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The end of the avgas piston twin?

The avgas avtur is very interesting discussion if only as such an important reminder the extent to which this can ruin your day whichever type you fly.

Peter wrote:

The trickiest one might be the DA40 which is plentiful in both versions.

Which is another good reason to make a habit of systematically samping the fuel after having refueled, and smelling the contents (and the roses )

I have done this my whole aeronautical life after having been told some horror stories of people inadvertently uplifting water into the tanks, but lately I have become somewhat sloppy with this. I will hereby straighten myself out.

LFPT, LFPN

Which is another good reason to make a habit of systematically samping the fuel after having refueled, and smelling the contents…

I don’t think you can tell the difference between AVGAS and the typical mixture of AVGAS/Jet A1, which you will get by topping up a non-empty tank, by look and smell without a clean sample for comparison. The smell and coloring of AVGAS is very dominant.
The only way to make sure that the proper fuel is pumped into the tanks is being present when it happens ( which is SOP in most commercial outfits unless a company mechanic or technical representative is on site).

EDDS - Stuttgart

Many / most “FBOs” are reluctant / will not fill without the pilot being there, however, how many pilots verify the type of fuel delivered may be questionable. It is a frequent mishap at car pertrol stations.

Fuji_Abound wrote:

It is a frequent mishap at car pertrol stations.

I imagine a major factor there could be habit in combination with a change of car – just doing what you always do not realizing it’s a different car.

Twins are very expensive to rent nowadays

From here

I no longer fly a Baron 58 or a Seneca 5 simply because I don’t really need the bigger aircraft any more and the cost difference in rental has grown hugely.
DA42 all inclusive fuel, TKS fluid, IFR European database €420 per hour
Baron and Seneca €750 inclusive per hour.
One must not forget the TBM700 is a development of the Mooney 301 and the avionics were top of the range at the time. Now as NDB’S and VORs are disappearing gradually, they are no longer top of the range and will not meet certain standards.
As for RVSM, how many on here want or need to fly that high on a regular basis.

France

gallois wrote:

DA42 all inclusive fuel, TKS fluid, IFR European database €420 per hour
Baron and Seneca €750 inclusive per hour.

Wow. that is quite a difference. Yea under these conditions I’d prefer the DA42 as well. Might as well learn to fly a stick finally…

Here the Senecas have mostly disappeared from the training market and have been largely replaced by DA42’s as well. Barons are in many cases over 2 tons so they have disappeared totally.

My favorite twins still are the Twin Comanche and the Travel Air, both below 2000 kg, both reasonable range and in the case of the turbo twin comanche quite fast. Recently however I’ve also come across the Grumman GA7 which appears to be a quite lovely little twin with a similar range and speed of the non TC’d Twin Comanche but a lot less complexity (Fuel system primarily).

LSZH(work) LSZF (GA base), Switzerland

The Grumman GA7 (IIRC is the Cougar). It should have had a much longer life span. I believe Socata bought the rights/licence in order to make a twin TB so that the range went TB9,10,20, twin. Sadly, they never got round to it and instead rationalised by phasing out the manufacture of the TB range.
Instead they had an agreement with the owners of Mooney to develop the 301 (?) into the TBM 700 which success possibly led them to drop the piston market. Socata of course had a close relationship with Mooney over the years and at one time, owned Mooney (IIRC).
The Cougar, Beech Duchess, and Piper Seminole all have similar figures and all IMO flew nicely and were stable IFR machines. But they weren’t as quick as the Twinco,or as fuel efficient, averaging 72lites per hour at around 140 to 150 knots IAS. The real load carrying figures were quite good and possibly a little undervalued when compared with other twins in the less than 2ton capacity. IIRC my PA44 had a MTOW of 1730kg with an empty weight of 1100kgs. Like the DA42 they are mostly used in training.

France

I found a pretty good article on the Cougar, which incidently also puts some light in Daher’s role in the fact that the attempt to resurrect it failed miserably.

https://www.aopa.org/news-and-media/all-news/2018/january/pilot/a-rare-cat

LSZH(work) LSZF (GA base), Switzerland

gallois wrote:

The Grumman GA7 (IIRC is the Cougar). It should have had a much longer life span.

I agree. I am just playing with the POH of the Cougar and it looks like a very good alternative for someone looking at a Twin Comanche or Travel Air, particularly if they are not too fond of complex fuel systems.

It appears the Cougar is a 140-150 kt light twin, which at these speeds has a fuel consumption (total) of between 13 and 16 GPH. The range appears to be an equally solid 1000 NM, which is significantly more than i.e. a Seneca I or if I recall right the Duchess or a Seminole.

Useful load is also not bad and adequate enough for a 4 seater at roughly 600 lb with full fuel (118 GPH).

Systems are quite easy in comparison, 2 fuel tanks with internal pumps and simple on-off-crossfeed valves.

Cabin seems to be quite roomy and comfortable.

Yea, well, after that lottery win or like that… but I recall one for sale on Planecheck a few months ago for the price of a PA28. It was gone in days. No wonder.

LSZH(work) LSZF (GA base), Switzerland
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