Route plan question

[pilot4ever101]

for a cross country trip from CNF4-CYGD with one pilot male standard weight(210), one male passenger standard weight(206lb) and 2 female(172lb passengers standard weight,with 70 lbs of luggage total in a Cesna 172s (1700.86lbs)

i am trying to do a flight plan for this but the aircraft will be over the maximum gross weight limit, i have asked my instructor and he has told if you will be overweight for the trip than figure out a solution. I cant seem to find a way to reduce weight, of course fuel will be a factor but i would still be overweight. please any help would be appreciated.

[bring me the horizon]

Use actual weights and make a refueling stop along route.

[pilot4ever101]

I have to use standard weights according to AIM for male and female passengers for this question

[PilotDAR]

I have to use standard weights according to AIM for male and female passengers for this question

Well Hmmm... I struggle to imagine a real world flight planning situation where you would knowingly use incorrect weights for the planned load. I can't speak to the situation about "the question" (and I have seen some exam questions which were simply wrong), but the situation is pretty clear: a 172 will carry x many pounds, a part of which needs to be adequate fuel. You can carry adequate fuel for several shorter legs, or disappoint a passenger or two, or select a plane with a greater payload. Anything else is trying to defy physics, regulation of both. The AIM standard weights are there to remind you that in general, people weigh more than the FAA thought they did when they worded the certification design requirement.

When I read the conditions of your flight, four heavy adults and 70 pounds of baggage in a 172, it already sounded that anything beyond a local flight would not work out well. The fact that a plane was manufactured with four seats, does not assure that it will carry four adults very far. For your amusement, the actual design requirement reads:

(2) Assuming a weight of 170 pounds for each occupant of each seat for normal category airplanes and 190 pounds (unless otherwise placarded) for utility and acrobatic category airplanes, not less than the weight with--
(i) Each seat occupied, oil at full tank capacity, and at least enough fuel for one-half hour of operation at rated maximum continuous power; or
(ii) The required minimum crew, and fuel and oil to full tank capacity

If the plane cannot demonstrate (i) & (ii) of the certification requirement, it cannot be certified. Notice that there is no mention of baggage in that requirement, despite the fact that the manufacturers try to trick pilots, by providing a compartment, with a placarded maximum to put in the baggage!

And, from accident report A04H0001 (Cessna Caravan Pelee Island, 2004)

3.2 Findings as to Risk
............

The standard passenger weights available in the Aeronautical Information Publication at the time of the accident did not reflect the increased average weight of passengers and carry-on baggage resulting from changes in societal-wide lifestyles and in travelling trends.

The use of standard passenger weights presents greater risks for aircraft under 12 500 pounds than for larger aircraft due to the smaller sample size (nine passengers or less) and the greater percentage of overall aircraft weight represented by the passengers. The use of standard passenger weights could result in an overweight condition that adversely affects the safety of flight.

Actually weighing what you intend to carry, and computing a W&B based upon actual weights, is always the best answer. If the best answer tells you that what you'd like to do won't work, it's hard to make a correct test answer saying it will...

For one of my trips, in a plane I own, I computed weights to the pound and fuel burn to the liter for every leg in advance. At certain points along the trip, I had to take on a full drum of fuel, or abandon it, so I wanted to assure that I did not takeoff overweight, nor arrive carrying so much fuel, that I could not take on the fuel I'd paid [lots] for. With good planning, it worked out well...

[photofly]

for a cross country trip from CNF4-CYGD with one pilot male standard weight(210), one male passenger standard weight(206lb) and 2 female(172lb passengers standard weight,with 70 lbs of luggage total in a Cesna 172s (1700.86lbs)

i am trying to do a flight plan for this but the aircraft will be over the maximum gross weight limit, i have asked my instructor and he has told if you will be overweight for the trip than figure out a solution. I cant seem to find a way to reduce weight, of course fuel will be a factor but i would still be overweight. please any help would be appreciated.

Four passengers and baggage in a 172? Yeah... no.

The solution is to leave one person and the baggage behind, and/or make two trips to ferry everyone and everything. The instructor is trying to get you to realize for yourself that you can't fill the seats and take baggage in a small plane.

[7ECA]

Sounds vaguely like the sort of flight planning question one receives as a part of a flight test. photofly and PilotDAR have it right, there's only so much one can do with a "mighty" buck-72. Flying four people, plus their crap and fuel; ain't one of them.

Figure out what you can carry, if everything (or part load, etc.), and then how much fuel - what's your range/endurance. Then, decide if you can make the trip in one go, or if you need an intermediate fuel stop. Or, as mentioned fly part of the load then double back and finish the trip off.

[pilot4ever101]

Sorry I don't know if I was clear I meant 3 passengers and me the pilot, so in total 4 people on the flight, yess it does seem like a trick question thinking about it now, a double trip does seem like the most reasonable option. And ya I saw some people suggesting exact weight of individuals but it's a scenario based question , was told by instructor to use the standard weights given to adult male and female according to AIM. I do appreciate all your help guys thanks.

[AuxBatOn]

I have to use standard weights according to AIM for male and female passengers for this question

Not sure which AIM you are using but...

3.5.7 Computation of Passenger and Baggage Weights
To compute passenger weight, the following methods are used: actual weights, standard weights and segmented weights.
NOTE:
For aircraft with a passenger seating capacity of less than five, the use of actual weights provides the greatest accuracy in calculating the weight and balance of the aircraft, therefore the use of standard or segmented passenger weights is not recommended.

[pilot4ever101]

Its scenario based my instructor just told me you will have 2 female passengers and one male passenger. All together there luggage will be 70 pounds. For the weights of the individuals use the weights mentioned for standard a male and female during summer time on AIM.
AIM section 3.1 - Standard Male 12 years and older weight summer - 206 lb
Standard Female 12 years and older summer weight - 172 lb

[PilotDAR]

my instructor just told me you will have 2 female passengers and one male passenger. All together there luggage will be 70 pounds.

"Their" luggage.....

Here's a clue for you... Answer the question as though you are the pilot in command of the flight, not your instructor. In the scenario with you as PIC, your instructor has no responsibility for what/who you carry - you are fully responsible. Therefore, you only have passengers if you agree to carry them, based upon what you are able to do. You, piloting a 172, are not able to carry all of these people, and their bags. So for the planned flight, not all of these people will be your passengers.

Looking at this scenario from my considerable experience loading up Cessnas, this is much less a math question, and much more a decision making question. The right answer is to decide that you're going to have to tell some of these people that they will not be your passengers for this flight - maybe the next one....

Viewed looking at the situation from the aftermath side, would you rather tell people why you can't carry them as planned? Or tell the TSB why you tried, when the math didn't work for the flight? This is the teaching point here....

Thinking back, I don't recall ever flying four adults in a standard 172, I've done it a few times in a 182....

[ayseven]

PilotDAR has your answer. It is a decision making exercise. YOU are the PIC, and YOU decide whether you stop somewhere along the way for fuel, or ditch bags/passengers. The clue is in the instructor wanting you to use standard weights. YOU can decide you want NO passengers, and YOU can decide to go with minimum fuel and a stop. Training people to be competent and safe pilots is not about stick and rudder alone. In fact, that is usually not the most important part.

[455tt]

What bothers me about the scenario given is that you are asked to do something contrary to the current TC AIM: for 3 passenger seats, you are supposed to use the actual, estimated or volunteered passenger weights and not the passenger standard weights. AuxBatOn has kindly provided the reference, and PilotDAR has kindly provided the safety reasons.

When your instructor tells you that you must use the passenger standard weights and the current TC AIM tells you not to, this in and of itself raises important pilot decision making issues.

If your instructor, during a flight, tells you that you must exit the aircraft and climb out onto the wing, would you do so?

[youhavecontrol]

Most instructors that give you an AIM standard weight do it for a scenario they want you to plan... not a real flight. They mostly do it that way so you have to look it up if you don't know it, and it forces you to flip through the AIM a bit.

The scenario's solution is as simple as this: Crunch the weight and balance numbers in a way that allows you to calculate the maximum fuel you can carry without going over the limits. Then, determine if that amount of fuel can get you to your destination, plus reserve, etc. If it's not enough, you either ditch someone/something or make a fuel stop. If it can't be done, it can't be done. Full stop, exercise complete.

[455tt]

Most instructors that give you an AIM standard weight do it for a scenario they want you to plan... not a real flight. They mostly do it that way so you have to look it up if you don't know it, and it forces you to flip through the AIM a bit.

Scenario training is fine as long as you follow the rules to complete the scenario.

Training a 172 student pilot they can use standard passenger weights is incorrect and can have safety issues, since using standard passenger weights can cause gross under-calculation of the aircraft actual loaded weight (and balance).

Instructors sending their students off to the TC AIM to find and apply TC standard passenger weights to complete sample loading calculations in the manner suggested creates the improper impression with student pilots that using TC standard passenger weights can be applied in all cases when this is not the current accepted procedure.

Whether the flight will be "real" is not the issue; the issue is to follow the proper recommended procedure, for reasons of safety.

[youhavecontrol]

Instructors sending their students off to the TC AIM to find and apply TC standard passenger weights to complete sample loading calculations in the manner suggested creates the improper impression with student pilots that using TC standard passenger weights can be applied in all cases when this is not the current accepted procedure.

The question of whether people actually did that was asked in a TC audit of the school I worked at. It was something they asked all of us and thankfully they didn't find a single person that thought that way. I felt we did a decent job of explaining how it worked. Perhaps that was not the case in other flight schools, which might have been why they were asking that question.

[PilotDAR]

Instructors sending their students off to the TC AIM to find and apply TC standard passenger weights to complete sample loading calculations in the manner suggested creates the improper impression with student pilots that using TC standard passenger weights can be applied in all cases when this is not the current accepted procedure.

I agree.

Standard weights should only be used if you have no other way of determining your total weight of people. If you're flying anything with ten seats or less, the one by one ask, and estimation if they told you the truth will be more accurate than "standard weights". Yeah, I know that people take a load of people without knowing their weights, but it's wrong, if knowing their weights is practical. I stopped flying for an operator, because they refused to enable me to weigh the passengers, and insisted on flying them by body count rather than weight.

The lesson should be to make the determination using the best method possible, not to default to a less precise method first...

[7ECA]

It's a scenario, not an actual flight. I get the annoyance that standard weights are being "abused" in a situation for which they are not "applicable" based on the writeup in the AIM; but it's a simple scenario that gets used quite often in flight training. Take an aircraft, from Y to Z with all the seats full and X amount of baggage - figure it out...

It almost invariably ends in a discussion on decision making; well we can fly all the passengers and their bags - but we won't have enough fuel to legally make the trip in one leg. Okay, so what can you do instead? Well, we could break the trip up into two (or more, as required) legs taking all the pax/bags and refuel at airport V...

I've heard this scenario on multiple flight tests, PPL, CPL, and Multi., and always "using standard weights". Obviously, using actual weights is the most accurate system possible when it comes to weight and balance, but in a theoretical "scenario" is it the worst possible option? Or, does it possibly give students an insight into the vagaries of standard weights?

[photofly]

Shoot the instructor, I say. They're clearly incompetent.

[kevind]

Maybe part of the exercise was to have him read the AIM and find out that he should be using actual weights for a plane with less than 5 passenger seats

[NotDirty!]

Just do two trips! More flying for you!!

Now is there a further complication, such as you cannot leave the two females together, or the male with the wrong female? Then it becomes like classic brain teaser with the rowboat and the animals that will eat each other if left together...