Would you or do you takeoff above MTOM?

@huv, yours are thoughtful comments. By training I try to think of things from first principles and understand sensitivities and gains. The world is never black and white in actuality.

Re runway and taxiway center lines, I was surprised when a friend and mentor suggested I simply put the line between my feet, even on a side-by-side plane. At first I thought that might reflect his experience in tandem seating F4s and as an instructor in T-28s, but he later explained that he’d suggested the same to 1st officers when he was an L1011 captain, because the pilot would hold constant position better that way. I still prefer trying to keep the spinner on the line, even though I think he’s correct. Maybe that is one definition of anal for aviation.

Silvaire wrote:

I still prefer trying to keep the spinner on the line

I tried that but the centre line lights projected too much and made for a VERY bumpy ride!

huv wrote:

Most 2-seat aircraft are frequently flown overweight, simply because the pilot regard them as aircraft for 2 “standard” persons. Most are 1 adult + 1 child -aircraft. And so those pilots simply adjust to the resulting performance. Done cautiously, that will work. Similarly most 4-seat aircraft are flown overweight when they are used as 4-seat aircraft. However, that limit seems to be more widely known, so that PA-28 and C172 pilots flying with 4 people tend to get remarks about it and so is unlikely to remain ignorant.

True, in many cases but not in all. I do like old fashioned machines like the PA28-180 which is one of the few “true” 4 seaters. The one in my database is pretty representative and allows 460 kgs useful load, which means with fuels to the filler edge around 360 kgs for pax and bags or 323 with full fuel. The Grumman Tiger will lift out around 340 kg when filled to the filler neck and 300 full. The C182 is a true 4 seater. They exist, but they rarely are the newest, nor the fastest kids on the apron.

So I think Cobalt’s definition of planning with -2 seats is in most cases accurate, well, for 4 and more seats of course.

huv wrote:

The problem with ignorance, additionally, is that if you haven’t thought about weight, you probably don’t know much about your CoG, either. And being out of CoG range is something you cannot usually extrapolate your way out of.

CG is definitly more deadly than overweight yes. Running out of control authority to counter the effects of bad loading is a horrible thing to happen. And that is why pilots should not only check the CG at take off but also at landing. In some planes, as fuel burns off, the CG moves quite a bit.

The aircraft I fly has an upgraded engine (from Thielert 1.7 to Centurion 2.0s).
Performance has increased significantly, but the POH has not been updated so I’m legally limited to the 1150kg MTOW of the 1.7 Thielert.

I prefer to depart slightly over MTOW rather than flying tight on fuel. I use my own limit but always make sure that I’m within limits on paper

I prefer to depart slightly over MTOW rather than flying tight on fuel. I use my own limit but always make sure that I’m within limits on paper

Is MTOW just to do with the amount of engine power?

lenthamen wrote:

I’m legally limited to the 1150kg MTOW of the 1.7 Thielert

Engine power is not the reason for the 1150 kg limit.

11. The maximum take off mass of 1200kg (2646 Ibs) is only approved if mandatory
design change MÄM 40-227 and a main landing gear strut by MÄM 40-123
maximum landing mass of 1150 kg (2535 Ibs) or the tall MLG strut in accordance
to OÄM 40-283 is installed.

Reference here.

Edit: Engine power is probably not the ONLY reason for the 1150 kg limit.

huv wrote:

Most 2-seat aircraft are frequently flown overweight

Where is this data published? A LSA has a 1320 pound gross max. Flying heavier is a pure violation of the type-certification. If you survive the crash you won’t be flying again if caught doing it.

Why the impulse to break the rules? Is it a game of chicken some feel a need to play?

Mooney_Driver wrote:

in many cases but not in all. I do like old fashioned machines like the PA28-180 which is one of the few “true” 4 seaters.

Exactly, and that is part of the reason I am still the happy co-owner of a PA-28-236 Dakota that will load 4 average adults, 6 hrs of fuel and 60 kg of baggage and still be within legal and practical limits. I do not believe it is ever flown overloaded. My point was just this: according to my observations, small private airplanes that are easily overloaded, are frequently flown overloaded.

One of the problems seems to be that potential buyers often check actual empty weight too late (if ever), when they have already fallen in love with a specific airplane. When someone is talking to me about buying a specific aircraft, I always ask them if they have checked its actual useful load and related that to their intended mission.

After the airplane is bought, it seems that some pilots just fly their intended missions, taking off at whatever weight that yields. I know for certain that some of those are often overweight, sometimes substantially so. Some set personal limits that tend to limit the amount of overweight, e.g. “max 2 adult passengers with fuel to the tabs”.

I do not mean to imply that most pilots do not care. Most pilots I know respect the limits, some accept/risk a little overweight (“on long runways”) and then there is a few that either do not care or like to experiment.

Cobalt wrote:

We recently had another thread called “normalisation of deviance” – this is a fantastic example.

+1 Indeed.