Flying overweight
 

Reading through the latest June pulications of AAIB it's suprising how many people are flying, and crashing, overweight. Both the PA28R at Oban and the R44 in Cumbria.

Do pilot's routinely fly overweight ? Or is it just the ones that inevitably crash.

I am always meticulous over the W&B. In a Pa28 with 2325lb MTOW is usually overweight by a few lbs with 2x 230lb men and full fuel. Yet I've witnessed people take off in that configuration.

Does everybody fly a couple of lbs over ? Or is it just the ones that crash ?

I suspect it's more common with smaller aircraft where the margins are slimmer with the usual configuration of 2 chaps and full fuel. I would imagine that almost every training flight in C152s where I trained takes off overweight.

I think you need to separate the aircraft which crash because they are over weight and the aircraft which are found to be overweight after an accident which had nothing to do with being overweight. In the case of the Oban accident the aircraft was overweight but it is very unlikely it contributed to the accident.

I think a lack of planning tends to kill people. Lack of planning increases the likelihood of being overweight and out of balance, but it also leads to flying in poor weather, not doing a good DI, etc etc. Added to this is that some pilots have not done a W & B since qualifying. I use Navbox for my w & b and have a print out of the graph in the aircraft for refrence.

As to how frequently people fly outside W & B, it is hard to say with any accuracy. You can rarely tell by just looking as the aircraft parks up.

Rod1

MH152
You've hit the nail on the head. The attitude of many flying instructors is "It'll be alright there's a big safety margin." The student thinks this is normal.
I learned to fly in a C152 and occasionally an aerobat with even less available payload. The instructor & I were nearly 30 stone between us. With full tanks we were well overweight but the little 152s flew perfectly.
I have since discovered not all aircraft are so forgiving.
DO

Although equally illegal, I would suggest there is a big difference between accidentally flying overweight, and not being aware of it, and with flying overweight, while knowing how much overweight you are, the position of the C of G, and the effect that this will have on aircraft performance, stability and handling

If you fly outside the certificated W&B limits, you are almost certainly operating illegally, have just compromised your insurance and appointed yourself to the role of test pilot. :eek:

Yes, the C152 and others will fly over-gross, but you are just more hostage to fortune than usual if you accept it. Out of CofG is particularly hazardous IMHO. Put the two together and ... :=

Caveat aviator.

I recently took the decision to take off marginally (about 50lbs) overweight in a 172 on the basis that the 2.5 hour flight would leave me well within the W&B when landing at the planned time (luckily I didn't have an emergency or unplanned early landing so that panned out OK).

This left me wondering if insurance wise, had push come to shove, would the insurance be void for the entire flight or just the period of the flight when the aircraft was overweight.

It also left me wondering just how forgiving the limits are - I had a couple of female passengers who were quite uncomfortable about giving their weight & a chap who didn't know his, so short of installing scales in the club the accuracy of self report W&B info must be subject to scepticism.

Regards all, enq.

An interesting suggestion. Without having taken it through a test flight schedule in that configuration how would you know "the effect that this will have on aircraft performance"? The W&B diagrams weren't drawn up by someone who thought "Right, weight x, C of G at y, that's going to cause it to do z." They were arrived at as a result of flight testing.

How much overweight is TOO much overweight? How far outside the w/b graph is TOO far? This is what bothers me most about loading outside the limits. Our performance graphs don't provide this information because if they did the graphs and limits would be different. Ofcourse there's a certain safety margin which is just that, a safety margin. If you don't know the exact weight and it happens to be 100 lbs more than you think, is it going to kill you? Probably not, but calculating with 100 lbs overweight and then actually having 200 may put you in a dire situation.

Stick to the books.
As for training overweight. My god, what are we teaching people...
Perhaps 3 inches of ice on the wings is ok too.
What about 3 quarts of oil?
How high above the 1500 foot ceiling can you go before it becomes dangerous?
How about that TFR? Is 10 miles into it OK?
A 300 m grass runway, will it be enough for takeoff on a 35degC day at 5000 feet in a C150 at 100 lbs over gross?

If we don't use ALL the limits as limits all the time, how do you know which ones are OK to break, and when?

While training in a warrior we did w&b for steep turns etc and found out with 2 of us were both 17 stone could only carry 10 gallons of fuel and stay in the correct c0g for unusal manovering, needless to say we took tabs on 1 side as running out of fuel would have been embarrassing. Had a share in a 140 after that and was allways damm carefull on w&b as 140`s are easy to overload re Sandown last year.

Like everything else, bit of common sense always helps.
Taking off 10lbs overweight from a long tarmac runway is probably not a mortal sin.
The same, on a short grass strip on a hot day, could be critical.

Just because the speed limit says 50mph, you are not gonna drive at 50 in torrential rain and heavy traffic...

The same road, no traffic, good weather, might feel extremely slow at 55..

Ivor

New rule from EASA. To maintain the rating no FI should weigh more than 70 kilos. That should improve pay and conditions for those who are left!
DO

If you take off weighing above the MTOW and have an incident that involves an insurance claim, the insurance assessor will calculate your total AUW at take-off and if an ounce (gram) over your MTOW for that flight, they will not pay out, and you may also find the CAA chasing you for flying illegally.

Families of any fatalities may also sue you/your estate for the death of their loved one and your gross negligence! Is it worth it?

It is very easy to create an excel chart of your aircraft w&b. It takes 10 minutes to try some 'usual' situations and explore what happens to the cofg.

I've done that for the last 3 aircraft I have flown regularly and it has given me a good feel for whether or not a detailed w&b is needed. In the vast majority of cases it has not been necessary.

On the majority of aircraft getting outside the cofg limits takes a loading that looks unusual. Overloading is really more of a performance issue - unless you are deliberately going to do things which stress the aircraft - like aeros.

One of my aircraft had a detailed set of performance curves at varying weights which would allow you to comfortably extrapolate performance beyond mauw (well to a point probably). And if you stayed inside those (granted unproven) limits you could probably fly forever without incident.

And that is the crux of the issue many small aircraft are routinely overloaded and nothing happens apart from the performance deteriorating somewhat. However try two flights back to back in the same light aircraft - extreme forward cofg and extreme rear cofg at similar-ish weights. I've done that in my present aircraft as one of those 'interesting things to do'. And it certainly was - you would barely believe it was the same aircraft. A real eye opener.

A widely held misconception on various flying forae.

The insurers would have to prove that the overweight condition was causative to the incident to avoid payment. Of course, there may be many incidents where it could be argued W&B was contributory, but equally, there will be many incidents where it has no relevance)

I am not condoning overweight flying though :=

This is not acceptable, ever.

As a flight instructor, I have no tolerance for an operation out of safe limits, or operating outside the aircraft limitations. That includes the weight and balance. A student must complete a weight and balance calculation before every flight, and it is NEVER acceptable to operate, or allow a student to operate overweight or with the center of gravity outside limits.

Particularly in the instructing arena, it's a sacred responsibility on the part of the instructor to provide an example. A student should never be given the impression, not even implied,that operation that is unsafe or illegal is in any way acceptable. It's not.

If a student wants to fly in a Cessna 152, then the numbers must work out...otherwise the student will be moving to a 172. Even if the numbers work out but performance is compromised to the point of safety (very likely at many of the airfields where I've instructed...which have 10,000' density altitude or more in the summer), then we're moving to the bigger airplane.

Overweight operation isn't acceptable in any other kind of flying operation, either. I often find that weight must be reduced for performance reasons, rather than the actual weight limits, before the weight limits are ever reached.

Check the weights.
 

Have you actually ever had the weights confirmed?
I've come across three aircraft that were way off what the numbers were supposed to be when we actually used the scales. One of them had an actual cog way aft of datum. When I started to tear things apart I found a jackstand base, and two large wrenches that weighed 20 pound apiece, nicely wrapped in bubble wrap tied up in the tail. All in all that plane was 290 pounds empty over the 1675 that it was supposed to be. How long had that extra weight been there? How many flights had been conducted over gross and aft of allowable cog?

I carry two weight and balance charts from Navbox in my flight bag.

One is me amd Mrs Johnm with full fuel and a bit of luggage and kit, the other is me and Mrs Johnm our two fat friends and tabs fuel and a bit of luggage and kit.

Both fit the profile of my Archer 2 and allow us to get across the channel happily :ok:

Using data from the POH, I made my own little A6 weight and balance forms for the two a/c I fly. With experience I found the weight calculation vital under some circumstances (eg full tanks, 2/3 or more heavy males) and the CG less so. For every flight other than solo or 2 on board with half fuel, I scribble down the weights onto my form and add them up to check I'm within the T/O and landing limits for my a/c. If the config is slightly different (couple of cases of wine to bring back from France) then I do a full CG calculation too.

If anything happened, even through no fault of one's own, this is the first thing the AAIB would be doing. If you're too lazy to know where you are in relation to the MTOW of your plane, what other shortcuts are you taking?

If there aren't any there go and buy some.

(In my club, last time I looked, they were hidden under a bookshelf, but you knew where to look if you needed them. Eg, if an instructor said "ok, do the W&B for this check flight then" you'd tell him to get on the scales.)

I am always within W&B....I do sometimes lose about 15 Kg though ;)

Actually, joking aside, what determines max weight? I ask because I know I have flown over weight - or rather been flown in my aeroplane over weight. When I bought the share I did a test flight, all 4 of us went on the flight. Not knowing the aeroplane at the time, the owner said it'd be ok, and it was, we were off the ground in about 200m, 4 up (Rallye 160 HP). After buying my share and calculating W&B I found that 2 large adults and full fuel would put us at about MAUW, so we must have been over weight by 100 Kg or so. Despite being overweight the CofG was withing spec (which I'd say is more important).

However there was no noticable performance loss and I was amazed at how we had performed.......so who and what determines max weight? The Seneca in the USA has a higher MAUW than a Seneca in Europe so is it always dangerous I wonder, to fly over weight?

Well yes, but. For aircraft handling but there are times when performance matters... a lot. High density altitude operations come to mind. Short runways. Obstacle clearance. All those nice charts in the manual for T.O distance over a 50 ft. obstacle suppose that the aircraft will deliver specified rate of climb. Reduce that rate of climb an you can find yourself in dangerous territory. I had a sphincter-tightening experience in my previous Cherokee 140 once. There were three of us; I'm fairly heavy at 200 lb, but my two passengers were 140 and 125 lb respectively (both pilots). We were just a bit under MGTOW; field was 2500 ft, soft (sand and gravel), and had obstacles. And it was at about 2000' above sea level. And it was a hot day, about 30C. We cleared the treetops by a very uncomfortable margin.

It was one of those "I learned about flying" experiences that you'd read about in Flying magazine. I knew, roughly that at MGTOW 2500 ft was OK for the Cherokee, but I hadn't thought that only 2000 ft above sea level there would be such a performance drop. When I got home I plugged the numbers into the charts (I know: should have done that first. I now know better). Well, I was surprised to learn... the available field length/obstacle clearance distance was right on the limits for density altitude, and the soft field correction.

And that wasn't even above the maximum.

I now own a Beech Sundowner 180, and it has considerably more payload. but also, a greater fuel capacity (with two markings on the tabs for partial fuel load computation) so it requires more careful planning. At sea level, standard conditions, max all-up weight, the distance to clear a 50' obstacle is 1860 ft. I frequently fly to a 1600 ft paved strip in the Gulf of St. Lawrence. Beautiful spot. Fortunately no immediate obstacles, and usually a good stiff headwind, but it is short enough to concentrate the mind, and to make me ensure that I know I am within the performance envelope.

I also once owned a C150. Great little aircraft but with one big flaw: the ability to land in a distance way too short for takeoff! With two chaps on board, climb rate was nothing to brag about.

So, yes, to an extent CofG can be more dangerous, especially exceeding the rear limit. Assuming you can safely get it into the air, as you will have considerably less performance on take-off if you're overweight.

There is no excuse for flying overweight. What the aircraft might be certificated for in another land is really quite irrelevant. Is your airplane certificated for that weight? No? Then you're not legal, and have no business exceeding the weight.

Do you know of a surety that another certifying agency has done so with or without structural reinforcements?

Weight isn't just about performance. It's very important, and often more restrictive than the max gross weight restrictions, but there are other concerns. Weight in the fuselage only contributes to a greater wing bending moment, putting more stress on the spars and skins in monocoque or semimonocoque wing. In a turn this stress is fruther compounded, and in turbulence even more so. The load is even more magnified at the upper reaches of the speed limits for the airframe. What may seem minor sitting on the ramp or a straightforward takeoff may be another matter at the design dive limit. An airplane out of the CG envelope may fly fine, but an inadvertant spin may go flat or become unrecoverable.

Regardless of the implications, if the aircraft isn't certificated to fly at that weight, and you're not legal to do so, then you should not, may not, and must not.

Declaring their exact weight might be socially unacceptable for some people, but you can always remind them that they are under no obligation to get into the aircraft at all.

I find a good rule of thumb to be, accept whatever weight the person declares (provided you believe that to be reasonable - ie, a fattyboombah declaring she's 60kg is not reasonable), but add ten kilograms to their declared weight.
If your totals taking into account this buffer zone go outside, or close to your W&B limits, then get out the scales and insist on actual weights.

Interesting thread,

I wonder how many GFT's were conducted in 152's with a CAAFU examiner on board. :}

Are you suggesting an examiner must reach a certain weight before being perverted, sorry promoted to CAAFU?
DO

Mariner9,

Which insurance company do you work for?

The small print on my policy states that if I fly outside the limitations of the permit (exceeding MTOW) then the cover is withdrawn!

Insurance does cover negligence.

The insurer cannot (generally) prove the pilot did it intentionally, which leaves just negligence and this is covered.

The stuff where insurance will take a walk is where the paperwork is duff e.g.

- duff/expired CofA
- invalid pilot license/rating (though they will pay out if a plain PPL departs VFR into OVC002 and kills himself immediately, because flying at 199ft is legal if you meet the 500ft distance rule)
- N-reg not owned by a US citizen and thus CofA is void (etc)

I don't condone over-MTOW flight of course. But technically it does work - you need to understand what happens. For small excesses, say a few % over, nothing happens, but you need more runway. Each 1% on weight means at least 2% more runway.

C of G and W & B is an interesting topic which I suspect is much overlooked, post PPL; when I initially approached my flying club to do a ppl, I did the 1st 2 lessons in a Trauma-hawk before someone pointed out that, with fuel to tabs, the CFI and I wouldn't get out of the airfield on an ISA day....so how was I ever going to sit my GFT?

I then bought a PA28 140 - which I loved to bits but, with full fuel and myself and another rugby player type in the front, it was noticeably forward of the C of G. I only did that once. How the Sandowne incident pilot thought he was going to leave the field on a hot day with 4 adults and full fuel, I'll never understand.

I now own an Arrow III and with 36 USG of fuel, you can load 4 normal adults, which removes a bit of the guesswork.

A PA28 235, by contrast, requires almost no thought to loading; With fuel to tabs, if you can physically fit it in the aircraft, it'll get off the ground.

The a/c which I think is hugely disappointing in this respect is the PA46 (in almost any guise) as you struggle to get 4 adults, bags and a decent fuel load, legally. What were piper thinking of?

Since the PA46 was designed for the American "a 20,000m hard runway in every town" :) market, I don't suppose Piper thought the liability was significant. Another 10 seconds with 350-500HP and you will be airborne.

The USA gets significantly more utility out of a plane which cannot do more than a few hundred nm with 4 people, than Europe with its relative scarcity of runways.

Anyway, this is one of many good things about the TB20. In 6 years, I have had to watch W&B only once, which was quite a long trip with 4 adults (me and three real fatties) when I had to depart with just 4hrs' fuel for a 2hr trip. I was not happy because the destination was likely to be fogged in (widespread) and in the end I cancelled and the subsequent mayhem (not everybody cancelled) borne out my decision. 1 W&B issue and zero crosswind-limit issues in 6 years is not bad going!!

There is no physical difference in the aircraft. European Senecas are invariably certified at 1999 Kg to avoid Euronav charges (> 2000 Kg).

The usual MAUW for a Seneca is 4570 lbs (2072 Kg). I assume that the operators have done their sums regarding the "loss" of 73 Kgs useful load verses Euronav charges and decided in favour of the former!

You could operate a european Seneca at the factory MAUW - There is nothing stopping you other than the paperwork - but you would then be liable for the charges

None, but have been engaged by most of the leading Underwriters as a consultant surveyor. In the Marine insurance field primarily (and dealing with considerably higher claims) but the principles are the same.

IO's comments above re insurance were (to use the modern vernacular which I usually deplore ;)) spot on :D

It's sometimes possible to work backwards...."you are ok for this flight as long as you're under 17 stone."

Sometimes the answer is obvious, (I know, don't ass....u...me.)

Fat nacker brothers can cause concern.:)

In't there a video on youtube of an overweight cessna plunging earthwards?


http://youtube.com/watch?v=yaimogfse9c

Sounds like if you've flown in the US at all, you've never been away from the east coast.

I'm confused. Mariner9 said:
But IO540 said:
and Mariner9 says:
Are you saying that if someone flies with an expired C of A, that fact would have to be causative in the loss in order for the insurers to avoid payment? Is that different from flying in violation of the limitations of the C of A?

Finally, is there a difference between the cases where the insured is dealing as a consumer and the case where the insured is a business? (My impression was that in the latter case at least, a breach of the terms would be regarded as a breach of contract and would void the indemnity. Or does that breach have to be material?)

I have never seen an example presented of an insurer denying coverage in an accident (particularly for third party liability vs. hull insurance or injury to the pilot vs passengers) for a breach of regulation (expired CofA, flying to France on an NPPL, flying overweight, etc.). This issue of 'if you .... your insurance will be invalid and not payout' comes up regularly, but to date I have seen no referenceable example. One would expect people to sue in these circumstances and there to be some public domain information on the allegations and at least the general terms of settlement.

On the otherhand, there are probably a good number of examples of insurers not paying if the insurance has expired, the bill has not been paid, they have been materially lied to on the application, the pilot is engaged in a clear criminal activity, etc.

In past times, I used to trust what the experienced pilots told me about weight and balance, and particularly so, if it was their plane I was flying! I've learned my lesson, though it took a few! One C182 owner told me: "take it real careful, she's heavy today" after he had loaded it. I flew it out of a 1600 foot gravel runway. When I unloaded it, the weight had been 800 pounds overgross! I wish I could say that was the last time I did that... I stopped flying jumpers in a C185, because the jump club insisted on "one more jumper", which was more than one more jumper over gross. During a genuine flight test to investigate the weight and balance of another 185, I was told after the flight that an error had been made, and I had been 4" behind the aft limit, at gross weight. No wonder it was so hard to recover from the spins I was required to do!

So then I started to learn! For another flight test in a 185 float plane, I had it loaded with bagged gravel, all tied down in the back, to ballast me up to gross at the aft limit (spun much better within limits!). I land, and at the dock, who meets me? The authorities! Ramp check! Ha, I had the W&B form, and it was perfect!

I have approved special purpose overweight operations, but you sure have to be careful. That means the testing has been done, and the operating limitations spelled out and followed. If you have to aboart a takeoff, do the brakes have enough capacity to stop you? If you have to land right back, can the gear take to added load? Can the twin till make it out on one engine? What do you have to do if you hit a gust? Etc. There are many things to think about...

We learn that accidents rarely happen from just one cause, its the combination that gets you. W&B is a big one in the combination. It may not get you all on its own right away, but add in the engine failure, flight control failure, icing, gusty cross wind, severe turbulance, and you've really set yourself up for trouble. Then, if you're lucky, you're alive enough to try to explain why you tried that in the first place! Sometimes overgross has to happen (ferry fuel, for example). Such operations can be specifically tested and approved, there will be other limitations to keep things safe.

Otherwise, if you're going to fly overweight, you're taking about the same chances as exceeding Vne, or the manuevering limits. Sounds like you're not using the right plane of the job in the first place - there's always a bigger one somewhere!

We've all done stupid things, let's help each other learn and don't do it anymore...

The problem arrises in training aircraft because most of the aircraft in question were designed in the 50's and 60's when the mass of the average American was about 120-140lb's, now the mass of the average American (and Brit) is heading towards the 180-200lbs mark, meaning that we cannot take an aircraft full of fuel and passengers like they did when these aircraft were first designed.

My CPL instructor said for commercial reasons you mat have to fly slightly overweight but as long as you are forward rather than backward of the datum. He did say however it was entirely up to the commander what decision ws made.

If the commander makes the decision to fly slightly overweight, he or she has descied to either misrepresent the true configuation of the aircraft on a weight and balalnce document, or to produce a true representation of the configuation, which would later be the evindence that the authorities would use to find fault, and the insurance company would use to deny a claim.

Such a decision is the same as deciding to fly with a known defect in the aircraft. You are deciding on behalf of the crew, the passengers, and aircraft owner, and the insurance company. They are all entitled to have their opinions considered. You might be willing to say in advance to each party that you are going to deliberately fly with a nav light U/S on a day only flight, but I bet you would think twice before you told each that you were going to fly the aircraft overweight!

If you need to carry members of our heavier society, either carry fewer of them, or choose a bigger plane. Also consider that nearly all aircraft design is predicated on 170 pounds per seat. That is not only for weight and balance planning, but the seat and floor strucure, and seatbelt attachements. We all know that there is reserve strength built into aircraft, but when I see a really large person in a seat wich I know was designed for a 170 pound person, I have concerns. When I see three or four large people in an airliner row, I get even more concerned.

A Cessna Caravan crash in Canada a few years back had as its root cause, the decision the pilot made to carry a person in each seat, and then embark into icing conditions. It might have worked, other than each of the persons was reported as being heavier than the standard 170 pounds, some apparently, by quite a lot. The plane was quite overweight, and the pilot decided to fly it. He de not make that decision again.

A decision to fly within the limitations is the only decision you are entitled to make, unless you are on a design flight test.

I am sure there are many flights made overweight and as such illegal. Just because people 'do it all the time' does not make it right.

An interesting choice for the Commander to be able to over ride the design authority. I would be questioning what else my CPL Instructor is misleading me on. Also if you ever get a job flying commercially please let us know who with so we can seek alternative carriers!!