Passing the western end of Heathrow on the M25 yesterday we were briefly underneath a very low A380, altitude around 250 to 300ft ?, you really appreciate the size of the A380 at that altitude! I know estimating altitude from the ground is not a precise art, but my son was with me, he is an experienced glider pilot and instructor, and said it was "very low".

Is it fair to say that departing A380 flights, by their long-distance nature, take most of Heathrow's 12000ft to get airborne? That one looked as though it had.

EGCA

I very much doubt ANY aircraft would still be at 300 feet by the time it crossed the M25 - unless it was in trouble!!

I think your son just underestimated the altitude due to the size of the aircraft.

Is it fair to say that departing A380 flights, by their long-distance nature, take most of Heathrow's 12000ft to get airborne? That one looked as though it had.

The A380 needs no more runway than a 747-400.

I agree with groundloop. It's nigh on impossible for ordinary mortals, including pilots and air traffic controllers, to accurately estimate the height of an aircraft above ground. If that A380 really had been at 250-300ft we'd have heard a great deal more about it by now.

I got my first chances to see the A380 "close up" twice in the last few weeks - a Singapore aircraft inbound to Heathrow over Greenwich (3000'?) and a Qantas example outbound Heathrow overhead Coulsdon (7000-8000'?) heading towards Dover. Can't get over how big they looked...

My office window is about 5-6 nm west of Heathrow and I see it all daily. I can tell you that the A380s on departure pass by at pretty much the same altitude as long haul 747s.

I would say they are up a bit earlier than the B744s as they are certainly quieter and more powerful, but derated take offs abound of course.

I'd agree with SOE.

I've watched the A380's take off many many times at LHR, and very often it is airborne earlier than 747's, which surprised me at first considering that LHR-SIN is one of the longest non stop routes currently operated from LHR.

Obviously various factors are at play here that as a bystander, I would not know, such as TOW, wind direction, de-rate etc etc but when the SQ 744 was still operating into LHR when the A380 was only in once a day, there was a noticeable difference in the runway used for the same route.

:)

Weeell just maybe the 380 doesn't stop as well as the 744. Requiring a longer stopping distance would require better acceleration to use less runway before reaching V1.

I don't know but, using less runway doesn't necessarily equate to better performance per se. It's impossible to tell by observing.

The A380 has a MTOW of 560 tons compared to 397 tons of the 744. It's engines are just slightly more powerful to the 744. A difference of 10 000+ lbs per engine.
But it's wings lifting capability is much better compared to the 744 giving it a shorter take off run to the 744.

I think it is around 20,000 lbs extra thrust per engine RR A380 are 84,000+ lbs

RR 747-400 is 59/60,000

SIA B744 with the Pratt & Whitney are 56,000lbs max.

Using SIA as a reference, their B744, as parabellum mentioned, is 56,000 lbs max per engine.
The A380s are rated 70,000lbs per engine. So, the exact diff is 14,000 lbs per engine.

Modern engines max thrust could be changed by changing their DEP as per operators requirements.

Thanks all. I guess you are right, we under-estimated the altitude due to to its size.
Impressive all the same!

As a total aside, Sunday was my first ever drive into Central London, moving my son's things from Egham to nearer the action in London. I thought in my innocence that Sunday would be quiet on the roads.....no chance, I dont know how you cope with it!!

Thankfully back in the wilds of Herefordshire in one piece.

EGCA

I once saw an old Pan Am 747 take-off over the M25 - a -100 or a -200. This is around 20 years ago.

It was incredibly low - way lower than anything I have ever seen since. I'd have put it at 200-300ft if that.

I work just outside the Manchster TMA and controled airspace is above 3500ft, so I know that nothing into Man is below 3500ft.
We are about 500ft above sea level wich means that aircraft are never below 3000ft above us..
But when ever a 747, 777, A330, go past someone will say look how low that one is, I have given up trying to put them right, it's cos they are so big compared to A320s or 737s.
I have found if you can read the reg then they are below 1000 feet!!!!!

I once saw an old Pan Am 747 take-off over the M25 - a -100 or a -200. This is around 20 years ago.

It was incredibly low - way lower than anything I have ever seen since. I'd have put it at 200-300ft if that.
The mainstream Pan Am fleet was -100s, the first built. They were well known for poor performance on climbout. Pan Am used them on westbound nonstops to Los Angeles/San Francisco, which BA would not do with the type, on the basis of poor performance, until their significantly more powerful -200Bs came along in the late 1970s. But Pan Am continued with their original fleet through to the end.

Among other ATC comments on seeing such Pan Am departures to California on a hot summer's afternoon were a Hedge Clipper (my favourite), and, when on easterlies, a Piccadilly Line departure.

EGCA. re: driving in London. Sunday afternoons / evenings are worse than Monday mornings !

I tend to find best times to drive in or out are >10am<2pm Mon Fri. <11am Sat & <12pm Sun or >1am<5am any day:ugh:

Back to the thread.... can someone who is currently based out of Hethrow indicate the usual angle of ascent when departing on 27R/L ? I read recently, due to fuel saving measures by airlines at Stanstead, pilots are being instructed to forget the 20* angle, for a 15* angle.

Residents are becoming annoyed by the added noise. Wonder what the green army would say? Saving fuel ! More noise !

BA used to file FPL to KSEA with LAX/SFO listed as diversion. If they arrived near KSEA with sufficient fuel, they would then 'divert'.
I was radar monitor at the old LATCC Radar unit (where Compass Centre now stands) when the first Pan Am 747 departed Heathrow for a demo out to STU and back. Half full of passengers and not much fuel; the first transmission to London Control after departure was 'London, I'm not gonna make 4000 by Woodley'!!

The A380 takeoff is deceptive. I can watch EK go out of DXB from my sunbed on a roof top pool, 30 storeys up and about 4 kms from the end of the runway and maybe 1km lateral.
The 'Fat Lady' appears not to have gained as much height as she wafts by - but actually she is at the same height and speed as any other widebodied bird.
Something about the size and attitude (seems not so 'nose-up'....) fools the observer - or at least fools me. ;)
Maybe the reason for the original post in this thread.

BA used to file FPL to KSEA with LAX/SFO listed as diversion. If they arrived near KSEA with sufficient fuel, they would then 'divert'.
This was a common technique in those days, refiling their flight plan when mid-journey. Pan Am (again) did the same thing when they started New York-Tokyo nonstops with 747SPs around this time, they would initially file for Anchorage and when approaching Alaska, if there was sufficient fuel (as there normally was, of course), would refile for Tokyo. Fuel reserves percentages which were excessive for ultra-long flights not entirely over water were part of the issue. Sydney to LAX would be a different matter.

I am surprised that BA would initially file for Seattle when headed for LAX, as the typical route, still followed today, is well to the south, overhead Winnipeg and Las Vegas.

Is this why all those wonderful Air Canada and Worldways Tristars were "Cleared to Mirabel" from Prestwick when they were all going to Toronto? Suspected it was a fuel thing.

The fuel thing plays a large role Skipness One Echo, but also load, number of engines and the optimized power that Airbus uses.

Here is a picture serie taken from the top level of the ramp to T5 (the one with the shark teeth thingies) of aircraft taking from runway 27L on the last Sunday of August this year. On the pictures the climb out angle is given.

http://www.plane-spotter.com/Jpegs/840/Climb_out/09-4_G-VATL.jpg
To LAX - VS0023 - great circle distance 8,780 km

http://www.plane-spotter.com/Jpegs/840/Climb_out/13-4_A7-AGB.jpg
To DOH - QR0012 - great circle distance 5,246 km

http://www.plane-spotter.com/Jpegs/840/Climb_out/16-0_G-BNLP.jpg
To SEA - BA0049 - great circle distance 7,725 km

http://www.plane-spotter.com/Jpegs/840/Climb_out/16-0_G-VIIW.jpg
To NRT - BA0007 - great circle distance 9,615 km

This last one is taken at a different airport - Oslo Airport in September - and the Icelandair Boeing 757-200 was only inches from a tail strike as it rotated.
http://www.plane-spotter.com/Jpegs/840/Climb_out/19-0_TF-FIP.jpg
To KEF - FI319 - great circle distance 1,899 km

I went LHR/SEA in 1977 on Pan Am 747 and we went very far north, almost polar it seemed, wouldn't BA do the same in those days? It would bring them down over SEA and an hour or so before TOD for SFO, hour thirty for LAX, approx.

I remember a story years ago about one of these marginal Polar route departures from, I think Gatwick.

The 747 in question was being held low by ATC (due to traffic) whilst routing around London. The captain was getting restless.

Eventualy he had had enough and said to ATC "London Approach, If we don't climb right now we won't make Los Angeles", to which the immediate reply came "Sir, if you do climb right now you won't make Manchester!"

Always made me smile :p

This was a common technique in those days, refiling their flight plan when mid-journey.

Still is today on some marginal routes. The trick is when filing for a destination nearer than your original destination this enables you to carry less "contingency fuel" in the fuel load calculations. Particularly useful when operating at Max Take-off Mass. You can then sacrifice fuel load for payload. That extra 3-5% contingency fuel can be quite large.

Once approaching "filed" destination, and if fuel burn was as expected, you refile a flight plan in the air for your "real" destination - now that you are much closer to your real destination contingency fuel requirement is now very small.

<<Eventualy he had had enough and said to ATC "London Approach, If we don't climb right now we won't make Los Angeles", to which the immediate reply came "Sir, if you do climb right now you won't make Manchester!">>

Pity "London Approach" would have had nothing to do with something climbing out of Gatwick!! Amusing nonetheless..

The routes across the Atlantic vary depending on weather systems so aircraft derive benefit from tail winds. On my last trip to LA we flew well north but the return trip was straight across the USA, across the Atlantic to southern Ireland.

Pity "London Approach" would have had nothing to do with something climbing out of Gatwick!!

I couldn't remember the exact name of the sector but it was whoever handles the LGW departure that goes in the general direction of Detling-E London-Lambourne-Welin-Trent.

OK.. Very long ago it would have been London Radar/ London Airways. Nowadays it's London Control.

For sheer fright some of us can remember watching the first Pan Am 707s scambling for take off from the B.E.A. Runway Canteen belching black smoke and passing over the the Great South West Road at Hatton Cross at about 100 ft whilst B.O.A.C.s Comet 4s were 100s of feet higher on their take off. Ah!! the days of the first jet across the pond battles .:O:O

Wasn't there one 747 PanAm that wafted over Reading at quite a low height [below 1000 agl] on 3 engines way back in 69/70 time?

Sensationalist local Press talked about the pilot following the Thames Valley to avoid hitting any hills!

I am fairly certain I didn't dream the event........

aviate1138.. Maybe a year later than that.. I was driving to work with some colleagues and it went passed us as we were on the M4 near White Waltham. It was so low we couldn't see the wings. It got to 1500 ft near Compton, then turned south to the coast and dumped fuel. Soon after it arrived back I was on duty with the driver of the car. We said to the pilot: "You frightened us to death as we drove in". He fell about and said something like: "Did you hear the bang?"

The episode earned the two of us standing-room only on the boss's bit of Axminster as questions were asked in Parliament, tapes played, etc.!!

That sounds very similar to the incident in 1987 or 1988 involving a Continental 747 departing LGW which experienced a compressor stall whilst taking off in high winds on 26L.

It limped into the air and if memory serves, disappeared behind the hills causing crash alarms to be set off - allegedly reaching 1500ft 20 minutes after take-off.

It also dumped fuel and eventually returned without incident. I believe there is a video of the incident taken by a passenger on-board which is on the internet somewhere.

A couple of comments

I stod in the car park of the pub at the end of the runway at Farnborough last year to watch the A380 arrive and it really does blot out the sky-that wing is just immense(and British too )

On the subject of LHR departues and the interesting days of 'coal burning' non fan 707s and early 747s. South African Airways who in pre Mandela days had some interesting routings and stop offs en route from London to Johannesburg Ilha do Sal etc possibly held the long take off run record. If I recall correctly their Monday flight unlike every other day was non stop and I can still see a SAA 747 -100 hurtling past the intersection of 28L (as it was) and the old 23R at what I think was described as 'block79' and hearing the wheels thundering train fashion over the concrete runway segments-that wouldnt have cleared the M25 by more than a couple of hundred feet other than the fact that there was no M25 back in 1973-4 was there?

PB

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To answer the OP's original question, on the day there were four A380 departures. The "lowest" of them over the M25 was still over 750ft.

re SAA 747 departure - I remember driving around the peri track at the end of 28L when it went overhead - just :eek::uhoh: - respect!

Working a little further out from LHR I find that the A380 performs well still in the upper levels, normally out climbing most of the B747's on similar routes.

The worst ones we get are the SAA A340-200's to Cape Town and the Sri Lankan A340-300's going all the way to Male (VRMM), Maldives direct.

Flightman: Many thanks. The departure was around lunchtime, say between 12-00 and 12-30 local.
I accept what you say because I assume you have actual data to verify what you have said.
It just looked a lot lower, . I ran it across my son again, and he said "500ft or less" . Clearly we were misled by its size.

Back in the Summer when we were outside his digs in Egham there was an A380 departure, and it "looked" as though it was flying slower that other aircraft passing over us. Again, it must be a function of the size of the aircraft, and a mis-reading of its height, and hence its apparent speed.

Regards

EGCA

EGCA. Yes I do have "access" to the data. :ok:

Regarding it's apparent speed, from my office I watch them rotate off 27R and yes, due to it's size it does seem that the A380 is travelling at a much slower speed than everything else. It's very deceptive.