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Why the N35 and P35 might be a sweet spot amongst Bonanzas

Assuming the airframe has been well looked after, in particular lived in a hangar, which for aircraft of this age and value would seem standard practice. These Bonanza types seem to be amongst the nicest. The S35 was the first to get the IO-520 which increased HP from 260HP to 285HP, but is heavier mainly due to the accessories and tendency to use a three blade propeller. The S35 is the fastest of the NA Bonanzas.

The N35 and P35 have the IO-470N engine which seems to be regarded very favourably. Belt driven alternator on the -470N seems to be a better arrangement and lighter than the -520 accessory drive. Shaft problems on a -520 alternator can produce interesting maintenance bills. They, the N and P, in theory sacrifice around 5 knots in cruise but sip a few gallons per hour less. 160KTAS/11-12USGPH might not be block planning, but owners are reporting this kind of number. An S35 might achieve 175KTAS on 15 USGPH.

The N and P also have simplified tanks with two wing tanks of 40USG each, 37usg useable. The older type had aux tank arrangements with the fuel return line coming back to the left main. On the N and P the fuel return comes back to the selected tank. The Bonanzas are rather prone to fuel starvation due to mis managing the fuel system, and the N and P is a big improvement.

It has the larger third window and better interior, with typical UL of around 1100lbs

Finally the instrument panel is a modern panel with a six pack, and dismissing the art deco piano keys.

Oxford (EGTK)

For me, the sweet spot is with the introduction of the IO520. I prefer the 66 or later because of the increased max GW to 3400 pounds. I have data on 11 P/N W&B and 84 V35 thru V35B Bonanzas. The average useful load on the 11 P/N’s is 1044 pounds whereas the V35+ it is 1184 pounds or an average increase of 140 pounds. Individual aircraft will vary. At the same weights, the performance of the later aircraft is better for takeoff, climb and cruise.

KUZA, United States

@NCYankee thank you for the feedback. 90% of the time I am flying solo or plus one, occasionally plus two. Arguably a Marchetti is more suited, but expect Beechcraft may be easier to maintain.

Useful load around 1,000 lbs plus works fine. The -520 just seems a step up in terms of maintenance and fuel, although with a step up in climb speed and UL.

These six cylinder RG tourers are a big step compared to basic FG four seaters, but as several forum members demonstrate they are practical European tourers.

Oxford (EGTK)

There is no real difference in maintenance between the two engines. The airframes are essentially identical. If you use a lower power setting on the IO520, you get the same performance and fuel burn. The difference is mainly in the extra power when you wish to use it and the extra useful load. I consider the V tail to be a good three adult person aircraft.

KUZA, United States

in the years between 1961 and 1965 and over some 1400 airframes produced the development of the model was fast. In essence a growing market for a fast, long distance comfortable tourer, that and pretty good looks.

As highlighted there is no discernable difference in airframe between any of the models in this range. Interior upgrades and then with the S an uprated powerplant in the 520 drove the model onwards in terms of sales and marketshare.

I tend to agree that the sweet spot lies between the N and P. Not because I own an N, but in all of my research on type there are trade offs as you get to the newer models.

I always thought I wanted a V35B, but also wanted to fly an S. This to gauge any difference between my own and the upgraded newer models.
I have done neither. There is another interesting factor though that most of the airframes in the range can be upgraded with almost anything you want. Tips, windshields, panels, engines etc. A factor in the longevity of the range.

I am hearing bad noise about the 520/550 range with cylinder issues. The 470N appears to be the strongest and certainly mine has never missed a beat, and is very very smooth. I also fitted a three bladed Hartzell and have done some minor engine upgrades but it still remains pretty stock at coming up to 60 years old.

(1961) M35 with a 260 hp Continental IO-470-N engine, increased fuel capacity, increased takeoff weight, and teardrop rear side windows, 280 built33
(1961) Experimental version, an N35 fitted with laminar flow airfoil and redesigned landing gear, only one built
(1962–1963) N35 with new instrument panel and improved seating, 467 built
(1964–1965) P35 with a Continental IO-520-B engine, higher takeoff weight, longer cabin interior, optional fifth and sixth seat, and new rear window, 667 built34

Fly safe. I want this thing to land l...
EGPF Glasgow

There is a pretty original model D35 on plane check since a while.

Might be something for a Bonanza fan who can’t afford a newer one. Pretty basic but has a 20 USG aux tank.

LSZH, Switzerland

@Mooney_Driver that does look a nice first generation Bonanza. 54 gallons useable on a E-185 is quite long legged. Am guessing there is VAT if it leaves Switzerland, plus transferring it to a local or N register.

Oxford (EGTK)

Some further thoughts on the D35 mentioned by @Mooney_Driver:

1. The Aux tank for this version is in the baggage compartment behind the bench seat, so adding to the aft CG planning of the type – also not so sure the venting of the aux fuel is that sophisticated, unusual for this option to have been installed
2. Does not appear to have flown for some years, and some of the recurring Bonanza items (gear/flap motors, wing bolts) are probably due, although some of these can be on condition
3. The electric propeller control/governor is a specific feature of this vintage, apparently they work OK but overhauling them probably needs specialist help
4. The engine was last overhauled 33 years ago
5. In addition to the ruddervator, the ailerons and possibly flaps are magnesium. The Bonanza prototype considered fabric covered flying controls, with modern fabric coverings this may have been an intelligent engineering solution.

The C through G types were the strengthened versions of the original V tail. They also changed the ruddervator chord and this resulted in the break ups and subsequent AD of the type in the 1980s.

This looks a nice early Bonanza, but you are acquiring an old timer with Piper Arrow performance, quirky systems and engineering, but still having to pay for Bonanza maintenance. The type also deserves to live in a hangar. It is an objet d’art, and should form part of a nice vintage hangar collection.

I use the Piper Archer as a value/performance datum. The type needs to comfortably exceed the utility of an Archer if you are going down the complex SEP route. The Arrow I always feel doesn’t quite beat the Archer on this criteria, and therefore by transitive logic this nice D35 doesn’t either.

The second generation starting with the H35 produced around 1,000 lbs UL, 160 KTAS and with wing aux tanks reasonable autonomy.

Oxford (EGTK)

Thanks Robert.

I have nothing to do with that plane but it caught my eye on my regular browse through the market. Some remarks I have read are that the most valuable with that plane is the hangar space it comes with.

In EASA land this plane also is Annex1, which may pose additional trouble.

LSZH, Switzerland

Unless one has very specific requirements which only one particular model fufils, all that “sweet spot” stuff is largely nonsense. Yes, some models are more desirable than others (for most people), but that directly reflects onto higher prices on the used market, translating into higher capital outlay / operating cost in the end. You mostly get what you pay for.

That said, after just a quick glance, this local copy looks like a really good plane and not too expensive. The huge tanks would allow you to bunker cheap fuel, for example when passing by the Channel Isles (very applicable to UK based operators). Below 1.5 tons, which is a factor in the UK. Not being approved for mogas is not a major downside for UK operators.

Mainz (EDFZ), Germany
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