Alright this is just a question because aircraft like the a380 have 4 engines and they take time to start so what I had to ask is In the user guide it mentions to not exceed 40% N1 but I think otherwise it will be too slow for taxing so I wanted to ask that should i or should I not exceed 40%N1 during taxi because I want to be realistic.
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They say that because they don’t want you to use too much power while taxiing (eg: taxing through grass, not taxiing on lines, etc). What I do is that as long as I am taxiing around 20-25 knots (10< around turns) then I am fine.
But yes, using too much thrust isn’t the best thing to do, so stay around 20-25 on straightaways, and 10 around turns (5 around sharp turns).
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(if i am wrong with this feel free to correct me)
I asked you about the power or thrust I need to use.
Use your best judgement… if you need a little bit more, then use a little bit more.
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Does it damage the engine or some sort of thing
This is pretty much the limit used IRL. Yes I means the larger aircraft take a bit of time to get moving but that’s the nature of them.
It’s just too slow especially when people behind you are waiting and you are going very slow with the a380 and many other aircraft.
Uh, no? The thrust levels used on takeoff are much higher…
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Is it like against the rules or something IRL
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I believe there is a N1 taxi limit rule IRL (but I don’t know what it is off the top of my head - I believe its between 40-50%).
N1?? 40-50??
For simplicity’s sake, let’s say 40% N1 is the limit. Some airliners like the newly reworked E-175 start speeding up on idle thrust already so a lower power setting can be used. Most airliners can go idle thrust on straight taxiways to save fuel. 40% N1 will not damage the engine and don’t worry about people waiting for you to speed up, take your time, why the rush? Rushing leads to violations if you aren’t careful, you can accidentally taxi through someone and get reported, you can get a violation for taxiing too fast or you could go off the taxiway. About taxi speeds, a general rule of thumb for most airliners is up to 30kts on straight taxiways and 10kts in 90 degree corners or sharper
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There’s really two distinctions here, breakaway thrust and actual taxi speed. From what i’ve read, in the 737 manual for example, the maximum breakaway thrust is 45% N1, but these things can change from aircraft to aircraft. And once you breakaway and start rolling you can slow it down a bit too. Your taxing speed is going to vary somewhat, but within ramp areas you are typically expected to go around a faster walking speed, and once you exit the ramp area you can kick up the speed a bit in the straights. You might find specific speed restrictions at airports, but the 30 knots is a pretty reasonable rule, although maintaining up to 25 on straight taxiways and 10-15 maximum in turns is reasonable.
In the US context, the FAR/AIM doesn’t really list specific speeds in the regulations that I can find, above would be reasonable guidance.
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FWIW. The majority of Operators (Spirit and American) have a 40% N1 max thrust setting for ground operations, 30 kts max taxi speed straight line and 10 kts max for 90* turns. In saying that sometimes if your heavy 40% takes a bit of time to really get you moving. All this is for is safety of jet blast.
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As for being realistic, the following quote is from: Engine Thrust Hazards in the Airport Environment (boeing.com)
(There’s interesting examples of FOD, foreign object damage, to both ground equipment and aircraft)
"An idling airplane can produce a compact version of a Category 3 hurricane, introducing an engine wake approaching 120 mi/h (104 kn or 192 km/h) with temperatures of 100°F (38°C). This wake velocity can increase two or three times as the throttles are advanced and the airplane begins to taxi.
At the extreme end of the intensity scale is a Category 5 hurricane, with winds greater than 155 mi/h (135 kn or 249 km/h). Residential and industrial structures would experience roof failure, with lower strength structures experiencing complete collapse. Mobile homes, utility buildings, and utilities would be extensively damaged or destroyed, as would trees, shrubs, and landscaping. At rated thrust levels, a jet engine wake can easily exceed the sustained winds associated with a Category 5 hurricane."
I was going from DXB-JFK. I started pushback and in the a380 Emirates I started engine number 1, after that I set my flaps and started engine number 2. If you know around 2 days ago there was very heavy traffic is Dubai so many people behind me were waiting and I begin to taxi with 39%N1 engine. I mean it went like 2 knots in 15seconds which is pretty slow because at the same time I was turning, so I decided to exceed the power to 50%N1 but I thought it was wrong.
That’s not the problem, while turn it just takes a long time to turn because the speed decreases due to friction in ground I think.
Sorry @adit but I that’s too complicated for me as I do not do so many calculations before takeoff so I didn’t understand what you are saying, it would be nice if you could give a summary on it.
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