Passenger load restrictions winter

[davidjohnson6]

Recently I flew from Fagernes airport near Oslo to London on a 737-800 - about a 2 hour flight. The runway is at least 2,000 m and the temperature was about -12 deg C, so the air should have been very dense and the wind didn't seem particularly strong. Deicing by the ground staff seemed well organised, it wasn't snowing and it looked like someone had done a good job of clearning the snow off the runway

There were under 140 pax on a 737 with 189 seats and there was a very clear message about "sit in your allocated seats" (presumably for weight and balance) and explicit mention from flight deck crew about the route routinely having significant passenger load restrictions. Conversely landing at Gatwick nobody gave a damn.

Now the question:
Why would such a flight from Fagernes airport in mid winter be so sensitive to weight/balance and passenger load ?

[PAXboy]

Depending on the carrier: What was in the hold?

[DaveReidUK]

There were under 140 pax on a 737 with 189 seats and there was a very clear message about "sit in your allocated seats" (presumably for weight and balance) and explicit mention from flight deck crew about the route routinely having significant passenger load restrictions. Conversely landing at Gatwick nobody gave a damn.

Now the question:
Why would such a flight from Fagernes airport in mid winter be so sensitive to weight/balance and passenger load ?

Did the crew specifically say, or imply, that the restrictions didn't exist in summer ?

[Hotel Tango]

I'm not familiar with the place but it could be to do with an engine out terrain clearance issue when departing inland rather than out over the sea.

[DaveReidUK]

Yes, terrain was my first thought, hence my question about whether a load restriction (not necessarily as extreme) also existed in the summer.

[davidjohnson6]

Fagernes as an airport is only really used by commercial passenger aircraft in the ski season for people wanting a week on the slopes. If there's no snow on the ground, no passenger airlines fly there. The only flights at the moment are passengers charters - I doubt they are carrying anything besides suitcases and skis, so the hold is probably not particularly overloaded. Looking at a map, it seems Fagernes airport is built on top of a plateau - it doesn't look anything like Chambery - I'm open minded but terrain doesn't seem that daunting.

Anyone familiar with Fagernes airport able to offer their pearls of wisdom ?

[2hotwot]

We flew in as pax to Fagernes on the 8th Jan. Wind on the ground light and variable - vis was good. Pilot diverted to Oslo after two missed approaches.

It was quite bumpy during the decent and before go around. I suspected wind shear.

I notice there is a curved approach on that runway presumably for obstacle clearance?

Does anyone know what the problem on that occasion was?

[Piltdown Man]

Weight and balance and performance are two different subjects. We don't know for sure that the aircraft was performance limited. But what was clear is that you were flying with less than a full load. The problem is that many aircraft, like the 737, are easier to trim when full; they are designed to flown full. So whenever you are not, it is important that people sit where they are meant to be in order for the aircraft to be in trim for takeoff. Being out of trim is very dangerous, probably even more dangerous than being overweight. But there is also another twist to this. Shrewd operarators like Ryanair have standard loading plans that allow rapid loading (of pax and hold baggage) with the minimum of calculation and paperwork. Even though these plans have 'fat' bolted into them it is important that people sit where they are meant to be for these plans to work. Once in the air, assuming trim drag is not an issue, you can normally go wherever you wish. The aircraft will be dynamically re-trimmed as you fly.

PM

[WHBM]

It's a Ryanair feature. In the days of open seating Ryanair used to close off seats at front and rear, dependent on the booked load (but none closed if a full load), effectively balanced either side of the W&B midpoint, so that they could ensure without further thought that they were within their limits. Everyone was sat scrunched in the centre with empty rows at the outer ends. Tough, you're on Ryanair. It was a crude centre-imposed approach in Ryanair style to ensure being within limits without anyone in the crew having anything to think about.

I believe they had actually had a W&B issue with a half load and all the pax choosing to sit at one end, which some regulator (possibly the IAA) had picked up. A normal operator would have the flight crew check the distribution when all seated and possibly get the cabin crew to redistribute if it looked wrong. FR take a different approach.

Nowadays there are allocated seats, but still a need to avoid any asymmetric distribution, so the various "excuses" handle this.