Weight & Balance with multiple stops

Question

When you have multiple stops for a single flight, without refuelling, how do you do deal with the weight and balance ?

For every single leg, or just from departure to arrival ?

Answer 1

(In the U.S.) According to 14 CFR 91.9(a) which states in pertinent part:

Except as provided in paragraph (d) of this section, no person may operate a civil aircraft without complying with the operating limitations specified in the approved Airplane or Rotorcraft Flight Manual, markings, and placards, or as otherwise prescribed by the certificating authority of the country of registry. (emphasis is mine)

And, 14 CFR 91.103, which states:

Each pilot in command shall, before beginning a flight, become familiar with all available information concerning that flight. This information must include -

(a) For a flight under IFR or a flight not in the vicinity of an airport, weather reports and forecasts, fuel requirements, alternatives available if the planned flight cannot be completed, and any known traffic delays of which the pilot in command has been advised by ATC;

(b) For any flight, runway lengths at airports of intended use, and the following takeoff and landing distance information:

(1) For civil aircraft for which an approved Airplane or Rotorcraft Flight Manual containing takeoff and landing distance data is required, the takeoff and landing distance data contained therein; and

(2) For civil aircraft other than those specified in paragraph (b)(1) of this section, other reliable information appropriate to the aircraft, relating to aircraft performance under expected values of airport elevation and runway slope, aircraft gross weight, and wind and temperature. (emphasis is mine)

These regulations, in my opinion, obligate the pilot-in-command to ensure that the aircraft weight and balance and operating performance are within the required limitations prior to each flight.

However, the regulations do not state that you must make a written computation of the weight and balance calculation prior to each flight. Consulting the POH weight and balance section, and performance tables, will show you whether or not your takeoff and next leg will remain within the (w&b) center-of-gravity envelope and in compliance with the necessary takeoff performance requirements.

Again, the obligation for the pilot-in-command is to ensure that the aircraft is always operated within the regulatory required and safety mandated limitations.

Answer 2

It's pretty simple on that type of aircraft if you're not adding or removing load at each stop. On the chart you simply calculate your CG without fuel (zero fuel weight), and with your max fuel load of the day. Draw a line between the two and if the whole line is in the envelope you know that each flight that day will be within limits. Carry that with you in case you get a ramp check so you can show you've considered the weight and balance for that flight.

Answer 3

From a private flying perspective there's no regulation stating you absolutely must do a weight and balance calculation before a flight, you have to ensure you are operating within the airplane's limitations.

I fly 172s and PA-28s mostly, usually just myself with just a flight bag, and I don't do a weight and balance calculation before every flight because I've done them for each airplane I fly already, and I know it will be within the envelope as nothing has changed. If I change those parameters, i.e. take more people or carry bags/cargo in the back I will do weight and balance. When I do the calculations I'll look at variable fuel loads so I will know how it will change as I burn fuel and ensure I'll be within limits for the duration of the flight, or be within limits for the return flight. So I won't do a weight and balance for the return leg unless something changes, for instance take on a passenger.

Performance calculations are not to be ignored, especially if you are operating close to weight limits, out of a short field, or at a high density altitude. You don't need to do the balance for that, just calculate the weight.

Answer 4

Depends. The question is one of takeoff performance mostly. I would do a W&B on the initial departure leg only, if my only weight changes on each leg are from fuel burn, and the subsequent legs are from airports with ample takeoff distance margin.

However, if an airport on my route is marginal from a takeoff distance perspective, my All Up Weight when taking off from that airport becomes critical and I would do a W&B adjustment to account for the reduced All Up Weight in determining if can get out of the strip in the first place. But I would be doing that estimation before I departed on the first leg anyway, and probably revisit it when at the airport in question to make sure my assumptions still applied.

Otherwise, if you just hopping around from 4000 ft airport to 4000 ft airport, there's really no need. In fact as a general practice I only do detailed walkarounds and engine runups on the first flight of the day, with more of a cursory once-over on subsequent legs to make sure nothing happened to it while it was parked.