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scottb613

Step Climb ?

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Morn'n All, Would the Tin Mouse typically use a step climb profile to reach cruise altitude ??? I am using Bob's FSBuild profiles - great piece of work by the way - and - I see FSBuild always uses a direct climb to cruise... Now the Mouse doesn't seem to have any issues getting there - so maybe the real world practice would have you using a direct climb to altitude... As far as a normal climb goes - we should pitch to keep the airspeed on the speedbug setting from the PCDS - correct ??? Well - providing we set the PCDS correctly and have the throttles set accordingly... So we don't reference the VSI at all - just pitch to maintain airspeed - same as in a GA plane ??? A final question on cruise altitudes... Any rule of thumb on how high to cruise vs distance to travel ??? OBTW: 100 knot tail winds last night from KMDW (Fly Tampa) to KLGA (ImagineSim) - nice ride in the ol' Mouse at 33K...Regards,Scott


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Morn'n All, Would the Tin Mouse typically use a step climb profile to reach cruise altitude ??? I am using Bob's FSBuild profiles - great piece of work by the way - and - I see FSBuild always uses a direct climb to cruise... Now the Mouse doesn't seem to have any issues getting there - so maybe the real world practice would have you using a direct climb to altitude... As far as a normal climb goes - we should pitch to keep the airspeed on the speedbug setting from the PCDS - correct ??? Well - providing we set the PCDS correctly and have the throttles set accordingly... So we don't reference the VSI at all - just pitch to maintain airspeed - same as in a GA plane ??? A final question on cruise altitudes... Any rule of thumb on how high to cruise vs distance to travel ??? OBTW: 100 knot tail winds last night from KMDW (Fly Tampa) to KLGA (ImagineSim) - nice ride in the ol' Mouse at 33K...Regards,Scott
The answer to your first question is yes, sometimes. In my 2,000 hours captain experience on the real -200 there was never a problem going straight up to FL330. However, if you had any fuel at all in the center tank you wouldn't be able to make FL350 for a while. We used to take off from Montreal for Florida and go up to FL310 initially. At about NYC the center tank would empty and we would be light enough for FL350. But then we usually couldn't get FL350 because of traffic! Those were the days!Second question also yes, follow the PDCS speedbug.Third question: there's no rule of thumb that I can remember. There are charts in the flight manual that enable you to choose a FL that is most efficient for the leg distance.

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Hi Investdude, Thanks for taking the time to respond... It's great that we have some real world mouse driver experience around here... If I recall correctly - the only mouse I've ever been on was with Peoples Express [which we have a very nice repaint in the file library for] flying the hop from Chicago to New York back in the late 80's... I was stationed at the Great Lakes Naval Training Center for a while - so I used them a bunch... Cash registers in the aisle - too funny... Appreciate the help...Regards,Scott


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Small chart from the AFM for -17 engines for cruise WT @ optmium/MAX FL:M.7287,000/ 112,000lbs*: FL370¹100,000/ 120,000lbs*: FL350112,000/ 120,000lbs: FL330120,000/ 120,000lbs: FL310M.7485,500/ 106,000lbs*: FL370¹94,500/ 113,000lbs*: FL350104,000/ 120,000lbs*: FL330113,000/ 120,000lbs: FL310M.7875,000/ 90,000lbs*: FL370¹82,000/ 100,000lbs*: FL35090,000/ 108,000lbs*: FL33099,000/ 117,000lbs*: FL310108,000/ 120,000lbs*: FL290*ISA. deduct 750lbs* for each 5°C above ISA¹ Some -200/adv recieved an improved pressurization system that allows the acft to climb to FL370


Gustavo Rodrigues - Brazil

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this will help you out planing cruise in optmum:M72 FF @ FL310/330- 2600/2700pph/eng+1000ft above optimum: 2% extra burn-1000ft bellow optimum: 1% extra burn@ fl350, you can expect 2400pph.for mach 78, expect a fuel burn of 3200pph/eng.


Gustavo Rodrigues - Brazil

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this will help you out planing cruise in optmum:M72 FF @ FL310/330- 2600/2700pph/eng+1000ft above optimum: 2% extra burn-1000ft bellow optimum: 1% extra burn@ fl350, you can expect 2400pph.for mach 78, expect a fuel burn of 3200pph/eng.
just out of curious, after studying the performance file for Tinmouse in FSBuild, I found that no matter how heavy the plane is, it seems the fuel burn is always less when flying higher. So should I fly higher ignoring the weight?

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just out of curious, after studying the performance file for Tinmouse in FSBuild, I found that no matter how heavy the plane is, it seems the fuel burn is always less when flying higher. So should I fly higher ignoring the weight?
Fuel burn will always be least the higher the FL.But at any given weight there will be a max ceiling.So...NO you cannot ignore the weight. Generally, unless you are on a short hop, you want to climb initially to the max FL for your given weight for max efficiency in fuel burn.In reality other factors such as weather considerations , especially wind speed/direction will also have their part to play in choosing initial cruise FL

Peter Schluter

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Fuel burn will always be least the higher the FL.But at any given weight there will be a max ceiling.So...NO you cannot ignore the weight. Generally, unless you are on a short hop, you want to climb initially to the max FL for your given weight for max efficiency in fuel burn.In reality other factors such as weather considerations , especially wind speed/direction will also have their part to play in choosing initial cruise FL
I've just tried... I can struggle to FL360 with GW of 108k pounds, and even enjoy lower fuel consumption than at FL340. Seems the optimum level is not modelled in TM

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I've just tried... I can struggle to FL360 with GW of 108k pounds, and even enjoy lower fuel consumption than at FL340. Seems the optimum level is not modelled in TM
It is. the biggest deal is the reduced margin for buffet (1.3 turns).Done a sim flight recently (train IFR flying), and flying bellow optimum my expected fuel burn at given altitude was around 3% higher due being heavy and ISA temp above standard.short flights you barelly will notice the difference. Try long flights, even you manage to hold your altitude with a whigher pitch setting, the fuel burn will not be good as espected to sustain a flight at or above your maximum alt.

Gustavo Rodrigues - Brazil

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