Pilatus PC-6 Porters - different wheels?

[Critical Reynolds No]

Hi all,

Not sure if this is the right place but please move as appropriate.

Having an argument with a mate about different wheel options for Porters, I thought there was only one option but he swears there are two options in diameter. If so, what are the differences and what applications were they used for?

Thanks

CRN

[treadigraph]

I'm pretty certain I've seen the odd Porter with larger than normal diameter wheels/tyres - whether they were a factory option or modified later I've no idea.

If you google "Pilatus Porter" and have a look at the images, some do appear to have larger wheels (If you can get through all the models and FS images!).

[Saint Jack]

The larger diameter tyres often seen of this type of aircraft (i.e. bush aircraft) are commonly referred to as ‘tundra tyres’ and are used where take-offs and landings are to be made on soft ground. The larger contact area of the tyres spread the weight of the aircraft over a greater area and prevent the aircraft getting bogged down.

[forget]

All you'll ever need to know about Tundra tires.

Tundra Tire Nation | Flying Magazine | The World (http://www.flyingmag.com/tundra-tire-nation?page=0,3)

[Planemike]

I have in front of me the Pilatus sales literature for the Porter:-

"Oversize wheels can be fitted on the main landing gear:
O.D. 32 in (approx.)
Size 11.00 - 12 8PR
Inflated pressure 20 psi. "

For comparison the standard wheels are:
O.D. 24 in (approx.)
Size 24.00 - 7.7 8PR
Inflated pressure 49 psi.

Yes all the quoted figures in the literature are Imperial.

So yes, there are certainly two options, and of course you can fit skis, (the one I flew in had skis, Mount Cook New Zealand). No mention of floats but seem to recall I have seen a photo of a Porter fitted with floats.

Planemike

[twochai]

The larger diameter tyres often seen of this type of aircraft (i.e. bush aircraft) are commonly referred to as ‘tundra tyres’

Tundra tires are much larger and lower pressure than the oversize wheels described on the Pilatus Porter. Some of the real tundra tire pressures are as low as 8-10 PSI, IIRC. The problem after landing on the tundra is walking on the surface - it's just too squishy!

[Critical Reynolds No]

Thanks everyone for the quick replies. Yeah I didn't think they were Tundra tyres.

Thanks Planemike for the official data.

Does anyone know if the Air America Porters were fitted with the bigger wheels? (Watching that damn movie started the fight!!).

Thanks again.

CRN