Malaga, mountains, weight...
Thread Starter
Malaga, mountains, weight...
Yesterday afternoon I boarded a Jet2 737-300 at Malaga for a flight back to Leeds/Bradford. The captain told us that due to operational reasons we could not take off in the preferred direction and that we would therefore not be be able to clear the mountains (his words) and hence 40 odd cases were being off-loaded, we would still be too heavy with the required fuel so we were taking on less fuel and then stopping in Toulouse to refuel.
The weather was warm (about 21 degrees) and there appeared to be little wind.
Can someone tell me what this is all about, does Malaga have a runway that is effectively useless in one direction? Is this a common occurrence?
I did a couple of searches but couldn't seem to find the answer.
I'm only SLF, so please be nice...especially as I'm sure I'm posting in the right place.
Dan
The weather was warm (about 21 degrees) and there appeared to be little wind.
Can someone tell me what this is all about, does Malaga have a runway that is effectively useless in one direction? Is this a common occurrence?
I did a couple of searches but couldn't seem to find the answer.
I'm only SLF, so please be nice...especially as I'm sure I'm posting in the right place.
Dan
Last edited by danielsirrom; 30th Nov 2012 at 20:25.
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It's effectively about climb gradients on the SID. I'd guess you were on a B1 powered 737 (less powerful engines) and a combination of weight and temperature would mean that the required performance just wasn't there.
Malaga has departures towards high ground thus the higher climb gradient requirement on the runway 31 and 30 departures. The other departure is initially over the sea hence not such a high gradient.
Malaga has departures towards high ground thus the higher climb gradient requirement on the runway 31 and 30 departures. The other departure is initially over the sea hence not such a high gradient.
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Yep, maybe the tailwind exceeded limits, it's only 10kts. Tailwind has a drastic effect on performance and, if it is the case, probably meant the performance of the other runway may have been even worse.
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Many airports have take-off weight restrictions. The mountains to the north west of Malaga would reduce the weight that could be lifted. But to be fair, 21˚C is not that much. However, a quick wizz to aena.es (Spanish Aviation Authority's website) shows on most departures a climb gradient of 6% or so. And even the most asthmatic of aircraft should be able to achieve this. So I'd suggest that was a combination of wind, temperature, basic weight (was this aircraft fitted with a cargo door) and a deficiency of some description which reduced the weight lifting capability of the aircraft. The reason you were given was almost certainly correct and quite reasonably you were not given the full details. However, this is not the way you run a low cost airline. Fuel stops cost a fortune and waste the best part of an hour.
PM
PM
PM
PM
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PM, all of our QCs are switchable between B1 and B2 (20k or 22k) and are always B2 for passenger ops. They have better performance than a standard airframe with B1s.
How long is the runway?
Field length limit for a B1 at 22C, flap 5, sea level with no corrections is 64.2 tonnes for a 9000' runway which is above MTOM.
I can't recall the distance to obstacles at Malaga but for comparison a 500' obstacle at 5NM gives a limited weight of 53.6 tonnes.
An empty B1 is about 33.5 tonnes APS. Stick on 14 tonnes of people and bags and roughly 9 tonnes of gas and you're getting close.
How long is the runway?
Field length limit for a B1 at 22C, flap 5, sea level with no corrections is 64.2 tonnes for a 9000' runway which is above MTOM.
I can't recall the distance to obstacles at Malaga but for comparison a 500' obstacle at 5NM gives a limited weight of 53.6 tonnes.
An empty B1 is about 33.5 tonnes APS. Stick on 14 tonnes of people and bags and roughly 9 tonnes of gas and you're getting close.
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That's a B1, pax version.
They would by that point be working on a single case performance which effectively takes everything into consideration. Looks like quite a low QNH in Spain at the mo and that would hurt as well.
I've been in and out of Malaga in a B1 on hotter days. So I'm slightly bemused by this.
What was the passenger load like?
They would by that point be working on a single case performance which effectively takes everything into consideration. Looks like quite a low QNH in Spain at the mo and that would hurt as well.
I've been in and out of Malaga in a B1 on hotter days. So I'm slightly bemused by this.
What was the passenger load like?
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Isn't this a semi regular occurence out of AGP? I have twice been on flights which have taken off towards the mountains, done an almost immediate 180 to head out to seas and then done yet another 180 to head back north over the mountains. What precluded this particular Jet2 aircraft from doing so and thus ensuring adequate clearance of the hills and also preventing a costly fuel stop and expense of delivering late bags?
Last edited by PhilW1981; 1st Dec 2012 at 18:42.
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Phil, that sounds like an old SID. I don't think it's used anymore because of the new runway operation but it would still have climb gradient requirements that must be achieved.
We don't just make up any old departure route we like you know.
We don't just make up any old departure route we like you know.
