Any Twin Comanche Drivers?

[xxilim]

Hi all,

I'm a private pilot in the process of organising a twin rating for myself.
For all practical purposes I'm going to be doing the rating in a Twin Comanche, specifically a PA39 with tips tanks, non turbo.

Any one have any tips or advice for the Twin Comanche? Or even a twin rating for that matter?

I'm a bit perplexed with the flight manual I have too... mind you it's a "Copy" so it could be incomplete.
There appears to be no "Time to climb / Fuel" chart or a Vxse speed published? Is this normal?

Cheers for any advice. :ok:

Craig.

[Ex FSO GRIFFO]

If this is an 'initial' twin rating, why do it in the PA-39, which, with the contra rotating props will not teach you a great deal about the 'critical' engine?

Why not in a 'straight' PA-30, which is a good training twin...you will learn the value of S/E speeds, procedures etc...
:D

[HEALY]

Hi

Did a couple hundred hours in one and learnt a few lessons.

1) Needed some ballast in the back for training and only 2 up front
2) Manual gear extension requires 3 arms, 6 legs and 3 chapters of a Karma Sutra book to operate
3) If the bladders dry and unstick they can "float up" and give false indications of fuel
4) In the flare the turbulent flow from the wings tended to reduce elevator authority and made for some very hard landings, not helped by big fat low compression undercarriage
5) Barely climbs on 2 engines in warm weather let alone one
6) I think I remember the fuel caps to be finicky as well

May all be horse s@@t and only I had these happen issues but otherwise survived

[xxilim]

Hi Griffo, reasoning for the PA39 is that I needed a twin that's based locally, I had two choices, the Comanche or a 310. For insurance reasons I had to go with the Comanche.

Thank Healy, I've heard they're a bit painful to land. Do you recall much about fuel planning etc? With all the emphasis on fuel management I find it hard to believe there's no fuel to climb chart in the manual?

[HEALY]

Sorry bud, years since I flew it but I think it had two 160hp donks. The fuel flow is about double that of maybe a 172 but I'm guessing. I don't recall ever adding any margin for the climb to be honest, Again it may only of been the one I flew but leaning at altitude the fuel flow gauges look like they are close to running in nothing just due to where the indications sit.

Another thing I thought of was the fuel transfer system as well, you have 6 tanks in total and the selectors are on the floor, poorly maintained these can be knocked out of place causing mild heart issues! Whenever you got a splutter the memory actions was down to the floor and switch both to mains straight away

[Gulfstreamaviator]

I flew a twin and single com.

Apart from having a great time in both, I remember the ground effect with the very low wing and the short legs, it would float for two weeks every time I tied to land.

Flul efficient...very.

Comforable ride very.

Sorry no numbers or manuals.

enjoy the twin com....

glf

[fl610]

Thank Healy, I've heard they're a bit painful to land.

Land on the nose wheel, then gently lower the mains to the ground! :}

[xxilim]

Thanks for the heads up guys.
I'm sure it'll be a nice machine to fly.
I'll just have to dig around and find out whats up with the climb fuel planning.
With comparison to the A36 I usually drive, the PA39 manual just seems incomplete and messy... :confused:

Cheers, Craig.

[tecman]

Quite a few bar hours have been spent comparing the A36 and PA24. As always it's horses for courses but, for what it's worth, I favour the view that says the Comanche is much more of the 'pilots' aircraft. It's a bit more demanding to handle but rewards the ego when flown well. There is a fair bit of handling folklore associated with both the single and twins but be wary of falling into the traps of e.g. excessive approach speed. You can do really nice landings, with lots of flap, at the book speeds. Generally, if you find yourself floating, you're doing it wrong. Similarly, if you're 'arriving' hard, a short application of power around the flare can work well.

Having said that, there are some delightful idiosyncrasies which I presume come mainly from the wing form (which is quite symmetrical, as I recall). I've noticed it mainly with the singles that have the tip tanks but it's a cool thing to be able to float a few cm above the runway - seemingly for ever - on a calm day. The smallest deflection of the little finger on the yoke will then land the aircraft.

By the way, the manual style may simply be an age thing. These aircraft are all getting pretty long in the tooth now. Not sure what vintage your A36 is but, in general, you see a lot of difference in manuals from the 60s and 80s.

Enjoy the training and avoid those 'twin catastrophe' stories. :)

[xxilim]

Tecman, I just learnt that the "GAMA" POH specification was introduced 3 years after this PA39 was built, so that probably explains the messy manual.

I'll see what the local instructors have to say about the fuel planning.
Considering it's not a familiar aircraft I don't feel comfortable with those "Rule of thumb" applications for climb.

Thanks for the info/advice everyone :ok:

[Wally Mk2]

There's plenty of info on the Net about the "twin can" as they where affectionately known:-)
Did my IFR rating on one a 100 yrs ago in TW during Jan, half tnks 2 up & one donk, keep an eye out for a good cleared flat field!:-)
Nice to fly though, kinda like an old Jaguar sports car:-)
160HPx2 & a 160 kts, not much around that could match those figures back then.
If you are prone to reacting to fuel vapors within the cabin then I'd suggest lots of fresh air directly at yr face, the fuel system leaked like a sieve at the fuel selectors which as has been said was a night mare with wear.
I used to plan on 60 ltrs an hr (longer flights)& that worked out pretty good as the extra power/fuel used in the Clb was somewhat negated with a lower pwr setting for descent.
The 12v U/C system ( I think a lot are 24v these days)can be a problem to if not serviced reg. A smaller nose wheel when fitted helped with the wheel barrow type Ldgs the twin can was renowned for. Fly it on in a 'flattish' attitude using pwr where needed worked for me. Flaring & trying to hold it off would usually mean hello I have arrived !:-)
They had a bad reputation when they first hit the skies but like all thoroughbreds they needed to be treated with luv & respect:-) Bit like the misses..........phew thank god for Ebay!:E

Enjoy the ride, as towards the end of yr career it's those days flying challenging machines that will live on in yr memory:ok:


Wmk2

[tecman]

Wally, the Janitrol gasoline heater was a worry, too. Must have been sounder than they looked, or else everyone did what we did and wimped out, preferring the cold.

[Wally Mk2]

'tecy' fortunately a lot of those old gas burner heaters didn't work properly anyway, most likely saved a few lives without even knowing it!

Flying up around Tammy in Jan an A/C would have been better but the drag on one eng with a compressor turning would mean certain death if ya couldn't turn the bugger off!:-)


Wmk2

[KeepItStraight]

I've got about 700 hours on the PA30 and have instructed on it. The Twin Comanche is a good honest twin. It feels like a sports car to fly, it has nice harmonised contriols.

You should get about 165 to 170 knots true at about 7000 to 8000 feet.

Don't sweat the climb figures too much. Plan on 65 litres per hour cross country (including climb) and about 75 to 80 per hour for training and hacking about when you don't get to lean it properly. If you really have to have a climb figure I would say about 75 litres per hour.

On an ISA day at sea level you should get around 160 FPM single engine at 3725 lbs (1690 kg) which is MAUW with tip tanks full and about 260 FPM at 3600 lbs 1635 kg MAUW with tip tanks empty. Note I said should get, aircraft condition and ambient conditions will play a big part in actual figures.

As already mentioned the PA30/39 can be a challenge to land nicely one or two up, this is because the C of G is at the forward limit. With some ballast in the luggage area or rear pax it lands much nicer. Landing with reduced flap settings can help when just two up.

I very much doubt any have been converted to 24v. The undercarriage system is very simple and robust and gives very few problems....provided like any piece of machinery it has been properly maintained. Despite what someone posted the emergency extension process is simple and easy.

There again the some comments that have been posted about the fuel system indicate poor maintenance. There should be no fuel smells. The bladders don't become "unstuck" due to them becoming dry. There is no transfer system, the fuel is fed directly to the engine from the selected tank. The selectors are not easily knocked.

The main and aux tanks have bladders which are held in place with clips, it is possible that some clips can come undone which means the tanks will not hold to stated quantity so you do need to be careful until you know the aircraft.

Make sure the fuel caps and the seals in the fuel doors on the mains and aux tanks are in good condition. Other wise you may get rain water in the tanks particularly the aux tanks. Always, always, always, do a thorough fuel drain from the fuel selectors, preferably into a container so that you can see what you've drained. The drain tubes are under the belly of the aircraft. CASA knew better than Mr Piper and insisted in having drains inserted into the wings as well, draining from these alone isn't sufficient IMO.

Hopefully your instructor is Comanche knowledgeable.

Don't be too concerned that it's a PA39 rather than the PA30. True it has no critical engine but otherwise it'll do the same things and you'll learn the same things, the speed will be slightly different for Vmca.

As has been said the Comanche was built before the GAMA standard POH was introduced. The manual is rather basic however there is a GAMA style POH available from the International Comanche Society that has much of the info you're looking for.

I'm sure you will enjoy the Twin Comanche. There is no other light twin than can match it's performance, payload, range etc.

[poteroo]

Very good info from K-I-S.

I used 56 LPH for longer range flying the PA-30B or C, and flight planned on 150 KTAS for very conservative numbers. They fly a whole lot better with weight spread through the cabin.

Can I recommend anyone thinking about range and endurance in the PA-24 and PA-30 Comanches read Into the Wind-The Story of Max Conrad by Sally Buegeleisen.

Conrad, (1903-1979), was a contemporary of Lindberg and other pre WW2 aviation legends. He died with over 50,000 logged flight hours in his logbook. He made 150 ferry flights over the Atlantic, and 30 over the Pacific.

He recorded a PA-24 flight of over 58 hours airborne, and a PA-30 flight of 6,830 nm from Capetown to Florida. Some of his fuel miserly flights in Pipers are still world records. He was recognised by several prestigious awards, and is considered one of the greatest ferry pilots of all time.

happy days,

[Capt Casper]

I have an original Piper Twin Comanche Owner's Handbook.
I scanned the following from the performance section, the numbers are page numbers:-

SECTION IV
PERFORMANCE CHARTS

Take-off Distance Over 50 Foot Obstacle.....................37
Take-off Ground Run................................................38
Take-off Distance Over 50 Foot Obstacle (Short Field)..39
Take-off Ground Run (Short Field) ............................40
Best Rate of Climb Speed ........................................41
Single Engine Rate of Climb......................................42
True Airspeed vs Standard Altitude............................43
Range vs Standard Altitude......................................44
Enroute Single Engine Service Ceiling........................45
Landing Distance Over 50 Foot Obstacle....................46
Landing Ground Roll...............................................47
Landing Distance Over 50 Foot Obstacle (Short Field) 48
Accelerate - Stop Distance .....................................49
Altitude Conversion Chart ......................................50
Power Setting Table ..............................................51

If you pm me a private email address, I can send you any of the above in PDF format. There is no climb fuel graph.

Quoted consumption - 84 USG useable leaned to best economy
17.2 gph @ 75% 800 sm @ 8000'(std Alt) inc 45 min reserve
15.2 gph @ 65% 860 sm ditto
13.4 gph @ 55% 910 sm ditto
11.2 gph @ 45% 975 sm ditto

I presume the above would include the climb, but it doesn't say so.
You then have to do all the conversions - ANM to GNM, USG to Ltr, Std Alt to Press Alt etc.

Practically we used to use rule of thumb with a fudge factor which was acceptable to reasonable people once upon a time, but I doubt if NASA could satisfy the CASA bureaucrats these days.

[xxilim]

Thanks once again everyone. There's been an overwhelming amount of responses, I really appreciate it! :D

[Ex FSO GRIFFO]

Hi Mr XXiLim,

Thanks for the response, if you only have the two to pick from, then go for the PA-39, you will enjoy it.
As has been said by others, it is a pleasant aircraft to fly.
When landing, just learn to hold off whilst she floats a little - that wing trailing edge with flap down is not far from the ground, so you will get some effect.
Where your A-36 'clunks on' in comparison, the PA-24 Single, and PA-30, basically share the same airframe / wing, and share the same 'float', although with the single, the approach speed can be less.

I found the '30' to be an 'honest' aircraft, in which you do learn to be 'accurate' with S/E speed / power etc, otherwise the VSI may not show much 'up' at all.....but that's a good learning machine, and there are many other aircraft in the 'real world', which, with a reasonable load, will perform likewise......
I have no experience on the '39'.

As an aside. the POH I had at the time had about 3 pages devoted to the fuel fired heater in the nose - how to start / manage etc - more space than was given to some aspects of actually operating the aeroplane...
It was also said in the same POH that, said heater used 'so little fuel' that its consumption rate was not significant, and for practical purposes, could be ignored.

I still took it 'into account' when used.....'Old Habits' etc....

Good Luck, and ENJOY!!!

Cheers:D

[tinpis]

Hazo's Bankstown churned out many IFR ratings with them little buggers in the 70s. Seemed pretty well suited to the task

[404 Titan]

I did my initial twin rating and MECIR in a PA30 back in the early 90's and have about 250 hours total on type. I haven't flown one though since 1996 so my memory is fading on the specifics but I do remember it to be a very honest little platform. In particular it taught proper fuel management from day one with 6 fuel tanks and strict restrictions on when you can use and/or transfer fuel from certain tanks. It put you in a very good position to later operate and deal with other aircraft with similarly complex fuel systems, ie C310R.

The PA30/39 has never been an aircraft that easily allows the pilot to produce good landings on a consistent basis, a bit like my current steed, the A330/340. I personally have never been in favour of holding any aircraft off more than usual in ground effect to achieve a smoothish landing. Touch down point is far more important especially on short bush strips and using one technique for landing all the time is preferable especially if one has limited experience.

[PA39]

Have owned two tin cans, a 30 with C/R and a 39. 39's have a bigger (thicker) stabilator. 150 kts TAS and 60 lts p/h. For me they were economical, huge endurance ( 7 with tips) go ok at 150, solid and comfortable. The small nose wheel STC made the TC a much better aircraft to land rather than the controlled crash. Again, For me they are the best bang for buck in the little twin range. The C/R was better balanced but really made for two critical engines...to quote Jimmy H. lol

[Feather #3]

Interestingly enough, I had occasion to borrow a mates's PA-39 the other day to go bush in a hurry.

With only two on board plus out-and-back [sorry Owen!] fuel, the only way it could meet the trim requirement was to seat my wife in the middle seat. We had minimal overnight baggage and our usual 15l water drum right in the back.

This made the flare and touchdown just fine, plus the fact that my wife felt she'd spread out in First Class! ;)

After 40 years of airline flying, I was able to use this aircraft to do my first GA CIR renewal following the endorsement and GNSS rating. It's a delight!! :)

G'day ;)

[Dog One]

Lots of instrument ratings done in CON and WDD at YMMB in the 70's.

[ForkTailedDrKiller]

I got about 3 hours of SEX back in the 70's! :E

[Wally Mk2]

...sheeez Dr:8 how can ya remember that far back?:E............& what have ya done since? That's a looooooong time between drinks there:E

Looks like plenty of good memories here of the old twin can.

What was the name of that other 160HPx2 light twin? Grumman something? Never heard much of that machine.
Bugga, old age...Cougar...yeah:ok:



Wmk2

[KeepItStraight]

Have owned two tin cans, a 30 with C/R and a 39. 39's have a bigger (thicker) stabilator. 150 kts TAS and 60 lts p/h. For me they were economical, huge endurance ( 7 with tips) go ok at 150, solid and comfortable. The small nose wheel STC made the TC a much better aircraft to land rather than the controlled crash. Again, For me they are the best bang for buck in the little twin range. The C/R was better balanced but really made for two critical engines...to quote Jimmy H. lol

I've never seen the benefit of the PA39 other than marketing spin. If you need the lower Vmca a C/R gives then you have other big issues as well.

The PA30 climbs better and goes faster. It's a well know fact C/R engined aircraft need more power to go as fast as the non C/R variant. That's why Piper made the C/R Navajo 325 Hp compared to the 310 HP non C/R.

From an ownership point of view with spares etc the props are different as are the starters. I'd take the PA30 any day.

[PA39]

The '39 was introduced because of the stall/spin accidents. Nearly 4000 hrs in TC's. Robertson STOL changes the aircraft completely...added MTOW 4 up full fuel and bags. Have to disagree the 30 is faster. Bout the same, many TC's are rigged incorrectly, condition of paint, dings etc all have to be considered. They are a mighty aircraft...if you get a good one. I liked the 39 because there were only 155 manufactured before the flood at Loch Haven and as such they are pretty unique. True the starters etc can be a pain in the arse.

[ForkTailedDrKiller]

I got about 3 hours of SEX back in the 70's! http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/evil.gif

I thought someone would have picked up on it by now apart from Wally and his dirty mind! :E

http://www.airwaysmuseum.com/general%20images/VH-SEX-Herald-22-11-69.jpg

Dr :8

[PA39]

Gee Forkie I used to know the driver of SEX many years ago. Member of the ICS. Had forgotten all about it....the aircraft I mean! :))

[27/09]

The '39 was introduced because of the stall/spin accidents.

I thought the rudder gap seal AD, the stall strakes AD and the artificial increase to the placarded Vmca AD were the responses to the stall spin accidents. In reality the stall spin accidents were a result of the training practices required by the FAA, practices that have since been changed.

[Ex FSO GRIFFO]

****e Forky,

I did my CPL & Instr with Aircraft Rentals - John Cougle principal, and the Hon. 'Father' Ray McLean the CFI...and well remember the night we 'toasted' the proposal to reserve the rego's 'SEX' 'SIN' & 'SON'....and park them outside in that order......
SEX was delivered, whilst the other two were delayed and then went somewhere else.....
Just after I got my CPL in 1966.... Happy Daze.....
:ok:

[PA39]

Yes the stall strips were added to reduce the accident rate but after the number of prangs The Comanche which had a disasterous reputation, Piper bought out their "ultimate" safety development...the C/R. Then they bought out the official CR/R with the Robertson. However a go around with full flap should you have an assymetric flap occurrence you were basically cactus unless you were quick enough to retract the other side and recover the situation...so they bought out a mod (spring) to prevent full flap assymetrics.

The tin can was reasonably vunerable to flat spins once assym. Saw one spin in from 6000 while the pilot screamed through the radio, all the way to the ground.

Jimmy H asked me 30+ yrs ago if I could REALLY fly the TC I had approx. 1500 hrs in them. He took me up, went assymetric, into a flat spin and ONLY recovered with assymetric throttle movement amd control column pull and shove. Made me do it over and over again until he was satisfied I could recover correctly. THEN I could handle a TC.

[Wally Mk2]

Christ '39' one has to wonder the merits in doing that. Sounds very risky & that's why that sort of thing is not taught generally in any airframe for that matter.
I got my 'twin can' endo a 100 yrs ago & it didn't include anything like that but I was told to be aware of that sort of thing if coming close to a stall in a VMCA situation.
Old Jack Funnel (may he rest in peace) at MIA showed me how not to get into an unsafe scenario in the '44', that was more valuable to me at the time I reckon being green as a blade of grass on twins.

Go-around with full flaps down in any light twin is fraught with danger, one has to wonder again the wise-ness in that maneuver.

Anyway at the end of the day every pilot is as safe as his prior training, the most valuable of that is how NOT to get into those situations in the first place.


Wmk2

[KeepItStraight]

He took me up, went assymetric, into a flat spin and ONLY recovered with assymetric throttle movement amd control column pull and shove. Made me do it over and over again ......

I have to agree with Wally about the merits of doing that. That would have to be the stupidest or bravest thing I've read about for a while.

I bet the Twin Comanche isn't the only twin that would go into a flat spin.

True the Twin Comanche had a bad rep but as has already been mentioned by 27/09 this was partly due to the FAA training requirements at the time ( low level Vmca demos), but to deliberately spin one I find incomprehensible!!!!!!!!

I was lucky enough to have received some very good advice from a Comanche guru in the US, he had owned a flying school with Twin Comanches. His advice was to never let the aircraft go past 45 degrees angle of bank during a Vmca exercise. He has some other very good tips as well. I have given many hours of type intro and IFR instruction in the PA30 without ever having a problem.

Go-around with full flaps down in any light twin is fraught with danger, one has to wonder again the wise-ness in that maneuver.

Cannot agree more

Anyway at the end of the day every pilot is as safe as his prior training, the most valuable of that is how NOT to get into those situations in the first place. Precisely. Most people get themselves in sticky situations in a training environment by trying to be too clever or "realistic".

[PA39]

Wally Mk 2, Jack Funnell was a great aviator and an even greater gentleman.

On rare occassions a go around in a light twin with full flap is inevitable....some dick wad pull out of the holding point onto the rwy as you pass committal height on short final. It happens.

[Wally Mk2]

Yeah good 'ole JF, everybody loved Jack, a real character:ok:

He once told me whilst I was killing time in MIA that CASA pretty much made it too hard & not worth while anymore to own/operate the twin, he stuck to his beloved SE toy planes.
It was a privilege to have known Jack, I hope he's up there somewhere moving aside as he always did for the 'big boy's to come on into MIA unhindered:)

Soz for the thread drift guys but it's worth t!:ok:

Yes '39' I know there might be the odd occasion where a go-around is the safest option but the secret there in say yr scenario is to gain speed in level flight first b4 pulling up the first stage of flap as climbing initially wouldn't be the priority.
If there was ever a slight chance that a go-around might be needed at the last minute then providing the rwy was adequate length wise App flap was used for ldg giving one a better margin, just the way Jack said to consider it & I never forgot that.
I used to drive the old DH104's, full flap meant (40deg's) you where committed & going only one way...down !:-) I used to treat all light twins the same way full flap was the same as applying the brakes, it's all part of stopping:-)

Wmk2

[Capt Fathom]

Come on guys, it's just an aeroplane! Lets get it down off its pedestal!

[MakeItHappenCaptain]

Go-around with full flaps down in any light twin is fraught with danger, one has to wonder again the wise-ness in that maneuver.

Couldn't agree more, Wal. The Seneca is another that will roll on it's back if a full flap go-around becomes asymmetric.

And yep, PA39, I have had more than one of the aforementioned numptys do that.:mad::ugh:

[Capt Fathom]

The Seneca is another that will roll on it's back if a full flap go-around becomes asymmetric.

I doubt that is the sole domain of the Commache or Seneca!

Given full flap, high drag, low speed and asymmetric thrust, I think most twins would roll on their backs!

[T28D]

The PA 31 certainly will, in a fluffed VMCA demo at altitude the view of the ground was clear in the top of the windscreen quick smart, very sobering event.

[Virtually There]

Glad I only fly the PA24-260 and not the twin! But (being pretty much the same airframe) the single is also susceptible to asymetric flap retraction - which has happened to the owner of the plane I now fly (same plane).

That aside, it's a lovely machine to fly. I'm only a PPL, but I did my retrac on the Comanche and haven't looked back since: loads of shoulder room, great performance (160+kts for the single - who needs a twin?), good endurance (four tanks), seating for four adults and two kids (or five adults), and nice firm handling. Landings seem to work best for me by sticking to the numbers and dragging her in with a little power before putting her down. If you come in too hot with no power, she'll just keep floating.

Oh, and I don't think anyone has mentioned the odd trim winder in the roof, yet. That takes a little getting used to until you remember to wind back for nose-up and forward for nose-down

Anyway, I know this is a bit off topic, but I do love the Comanche!

[Mach E Avelli]

For many years Oxford Air Training in Blighty had a fleet of Tin Bombs used for I.R. training and tests. For their time, they were well fitted out, with HSIs, RMIs and de-ice boots.
'Students' like me converting foreign licences did not get endorsed on type. Also we never got to land it. That bit was always done by the instructor or the examiner. I suppose landing a Tin Bomb every day was the only thrill available to the poor old Poms back then, what with the War being over and all. Quite bizarre really. The CAA Examiner showed up in full four bar regalia and wore a hat - all designed to intimidate, I suspect. The test was purely to see if you could fly accurately on instruments, remain situationally aware and keep ahead of the ice. The asymmetric exercise was a joke - all you had to do was identify the engine - no drills required! I got the impression they were a bit scared of the aeroplane, but could not see why. It seemed quite docile to me and made an excellent instrument platform.
So, my logbook shows 8 take-offs and no landings in a Tin Bomb.