Although the majority of my multi time was in the zinc chromated, modified Clark Y airfoiled, load shifting (and pleasantly flying) Aztruck, I feel that as there is a regular discussion on forty year old multi pistons, some praise should go to the spare parts bin assembled Seneca 1.
The Seneca 1 must have been a Lock Haven accountant’s wet dream – product of a metaphorical tryst between the Arrow 2 and the slab wing Cherokee Six. Somewhere along the way they slipped counter rotating engines passed the bean counters, which combined with a proper fin and rudder, and the long lever arm of the Six fuselage, has resulted in one of the safer piston twins produced.
Control harmonics might be the anti thesis of the best de Havilland standards with anemic ailerons, a heavy stabilator (especially with forward CG), and a rudder/aileron interconnect to place the proverbial lipstick on the agricultural controls. The aircraft accordingly has a low demonstrated crosswind limit of 13 knots, mainly due to running out of aileron and the risk placing an excessive side load on the downwind main gear. It also wants to wheelbarrow when lightweight, but this is not unusual for light twins operating at training weights and can be managed with proper technique.
Perhaps the accountants felt that the Arrow landing gear was like the Bonanza, the design of which was happily used on the Baron and even the Duke. In any event the Aztruck’s aircraft carrier strength gear, and old fashioned hydraulics, was not an inspiration. The landing gear has been a weak spot for the Seneca 1, but in a strange testament to its commercial utility, many a Seneca 1 is restored to service following a landing gear mis hap, sometimes more than once (!), while more glamorous twins end up in the spare parts bin.
Asymmetric it will perform adequately as a trainer if flown correctly. Any deviation from blue line, or side slip away from the slight bank towards the live engine, and the Six fuselage lops off several 100 fpm off the gentle 200-300 fpm ascent. The good asymmetric manners from the large fin/rudder, long fuselage and a four cylinder relatively underpowered Lycoming means that the type has not had a Vmc loss of control in training. Commercially it meets Class B performance, which is not that much. A single engine service ceiling at max all up mass of 4,000 feet may not be as good as a Baron but is representative of light piston, normally aspirated twins.
As a personal twin it offers an honest six seat cabin with two doors, and with the tanks at wet bottoms (ie half full, each wing has two tanks of equal capacity -slightly less than 25 USG-which are interconnected and filled from one fuel spot on the outer tank, so visual wet bottoms means that the inner tank is full), you can usually fill the cabin with five and juggle the CG with baggage in the nose. Passengers enjoy the ride but there is a need to control a tendency to slight Dutch roll. There maybe a Seneca 1 with a yaw damper, later models have them, but I haven’t seen one.
Real life cruise is 140 KTAS using 18 usgph, with a 560nm range with IFR reserves. Slightly better than an Arrow but with a more spacious cabin and load carrying ability. It has 1300-1400 lb useful load and does not incur airways charges. A decent Seneca 1 can be usually be found for less than an Arrow.
Because most Seneca 1s have had to work for a living eventually the airframe shows its age (loose rivets behind the engine on the trailing edge, a sign of heavy landing abuse) and becomes uneconomic to repair. However, if the airframe is in good condition, the type is very easy to maintain and this maybe the reason for its longevity. Unlike the later turbo charged models, which also gave up useful load despite increased gross weight (still on the same Arrow gear), the risk of engine mis management is low. The later models have better ailerons and slightly better handling.
Private Seneca 1 owners tend to treat this unfashionable twin as a keeper, knowing they are getting a high utility twin which is not going to bite them either through handling vices, or maintenance surprises.
Nice one, Robert!
That said, and all bean-counting aside, I think there is just no comparison between a Seneca I and the truely wonderful, classy Aztec. After all, they are in a bit of a different class.
I only have experience flying the Seneca 2 and love the aircraft. I would not want to do without the turbo-charged engines though. I seriously consider(ed) buying a Seneca 2 as its payload, range etc. are not bad at all for 4 people travelling around. If you get the EASA below 2 tons version, you don’t pay airway charges. It takes a lot of luggage with 4 people and can have extended range tanks. Plus: boots, de-icing, heated propellors and AP. What else do you want except for a Pilatus PC12, TBM900 or something like a Cirrus Jet?
I’ve flown the Seneca 1 as well as the II and III.
While I loved the 1 dearly due to the fact that it was much more affordable (about 100 CHF/hr less than the II), it was ok for rather short legs only. Longest flight I did with a 1 was about 3 hours, coming up to approximately 420 NM. As it had Rajay Turbos, it had quite a good performance.
My favorite Seneca has to be the II. Most bang for buck as I recall. With the 123 USG tanks, the II could do about 1000 NM non stop at about 160 kts at breathable altitudes. Some with new props can go slightly faster than that. The service ceiling single engine is also more than sufficient for a plane that class. As Aeroplus sais, it’s got all you really need.
Nowadays, prices between a 1 and 2 are almost similar, so for the same money I’d always go for the 2.
I’d strongly consider buying one if I had the means to operate it.
Aero+ modern turbo chargers, especially with intercoolers, are very reliable but I always have at the back of my mind the risk of engine fire (normally aspirated engines are obviously not immune to fire risk, but the turbo adds another potential source). As the turbo allows a higher optimal cruising altitude, the ability to perform an emergency descent before the fire reaches the spar is a more unlikely scenario, and unfortunately there are accidents where the engine fire in a multi engine has reached the spar resulting in the wing failing.
In this sense the cabin firewall of a single may provide a more robust defence.
The Seneca, however, shows only three fatals following an engine failure in the AOPA NTSB database, two of which were due to poor maintenance followed by poor asymmetric technique (one a take off below Vtoss resulting in a Vmc rollover when an engine failed, the other the pilot lost control in a he circuit following an EFATO – he had made a precautionary landing the day before due to engine problems on engines beyond their TBO).
Confirms my thesis that it holds one of the best safety records following an engine failure.
Can the spar not be fire protected?
This is done in steel construction buildings nowadays, for example.
So … how many engine fires are there in the database related to the Seneca 2 or 3?
Of the three events recorded related to engine failure, none. Does not mean that there have not been engine fires. I experienced an engine fire, fortunately on run up (exhaust manifold decided to expire, reminding you that there is more to an engine overhaul than shipping the core to the overhaul shop), which would not figure in any database as I shut the engine down and got myself towed back.
A careful trawl of the database will reveal that multi Pistons do experience engine fires which lead to serious accidents, the AOPA NTSB fortunately shows no fatal related to the Seneca, and very few related to engine failure – see my earlier post.
There is and was always a lot of debate going on between Twin Engine versus Single Engine in relation to safety. In the end, risks cannot be ruled out and I bet that the pilot proficiency and skills are of most important in any aircraft you fly. What I like about the Seneca 2 in relation to the SR22T is its capacity to hold 4 adults plus lots of luggage, skis, snowboards plus a lot of fuel. More than I could bring along in the Cirrus. I was just surprised in a positive way when I flew it recently to Courchevel with my brother, son and a friend. It had room enough for the skiing stuff and lots of performance left.
AeroPlus wrote:
What else do you want except for a Pilatus PC12, TBM900 or something like a Cirrus Jet?
a pressurised cabin :-)
