BAe146 Icing Limitation
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BAe146 Icing Limitation
Quick question for the 146 drivers out there. We all know the 26000ft limit for flight in known or forecast icing conditions but is that FL260 or 26000ft? Reason being we regularly fly at FL260 in icing conditions but not above.However on days with large differences between QNH and standard setting actual aircraft altitude could be a lot closer to 27000ft and hey presto we've exceeded airframe limitations.....time for rollback!!! Maybe I've made it about as clear as mud but I think you catch my drift! Any feedback appreciated especially from anyone at Avro?
[This message has been edited by Deep Stall (edited 15 February 2001).]
[This message has been edited by Deep Stall (edited 15 February 2001).]
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I think you may interested in reading the following report....it documents how all 4 engines on a 146 rollbacked in flight and bacame a very expensive glider with passengers onboard.
"The investigation determined that during high altitude cruise, the aircraft entered an area of moist air significantly warmer than the surrounding air. This resulted in a need to select engine and airframe anti-ice which in turn placed high bleed air demand on the engines. Under these conditions the fuel control units were unable to schedule sufficient fuel to the engines, thereby causing them to lose power, a phenomenon known as ‘roll-back’."
Summary : http://www.basi.gov.au/acci/jjp.htm
Report : http://www.basi.gov.au/pdf/vh-jjp.pdf
"The investigation determined that during high altitude cruise, the aircraft entered an area of moist air significantly warmer than the surrounding air. This resulted in a need to select engine and airframe anti-ice which in turn placed high bleed air demand on the engines. Under these conditions the fuel control units were unable to schedule sufficient fuel to the engines, thereby causing them to lose power, a phenomenon known as ‘roll-back’."
Summary : http://www.basi.gov.au/acci/jjp.htm
Report : http://www.basi.gov.au/pdf/vh-jjp.pdf
I think that F260 would meet the requirement.
As the problem is associated with the density of the air, then to stretch the point you would really have to work out the density altitude each time.
Our company imposed a furthur limitation of F250 though.
As the problem is associated with the density of the air, then to stretch the point you would really have to work out the density altitude each time.
Our company imposed a furthur limitation of F250 though.
