Bae 146 icing
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Bae 146 icing
A little bit of knowledge is dangerous I suppose so therefor I am dangerous.
I have a cursory idea about the process of certifying an aircraft for flight in known icing conditions. The BAe 146 has that many restrictions and performance penalties when in icing conditions it almost seems to me that they should have made vast improvements to the anti icing systems in the beginning and certaintly in the meantime. What exact criteria were used to assess the suitability of this airframe in icing conditions during the initial flight tests and why have BAe not been more aggressive in rectifying the many limitations placed on the 146 in icing conditions since certification?
[This message has been edited by sprucegoose (edited 02 February 2000).]
I have a cursory idea about the process of certifying an aircraft for flight in known icing conditions. The BAe 146 has that many restrictions and performance penalties when in icing conditions it almost seems to me that they should have made vast improvements to the anti icing systems in the beginning and certaintly in the meantime. What exact criteria were used to assess the suitability of this airframe in icing conditions during the initial flight tests and why have BAe not been more aggressive in rectifying the many limitations placed on the 146 in icing conditions since certification?
[This message has been edited by sprucegoose (edited 02 February 2000).]
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Spruce,
Apart from the 1936 standard airvalves, there is only one problem with the 146: the engines cannot supply enough air to drive the airframe anti-ice and the engine itself is susceptible to internal icing problems. The solution is the LF507F: no icing restrictions.
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Stay Alive,
[email protected]
Apart from the 1936 standard airvalves, there is only one problem with the 146: the engines cannot supply enough air to drive the airframe anti-ice and the engine itself is susceptible to internal icing problems. The solution is the LF507F: no icing restrictions.
------------------
Stay Alive,
[email protected]
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Ya Mon,
Thanks 4dogs. I think that there is really never been a significant problem with the 507H either but it gets lumped in with the 502 series of engines. Why this extreme short fall in performance was allowed or overlooked at certification has me baffled. Christ the dam thing was built in the snow!!
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"No kitty, those are my Cheezy Poofs.
NO KITTY, MY CHEEZY POOFS!!"
Thanks 4dogs. I think that there is really never been a significant problem with the 507H either but it gets lumped in with the 502 series of engines. Why this extreme short fall in performance was allowed or overlooked at certification has me baffled. Christ the dam thing was built in the snow!!
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"No kitty, those are my Cheezy Poofs.
NO KITTY, MY CHEEZY POOFS!!"
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Yes the BAe146 was built in the snow. Where I fly I am more likely to see ISA + 25 than ISA. But with low freezing level, lower density altitudes mean more air flow reducing the chance of the roll back. Originally temps of -40 degrees C no icing was thought to exist. Now all temps below 0 degrees C Icing are thought to form. Part of the reduced risk for roll back is better air sharing between # 1&2, and # 3&4. My Co now has better equipement to achieve this. Also new fans give us 5 degrees better temp margins. The # 4&5 bearings have been combined to reduce vibration. Not sure this has worked as it should.
As for better engines, my understanding is that BAe do not gaureentee it will solve the problem. The new attachment point on the airframe are very expensive. Not that I understand why the great expense, this is a major factor why the engines are unlikely to be changed.
All acft have limitation. I just try not to fight these ones.
As for better engines, my understanding is that BAe do not gaureentee it will solve the problem. The new attachment point on the airframe are very expensive. Not that I understand why the great expense, this is a major factor why the engines are unlikely to be changed.
All acft have limitation. I just try not to fight these ones.
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Alistair McDicken and Alan Bezer of BAe gave an excellent presentation on roll-back in the Bae 146 to the SETP European Symposium in Manchester, in May 1998. If you know an SETP member who has access to the symposium Proceedings, suggest you borrow same for some useful backgound info on the subject.
