who can tell me why the passenger jets seem to fly lower when we have lovely hot or even nice weather. We see a lot of the flights going over our area which seem to be coming out of Manchester. Is it because of air pressure or something like that ?
It's not a critisism because we enjoy looking at them and imagining the destinations.

I can't tell you the reason but I can tell you two or three effects of the hot weather which can have an effect on altitude.

All aircraft fly at either a height (above ground level) or an altitude (above sea level) that is determined by using a pressure sensitive altimeter. This is a huge subject in its own right, but in the simplest terms the pilot will set the pressure of the air at sea level over which he is flying. When going into or out of an airport this is the pressure of that airport and is exact and accurate. When flying cross country, it is the average pressure for a large area. When flying above certain altitudes on on Jet Airways it is a standard international setting of 1013 Millibars (29.2 inches of mercury). If the you fly with 1013 set, at say 10,000ft and the local pressure really is 1013 then you will be at exactly 10,000ft. If the local pressure is higher or lower then you will be 31ft higher or lower than you think for every millibar different, but so will everyone else so there are no conflicts.

The second effect of the weather is that warmer weather often doesn't come from the Atlantic, in particular the prevailing winds may be southerly or more easterly. Most runways are built east-west but the majority of the time you land towards the west as the wind will be coming from that direction. This means you are also more likely to be approaching the runway from the eastern side. When the weather changes and winds favour the more easterley runways then all this is reversed and you will see aircraft setting up for an approach that you never normally see or they may have decended earlier because they are now keeping to the western side of the airport.

The third possible effect if that this kind of hot weather brings thunderstorms. Aircraft don't like thunderstorms and avoid them at all costs. This can mean flying lower or in areas where they don't normally fly.

[KenH]

Originally Posted by Jabberwocky

The ones that seem to be passing over head to some other airport seem to be almost at rooftop height too.

That is exremely unlikely, apart from anything else they would hit the rooftops. Even light aircraft rarely fly below 1000ft and larger aircraft much higher, except in the final stages of landing. If they are not about to land at(or have just taken off from) a licenced airfield then they can be prosecuted for being within 500ft of any building, person or vehicle. As a general rule they will be above 500ft if you can't read the registration number on the side or under the wind with normal unassisted eyesight.

[Jabberwocky]

Interesting stuff.
They DO appear to be very low though, and a few weeks ago we had a Spitfire and a Dakota circling the area for some reason, and they were a brilliant sight and seemed to be at streetlight level.
Ovviously they were far higher but it was still a thrilling sight.

[KenH]

Originally Posted by Jabberwocky

Interesting stuff.
They DO appear to be very low though, and a few weeks ago we had a Spitfire and a Dakota circling the area for some reason, and they were a brilliant sight and seemed to be at streetlight level.
Ovviously they were far higher but it was still a thrilling sight.

The reason I know that a spitfire won't be at rooftop height is that they cost a fortune. If the prop stops then, at a low height, you are landing on top of whatever is in front of you. At 10,000 ft a light aircraft can glide for about 20 miles (some as much as 25-30 miles) which gives plenty of scope for finding a suitable field to land*




*the press will still describe this as "plummetting towards a primary school having narrowly missed a hospital".

[KenH]

I have thought of a fourth possible reason why there might appear to be more low flying aircraft when it is hot. It might be that with a clear sky you see aircraft that are normally above the clouds. There may also be more flights because it is a holiday time of year.

[muddycoffee]

Originally Posted by KenH

I have thought of a fourth possible reason why there might appear to be more low flying aircraft when it is hot. It might be that with a clear sky you see aircraft that are normally above the clouds. There may also be more flights because it is a holiday time of year.

I was going to suggest that.
The fact that the sky is unusually clear in this hot weather, might mean that some people are noticing aircraft which they don't normally notice.

Also there isn't much wind at ground level, so maybe the noise of the aircraft seems louder because it is not being disturbed as much on it's way to your ears on the ground.

There is also the possiblitiy that older noisier aircraft are in the skies as well as quieter more modern ones, as the holiday industry gears up for the busiest part of the year with all the holiday traffic.

[Joanl]

Originally Posted by Jabberwocky

Interesting stuff.
They DO appear to be very low though, and a few weeks ago we had a Spitfire and a Dakota circling the area for some reason, and they were a brilliant sight and seemed to be at streetlight level.
Ovviously they were far higher but it was still a thrilling sight.

Plust at the moment it's the Farnborough show and the old planes might be passing over on their way back to where they live when they aren't taking part in anything and a couple of weeks ago the same could apply for the Waddington one. Just a thought.....

[YakQueudrue]

KenH, you appear to be the man with all the answers, so can you explain this:

On mOnday I was at Hathersage swimming pool, it was extremely busy and all of a sudden, I saw a large, 1940's style war plane fly by at practially roof top level. It was heading directly towards the hills and swerving off to the right.

Now I saw it, and went bloody hell, but no one else appeared to even see it.

[KenH]

Originally Posted by YakQueudrue

KenH, you appear to be the man with all the answers, so can you explain this:

On mOnday I was at Hathersage swimming pool, it was extremely busy and all of a sudden, I saw a large, 1940's style war plane fly by at practially roof top level. It was heading directly towards the hills and swerving off to the right.

Now I saw it, and went bloody hell, but no one else appeared to even see it.

Yes, you are on the wrong thread, you need the "ghost thread".

[Joanl]

And there's a Canberra doing a farewell flight this week around the country. It was over here yesterday (Bournemouth Airport).

[angle20]

Originally Posted by KenH

All aircraft fly at either a height (above ground level) or an altitude (above sea level) that is determined by using a pressure sensitive altimeter.... When going into or out of an airport this is the pressure of that airport and is exact and accurate....When flying above certain altitudes... it is a standard international setting of 1013 Millibars (29.2 inches of mercury). If the you fly with 1013 set, at say 10,000ft and the local pressure really is 1013 then you will be at exactly 10,000ft. If the local pressure is higher or lower then you will be 31ft higher or lower than you think for every millibar different, but so will everyone else so there are no conflicts.

Interesting, Ken.

[Jabberwocky]

Originally Posted by YakQueudrue

KenH, you appear to be the man with all the answers, so can you explain this:

On mOnday I was at Hathersage swimming pool, it was extremely busy and all of a sudden, I saw a large, 1940's style war plane fly by at practially roof top level. It was heading directly towards the hills and swerving off to the right.

Now I saw it, and went bloody hell, but no one else appeared to even see it.

Did you check Google as I suggested?
There are a few mentions of phantom planes in that area and on the moors.

[Mathom]

Originally Posted by YakQueudrue

KenH, you appear to be the man with all the answers, so can you explain this:

On mOnday I was at Hathersage swimming pool, it was extremely busy and all of a sudden, I saw a large, 1940's style war plane fly by at practially roof top level. It was heading directly towards the hills and swerving off to the right.

Now I saw it, and went bloody hell, but no one else appeared to even see it.

Oooh, that does sound like the Hathersage ghost plane!

[KenH]

Originally Posted by angle20

Interesting, Ken.

I need to get out of the house more.

[Jabberwocky]

It IS interesting though!
Im watching this thread like a hawk, im getting a real interest in aviation since I moved to Leicestershire, so Im learning lots here.

[KenH]

Originally Posted by Jabberwocky

It IS interesting though!
Im watching this thread like a hawk, im getting a real interest in aviation since I moved to Leicestershire, so Im learning lots here.

You should have a look at an aviation forum such as www.flyer.co.uk

[Jabberwocky]

Thanks for that!
I added it to faves and Ill take a look later.

[deecee]

thanks for the input folks, keep em coming though