My 172A is headed westbound later this summer. This mighty beast with a fire breathing O-300 and a rip snorting 145HP (on a good day) has never crossed the mountains in the time I have owned it. I have flown it over most of the US other that the NW states. Having hunted out west, I know how engine wheeze and struggle for any power.

I will be flying with my son from Park Rapids, MN to Southwestern, Oregon. This is a first for me at very high altitudes as I rarely fly more than a couple thousand feet AGL. I did go to over 12K flying to AZ once, but that was many years ago.
It'll be my son and I and baggage, basically the limits for an old 172 at high DA. Any changes to this route, tips, or advice would be greatly appreciated. Thanks for any and all help!


The preliminary proposed route:
KPKD > 46D > KGGW > KHVR > S27 > KSZT > KCOE > KHRI > KBDN > 64S > KMFR

Looks like a fun trip, should be no problem. 2 people in an old 172 actually performs pretty well.

That proposed route going over looks good for lower mountain crossings. Coming back with prevailing westerly winds could be a bit more direct using hydraulic leverage up. Be aware however going West into prevailing westerlies in less abrupt mountains that there will be less vertical space available in shallower drainage. A turn back, a canyon turn back, can be dicier there than in the bigger mountains. While more horizontal space is available, don't be as carefree when using wind at an angle to your ridge going up. You may be well above everything but downdraft off higher stuff on further up can put you below the pass. Be aware of close drainage nearby at all times for egress when something unexpected happens.

Use thermal heat during the higher sun part of the day to give the old 0-300 a hundred percent boost up at times. Fly slow to spend some time in this up. That updraft will almost always be followed, and preceded, by a downdraft. Fly fast through down air so it can take less of a bite out of your altitude. Remember God is King, not your little engine. Work with him.

MTV should be able to help you with the particulars on that route. Also long range plans vaporize with weather and such. Be flexible.

Can't comment on either end of your proposed trip, but during the "oil boom" a few years ago I did a couple of round trips between COE and SDY and Williston. Like you, I was doing it in my long-suffering, wheezing 172. Here's what I did.

An experienced Montana pilot advised me to stop at Malta, MT (M75). They had an old Suburban as a courtesy car that was well known in town. Had to pump the brakes a few times to stop the rig. Stayed at the "Maltana" motel. Older but adequate. Talked to a local pilot about routing, he advised flying south and seeing the Missouri River drainage. It was worth it. Landed at Fort Benton(79S) for fuel. On that trip we went over Rogers Pass near Lincoln, MT, and on to St. Ignatius (52S). The runway here starts to look short on takeoff at High DA in a loaded 172. From there direct back to COE.

Another time I stayed further north and fueled at Shelby (SBX) then ended up testing the old plane's sevice ceiling at 13,450'. I was trying to go through the Marias pass, but too many clouds. After picking my way through the tall rocks; stayed high at 8,500 and then direct to COE.

A few notes, (maybe a rant or two...). The "large" FBO's fueling facilities at Kalispell City and I do not get along. There is another fuel pit on the west side that worked better for me. If you have never been into S27 before, it can be hard to pick out visually as it blends in with beautiful downtown Kalispell.

Fuel is cheaper at SZT than COE. I paid $4.55 at Sandpoint 2 nights ago. If you don't have a reason to go to COE, I would avoid it. It can turn into an aerial "Wild West Show" rather quickly.

Keep an eye on the barometric readings as you travel in mountain country. Big differences between one side of the hills and the other can mean some unwanted excitement.
Have a great time on your trip!

Well....when you get to S27 (Kalispell City), you're only about 20 miles from me, so might as well come on out!!! Fuel in Bonners Ferry, ID is at least a dollar a gallon cheaper than Kalispell, so that's a good thing to keep in mind too.
John

Thanks everyone for the helpful hints!! Greatly appreciated!

John, I will definitely mention the invite to my son as he met you several years ago when he traveled there to look at a 170.

I wouldn't worry too much about altitudes. Come down this way, via the "southern Montana" route. But, that 172 will do okay, just use some common sense, and pay attention to density altitudes, especially in the afternoons.

As noted, stick with the smaller communities for fuel and overnight. Many of the smaller town airports in MT have courtesy cars.

At some point, no matter which way you go, you're going to have to get to around ~ 8500 feet to be comfortable, unless you like being really low in the rocks. Just plan the higher crossings for fairly early in the day.

And, eastern Montana and North Dakota do have a tad bit of wind.....or so I'm told...

MTV

It can get really hot in the middle of summer in Eastern and central Washington and Oregon, as it is mostly desert. Frequently 100 degrees plus. Density altitude can be a challenge. I used to own an early 172, and on a few days with two people struggled to get above 7,500 with OAT at altitude in the 80s. It isn't usually like that, but it can be. Expect to be flying at 6,500'-8,500' in the middle of the day to be comfortable and not want a puke bag.

Interesting route. I flew a similar route to Saint Paul, MN to install amphibs on the Scout back in May 2009.

I encountered major convection (instability, TS ) , afternoon turbulence, and strong diurnal winds. Most folks and FBOs are really friendly in those parts. DA can be seriously dangerous but not insurmountable.

Below are the waypoints you posted to help me visualize the terrain:

The fuel situation at S27 can be busy at times, summer charter flights and lessons and a tight fit at the pump at Red Eagle/Montana Air Adventures on the east side of the field. On the west side Diamond Air's pump has more space and no where near as busy.

Keep an eye on any fires out this way, you don't want to get 'smoked'.