Procedures for descent from too high or heavy
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Procedures for descent from too high or heavy
This question is prompted by the several discussions of weather phenomena that could, (I know not all professionals agree this is possible), bring a “bubble” of much warmer air up or down into the flight path of a plane.
I wonder if you could educate a non-pilot about flight procedures when an airplane is found to be too high or too heavy for the atmospheric conditions.
When a pilot determines the stall and mach buffet speeds are too close together what is the procedure for descending to an altitude where the pilot feels there is sufficient distance (speed) between the stall and mach buffet speeds?
What exactly is the procedure for descending to the appropriate altitude if an overspeed condition is only a few knots ahead of cruise speed?
What instruments does the pilot use to safely descent to the appropriate altitude?
When and how does the pilot determine the appropriate lower altitude?
How much does the procedure vary between various planes of the same relative size, vintage, and different control philosophy?
Is it possible to follow the procedure without an accurate airspeed indicator?
Is it possible to follow the procedure without an accurate altimeter and/or VSI?
Is it possible for an updraft, source is irrelevant; to have sufficient energy to quickly carry a heavy transport aircraft upward far enough that the upper/lower speed margins are suddenly insufficient?
Thank you for any information you can provide. I am not a pilot and have no aviation experience. However, I do have a solid mathematics background and understand some aero and hydrodynamics due to 40 years of racing high performance sailboats and sailboards. Any details would be appreciated.
I am not a journalist, just a retired computer geek who spent a lot of time designing real time data acquisition and control systems for dangerous land and sea-based processes.
I wonder if you could educate a non-pilot about flight procedures when an airplane is found to be too high or too heavy for the atmospheric conditions.
When a pilot determines the stall and mach buffet speeds are too close together what is the procedure for descending to an altitude where the pilot feels there is sufficient distance (speed) between the stall and mach buffet speeds?
What exactly is the procedure for descending to the appropriate altitude if an overspeed condition is only a few knots ahead of cruise speed?
What instruments does the pilot use to safely descent to the appropriate altitude?
When and how does the pilot determine the appropriate lower altitude?
How much does the procedure vary between various planes of the same relative size, vintage, and different control philosophy?
Is it possible to follow the procedure without an accurate airspeed indicator?
Is it possible to follow the procedure without an accurate altimeter and/or VSI?
Is it possible for an updraft, source is irrelevant; to have sufficient energy to quickly carry a heavy transport aircraft upward far enough that the upper/lower speed margins are suddenly insufficient?
Thank you for any information you can provide. I am not a pilot and have no aviation experience. However, I do have a solid mathematics background and understand some aero and hydrodynamics due to 40 years of racing high performance sailboats and sailboards. Any details would be appreciated.
I am not a journalist, just a retired computer geek who spent a lot of time designing real time data acquisition and control systems for dangerous land and sea-based processes.
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Questions, questions.....
"an overspeed condition is only a few knots ahead of cruise speed?"
I'm not an airline pilot, but I gather the airline SOP is that the calculated cruise altitude allows something like a 1.2 or 1.3 G boundary boundary from high and low speed buffet. So a "few" knots shouldn't happen, in normal flight. If you have got less than this, they'd need to request descent to a lower altitude, giving a higher margin due to the denser air. Depending on airspace rules, that could be as low as 1000 feet.
Descending, or flying, at the recommended turbulence pentration speed (normally given as a mach at high altitudes) should give you the best margins, until the margins are re achieved.
Use that math background of yours, assume 35,000 feet, and -57 deg C, a hypothetical aircraft suddenly flies into this "bubble of warmer air", and the mach suddenly jumps from .83 to .78
How much did the temperature rise?
I'm not an airline pilot, but I gather the airline SOP is that the calculated cruise altitude allows something like a 1.2 or 1.3 G boundary boundary from high and low speed buffet. So a "few" knots shouldn't happen, in normal flight. If you have got less than this, they'd need to request descent to a lower altitude, giving a higher margin due to the denser air. Depending on airspace rules, that could be as low as 1000 feet.
Descending, or flying, at the recommended turbulence pentration speed (normally given as a mach at high altitudes) should give you the best margins, until the margins are re achieved.
Use that math background of yours, assume 35,000 feet, and -57 deg C, a hypothetical aircraft suddenly flies into this "bubble of warmer air", and the mach suddenly jumps from .83 to .78
How much did the temperature rise?
Last edited by hawk37; 14th Jun 2009 at 11:33.
The bubble of air would be 28.5 degrees warmer. How big are these magikal bubbles?
Didn't I blow past you at Semiahmoo bay a couple months ago 
?
Originally Posted by TacomaSailor
due to 40 years of racing high performance sailboats
?
