Q400 performance info?
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Join Date: Jul 2006
Location: Scandic
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Q400 performance info?
Gentlemen!
When I drove around in the B737, I could use the Boeing FPPM to find info on aircraft performance, and CFM would invite pilots to their courses on engine handling. On the Q400, Bombardier has, apparently, decided that customers must do their own flight testing, and that operating data should be a well kept secret. Likewise, the engine manufacturer refuses to provide information on, say, what is appr. zero-thrust torque during descend, what can be gained by using the assumed temperature method (effect on engine wear, fuel and maintenance savings etc.) - i.e. all of the things that are important to the operator!
Beats me...
I am primarily interested in graphs; drag polar, power- and drag curves etc. - anything I can use to show that "the step" does not exist, and that the last few per cent in torque/Nh (cruise pwr) will mostly increase fuel flow - not TAS...
Is flight test data available from any source, or is it considered an industrial/commercial secret? It sounds kinda odd that important information is withheld from customers
When I drove around in the B737, I could use the Boeing FPPM to find info on aircraft performance, and CFM would invite pilots to their courses on engine handling. On the Q400, Bombardier has, apparently, decided that customers must do their own flight testing, and that operating data should be a well kept secret. Likewise, the engine manufacturer refuses to provide information on, say, what is appr. zero-thrust torque during descend, what can be gained by using the assumed temperature method (effect on engine wear, fuel and maintenance savings etc.) - i.e. all of the things that are important to the operator!
Beats me... I am primarily interested in graphs; drag polar, power- and drag curves etc. - anything I can use to show that "the step" does not exist, and that the last few per cent in torque/Nh (cruise pwr) will mostly increase fuel flow - not TAS...
Is flight test data available from any source, or is it considered an industrial/commercial secret? It sounds kinda odd that important information is withheld from customers
There must be data available. At Tyrolean Airways, the flight planning programme is able (and has been for a rather long time) to calculate fuel requirements vs. TAS and enroute time based on at least 4 different power settings. Also, at least empirical data must be there with regards to the use of reduced takeoff power and its effect on engine lifetime.
The "raw" data beyond the graphs available in the OM-B is not made available to crews, only via the flight planning systems. Maybe contacting VO flight operations would be an option?
Empirically, though, I do share Your point of view with regards to reduced power in cruise. Using intermediate or long range cruise power will reduce the IAS by around 20-30kts (TAS effect is obviously FL and temperature dependent) but reduce fuel flow by more than 20%. Of course, headwind will reduce the savings to a point when reducing power may even result in higher total consumption.
The "raw" data beyond the graphs available in the OM-B is not made available to crews, only via the flight planning systems. Maybe contacting VO flight operations would be an option?
Empirically, though, I do share Your point of view with regards to reduced power in cruise. Using intermediate or long range cruise power will reduce the IAS by around 20-30kts (TAS effect is obviously FL and temperature dependent) but reduce fuel flow by more than 20%. Of course, headwind will reduce the savings to a point when reducing power may even result in higher total consumption.
