On the Dash, we have 3 different weight restrictions that have to be met. First, and usually the limiting factor, is zero fuel weight. This is the maximum weight the airplane can weigh, minus the fuel. Max takeoff weight is next, then max landing weight. Zero fuel weight is generally where we run into problems, but it can also occur on the other 2.

We fly 3 versions of the Dash 8. The 37 seat -100 and -200, then the 50 seat -300. The -200 and -300 series are very capable aircraft. Seldom do we leave anything behind with these 2. The -100 is a different story.

When the -100 was built in the mid '80s, the assumed weight for passengers and bags was much lighter than the assumed weights we are required to use today. Back then, you could fill all 37 seats and the baggage compt. with little trouble. Now, the useful load of a -100 is around 33 to 35 pax, and 35 to 40 bags.

The way we figure it all out when it comes time to push is simple. We use the assumed weights for pax and bags. An adult is assumed to weigh 184, a child (under 12) is 76. A checked bag is 30 lbs, and a carry on (yellow tagged only) 20.

Lets say we've got a -100 on the PHL-ISP flight.

The a/c weighs 23,850 lbs. (The crew, our bags, supplies, and fluids are part of that number). We have 37 people trying to go, with 31 checked bags, and 18 carry on (yellow tagged / going in the back). 4 of the pax are kids under 12.

Aircraft: 23,850
Adult pax: 6072
Children: 304
Checked bgs: 930
Carry on bgs: 360

Add these up for our zero fuel weight, which must be less than 31,400. The above gives us 31,516. Too much to carry. We've got to lose 116 lbs. we can either bump one pax, or 4 checked bags. That will get us below 31,400. Our usual fuel load is around 4000 lbs, so we'll be OK with the max takeoff weight also. The fact that kids are lighter is saving us from bumping more stuff.

With a -200, the ZFW is 32,400, so you can already see that we'd be able to take everything. The trick with that model is the max landing weight is 34,500, so we must burn enough fuel to be below that. Still not a factor since we're going to burn about 1500 lb on the trip.

A -300 is even better. ZFW of 39,500, max TO of 43,000.

Lets say 47 adults, 3 kids, 64 checked, and 28 carry ons.

Airplane: 27,320
Adults: 8684
Kids: 228
Checked: 1920
Carry ons: 560
ZFW= 38,712 (way under)
Fuel: 4000
TOW= 42,712 (away we go, and bring on the jumpseater to boot, he's 190 lbs)

Its simple to do, but the tricky part is for us to make sure we get as much on the airplane as we can. The First Officer usually does this part, and it almost becomes a contest amongst ourselves to see who can pack the most on the airplane.

When we add more fuel for bad weather, our payload goes down. This is also something that must be taken into account. Additionally, the assumed weights go up during the winter months. Also, carry on bags that are carried in the cabin do not count for weight calculations. If we have to pull bags and leave them behind, we will always pull checked bags and not the yellow tags.

I apologize for the long dissertation, but I know we inconvenienced you, and you deserve an explanation in more detail than what the gate agent was able to share.