Chieftain or Navajo

[thrust clb]

Hello guys. I'm looking at buying either a Chieftain or a Navajo . I currently use an Aztec for cargo and some pax operation. Any operators out there care to give some feedback on the following questions:

1. Do the engines generally make it to TBO? (1800hours).

2. What is the realistic gps groundspeeds and fuel flow do you see at 8500 feet?

3. Are the undercarriage as robust as an aztec?

Thanks!

[glekichi]

2. 180kt 160L/hr for the Chieftain - 32"@2200 running R.O.P.

[Triple Captain]

1. Do the engines generally make it to TBO? (1800hours).

I have seen them go both ways. I few years back we had a fair bit of cylinder trouble with the blue seal A1 series and I know at least 4 cylinders on 1 engine had to be changed about half life within 300-400 hours of each.

Turbos seem to be more of a problem these days with much lower time pilots and with pilot turn over - more training etc.

2. What is the realistic gps groundspeeds and fuel flow do you see at 8500 feet?

170kts / about 140 l/hr in the cruse but as a block fuel flow for the entire flight Navajo 155 l/hr, Chieftain 165 l/hr. Can burn around 240 l/hr in the climb

I have seen quit a bit of difference in cruise FF between same engines models 18-24 GPH

3. Are the undercarriage as robust as an aztec?

Never flown the aztruck but have operated both Navajo's and Chieftain from grass, gravel and short strips without trouble. Problems with the micro switches is the main issue I have had with them - wheels not wanting to go up and not indicating 3 greens. Also there is a lot of difference between models with single and double calliper brakes!

If you want a machine with all the gear on it find a PA31-350-1020.

In my experience: (I'm not an owner)

- Navajo at MTOW performs better then a Chieftain at MTOW.
- Navajo's usually have 10-15 L more usable fuel and burn 10 L/hr less then Chieftains.
- Unless you are always flying long sectors make sure the PA31 has the undercarriage mod "Red Legs" otherwise you will be landing weight limited.

[ZEEBEE]

Pretty much agree with all that has been written, but don't expect to see even 170 knots with reasonable power/fuel flow settings loaded up to gross.

Chieftain is easier to keep in CG than the Nevergo that can too easily fall aft of the CG unless you have sufficient weight to load into the nose compartment. However, a fully loaded Nav is less of a dog than a fully loaded Chieftain.

If the Chieftain rings your bells, then try to get one with the heavy duty brakes and extended flap mods. Will pay for themselves in getting into the shorter strips of the outback.

Also be aware that the gear warning horn is only enabled when the flap switch is in the DOWN position. If you flip the switch back to neutral after selecting the desired amount of flap, you will have just bypassed the gear warning circuitry.

And finally, be aware that the magnetos on these are NOT TRULY INDEPENDENT. Both mags get driven from the same drive shaft. If one magneto craps the drive, you've lost that engine, no matter how good the other mag is.

Great aircraft though.:ok:

[tinpis]

3. Are the undercarriage as robust as an aztec?


Waddya got planned? :hmm:

IMHO the Navajo -310 is a much sweeter better performing little plane all round
Must be getting tough to find a good one now they be getting on a bit?

[Stationair8]

Triple Captain is spot on with his info.

The advantages of a Chieftain,
-wing lockers,
-most have the cargo door as standard,
-most have a crew door as standard,
- if you are carrying bulky freight that extra fuselage length could come in handy,

The disadvantages of a Chieftain,
- most have been flogged on RPT so have high total time,
- some were restricted to approach flap setting for landing due to an AD
- AD on the prop hubs aswell in the 90's
- two different engines due to counter-rotating props
- lots of variation in radios, instrumentation etc
- airframe damage around the passenger door from years of abuse etc
- for some they have different brake combinations, which could give you grief in the hip popcket.

Advantages of the PA-31/30
- good performance out of a short strip compared to Chieftain
- only one engine type for the PA-31/310
- still some very low time ones about

Disadvantages of the PA-31/310
- most bulit without crew and cargo doors and wing lockers as these were factory options or not available.
- production life from 1967 until 1984.

Having flown Chieftains on RPT, they are a pretty honest aircraft, just need to be aware of little things such as micro switches on the gear legs, keeping the roller's lubricated on the gear legs, engines normally go full life if you operate them the right way and good endorsement from somebody that knows what the aeroplane.

The nicest PA-31/310 I flew was one with crew and cargo door, wing lockers , 40 degree flap and from memory dual caliper brakes, very sweet to fly and good in an out of short strips. Also flew one of the very first PA-31/310's in the country and that old girl would TAS out at nearly 200 kts at 10,000 feet at 31"/2200rpm. Mind you an old timer had flown in the WA in the great boom of the 60's and reckons the hours on the M/R were fictious when we operated in the mid 90's.

[tio540]

Good posts chaps, great to see a positive post.

My two cents worth:-

Get the Chieftain with crew door and red leg kit, and it has more seats, better uplift, and will be easier to sell, than the Navajo.

You will block close to 162-165 litres per hour.

Gear problems not really an issue provided the undercarriage is kept clean, and greased.

Engines will make TBO depending on where they are overhauled. Factory remanufactured is really the way to go, and naturally are dearer.

100 hourlys can cost lots.

Great machine.

[Triple Captain]

Triple Captain is spot on with his info.

Oh Thank-you.

The advantages of a Chieftain,
-wing lockers

Some of the later Navajo's do have wing lockers. The interesting thing is the Navajo's without wing lockers are lighter and either higher ZFW or MTOW (I cant remember exactly, it's been a while) but they will carry more.

The biggest problem without winglockers (Navajo) is the floor loading limit of 690kgs (freight config) which is quiet easy to reach which would limit you to a total of 781 kgs freight (91 nose + 690 inside).

And then there is the panther kit mmmmm :)

[tinpis]

Snap

http://cdn-www.airliners.net/aviation-photos/photos/2/8/9/1031982.jpg

[thrust clb]

wow. thanks for the great response. i guess i will go with the navajo 310 then. been thinking about the 402 for a while but the spar issues keep coming up. thanks again for the wonderful feedback!:ok:

[Skystar320]

Go for a Chieftain! I remember being flown in and out of some rather tight situations rather quickly

[Aquaplaner]

The interesting thing is the Navajo's without wing lockers are lighter and either higher ZFW or MTOW (I cant remember exactly, it's been a while) but they will carry more.

Aftermarket Vortex Generator kits are fitted to most but not all Navajo / Chieftains in Australia. The fitment of a VG kit allows an increase to the maximum takeoff weight. The actual increase would vary between kit manufacturers but if my memory serves me correctly the MTOW on a PA31-310 Navajo goes up by 154kg (no wing lockers) or 100kg (with wing lockers).

The "Red Leg" kit referred to in a previous post involves some strengthening mods to the undercarriage. This mod allows an increase in the MLW up to that of the increased MTOW with the VG kit fitted.

I'm not sure what you are planning on using the aircraft for. You would be able to get your Aztec in and out of shorter strips than a Navajo. As far as the undercarriage being as robust as the Aztec, the PA31 is configured differently. Main wheels retract inboard as opposed to forward in the Aztec and there are hydraulically actuated gear "flipper" doors and nose gear doors in the PA31 which add complexity to the gear system. I would expect the PA31 undercarriage to be more maintenance intensive than the Aztec. At least you will have two hydraulic pumps!

There is also a PA31-325CR?? A Navajo with more powerful engines and counter rotating propellers. I have never flown one but think there are a couple around.

[CharlieLimaX-Ray]

Piper Navajo's either came with factory installed wing lockers or Nyak aftermarket wing lockers.
A number of Navajo's and Chieftains also had wing locker fuel tanks installed.
Still a number of nice low time PA-31/310's and 325's around.

[airman1]

Just my two cents......

You will find a Navajo when fully loaded becomes very switchey in pitch, the early model PA31 - 310's which didn’t have wing lockers are rocket machines and as Triple Captain stated the ZFW is increased. Not too many around and the ones about are usely already converted into freighters. The VMCA and blue line figures always vary with this machine depending on serial number (Wing locker & VG kit) always pays to double check each machines manual when dealing with a Navajo. Also when shopping around even if the flap indicator or selector isn’t placard 25 Deg or 40 Deg just check the flap rails to see if there is a restrictor (basically a bolt and washer) otherwise they may tell you the motor ratio AD has been completed but they have just changed the flap indicator to suit. Believe it or not I have seen this on a few machines! I always used to work off 150 Lts/hr for a Navajo and 31/22 power setting. Marvellous machine to fly when heavy out of short strips! :eek:

A chieftain PA31-350 - always found to be a very graceful machine to fly, but climb out at MTOW was always very interesting especially at night! The counter rotating engines are a real pain for spares. Fuel burn - 170 Lts/Hr and a power setting of 31/23. But from memory the fuel total on a PA31-350 is reduced to 690lts. So you can never go as a far as you can in a Navajo. The undercarriage is very robust as long as it is maintained.

In summary to own either machine my pick would be a later model Navajo:ok:

[tinpis]

Just a footnote
Jumping from one to the other the 310 seems a totally different airplane
If you don't need a 350, dont buy one.

[tio540]

The man said he wanted to carry freight and pax. The Chieftain will carry more, and the longer tail moment is nicer to fly.

[ZEEBEE]

The man said he wanted to carry freight and pax. The Chieftain will carry more, and the longer tail moment is nicer to fly.
Tio540
Agree with you re the need for the Chief, but providing the cg is kept well forward, the Navajo is the nicer aircraft to fly (IMO).

Also quieter with the props further forward than with the Chief's props right next to the cabin

just my 2c