Timeline for Why do airliners on autopilot climb during cruise?
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 30, 2021 at 21:31 | comment | added | Konrad | Now its obvious… thank you! | |
| Aug 30, 2021 at 17:33 | comment | added | Peter Kämpf | @Konrad You can either reduce speed or density. All you need to keep the lift coefficient constant while mass is declining is to reduce dynamic pressure. Climbing reduces density as required. | |
| Aug 30, 2021 at 9:42 | comment | added | Konrad | I don't get it - as an aeroplane loses mass, the speed (or rather dynamic pressure) for an optimum angle of attack decreases so it has to slow down (fly at lower IAS) to maintain it. So how it is possible for him to maintain speed while climbing? TAS increase compensates a necessary drop in IAS? | |
| Apr 13, 2017 at 12:59 | history | edited | CommunityBot |
replaced http://aviation.stackexchange.com/ with https://aviation.stackexchange.com/
|
|
| Jun 30, 2015 at 16:55 | vote | accept | BillDOe | ||
| Jun 30, 2015 at 16:45 | comment | added | Peter Kämpf | @KeithS: Almost - the thrust available from the engines goes down with density, so fuel flow is only dialed back in climb, when they run at maximum power. Note that the rate of climb will also decrease accordingly. | |
| Jun 30, 2015 at 16:38 | comment | added | KeithS | They also need less fuel overall to provide thrust in thinner air, and in fact the fuel flow rate has to be dialed back as the aircraft climbs or the turbines will stall from the rich mixture. So to a point, the higher the altitude, the better the fuel economy, until the air is too thin for the engine's thrust to maintain the desired forward airspeed. | |
| Jun 30, 2015 at 6:06 | history | answered | Peter Kämpf | CC BY-SA 3.0 |