Would you or do you takeoff above MTOM?

I think I’d agree that two seat aircraft are flown over legal gross weight more than some larger types, and its interesting to think why that may be the case. I’d propose the following…

• Two seaters are often flown for training, meaning both occupants understand what they’re doing, no passengers, and for types like the C152 the instructor may well be doing it every day in the same particular airframes. Legal or not he may have a well developed understanding of what he can get away with.

• More flying is done with two occupants in light aircraft than possibly any other number (my guess), regardless of the number of installed seats, and accordingly two seaters have less payload margin on an average flight.

• Weight affects climb performance more than any other factor. Given an overgross condition its arguable that reduced climb over obstacles is the most likely factor to cause an issue or accident. However, two seaters more often climb at low speed, meaning a relatively steep climb angle that provides margin of safety on takeoff. Something like a Super Cub climbs at a dramatic angle compared to a four seat Cherokee powered by the same engine. So its logical that more people would fly over gross in the Super Cub, although its also true that other larger types with steep climb angle are known for flying over gross: in Alaska for instance, where there are legal concessions that allow it under some conditions. Link

CG and for my planes particularly aft CG is something that I am very aware of, regardless of weight. Flying over gross is something I’d be very cautious about, but flying out of the loaded CG envelope is (more simply) something I don’t want to do.

Flyer59 wrote:

a true 4-seater,

Define please. Is this a reference to having four adults (2 @ 120, 2 @ 200 = 640), full fuel ( 90 gallons 540 lbs), 120 lbs of luggage and still being under MTOW? If so, the Cirrus SR22T with 1320 lbs of useful load can do it. So can the FDC4.

CG and for my planes particularly aft CG is something that I am very aware of, regardless of weight. Flying over gross is something I’d be very cautious about, but flying out of the loaded CG envelope is (more simply) something I don’t want to do.

Exactly.

It is surprising how often pilots load to “large” gentlemen into the front seats of a four seater. They have considered the weight and it is just within limits – no problem.

In fact in many types it is surprising how often the COG is not fine.

A friend of mine intentionally spun in exactly those circumstances and was very very lucky to recover. Potentially it is so very dangerous.

and then you take off over MTOW and need to land again straight away. While I cant think of a SEP that cant also land at MTOW, over MTOW and the parameters change. Agreed if it isnt much over MTOW perhaps not by that much, but as with all things, and as others have already said, how much is too much.

BTW is there a SEP that cant land at its certified MTOW?

a true 4-seater

You will pretty much need a twin, and then only certain twins.

You will not get 4 “normal” adults and full fuel into a 42 for example, and at MTOW you will want to be on your game with an engine failure on take off – there isnt a huge surplus of performance, never mind over.

You will however get 4 very large adults, full fuel and the kitchen sink in an Aztec and then some and still keep going up, so it is possible.

Fuji_Abound wrote:

BTW is there a SEP that cant land at its certified MTOW?

A DA40-180 certified for 1200 kg cannot land above 1150 kg IIRC.

Fuji_Abound wrote:

BTW is there a SEP that cant land at its certified MTOW?

The Mooney M20R Ovation has a MTOW of 3368 lbs and max landing weight of 3200:
http://www.mooneypilots.com/mapalog/M20R%20Evaluation/M20R.htm

Fuji_Abound wrote:

BTW is there a SEP that cant land at its certified MTOW?

DR250 Capitaine: MTOM: 960kg, MLM: 920kg.

Three very interesting examples. Thank you.

Cessna 400: MTOM 3600 lbs. MLM 3420 lbs.

SR22: Yes, it seems like quite a good load carrier, especially for a modern 4-seater. A few years ago I used to fly a SR22 G2 and a Piper Saratoga same vintage. Although the 6-seat Saratoga was fixed gear and without aircondition, its useful load was 6 kgs less than the 4-seat Cirrus’.

Only the new G5 version of the SR22T can carry 4 adults plus full fuel and some load. This is not possible on the earlier models.