Wind damage at Dublin
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You are quite correct that brakes are released as soon as you get onto stand, after the aircraft is chocked. This is to allow the brakes to cool down, during the turnaround, they normally only weld together, if very hard braking has been applied, in the case of an RTO. Parking brake pressure will normally dissipate over a long length of time, which is why the parking brake and chocks are applied overnight and in windy conditions.
However aircraft will swing around, as happened on this occasion even if chocked and the parking brake has been applied, if they are not pointed into wind. This is why, if high winds are forecast that the airlines get their engineers to park the aircraft into wind. It is also not unusual for the aircraft to be fuelled to add weight also.
This is one of the problems that airlines face when operating from large airports, it is very difficult to attach a bridge to an aircraft, if it is parked at 90 degrees from the centre line.
I wonder what would happen if the likes of BA, BMI and Virgin told the Heathrow Duty officer, that they wanted to turn their aircraft into wind on a particular day.
However aircraft will swing around, as happened on this occasion even if chocked and the parking brake has been applied, if they are not pointed into wind. This is why, if high winds are forecast that the airlines get their engineers to park the aircraft into wind. It is also not unusual for the aircraft to be fuelled to add weight also.
This is one of the problems that airlines face when operating from large airports, it is very difficult to attach a bridge to an aircraft, if it is parked at 90 degrees from the centre line.
I wonder what would happen if the likes of BA, BMI and Virgin told the Heathrow Duty officer, that they wanted to turn their aircraft into wind on a particular day.
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Pardon a possibly ignorant question from a PPLer but would parking in windy conditions with the ground spoilers extended do any good? Or do the spoilers simply retract once the hydraulics are shut down?
RU
RU
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This was obviously a very unusual event for DUB but I wonder if anyone there can confirm as to whether this was indeed a tornado, or something else such as a microburst? Tornadoes, be they large or small, tend to leave a very characteristic damage trail due to the rotating vortex. Microbursts, or intense downdraughts, on the other hand have a rather different effect in terms of damage, due to the downwards and outwards nature of the wind.
I am interested because parts of south west London were subject to a similar phenomenon last summer, which created siginificant damage but was definitiely not a tornado. Fortunately this particular "microstorm" missed LHR and its approaches, but only by a few miles. I think it is possible that the storm that hit parts of Paris last month was also some form of microburst, although I have seen less information on that one.
I am interested because parts of south west London were subject to a similar phenomenon last summer, which created siginificant damage but was definitiely not a tornado. Fortunately this particular "microstorm" missed LHR and its approaches, but only by a few miles. I think it is possible that the storm that hit parts of Paris last month was also some form of microburst, although I have seen less information on that one.
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Ground spoilers will retract without hydraulic pressure. However spoilers deployed will catch the wind even more and cause more drag, you don't want that. A large aircraft like the A330 parked nose into wind, braked, chocked, trimmed nose down will ride out a 73 knot wind. Flap around a bit but stay put.
If the aircraft is sideways on to the wind, you have real problems.
The wind will get under one wing, tilt the aircraft over, which gets the wind under the wing even more etc. This is probably what happened to the ATR 42, I have seen this.
Meanwhile the big jets all have huge fins. Imagine the wind blowing on one side of this, literally tons of force and all acting twenty or thirty feet above the deck. Eventually something has to give and the nose wheels shift sideways. Brakes, chocks, nothing will stop the aircraft weathercocking into wind. Very scary, tons of valuable metal spinning round until it hits something.
Primary prevention is parking the aircraft into wind and moving everything well clear. Easier said than done at the airports I have worked at however. Small stands, equipment everywhere, obstructive airport management...
If the aircraft is sideways on to the wind, you have real problems.
The wind will get under one wing, tilt the aircraft over, which gets the wind under the wing even more etc. This is probably what happened to the ATR 42, I have seen this.
Meanwhile the big jets all have huge fins. Imagine the wind blowing on one side of this, literally tons of force and all acting twenty or thirty feet above the deck. Eventually something has to give and the nose wheels shift sideways. Brakes, chocks, nothing will stop the aircraft weathercocking into wind. Very scary, tons of valuable metal spinning round until it hits something.
Primary prevention is parking the aircraft into wind and moving everything well clear. Easier said than done at the airports I have worked at however. Small stands, equipment everywhere, obstructive airport management...
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Why, whenever this sort of unexpected event occurs do we get some mo*on slagging off the airline as if it deliberately tried to delay them or their relatives (and making them pay full fare as well). I thought this was an aviation forum so surely anybody on here ought to understand the cost of having a "spare" aircraft or two hanging around for emergencies. Or know that the chances of finding a couple of replacements at short notice over a bank holiday week-end might not be too high. I despair at times!
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I heard the 330 took the full 73 kt gust right on broadside, and that huge fin just weathercocked it into wind!
Brakes on/off, chocks in/out, outflow valve open/closed
it would have made no difference!!!!!!
Thankfully nobody was killed/injured, good job they were not boarding at the time as the aircraft shot away from the jet-bridge
Workmaster, how many flights do you think would be cancelled if BA lost over 25% of their long-haul fleet at LHR due to a gust of wind???
Do you honestly think Aer Lingus want to cancel those flights and incur all that extra cost? If they could get a transatlantic hire-in this New Year bank holiday weekend then they would!
For somone who claims to have once been in the industry you should know better.
Brakes on/off, chocks in/out, outflow valve open/closed
it would have made no difference!!!!!!Thankfully nobody was killed/injured, good job they were not boarding at the time as the aircraft shot away from the jet-bridge
Workmaster, how many flights do you think would be cancelled if BA lost over 25% of their long-haul fleet at LHR due to a gust of wind???
Do you honestly think Aer Lingus want to cancel those flights and incur all that extra cost? If they could get a transatlantic hire-in this New Year bank holiday weekend then they would!
For somone who claims to have once been in the industry you should know better.
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I believe help is on the way in the form of a World DC-10, also something coming from Singapore (no idea what type) and a 747 from Spain.
The practice of releasing the Park Brake on turnaround is an SOP with most A330 operators. The brakes are carbon disc type so there isn't much risk of them 'welding' but it helps to speed up the cooling process after the landing, and I believe it also reduces damage to various braking components (seals mainly) through prolonged heat soak.
I guess the Aer Lingus crew confirmed chocks were in place (front and rear) before releasing the brake, and I'm pretty sure the guys wouldn't have considered releasing brakes if the wind was already gusting up to 75kts! I don't know exactly what time the incident happened but I believe it was late afternoon or evening. All ALT T/A arrivals are in by midday latest, so the crew may have left this a/c hours before the incident.
I'm not going to throw the blame onto engineering, but surely someone has to be in charge of the a/c when it is ramped on turnaround? What about Flight Ops management? Fleet Captains? Was anyone taking responsibility?
The A330 limitations say max wind for Pax Door Ops is 40kts...or 50kts if pointed into wind, and the Cargo Door limit is 60kts if into wind or leeward. It also recommends Pax Doors to be closed in winds over 60kts. In those kind of conditions there ought to be someone charged with the responsibility to look after the a/c if the cockpit crew are not there.
I would also suggest that it might help (if the a/c cannot be moved to point into wind) to have a tug connected so the nose can't swing around.
I wonder if all the recent redundancies in Aer Lingus have contributed to this in any way? With perhaps only one or two engineers on the ramp to deal with a dozen or more a/c there is every chance they just couldn't take the precautions they'd like to if they had the proper manpower.
Another expensive lesson for airline managements? I wonder whose head will roll! Thank God the cockpit crews weren't on board...I hope they won't be scapegoated anyhow.
The practice of releasing the Park Brake on turnaround is an SOP with most A330 operators. The brakes are carbon disc type so there isn't much risk of them 'welding' but it helps to speed up the cooling process after the landing, and I believe it also reduces damage to various braking components (seals mainly) through prolonged heat soak.
I guess the Aer Lingus crew confirmed chocks were in place (front and rear) before releasing the brake, and I'm pretty sure the guys wouldn't have considered releasing brakes if the wind was already gusting up to 75kts! I don't know exactly what time the incident happened but I believe it was late afternoon or evening. All ALT T/A arrivals are in by midday latest, so the crew may have left this a/c hours before the incident.
I'm not going to throw the blame onto engineering, but surely someone has to be in charge of the a/c when it is ramped on turnaround? What about Flight Ops management? Fleet Captains? Was anyone taking responsibility?
The A330 limitations say max wind for Pax Door Ops is 40kts...or 50kts if pointed into wind, and the Cargo Door limit is 60kts if into wind or leeward. It also recommends Pax Doors to be closed in winds over 60kts. In those kind of conditions there ought to be someone charged with the responsibility to look after the a/c if the cockpit crew are not there.
I would also suggest that it might help (if the a/c cannot be moved to point into wind) to have a tug connected so the nose can't swing around.
I wonder if all the recent redundancies in Aer Lingus have contributed to this in any way? With perhaps only one or two engineers on the ramp to deal with a dozen or more a/c there is every chance they just couldn't take the precautions they'd like to if they had the proper manpower.
Another expensive lesson for airline managements? I wonder whose head will roll! Thank God the cockpit crews weren't on board...I hope they won't be scapegoated anyhow.
Forewarned is Forearmed
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73kts will Weathercock most things if they are parked out of wind, in my experience the only chance you may have is if they are double chocked on the main gears & nose with brakes on.
I have even seen Aircraft Weathercock after the wing has been lifted causing the gear to be lifted out of the chocks, even with brakes on on a wet Apron.
I am not keen on the wooden type of chocks seen in photo's Flames earlier post in fact we refuse to use them where I work, due to weather conditions we experience from time to time.
It looks to me like no one had a chance at preventing this as there was no real warning, of the likley Gusts in the Squally conditions,or the Tornado & no time to set brakes double chock & put ballast on aircraft, tie things down etc.
I have even seen Aircraft Weathercock after the wing has been lifted causing the gear to be lifted out of the chocks, even with brakes on on a wet Apron.
I am not keen on the wooden type of chocks seen in photo's Flames earlier post in fact we refuse to use them where I work, due to weather conditions we experience from time to time.
It looks to me like no one had a chance at preventing this as there was no real warning, of the likley Gusts in the Squally conditions,or the Tornado & no time to set brakes double chock & put ballast on aircraft, tie things down etc.
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Maxalt, connecting the tug and towbar to stop weathercocking whilst meanwhile leaving the very big aircraft side on to 73 knots will result in a damaged towbar, possible damage to the gear, the gear doors and perhaps the nose gear attachment to the fuselage. There is a limit to the side force even the nose gear is designed to sustain.
However it may be feasible to reconnect towbar and tug when the aircraft is brought head to wind to assist in stopping it being blown backwards as a temporary mooring measure. In this way the force is fore and aft and the towbar shear pins offer an overstress protection.
Keeping control of big aircraft on the ground in wild winds is not simple alas.
However it may be feasible to reconnect towbar and tug when the aircraft is brought head to wind to assist in stopping it being blown backwards as a temporary mooring measure. In this way the force is fore and aft and the towbar shear pins offer an overstress protection.
Keeping control of big aircraft on the ground in wild winds is not simple alas.
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Not a good day for EI - I left SNN for LHR at 0740 but apparently there was industrial action soon after due reduction of check in desk numbers - a mate was unable to get on his flight to DUB. Then this.
As for me, I got to LHR and then onwards with BA to YYZ but one of our bags didn't (and still hasn't). Not a good day for us either!
As for me, I got to LHR and then onwards with BA to YYZ but one of our bags didn't (and still hasn't). Not a good day for us either!
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It sounds to me like a microburst type event rather than a tornado - there were no reports that I've heard/read/seen of any funnel sighting. The TV pictures of the damage in Clonee (overturned cars, tiles off 100+ houses) a few miles to the west of the airport were quite alarming. I'm several miles to the south of the airport and can't even remember what the weather was like here that lunchtime so presumably unremarkable.
It has crossed my mind once or twice in the past that a 'proper' tornado could do a severe amount of damage in a busy major airport (I've seen pictures of what one can do to a GA field). Granted the chances of a twister touching down in any one given spot is very low, even in American states that are susceptible, but does the likes of Atlanta, for example have a plan for dealing with the arrival of a tornado with short notice? I guess it would be a case of evacuating all passengers from aircraft on stand to the terminal to ride things out, stopping arrivals and perhaps getting any taxi-ing departures into the air and the hell out of there?
It has crossed my mind once or twice in the past that a 'proper' tornado could do a severe amount of damage in a busy major airport (I've seen pictures of what one can do to a GA field). Granted the chances of a twister touching down in any one given spot is very low, even in American states that are susceptible, but does the likes of Atlanta, for example have a plan for dealing with the arrival of a tornado with short notice? I guess it would be a case of evacuating all passengers from aircraft on stand to the terminal to ride things out, stopping arrivals and perhaps getting any taxi-ing departures into the air and the hell out of there?