Buying a twin (maybe seneca 2)

[one2go]

Can I ask you guys for some twin advice. A friend is thinking about buying a twin, he's looking at a seneca 2 at the moment.
The only people I've spoken to have said it's underpowered and no fun at all four up on single engine.
If this is the case what would you recommend?
It's really for touring with four adults, day trips and the like. Mainly from hard surface but possibly occasionally from an 800m grass strip.
thanks

[gcolyer]

I would say no twin is fun four on single engine!!

[High Wing Drifter]

The Seneca 1 is underpowered, but the 2 is turbocharged so single engine performance is considerably better (the 1 has an SE ceiling of 3500' so not good if flying over similar sized bumps - twice the chance of a failure and all that).

I've not flown the 2, only the 1 and 3 (220 turbo) and the difference between those is like night and day. However, SE performance in the 3 could be marginal on a hot day, managed about 75fpm clean during my IR test last Summer with about 900lbs in people and fuel and no chance of a positive climb with with gear, flap OR a fine prop in such conditions.

No problem from a reasonably low and flat 800m grass strip. For example the Seneca 1's ISA performance is a TODR of 700m.

I believe the 2 has a better a load capacity of 4400lb compared to the 1's 4200lb. But at 20 usg/hr (120lbs) crz consumption you will need an additional minimum of 33 usg (200lbs) of fuel just to depart, go-around, divert and land with reserves in addition to crz gas.

My ME experience is limited to the Seneca 1 and 3 so I'm not in a position to recommend anything, except for the blindingly obvious the later the model the better. Single Engine performance in most twins is marginal to say the least.

I understand that the twin Comanche is both a better performer and more economical.

[RatherBeFlying]

As before mentioned, twice the risk of engine failure and twice the maintenance costs to say nothing of the insurance premiums.

A turboprop single may be a better deal than a piston twin in many ways, especially considering the price differential between avgas and avtur depending on where you fly.

[easy307]

Wouldn't a powerful single do the job and be cheaper?

http://www.pprune.org/forums/showthread.php?t=290743

[Fuji Abound]

I think you need to provide some more information such as:

typical payload weight of the four adults,

typical mission - is speed important, what about IFR operations, and deicing,

and of course price.

As others have said you might want to clarrify why he wants a twin as opposed to a performance single of which there are a few than can carry a good payload and have a performance as good or better than most twins.

[Zero Thrust]

The Piper Twin Comanche can fly at 160 kts on 50 litres per hour and carry 4 or even 6 people if you fly on reduced fuel load.

Bear in mind that they also have the capability to fly for 5.5 hrs without tip tanks and 7.5 hours with tip tanks so reducing the fuel load still gives you more endurance than the average single.

I have owned a Cessna 182 and it burned 55 litres at 130 kts, the Twin com burns less fuel at this speed so MPG is better overall at any speed you care to choose.

Short field grass capability (I use 600 metres regularly ), a stable instrument platform, good spares back up... what else have the Romans ever done for us ? The list goes on.

If you don't believe me read the article in "Flyer" Oct 2006. The author of which has now gone out and bought one himself.

Some flight test info here that may help:

http://www.fergworld.com/articles/article_twin_comanche.php

http://www.planecheck.com/twincom.htm

PM me if you want more info.

[Wessex Boy]

I've seen a 1955 Apache advertised recently for £15k which looks very attractive, but I am sure that it would be ruinous to run and not give that much more performance over a more modern Warrior/Archer?

[Fright Level]

Mann have a Seneca with high time engines for sale. I hear they might accept in the region of £40k for it. It's parked up at Fairoaks.

Make sure the MAUW is under 2,000kg so you are exempt from nav charges.

[bookworm]

The Piper Twin Comanche can fly at 160 kts on 50 litres per hour and carry 4 or even 6 people if you fly on reduced fuel load.

Performance is spot on. 4 or even 6 people? Dream on.

I'm in the south of Germany, having been conveyed there majestically in our beautiful Twin Com (the same one pictured in the Oct 2006 Flyer article). However, with just two of us plus baggage for a holiday, I wasn't able to load full fuel (had to leave out 12 USG, in fact). With 4 people, endurance is down to about 3 hours to dry tanks. With 6??

I wouldn't have a different aircraft, but it's not a regular 4-up ship.

[rmac]

I've been flying a twin (C303) for six years now. SE performance with any real payload on take off will always be marginal. Good rule of thumb is max weight of aircraft in lbs divided by 20 will give you the minimum power required to keep it in the air, assuming you do your drills well (thats another question).

So with my aircraft max weight is 5250lbs and I have 250hp a side, so if I am full weight I know that I am not going anywhere in a hurry after EFATO. Likewise if the gear is down, or more than 10deg flap, and I haven't accelerated to VSSE, I am probably not going anywhere. Pre take off brief yourself and stick to it, know when your aircraft will fly on one and when it will not and be honest with yourself. If one gives up the ghost at a performance critical moment, retard the other and treat as for a single engine aircraft. If weight is good you have accelerated and are relatively clean, continue. For heavens sake, though, don't hang on to a bad position hoping that the laws of physics will miraculously change in your favour.

The benefit of the twin is really for long trips over water or hostile terrain, night and IMC flights, where if you are in cruise and stable, an average amount of skill and practice should still see you able to land the aircraft at a civilised location of your choice if you lose a motor :ok:

[sternone]

The benefit of the twin is really for long trips over water or hostile terrain, night and IMC flights, where if you are in cruise and stable, an average amount of skill and practice should still see you able to land the aircraft at a civilised location of your choice if you lose a motor

I agree with that, otherwise you don't need a twin, infact if you are not using frequently the above coditions flying a twin is more dangerous than a single (see the accident stats), and if do use the above conditions alot then you know that you are flying in seriously difficult conditions with much higher accident rates.

[Fuji Abound]

If one conks out the remaining engine will merely convey you to the crash site. You won't mind though, because you'll be so depressed about your negative bank balance that you'll be thinking of ending it all anyway.....

What a load of old rubbish.

Of course the accident statistics are poor compared with singles, but this is because so many twin pilots dont fly twins enough so their technique is poor when an engine quits, and because there are so many twins with marginal asy performance.

- I am just trying to be a bit controversial, cse I feel like it, and you couldnt be more correct about the negative bank balance. :)

For aircraft, even more than most things, buy the best you can afford it will end up cost you less in the long wrong.

[sternone]

For aircraft, even more than most things, buy the best you can afford it will end up cost you less in the long wrong.



And what would you advise for a light twin ?

[pumper_bob]

I think the Cessna 337 should at least get a mention. If you loose either motor on take off she will simply climb at a much reduced rate, appx 150-200 fpm. A good one can be had for around £50k or if you look at the American market with the £/$ at over 2 you can pick up some seriously good planes for not too much money. Not sure on the procedure/cost of getting them onto the G Reg though? Also if your purchasing the plane the ferry pilot would be happy to take you along, if thats what you want to do. I would jump at the chance of a trans atlantic ferry flight.
Speeds are up there with the other planes, 165kn cruise and decent payload. I think the U/C can be expensive in maintenance though and a lot of people will say the rear engine suffers from over heating. This can be alleviated with some sensible ground handling, eg not starting the rear engine untill you are ready to go. Allowing enough time for warming up though:ok: One other objection you might hear is that they are too noisy, the engines rev to 2800 and so the prop tips go supersonic hence the noise, but if you mention when calling for ppr that you will use 2500 for take off, assuming the runway is long enough, then you will allay most peoples fears of upsetting the neighbours!

[rmac]

Twin loses and engine doesn't want to keep flying, pick a field, use power on remaining engine to adjust G/S on finals to chosen field. Single loses an engine, too low on G/S for chosen spot, too bad. etc etc

The old saying, "lies, damn lies and statistics:. The arguments will go on and on.

Could it just be many of the anti twin lobby can't afford to run one ;)

[Fuji Abound]

And what would you advise for a light twin ?

I am becoiming a fan of the 42 .. .. ..

it is new, the avionics are superb, its cheap to run .. .. ..

but, it could be quicker, its sep is only a little better than marginal, it could carry weight better, its expensive, but should hold its value well with few problems for some years .. .. ..

with the new engines when they are no longer derated some the negatives may vanish.

Alternatively the Aztec is the opposite of the 42 .. .. ..

carries any amount of weight, bags of SE performance, reasonably quick .. .. ..

but its old, and even a good one will be costly to maintain and run.

[sternone]

with the new engines when they are no longer derated some the negatives may vanish.


Yes, they are announced since a while now, are there any da-42's delivered yet with those new 2.0 engines ?

The rate of production is 17 a month of the DA-42 ? How are they actually delivered with 1.7 or 2.0 ? I did not saw any tests with a 2.0 engine yet..

Whatabout the great Aerostar ? Fast, sleek, good fuel consumption, pressurized.... all you wan't from a twin... i'm still a little bit of a fan of the Aerostar, i hope i can fly one later in life

[Comanche250]

The DA-42 is a good aircraft in many respects however as Fuji says...its new and that is not always good. I've been hiring one for about a year and i've had a problem every time I've flown it! Engine failure, ECU failure, MFD failure, AHRS failure...the list goes on, that aside SE performance isnt all that bad when its light, bit of a b***h when its fully loaded though!

The aircraft that I hire has had no expense spared on it so it could be bad workmanship on the part of Diamond or the maintenance dept. or it could be the fact that its a new a/c and any problems have not been ironed out yet.

I would say though that when it works its an excellent bit of kit! As is the Seneca II although a bit more physical to fly than the 42.

C250

[B2N2]

There are giving away Aztecs in the US right now;

http://www.aircraftdealer.com/aircraft_for_sale/Piper_Aztec/211/page-1.htm

Three years ago the prices were significantly higher.
Add another $5000 for the ferry pilot and you have a N reg on board.

You could buy the bottom 4 for the price of a 42:


1976 PIPER PA 23-250 AZTEC F $129,500.00
1976 PIPER TURBO AZTEC $138,000.00
1977 PIPER AZTEC F $129,000.00
1977 Piper Turbo A ztec $144,000.00

[A and C]

The PA34-200T is a good workman like twin and has a reasonable range with 4 POB and the performance on one engine is OK for a light twin, the PA34-200 is marganal to say the least on one engine.

If you can afford a Beech Baron that would be a better move in terms of all round performance.

Please remember that ALL light twins have a time between leaving the ground and V2 when they cant continue flying if an engine fails, and even when "cleaned up" flying them on one engine is much more demanding than flying a modern twin engined airliner with only one engine working.

[High Wing Drifter]

Just to add to A and C's comment, the time it takes to go from 65kts (rotate with 25 flap in the Seneca 1 from a grass strip) to 83kts (VTOSS t/o safety speed, sometimes and arguably incorrectly called V2) is agonisingly long. One really has to restrict the climb to accelerate sufficiently quickly or else entertain the possibility of having to put down beyond the runway.

[Fuji Abound]

Engine failure, ECU failure, MFD failure, AHRS failure...the list goes on

You have been very unlucky.

are there any da-42's delivered yet with those new 2.0 engines ?

Yes.

How are they actually delivered with 1.7 or 2.0 ?

All now with the new engines.

You could buy the bottom 4 for the price of a 42:

True, but add in the cost of a couple of zero timed engines - £30K, and mode S - 4K fitted, annual service and fuel costs over a year and the difference is at least half, and having spent the money the aircraft is not worth a lot more than you paid.