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Do those weight and balance calculations

By John Quarterman

 

For most of the mid-fifties crowd, we learned to fly quite some time ago. In fact a lot of us learned to fly in the seventies and early eighties. This is also true for the majority of the recreational pilots in Canada as a whole.

Now it’s a delicate subject to be sure, but the truth is that back then we were quite a bit younger, and slimmer, and judging by the snapshots that many of us like to show off of our younger days flying and travelling over North America, our personal weights have increased steadily over the years since our early flying.

Of course that is not the only trend as people have been eating more and gaining mass and stature and people do weigh more at any given age than they did back a few decades ago.

Transport Canada recognized the trend in personal mass in a response to the TSB recommendations following the crash of Georgian Express Flight 126 on Jan. 17, 2004 and other crashes preceding it, and so back on Jan. 20, 2005, AIM section 3.5 (what was then the AIP) was updated with new Male and Female standard weights, including both Summer and Winter weights.

Many of us fly aircraft designed in the sixties, produced in the seventies and equipped with four seats. It is instructive to realize that these four-place aircraft such as the popular Cherokee 140, Cessna 172 and American AA-5 Traveller, Beechcraft BE-19 Sport actually were built with the concept that two male-female couples or even 4 males could be carried safely with proper fuel load management, and still carry adequate reserves for cross-country flights.

Of course using today’s standard weights, this is no longer feasible.

Even modern versions of these aircraft suffer from this trend. Exacerbating the problem is that many of these aircraft designs have been steadily modernized over the years, adding sound insulation, additional avionics, modern metal instrument panels, autopilots, 26g seats, beefed-up doors and wheel pants, and in some cases, oxygen and a turbocharger. All of these modifications while highly desirable in themselves, have added weight to the aircraft designs so that in combination with higher personal weights, they are really only four-place aircraft in name only.

In some of these aircraft the complication of a different landing weight as compared to the take-off weight has been introduced as the gross weight has been raised to compensate, but the landing weight was not. In other aircraft the gross weight has been raised slightly, but the overall useful load has declined.

So what can we do about this? Well in the first place we should - more than ever – be doing our sums and calculations before we launch. That means doing a full weight and balance using actual weights in accordance with AIM RAC 3.5.1 as part of the pre-flight planning.

It is tempting and convenient to assume that with only two people this is not necessary, but in fact it can easily be shown that in many aircraft, two large adults and a full extended-range-tanks fuel load exceeds both the balance and the weight limits. And failing to do the planning is illegal if it results in flying overweight.

The CARs require that aircraft be operated within the weight and balance limitations specified by the manufacturer. Actual passenger weights should be used, but where these are not available, the following average passenger weights, which include clothing and carry-on baggage, may be used.

Summer

Males 12 yrs up: 200 lbs or 90.7 kg

Females 12 yrs up: 165 lbs or 74.8 kg

Children 2-11 yrs: 75 lbs or 34 kg

Infants less than 2 yrs: 30 lbs or 13.6 kg

Winter

Males 12 yrs up: 206 lbs or 93.4 kg

Females 12 yrs up: 171 lbs or 77.5 kg

Children 2-11 yrs: 75 lbs or 34kg

Infants less than 2 yrs: 30 lbs or 13.6 kg

On the positive side of this issue, times have changed and technology has marched on to provide us with all sorts of new solutions. While we have yet to invent the general-aviation-friendly, human-weight-shrinking machine that most of us would like, we do instead have a ready assortment of flight planning and computer calculation mechanisms to choose from to manage our weight and balance calculations.

COPA has evaluated some modern flight-planning packages while aviating about the country, and all of them offer excellent facilities for turning out accurate weight & balance forms in a snap. And some of these programs are quite inexpensive.

So what’s the bottom line? – Do those weight and balance calculations.