Weight and Balance question
 

Yesterday I flew from AMS to Lyon. Prior to boarding our cards were changed and we were all dotted around in the rear portion of the plane (only a couple up front, and i don't mean the pilots).

Never seen this before. Is this normal? What is the reason? Is it cargo up front? It was a 737-400

The B737-400 when flying empty needs ballast in the rear hold to achieve balance, about 400kg. So with a light load it must be loaded from the rear. Usually putting all the bags in the back will do it, but perhaps there were not enough.

Aircraft are all different. The B737-200 had no probs at all. The B757 never has a problem. Our B767-300 sometimes have to limit freight in the fwd hold to get CG in limits, and always have to seat the pax further back. MD80 and F100 are a nightmare. Sometimes tail heavy and sometimes nose heavy.

I've another question concerning load and balance:
Most low-cost-airlines have free seating. How is the trim on the loadsheet calculated there?

There are two rules applicable to the 737-800 aircraft in order to conform to
trim requirements.

Rule 1: For a passenger count of 177 or less, Rows 3 and 4 are usually blocked off.

With average loads on the 737-800, trim problems may arise. However, to allow for free seating, balance limits are tighter in this system and, with certain load profiles, load planning is vital to ensure that limits are not exceeded and reloading required as a consequence. Accordingly Loading Rule 2 is often employed to ensure the flight remains within the trim limits.

There are two rules applicable to this aircraft in order to conform to
trim requirements.

Rule 1: For a passenger count of 177 or less, Rows 3 and 4 must be
blocked off at all times. (Rows 3 and 4 comprises 6 seats A-F incl.)

Some airlines’ policy is to block off rows 3 and 4.

Rule 2 allows the aft limits at ZFW and TOW balance units to be subtracted
by .4 units and added to the forward ZFW and TOW balance units for both
Scheduled and Charter flights PROVIDED (a) No passengers seated in the forward 6 rows and aft 4 seat rows, with a maximum of 132 passengers, or (b) 178 or more passengers carried.

This rule can be used in case “a” above as cabin crew will be able to direct
passengers away from restricted seats when the load is low.

It is helpful to think of these rules in terms of passenger capacity, as follows:
a.) Passenger load < 177..... Rows 3 & 4 should be blocked off at all times.
b.) Passenger load > 178.....all cabin seats may be used. Trim may be adjusted
by 0.4 units at either end if required.
c.) Passenger load < 132......Trim may be adjusted by 0.4 units at either end if
required, subject to front 6 and aft 4 seats being blocked off.

When the aircraft is well under it’s capacity, passenger seating is generally limited to the central part of the aircraft as to help insure the aircraft is within its operating C/G limits.

Thanks for the information

Ryanair may do this: Seating is not "really" free within the whole of the aircraft, some rows will be blocked off when pax enter the A/C. Thus choice of seats will be limited to a few rows.

Ye pays yer bit of money and yer makes no choice, yer sits down and shuts up.

This is a common practice amongs all -800 operators with open seating in addition to Ryraniar.

Those airlines who have assigned seating automatically restrict front and aft rows to reflect less than full flights and to insure that the aircraft is properly loaded within the CG limits. So you still pays yer bit of money and yer makes no choice, yer sits down and shuts up.

Thanks for the informations