Flights Achieving High Altitudes Mid-Flight

Hi IFC, hope everyone is having a wonderful holiday season!

With the holidays here, I decided to fly the A350, and one route I chose was AY132 from WSSS-EFHK on a Finnair A350. I love to be realistic with my routes, so I chose an FPL from Simbrief and began the flight. Something surprising I noticed was that AY132, for the last couple of days at least, has been climbing up to FL430 almost mid-flight, something I’ve never heard of so early on in an aircraft’s flight. Here is the latest complete FPL for AY132:

I tried to attempt this climb, knowing fully what may happen if the aircraft is overweight, and sure enough, I climbed to FL430 and my aircraft stalled.

My question is this: if I were to replicate this FPL as shown above in IF, what would a realistic pax load be for the aircraft upon takeoff at WSSS? I would love to replicate this, but I don’t want the aircraft to stall either. Any recommendations welcomed!

NOTE: I am aware that aircraft step climb to such altitudes. In fact, I stepped climbed up in this very flight as well from FL360. I just don’t understand how the aircraft managed to climb that high so early on in the flight. That is what I am trying to find out.

Thanks, safe flying, and happy holidays!!🎄


In the real world, in order to reach such altitudes, pilots need to step climb. Step climb is a series of altitudes to which an aircraft climbs and remains for a certain amount time before continuing their ascent to descent.

Yes I am aware of that, I stepped up to FL430 from FL360, as per the route shown in FR24. I just don’t know how the aircraft achieved such an altitude this early on in its flight?

Yeah I find that pretty interesting.

How many hours into the flight did the aircraft reach this altitude you’re referring to?

Remember that these pilots are carrying the exact amount of fuel. There is probably been a low demand for this flight therefor the aircraft has been alot lighter.

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I’m assuming they go so high purely because of the load. No offense to anyone from Finland, but the country isn’t that large in terms of population, so I believe there wouldn’t be as many passengers flying onboard. Obviously, there are times when it could be full, but it’s currently winter and Finland also gets quite cold, so my assumption is the load is quite low.

With less passengers, they have less cargo, and should need less fuel. Aircraft like the 787 and A350 also cruise quite high compared to planes like the 777.

If you’re doing a flight with a 50% full A350, you should be able to achieve those altitudes as well :)


Total flight time is about 12 hours, the aircraft reached FL430 at about 4 hours into it (~8 hours left to go)

4 hours honestly seems totally normal to me… The actual ascent doesn’t take more than 1-3 hours in general, especially with a lighter load as pointed out by the others.

It’s about a 12-hour flight, so in 4 hours, it probably shouldn’t be any higher than 36,000 or 38,000 when almost full. It probably would’ve climbed over a slower period, and near-full aircraft don’t always climb to 43,000 anyways with the exception of some like the San Francisco to Singapore flight does sometimes, because they’ve burned 12-13 hours of fuel.

All of it really just depends on the load and aircraft, and winds sometimes. An aircraft like the 777 probably wouldn’t be going much higher than 34,000 or 36,000 initially.

Looking at its flights in the early summer months, it began cruise at 34,000 sometimes, and sometimes just made its way up to 40,000 for the last hour or so.

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I wouldn’t be surprised if these flights only had 200-240 pax on them (60-80% loads) and minimal cargo, which leave you with a very light aircraft. If you wanted to replicate this in IF I’d try 220 pax, 1,000kg cargo, and 12 hours of fuel.

Looking back at 90+ days of history, the Flight in question here, Finnair 132, most of the time, fly according to step climb as; FL340 - (FL360) - FL380 - FL400.

The flight from Helsinki to Singapore is mainly a business route, and therefore mostly carries business travellers. Now businesses for Finnair in general for their Asian market has sunk fairly low Q3 of 2019. Much due to the uncertainty of how the situation is in Hong Kong, and the trade-war between US-China, Buuut!

The flight to Singapore from Helsinki, on the other hand, is striving. Holiday Season and New Years are here, many will want to spend time outside their home country, or those who do business in Helsinki will want to go home for New Years. A flight fully packed to Singapore is more likely than full flight going home to Helsinki. As I mentioned earlier, catering towards business, people are looking for alternative places to do so, besides Hong Kong as the situation is complicated at the moment.

December 24th and 25th, are the only two in particular that spikes during this period, and going back 365 days, the same thing occurred, and even in early-mid June of 2019. This flight, mainly catering towards business travellers but also a decent amount of tourists due to the relatively low price for families to travel with when it comes to Finnair.

All-in-all, the demand low to Helsinki isn’t due to the low population Finland has, it’s not like Singapore has more citizens, it is about demand based on calendar circumstances. Certain days of the year, there will be a higher demand in one way or the other, or maybe both.

If you take a look at their flights to Beijing, Osaka, Nagoya and tourist destinations such as Krabi and LA, they fare much better all year round, because they are more focused towards both groups of flyers, tourists and business. Japan for an instance is a market which Finnair has had strong relations to both culturally and commercially for a long time, which strives to be one for their most profitable routes to date. As for Singapore, there other flight options to and from HEL which may suit business in both directions all year round such as QR and EK.


I agree with what you are saying but your assumption about Finnair is not entirely correct. They market HEL as a European gateway to Asia and they focus on many Asian markets for that reason. So while there may not be that many Finnish passengers traveling on that flight, I’m willing to bet that there is a significant chunk of connecting pax from other European countries.

I’m sure there are, but right now, it’s winter and there’s likely a “lull” in passengers traveling to Europe because of the weather. Obviously, there are still a lot, but based on how high it cruised, the flight is definitely not very full.

Just a quick update, today’s flight as well, Dec 26, has climbed up to FL430 just minutes ago near Lahore, Pakistan (OPLA). This would, again, put the flight at FL430 a mere 4.5 hours into its 12 hour journey to EFHK:

Looks like this may be a recurring thing, at least for now…

It’s quite understandable that there aren’t many flying to Finland over Christmas time and New Years. There isn’t much to do as a tourist in Finland, which the other counter-part Scandinavian countries offer. As for the flight, it serves mainly as a business flight, a gateway from Finland to Singapore and vice-versa, I don’t see any particular reason for a large amount of travellers flying from Singapore to Helsinki during New Years. The Business aspect of the flight should peek again during January and going into Q2 of 2020, while lok at the flight going the opposite direction and there seems to be a bigger demand for flights to Singapore from Helsinki, mainly due to tourism, as many have day offs from work and winter break from school.

Business is always at a all time high, but the traveling part between the cities, don’t peek at all times of year, and you have to take into consideration how other neighboring Asian countries are doing economically, to get a bugger picture of why there may be more demand one way or the other, at certain times of the year for this particular flight.

Most of the pax Finnair carries from Asia connect further into Europe. If it was for O&D, im not sure this flight would exist. Im trying to say that you cant really estimate the loads for this flight, simply based on the Finland-Singapore market

Neither am I purely basing my words on this factor alone. Many variables come into play. We may never know the real load numbers for this flight but based of assumptions, facts that we do know and other numbers, we do have a minor picture if why this flight is able to climb to 43000ft fairly early into the flight but in the end, we don’t know the exact numbers for this flight in terms of weight, and other conditions that matter as well.

The market is a key holder, but only one aspect of this flight. That’s all I can say.

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Let’s not forget it’s Christmas time. Loads on the flights right now aren’t s big (especially when it comes to business travellers), which can easily be seen looking at Lufthansa very much reduced schedule over the past days. Normal service will resume and higher loads will lead to lower cruising altitudes. (Winds might be a factor at times too).

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I dont know about other places, but in my airport Christmas and New year period is the busiest of the winter, and flights are generally packed for obvious reasons

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