Mooneys over mountains - riding a mountain wave.

[carusoam]

Thank you CNOE.

Best regards,

-a-

[Bartman]

Thanks to CNOE and all for the discussion and different points of view.  I have never flown out west with the tall mountains, rather I fly routinely over the Appalachians and often over and around Mt Mitchell.  I have flown more times than I can count with winds of 30-40 and even seen calculated and forecast winds in the 50-60kt range. I am usually anywhere from 2,000 to 6,000 above terrain, and both departure and destination at least 100 miles from the rocks.   I have been in turbulence obviously, and some of it uncomfortable. I have experienced a small rotor in clear air a couple of times that was basically uncontrollable for about 15 seconds, and some smooth wave action.  Even requested a block altitude a couple of times due to wave action. However, in ten years of flying I have never experienced a sink rate greater than my climb and I can imagine that would be pretty unnerving. 

I can imagine one of the reasons is the Appalachians are basically one ridge with foothills on either side, whereas the Rockies are multiple ranges and multiple peaks with all of the complicated wind speeds and directions resulting. 

[RobertE]

Thanks, CNOE, for a fantastic and helpful Pirep, complete with maps.

One thing people seem to be missing is that you were dealing with a quartering tailwind.  The downdrafts were all after the peaks, not before.  And any rotor danger you avoided with elevation.  So what was the risk?  Well done.

There is one mystery.  I've, reluctantly, departed into a big time headwind over tall Montana peaks,ready to turn around if the turbulence got too bad or the mountain wave too severe only to find..... nothing.  So it's a mystery.  You did everything, it seems to me, in an entirely thoughtful and safe fashion.  Yet we never know what we're going to find up there.

[cnoe]

Thanks for the comments Bart and Robert. And Anthony.

FWIW there was an overcast then broken layer at 14,000' that ended several miles prior to reaching this mountain ridge. At the crossing there were no cap, lenticular, or roll clouds visible but as you know that doesn't mean there's no turbulence or waves.

Even though the sink rate exceeded my available rate-of-climb there was no noticeable sensation of dropping like you feel in a strong downdraft. Because of my generous altitude it didn't feel threatening and instead was a quite interesting experience.

I'd recently completed a paid course of study on aviation weather in which mountain waves were discussed in some detail. I was previously unaware of the importance of a higher stable air mass to reflect the rising air. A SkewT-LogP graph can sometimes help identify conditions ripe for wave formation. And amazingly the waves sometimes appear as lines of clouds on a high resolution satellite image.

I will never understand it all but I'm attempting to learn as much as my pea-brain will allow. That and a little luck as well.


Sent from my iPad using Tapatalk

[gsxrpilot]

I've been in and out of Durango on the same route as @cnoe many times. I've done it in an M20C, once toping out at 16,500 full loaded, and also at 17,500 in a turbo 252 (could have gone higher, but it was the dog's first time on the O2).  Regarding the flight in question, I would have been happy to be riding along with Chuck and probably wouldn't have even paused the movie on the iPad during the mountain wave encounter. There are a number of items to check for safe mountain flying, and Chuck had them all covered with plenty of margin to spare.

From his description, it was a perfectly safe flight and one I'd do again without hesitation.

BTW an engine out because of altitude is no issue, and unlikely until well into the flight levels. All good pilots should be comfortable with engine out's at altitude.

[thinwing]

2 hours ago, gsxrpilot said:

I've been in and out of Durango on the same route as @cnoe many times. I've done it in an M20C, once toping out at 16,500 full loaded, and also at 17,500 in a turbo 252 (could have gone higher, but it was the dog's first time on the O2).  Regarding the flight in question, I would have been happy to be riding along with Chuck and probably wouldn't have even paused the movie on the iPad during the mountain wave encounter. There are a number of items to check for safe mountain flying, and Chuck had them all covered with plenty of margin to spare.

From his description, it was a perfectly safe flight and one I'd do again without hesitation.

BTW an engine out because of altitude is no issue, and unlikely until well into the flight levels. All good pilots should be comfortable with engine out's at altitude.

My nephew was a real cheap guy...he would rent a 152 from the Fallon Nv flying club ,head over to Minden ,find some wave ,shut the engine down and soar for hours.They caught wind of it when he had the 152 out for 3 or 4 hours and the Hobbs only recorded .6

[1964-M20E]

1 hour ago, thinwing said:

My nephew was a real cheap guy...he would rent a 152 from the Fallon Nv flying club ,head over to Minden ,find some wave ,shut the engine down and soar for hours.They caught wind of it when he had the 152 out for 3 or 4 hours and the Hobbs only recorded .6

This would be interesting to do in the Mooney.

 

Dose that count a glider time?

 

 

[salty]

1 hour ago, thinwing said:

My nephew was a real cheap guy...he would rent a 152 from the Fallon Nv flying club ,head over to Minden ,find some wave ,shut the engine down and soar for hours.They caught wind of it when he had the 152 out for 3 or 4 hours and the Hobbs only recorded .6

How is this different to the owner than renting and stopping at a nearby airport for lunch for 2 hours?

[thinwing]

Just now, salty said:

How is this different to the owner than renting and stopping at a nearby airport for lunch for 2 hours?

Im with you salty!..but the Navy guys running the club took a dim view for some reason.Id like to believe he got the idea from his uncle!

[thinwing]

21 minutes ago, 1964-M20E said:

This would be interesting to do in the Mooney.

 

Dose that count a glider time?

 

 

Mooney =better glide ratio.....FAA says not with the moter on the front

[carusoam]

I used to catch some M20C glider time riding a ridge wave...  basically slow flight with the engine at very low MP...

The only problem was there was nobody to ask if this was OK or not.  Low MP, Low CHTs, low FF, building hours... the POH didn't have much info to support it.

The C152 I trained in would fly backwards in the same area, when the winds are right... 

PP ideas, not a CFI...

Best regards,

-a-

 

[cliffy]

I used to thermal my C-140 on good days with the prop stopped. I've ridden the sierra wave over the top of Mt Whitney in a C-182 still climbing good at 16,000' when I pushed over. On the east side of the Sierras over the Owens Valley, you can catch the wave going N-S and ride it for several thousand feet up and down perfectly smooth, NOT A RIPPLE, just go up and down trying to hold level flight.

My first instructor caught one over the Owens Valley in a DC-3 and topped out at 18,000 with the gear and flaps out and power at idle (sucking on the tube, if anyone knows what that is :-)

We feel wave action in jets up high even in the 35K' region. It was lots of fun in a short Lear 24 One had to disconnect the A/P and hand fly.

Flying out west brings in a new focus of thought patterns and makes the flights interesting- trying to pick the smoothest route. Sometimes no matter what you do, you get beat up.  

 

[Gary0747]

I fly the route over ABQ often flying between Phoenix and Michigan and have followed my brothers advice who flys out of Durango. He says if you want a safe comfortable flight do not go if the forcast winds at 12,000 feet exceed 25 knots regardles of how high you plan to fly. I have done this and avoided the thrills. 

[M20kflyer99]

I fly the route over ABQ often flying between Phoenix and Michigan and have followed my brothers advice who flys out of Durango. He says if you want a safe comfortable flight do not go if the forcast winds at 12,000 feet exceed 25 knots regardles of how high you plan to fly. I have done this and avoided the thrills. 

I agree with this. I fly out of KMTJ and TEX and if the winds at the peaks are getting over 25 I'm looking at the passes with much more thought and concern. This was especially important when I was flying a Cherokee 160 in the area.

[bradp]

I got a mini wave action flying over the Appalachian chain this past weekend.  Enjoying a 45 kt quartering tailwind at 9.5 k I was getting consistent oscillations of +/- 500 fpm every 30 seconds or so.  Perfectly glass smooth.