Pa-31p Mojave

[THE IRON MAIDEN]

Does anyone know much info about these aircraft.

from an operating cost and maintenance point of view? are they any good? or a bottemle$$ pit?

Any info will be welcomed.

Cheers Maiden. :ok:

[PLovett]

A comment from a friend of mine who has some time on the type:

"Powered by two hand grenades fused to explode"

He wasn't a fan of the type and did suffer an engine failure in one.:uhoh:

[Howard Hughes]

are they any good? or a bottemle$$ pit?
Turbo chargers, pressurisation? The more systems you have, the more systems you have to go wrong and cost MONEY!;)

[Stationair8]

Did my time in the Piper PA-31L Mojave, and found it a very good charter/aeromedical aircraft provided it is well maintained and your maintenance organisation does know what it is doing.

There was only 50 built in 1984, and from memory 4 came to Australia in the mid to late 1980's, VH-IGW/XGW/HFD. I have flown 3 out of the 4 in the country and one nice thing about was that they were all very well equipped including Loran and the other nice thing is they all had the same cockpit layout, even better if you have flown a variety of PA-31/310/325/350 and all the varieties in between!!!

The RFDS considered it as a replacement aircraft for their fleet of piston twins including C421B, B58's and PA-31/310/325/350.

The aircraft has a 10,000 cycle life on the pressurisation system, once you hit the limit the aircraft can only be operated unpressurised.

The big limitation in day to day to use is the maximum landing weight limitation, from memory you needed to fly for about 1 hour if you departed at MTOW 3368 kgs and a MLW of 3200kgs prior to landing.

Engines made it to full life and we also got an extension each time as well,
the engines didn't give much grief, the CP made sure you had a thorough endorsement and plenty of sectors during your ICUS. Simple do it the companies way in relation to engine handling or the highway. Interesting that the RFDS had theirs based at Bankstown for a while and it spent a fair bit of time in Hawkers workshop, with engine dramas.

The pressurisation system was good but like any piston aircraft had some minor snags, including damage to the door seal etc.


From memory TAS@FL150 190-200kts, F/F 160 LPH and allow 5 litres per 1,000 feet in the climb.

The fuel system was simple Left and Right, 80 us gallons up to the tabs, 95 us gallons was up to top of the wing and then full tanks was 119 us gallons aside.

The rest of the systems are basically Navajo/Chieftain.

Don't confuse the Piper Mojave with the Pressurised Navajo VH-BSF/SGA built in the early 1970's, a different beast altogether.

Not as good as a C421C, but still a very honest aeroplane.

[Oliver Klozof]

Ahhh, fond memories of the mighty Mojave…

In terms of operating cost, don’t expect any 25-year-old pressurised, complex piston twin to be cheap to operate or maintain :=

The Mojave was only built in very small numbers (< 50 or so from memory), and only in 1984. Consequently, they’re quite rare. Only 6 on the register here and very few for sale overseas.

Most have reasonable avionics and de-ice and are a heavy aeroplane. They’ll hold 900 litres of gas and go a long way on that, but expect to carry yourself, a change of undies and a toothbrush for payload. Very landing weight limited on short sectors too.

There is an STC for a higher 3,368 KG MTOW based on using a stage of flap for takeoff.

Dunno about the engines being “two hand grenades fused to explode.” Personally found the TIO-540-V2AD to be a nicer engine than the Chieftain’s. Indeed they are the same displacement and horsepower, though the Mojave has an intercooler plus different induction and exhaust setups. The Mojave being the only application of that engine makes it difficult and expensive to get parts at times.

Will dig out the info when I’m home and PM it to you.

Cheers :ok:

[THE IRON MAIDEN]

Oliver Klozof: That information would be great :ok:

Stationair8: So the C421 is a better option? thanks for that, more food for thought.

[Stationair8]

From the book Piper Aircraft,

Piper PA-31P 350 total built 50 at the LocK Haven factory.

Serial numbers 31P-8414001 thru to 31P-8414050.

Caa before it became CASA in their wisdom gave you a PA-31L endorsement, because somebody deemed it to be different to a PA-31P endorsement.

[Stationair8]

Each to its own, you are dealing with airframes that are between 30 and 22 years old.

The Mojave has the added advantage of not having geared engines and also having a cargo door to load a stretcher through, the disadvantage is that only 50 airframes were built and Piper has changed hands so many times in the last twenty years spares could be difficult.

The C421 has the advantage of more airframes with some being built as late as 1985, but on the downside the GTSIO can be joy to operate or a maintenance nightmare.

Nothing cheap about operating a pressurised twin!

Just ask the f#@kwits that operated a Mojave on a bank run.

Is it private operations or charter

[THE IRON MAIDEN]

its PVT ops

[gaunty]

:ugh::ugh::ugh::{:ugh::{:rolleyes::ugh::ugh::uhoh::\

[kingtoad]

If you're looking at a Mojave then you do need to consider the C414A and C421C. The C414A esp with the VG kit is a bit of a dark horse. Although watch the ones with the winglet mod, there is a noticable reduction in wing spar life (like about half if I remember correctly).

[pithblot]

Kingtoad,

Half sounds about right - the 421s with winglets used to go very well but I think the spar life was reduced to about seven thousand hours.

If you are thinking about old pressurised piston twins then you should consider a Duke, B60. Personally, I'd stear clear of that class of old aeroplane now. I reckon operating one would be about as much fun as practising bleeding.

Cheers,


Pithblot

[Dog One]

Out of them all, the PA31L would be a suitable private aircraft. Flown by one or two pilots, with good TLC maintenance, it should perform well for many years. Its as easy as a Navajo to operate and operated in the 16 - 20,000 region provides good range. Like all aircraft, even though de-iced, they accumulate ice pretty quickly and performance decreases. Its better to get out of ice as soon as possible.

From memory the C421 was heavier, but carried more fuel and operated nicely around the FL200 mark (especially the C Model), but he engines were a problem (even when shown lots of TLC). Perhaps Gaunty can fill us in on his experiences with the C421?

The PA31P was a man's aeroplane. GTIO - 541 engines - 400 hp on take off, noisy outside, smooth inside. Drank fuel, you could use up the aux's just climbing to FL200. Qld government had one (VH-SGA) and the old Air Tas operated BSF on aeromedical flights, until one clown ran a tank dry and switched tanks without closing the throttle, the resultant surge caused a counterweight to smack the bottom of a piston, which slowly came apart and on the next flight filled the oil filter full of metal, and was shut down due lack of oil pressure. Last I saw of BSF was outside GAM's hangar at Essendon. Although I do remember hearing that the owner used it on a rain making contract after that.

[THE IRON MAIDEN]

Thank you all for your comments.

It looks like the Mojave is a go'er...

Any tips and hints on flying her?

[Stationair8]

Good endorsement done by somebody with a some time in the Mojave, not some **** who just wants to give you an endorsement, and a few circuits for his/her ego.

Get the Mojave POH and have read up on the systems, and get some notes on the basics of pressurisation systems and how it works.

Brush up on your met because you will be operating in the mid flight levels.

If you haven't done much in turbocharged aircraft a bit of research on operating turbocharged engines won't go astray.

[gaunty]

Stationair8

Sage advice re Mojave training indeed.

But the type was a last ditch effort by Piper just before they went backwards out the door. It was a mongrel with bits from here and there cobbled together and hurried to the market without the benefit of years of development that produced the ultimately reliable C421.

The RFDS had a very brief flirtation with them which in my view had not much to do with whether it was suitable or not, I had a little bit to do with their change from the C421B to turbines. So I know the battles that were fought. The aircraft never got close to performing as advertised, and that wasa when they could get ti out of the hangar for long enough. Have a look at the charts for when the temps get to be more than a little warm.

Any rational and objective comparison shoews beyond any reasonable doubt should show THE IRON MAIDEN
if it has to be a piston the C421C is the answer. He may not know that this aircrfaft was the reason that Cessna in the first instance never bothered with a turboprop and went straight to Citations. The 421 went further higher and as fast as any of the then turboprops, so why build another, next step fron a 421 for owners was the C500 which started life as a C421 with turbines. And if you look closely there is a lot of 421 and T37 in the C500.

All pressurised aircraft of that vintage are now a relative vale of tears, some less so than others.

If you can find a late model low hour C421C or even a C414A Chancellor you will be miles better off for spares support and so on. GTSIO engines. ?? no more or less relaible than any other operated to the manual. Ran more than a few sets to TBO without a problem followed by routine overhauls and on to the next one.


Dont scoff at the C414A Chancellor, the next cab of the Cessna ranks was going to be this aircraft with the 402 engines at 325HP. Payload, range speed for East coast on one of these is line ball and economics cheaper than the 421.

There is a reason why it is harder to find a nice low hour 421 and easy to find the same in Mojave. Its worth the effort believe me.

[Stationair8]

Bit harsh on the piston powered Cheyenne, Gaunty!

One of the selling points for the RFDS on the Mojave was aircraft came standard with cargo door, whereas the C414/421 required the expensive large door modification.

As I said in my previous post the RFDS were desperate to standardize their fleets, so many different sections and so many different ideas. Cessna, Pipers, Beechcraft and GAF, must have been an aircraft salesman dream.

We tried to purchase VH-HFD and its extensive spares package(2 engines, 2 props) off the RFDS WA Section but was pipped at the post when they sold it to the RFDS TAS. The RFDS had done a very nice job of the medical fitout in the Mojave, but at the end of the day 190 kt piston twin isn't suited for the long distance in WA

We spent sometime talking to Airlines and Tasmania who operated VH-XGW on the air ambulance contract and they had a pretty good run with it, but obviuosly spent time and money training their pilots to do everything the right way. The chief engineer sang the praises of getting full engine life, and no major problems.