Your Opinions on a Navajo P

[Lead Sled]

hahahaha....I already feel like that.

Ok, so which aircraft/engines are NOT geared? I am feeling stupid, but aren't all piston engines geared? (maybe that was your point)

By geared, we're talking about engines such as the Continental GTSIO-520s and Lycoming TIGO-541s as opposed to the non-geared IO-520s, IO-360s and the like.

I've never flown behind a geared Lycoming, but I've got a couple of thousand hours in GTSIO powered aircraft (C421 & C411). We knew how to fly them and we never had a cyclinder problem with any of them. Just do your homework and fly them by the book. They'll run as advertised. However, they don't take ham-handedness very well.

FWIW, if I was looking for a pressurized twin to put on a charter certificate, I'd probably take a hard look at a C-414A.

'Sled

 

[erj-145mech]

The P navajo, the C-421, the C-411, Be-65 (Queen air), some Aero Commanders are some of the geared engined airplanes that I can think of off of the top of my head. Cessna 402's, 414's, PA-31-310/325/350 are honest six pax aircraft that are direct drive engines, but only the 414 is pressurized out of that group.

 

[dhc8fo]

The P navajo, the C-421, the C-411, Be-65 (Queen air), some Aero Commanders are some of the geared engined airplanes that I can think of off of the top of my head. Cessna 402's, 414's, PA-31-310/325/350 are honest six pax aircraft that are direct drive engines, but only the 414 is pressurized out of that group.

Actually, a 414 would be nice because I already take a yearly hit for the 300 series training at FSI. They cover the 400 series in the same training so there is a little savings for me!

SO, anything in particular to look at for in a 414? What about the recent wing spar AD?

 

[FlyingFisherman]

I'm not sure how 421 motors and the like are geared...but the FW-149D's motor was a Lycoming design made by BMW.

Now...it's geared 'up' meaning that on takeoff, the propeller was turning something on the order of 3600rpm. Do the 421's and other geared motors do the same or are they geared down in rpm?

 

[Junkflyer]

They're geared down so the engine can turn faster to make more power (rpm=hp) without the prop spinning too fast.

 

[Lead Sled]

I'm not sure how 421 motors and the like are geared...but the FW-149D's motor was a Lycoming design made by BMW.

Now...it's geared 'up' meaning that on takeoff, the propeller was turning something on the order of 3600rpm. Do the 421's and other geared motors do the same or are they geared down in rpm?

FyingFisherman...
I've never flown a FW-149D, so I know nothing about them, but never the less, I'd question a motor that "geared up" the propeller to turn faster - it doesn't really make sense. Typically, gearing is provided to allow the motor to turn faster than the propeller allowing the engine to be in its optimal power band while permitting the propeller to be operated at its optimal RPM without the tip speeds going supersonic - their efficiency drops off dramatically after that.

'Sled

 

[erj-145mech]

Flying Fisherman has it backwards, the -149 has a Lycoming GO-480 hung on the front. Same base engine as the Aero Commanders use. Engine turning some where in the neighborhoold of 3200 revs slinging the prop at 2200 ish. Not sure about the exact numbers.

 

[Lead Sled]

Actually, a 414 would be nice because I already take a yearly hit for the 300 series training at FSI. They cover the 400 series in the same training so there is a little savings for me!

SO, anything in particular to look at for in a 414? What about the recent wing spar AD?

It's been a LONG time since I last flew a 414, but once upon a time you only had to take an oral to cover the differences between any of the twin Cessnas (excluding the 336/337). If you're aready taking a checkride in a 310 or 340 then you may be practically good to go in a 400 series airplane.

As far as the spar AD goes, you'll want to talk to some knowlegable maintenance people and see how it's going out in the field.

'Sled

 

[Headwind]

The way I understand it the P Navajo had a geared Lycoming with well over 400 HP. It was unreliable, expensive to operate, and had a 1200hr TBO.
It was replaced by the Mojave with a 350 HP (not geared) Chieftan engine. This was basically a Chieftan powered Cheyenne. The Mojave had 350 HP - the Cheyenne (PT6-28) had 680 HP flat rated to 620 HP.
Compaired to the P Navajo, the Mojave had longer TBO (2000hr), better economy, more reliabilty, but it was underpowered. Not too bad with light loads, but I feel that if you need to carry 6 passengers in the flight levels you need turbine power.

HEADWIND

 

[casper1nine]

i may be wrong, but i too recall that the p-nav's engines were orphans. if you are looking at one that is ready to be replaced, you are likely going to have to overhaul that unit, as there is no ready supply of re-manned engines waiting to be shipped to you. if i recall, the specific model and series used on that airplane were for that airframe only, thus the short supply. some of you mtc guru's can double check me on that.

for what you described (keeping it piston powered), my vote would go to the 421c. geared engines in and of themselves are not a bad thing, and there are a ton of late production airplanes with good mod status to choose from.

-casper

 

[414Flyer]

Trying to run charter operation using a single P-Navajo is a sure way to go broke fast, as others have pointed out.

Using a single aircraft, orphaned airframe and engines, parts getting hard to find, is just asking for lots of expenses and downtime.

The main part of having a charter aircraft, is having a plane that is up as much as possible, which the P-Navajo would not be. If you had 2-3 planes, to ensure one was always up, would be better, but even more expensive too, unless you just found 3 real cheap, and could keep 1 up, 1 for a backup and 1 to part out. Suncare uses a fleet of P-Navajos (as of 2002), but even then they were talking about reengining with PT-6 in the future. Maybe they have by now.

Some people who try to operate P-Navajos or even Cheyennes are starting to look for junked airframes to buy, to have as a parts source. A cheyenne would make a far better charter aircraft, but still the same issues of airframe parts.

There is a reason a P-Navajo will be cheap, its because of low demand, for all the reasons listed in this thread. A standard Navajo would be better, as would a 414 too.

 

[NoPax]

Try an Aero Commander 500S - 6 Passenger configuration (7 including pilot), Lycoming IO-540 engines (not geared).

Its older sister (AC500B) has been very good to me over the past year as a cargo bird

 

[FlyingFisherman]

Flying Fisherman has it backwards, the -149 has a Lycoming GO-480 hung on the front. Same base engine as the Aero Commanders use. Engine turning some where in the neighborhoold of 3200 revs slinging the prop at 2200 ish. Not sure about the exact numbers.

You're absolutely right. I got so used to reading 3000+ on the tach I just went right to thinking "prop"

With that huge 3 bladed prop at 3200rpm those tips would be comfortably supersonic. Whoopsie

 

[FlyingFisherman]

And for those that might know...what's a 421 run at as far as prop rpm? I remember seeing 1800rpm somewhere but I was only a guest not the driver.

 

[NoPax]

And for those that might know...what's a 421 run at as far as prop rpm? I remember seeing 1800rpm somewhere but I was only a guest not the driver.

I got to fly an A model 421, about 2 years ago. I think it was 2200 for takeoff, 2100 climb, and 1700 for cruise. 1700 rings true to me.