| Topic: | Re:Re:Re:Re:Re:Re:Re:Re:Re:Re:Re:Cranes, towers and helicopters | |
| Posted by: | Raymond Havelock | |
| Date/Time: | 18/01/13 12:18:00 |
| Hello. I'm new to this site but a very interesting set of points have been made. As a former Helicopter co-pilot in the services I have to concur that there are some points that do come into play. I will try to keep this simple. If I go technical it gets rather complicated and tends to make watching paint dry attractive! Currently, and for most of aviation history in the UK, the Thames and the key A and M roads are used for navigation points and datum points for low level movements. Particularly for Helicopters. There are also different regulations for single and twin engined airframes. All the major tall obstructions are clear of airspace ie Crystal Palace etc. Special regulations and arrangements are made for movements within these zones. Only permitted in perfect weather conditions. In recent years, hi rise buildings are going up in proliferation along the river and in particular, near the flight corridors. This area is under one of them. Cranes and buildings have red marker lights but they are lost amongst red lights of road vehicles so close to these structures. Due to the Heathrow approach, Helicopters have to fly to strict regulation. With higher buildings appearing in the cross zones this reduces the scope should a problem occur, be it a technical or weather issue. And if a situation arises a pilot error may not be correctable. One thing almost always dismissed by planners and architects are airflow vortices that can be created by tall structures. This increases near water. A classic example of this is the BsI building in Gunnersbury which is always windy when there is no wind. This also affects the airflow above and around the tops of tall structures. Architectural engineers know all about this as their job is to ensure the buildings integrity. However they have no concern about the affect it has on the surrounding ground or airspace. This is why so many 'Brutalist' estates are often so windblown and why Chicago is the Windy city, a mix of wind from the lake, internal rivers and tall structures. Another poster is right, a helicopter cannot go up as there are descending fixed wing aircraft above. This is not an issue in places like Manhattan as there are no fixed wing aircraft permitted. London is now almost unique in this respect It is strange that in almost every major city, high elevation buildings are prohibited in approach corridors or along low level navigation crossovers. This is a new phenomenon for London but one that has been raised in aviation circles and is evident that economics, planners, developers and politicians do not want to acknowledge. Ironic given that so many developers use helicopters. If such an accident can occur with a pilot who was almost legendary in his experience and ability, then it can happen again. I think we will learn that he was trying to crash on the wasteland just 25m from the impact and avoid the several points in the vicinity which would have been really catastrophic. However, I do feel that some of the points raised are not knee jerk but question why pragmatic practices are now being brushed away without due consideration. The area between Chiswick/Mortlake - Kew and Brentford are highly vulnerable and have several hazards that are of concern to pilots who will always use diligence but weather and technical issues are always going to be with us. It is right that these issues do not get buried by those with vested interests as it is tempting fate. |