Mountain Wave Stories

[Swass]

Share your mountain wave experiences here. What happened when you entered one or what was the result. I have no experience with them and would like to hear what you guys have been through, especially light to medium sized aircraft.

 

[DashTrash400]

When I flew for Ameriflight out of Burbank last winter, my main run was AMF132, which takes a Piper Lance BUR-IYK-BIH-MMH-BIH-IYK-BUR...up to Mammoth Lakes CA through the Owens Valley. On a nice day, it was a gorgeous route, steaming up the valley between the Sierras & the Inyo/White Mtns...14k peaks on one side and 12-13k peaks on the other.

On a bad day though, it could be really bad. When the winter cold fronts out of the pacific reached down into California, and winds aloft were over 40 kts at 15,000' - you could count on 60-70 kts over the peaks and 100 kts through the canyons, aka severe turbulence. The run was not fun on those days. We'd just stay really low to get below the rotor, tighten the seatbelt, grab the glaresheild with one hand & the yoke with the other - and hang on! I got a fair share of bruises from that route.

Once a week, we did that route 2 hrs later than normal, so it was done in darkness. If the forecast was that bad, I'd have the company put a rush on things so I could still do the Owens Valley portion in the daylight.

One friday night, a weak cold front was coming across the Sierras, and most reports in the Owens Valley were moderate turbulence only, so I planned on a nighttime flight down the valley. Climbing out of Bishop, the air was fairly smooth, but it got progressively more turbulent as I flew southward towards Inyokern. By the time I was over the Owens Dry Lake, if you know where that is, I was in moderate-to-severe & not having a very fun time...but I didn't dare to descend out of the rotor due to the darkness, lack of ground lights, and high surrounding terrain.

Anyways, I have the power pulled way back and airspeed down to around 100 kts to take it easy on the old Lance, and about 20 mi out of Inyokern I start my descent. Around 6500' it starts getting pretty wild - I got knocked to around 70 degrees bank, twice. Suddenly, poof: everything goes absolutely silky smooth. I look at the instruments: 160 kts and increasing, VSI pegged upwards, altimeter winding up like crazy. I'd flown into wave, the only time I encountered it that low. I went from 6500' to 9500' in under 1 minute, power-off. At that point I was thinking, lovely...no oxygen on board, I gotta get out of this. I got permission from Joshua Approach to penetrate the restricted area just east of me, and soon found the "down" portion of the wave...lost the altitude just about as quickly as I gained it. Landed at Inyokern soon after, deciding I really needed to start pestering someone about getting a Chieftain route! Came to Horizon instead.

Those AMF Lances were old but they sure were solid airplanes.

 

[SkyWestCRJPilot]

Back when I was flying freight I experienced some pretty good mountain wave in Colorado. I was new and flying in a Chieftain on my route from Denver to Alamosa, Colorado at night. The canned flight plan route was from Denver towards the south flying on the east side of the front range towards Pueblo then west towards Alamosa. The whole route was flown at around 13,000 feet. One time while new and flying along this route the airspeed began decreasing as I maintained cruise altitude. Then I had to increase cruise power to stay above blue line. It was smooth air with no turbulence. Soon I had to increase power all the way to full power to stay above blue line in level cruise. That was something like 45 inches of manifold pressure. My fuel burn was trememdous and I began to worry if I would have enough to get to Alamosa. I had no idea what was going on. Just that I was in a downdraft that wouldn't ever end and I needed full power to just maintain altitude. Later I realized I was flying in the downdraft portion of the moutain wave paralleling the troughs and ridges and my southward route would continue to take me through this downdraft all along my route. I was rather inexperienced and didn't know what else to do. Looking back now I probably could have altered my course eastward and found the updraft portion of the mountain wave. I pressed on and flew with an agonizely slow groundspeed in this severe downdraft for probably 30-45 minutes with a huge fuel burn, not to mention it not being good on the engines to operate at such a high power setting. Eventually the downdraft subsided as I flew out of the mountain wave and I turned west towards Alamosa with enough fuel and landed.

After I realized what I had experienced I decided to alter the route I flew. Instead of flying southwards east of the front range right in the perfect spot for a continuous mountain wave downdraft I elected to fly a more direct route south/southwest bound at FL180 and climb above the front range. This new route worked much better and on nights that there was mountain wave I never experieced nearly such poor conditions again.

Later while flying the CRJ over the front range I have experienced mountain wave while we were crusing up in the mid 30's. This was only evident by the airspeed slowly decreasing or increasing by about 40-50 knots as the autopilot would smoothly adjust pitch atitude to maintain altitude. There was also no real turbulence during this either but it was rather smooth as well.

I hope this helps.

 

[Flyin Tony]

I dont know if this is mountain wave but I was going into Havasu last summer and It was a good 120f on the ground. Had the power all the way out and nose going down and trim all the way down, and I was still climbing.

 

[414Flyer]

I once hit the upward part of a rotor, when coming around the north point of the big island, flying counterclockwise towards Kailua Kona in a C-172. I was around 2K, and saw the VSI just go up, and up, and up, until the VSI was pegged, and it just stayed pegged. It will still silky smooth as can be, like the other person experienced too.

This went on for about 2 minutes, until I ended up around 7K, and once I came out of it, it was like some giant hand just abruptly grabbed the C-172 and shook it around like a toy.

 

[Kawasumi_Kichou]

Caught a good one over the Tehachapi Mountains, in a Turbo Arrow IV on my way from El Monte, CA to Reno, NV. Very strong NW flow aloft that day with 60 knot winds just about on the nose at 9000. Got the same kinds of huge up and down rates that the others have described here. What was memorable was the smoothness. An absolutely solid ride, not a single bump. The controller asked in a voice that just cracked me up, "Are you in a wave?". He mentioned everyone else in that area was doing the same thing--apparently we were all going up and down in perfect unison.

Later during the same trip I let myself get clobbered by the worst single burst of CAT I've ever been in, just west of Yosemite. No warning, just hit it square at about 160 knots. Knocked my flightbag and Jepps into the back seat. Immediately reduced to Va thinking to myself, "That was stupid." Climbed higher into worse but smoother winds and went on oxygen. The rest of the trip was uneventful. It was 3.6 hours of bumpy lessons learned.

 

[Ill Mitch]

Flying gliders out of Minden, NV and seeing the Pawnee towplane climbing up towards me (not towing a glider)...with the prop stopped. Gotta love wave.

 

[Crimson03]

Funny how sailplane pilots love wave, power pilots not so much ...
An excellent read on the joint AF/Civ wave project in the 50's is the book 'Exploring the Monster' SSA has it, saw a copy in the pilot shop at nashua once. When I bought mine it didn't show up on amazon, that might have been me screwing the search up.

 

[comander]

I was flying in canyons in guatemala, this was like my fifth hour after my ppl,very nice day,I had a mountain I was supposed to fly over in sight and knew I was already over it at that point,suddenly my c-172 made a 60 degree bank to the left and I grabed the joke and turned it to the right.it was such a surprise.
when I came to realize I was loosing altitude real fast so I whent full power but my airspeed was dangerously close to a a stall and my vsi was still going down maybe like 900 fpm. I realize I wasnt going to make it pass over the mountain and it was real close to me at this moment,so I made a 180 , gain much more altitud and then passed over it ,but it was very scary.

I had others but in a hanglyder, but this I think where thermals, and I was looking for them,however it is a rough ride to the crest, I have had fellow hanglyding pilots that couldnt come down when they wanted to.

 

[urflyingme?!]

Flying up the valley towards Mammoth at night!
YEHAHAAA
(Scary!)

 

[Flyin Tony]

Flying up the valley towards Mammoth at night!
YEHAHAAA
(Scary!)

I was comming home from RNO with a friend after work and we got upto 17K and tried to get over the TStorms. Well that didnt work. It was all ovc and one hole over BIH. We got below the layer and it was getting dark by this time. Last time I fly down the Owens Valley at night. We stayed right ontop of 395 to IYK and stoped there to put gas in the plane and look at the charts to see how we were going to get back to apv.

 

[barnyard]

Last winter I did a freight run from Lynchburg VA to Charleston WV in a 402B for Package Express and man did that run teach me about the mountain wave.

Lynchburg sits about 20 miles east of the easternmost ridge of the appalaichian mountains and with a strong wind out of the west I would get creamed every night... stuff flying around the cockpit creamed. I thought like a good freight pilot I needed to scream into the pattern every day trying to save every minute of block time possible... after a couple weeks I started slowing the airplane down well below Va about 50 miles out of LYH and hitting the ridgeline at a 45 degree angle to avoid going right through the worst part of the rolling turbulence. Might have added 5-10m on the trip but sure did save the a/c some wear and tear.

It's also pretty funny if you havent hit the wave in a while and you start to believe your skills have seriously deteriorated due to your inability to maintain altitude but after a few minutes you realize you're just riding the wave!

 

[urflyingme?!]

Snap! As a private I needed to fly my aunt up to BIH from LG, she had a sick friend. No FBO would let me take their plane!(Even the one that gave me the license!)

 

[secks]

Dumb question here. Exactly what is a mountain wave, and what causes it? How does it differ from an ordinary gust of wind?

 

[Moonfly201]

It was late December, and a strong cold front had just passed. Airports in NY and PA were reporting winds gusting into the 30's kts, but it was still relatively calm in New England. I was flying a Mooney from Providence RI to southeastern PA IFR along the airways that take you well outside the north and west side of the NY Class Bravo.

In and out of scattered layers at 8,000' I was approaching the southwest corner of the mighty (LOL) Catskill Mountains in southern NY, and was getting some turbulence. I asked and received a climb to 12,000' to try to top the clouds for a better ride. After leveling at 12,000', I approached SAGES intersection, which is a dogleg in the airway northeast of Lake Henry VOR, and on the lee side of the Catskill Mountains when the winds are out of the northwest.

I entered a downdraft, and as I pointed the nose up and powered up to attempt to maintain altitude at best rate (88kts indicated IAS), NY Center called me and asked if I was aware that my groundspeed was down to 20 kts. Told them that yes, I was experiencing a strong downdraft, and was unable to maintain 12,000'. He asked if I needed to declare an emergency and divert to the Sullivan County Airport and I said no, I had plenty of altitude and if I decided to divert anywhere, it would be downwind to the southeast. He said I could descend as necessary, and then he asked a turboprop in the area what the winds aloft were. The turbo-prop said at 15,000' the winds were 125 kts! Apparently, the jet-stream had taken a dip over the Catskill Mountains.

Up until this point, the downdraft had been smooth, but I was slowly descending into the tops of some clouds that had the upper edges very torn, with small wispy pieces of clouds floating just above the tops. As I entered this wispy stuff just above the tops all he** broke loose.

The worst turbulence occured that I have ever, to this day, encountered in any aircraft. The Mooney was temporarily out of control. My flight bag on the seat next to me was flying up to the ceiling, and then banging down onto the seat. Dirt and small gravel from the carpet was floating, my head banged into the window and I did all I could just to keep the blue side up. I tried to talk on the radio to inform NY Center that I was going to turn to the southeast but when I tried to talk it the headset sidetone sounded like I was a boxer taking body punches ... grunts came out instead of words.

At this point, the aircraft slowly started climbing, and the severe turbulence stopped. I never made it into the solid cloud top, only the torn wispy stuff. The severe turbulence probably did not last more than 30 seconds to a minute, but seemed like an hour. The updraft continued and my airspeed returned. The rest of the flight was normal.

On later trips along this airway, I noticed that there is a distinct "notch" in the Catskill Mountains about 8 or 10 miles northwest of SAGES intersection. I believe the jetstream lowered and funneled winds into this region which were magnified via a venturi-effect, which on this day created a very localized set-up for some memorable turbulence.

 

[Gulfstream 200]

Dumb question here. Exactly what is a mountain wave, and what causes it? How does it differ from an ordinary gust of wind?

very basic:

Its a strong flow of air over mountains/ridge lines that produce rolling "eddys" which can produce signifigent turbulence downwind.

typically just causes a "wave" type fluctuations in altitude/airspeed. Feels like your "riding a wave"..

typical over the rockies - especially in the winter.

 

[DashTrash400]

Flying up the valley towards Mammoth at night!
YEHAHAAA
(Scary!)

Well, from Mammoth actually. MMH-BIH-IYK-BUR. On a calm, clear night it wasn't bad - stay at 9500' over the center of the valley (US-395) & you'd be okay. If there were low clouds forecast or nasty turbulence I didn't feel like doing at night, I'd have the company get all the shipments to the plane early so I could do the Owens portion in daylight, or I'd reposition in daylight further down the valley and the couriers would drive to meet me. Going IFR was out of the question until south of IYK, as the MEA's were far too high for the normally aspirated Lance.

There was one time an unforecast snowstorm moved into Mammoth rather quickly...I was at the layover in town & saw it coming over the skihill, so I tore ass down to the airport, preflighted, & took off for Bishop just before it hit. Well I'm down at BIH and about an hour later, low clouds are coming in over the Sherman grade...end up taking off from BIH only a few minutes before it went like 900 BKN. I get down to Inyokern and am now looking at a really long wait for the couriers...and the weather starts going down there, too! At sundown, the couriers were about an hour away, and I could see there was no way I could do night VFR out of there, so I called company and said lets throw in the towel & bring me back to BUR. They said no, reposition to Fox Field (lancaster) and wait for the couriers there...nevermind it's a short drive from lancaster to BUR. So I do so, and it is REALLY late before the couriers arrive at the airplane...and then company calls, moderate icing has been reported over Santa Clarita at 7000', you're grounded in Lancaster! We'll get you a motel for the night.

Ah, those part 135 days...

 

[f18pugsley]

very basic:

Its a strong flow of air over mountains/ridge lines that produce rolling "eddys" which can produce signifigent turbulence downwind.

typically just causes a "wave" type fluctuations in altitude/airspeed. Feels like your "riding a wave"..

typical over the rockies - especially in the winter.

Actually, mountian wave is caused by strong wind (>40 knots or so) flowing perpendicular (or nearly so--30-45 degrees from perpendicular) to a mountain range. The result is a powerful standing wave of air similar to what you see in a river as the water flows over a rock--you see a standing wave of water.

The dangerous portion of the wave is the rotorcloud between the bottom of the wave and the ground. The rotor tore a glider in half (literally) during the Sierra Wave Project.

Here is a website of a German study that shows a nice picture of wave phenomena: http://www.ifos.de/mwp/Beschreibengl.htm

Like was said earlier, check out "Exploring the Monster" about the Sierra Wave Project based out of Bishop in the early 50s. Some notable achievements include world record flights to 45000+ feet and soaring a P-38 Lightning: On March 5, 1950, Bob Symons was flying his P-38 and took advantage of this little understood weather phenomenon to try something new. He soared the P-38 with both engines dead and propellers feathered for more than an hour between 13,000 feet and 31,000 feet. Maximum climb rate was 3000 feet per minute. My understanding of the story is that Bishop was obscured due to the wind, he was low on fuel, so he flew into the wave and soared the P-38 to LonePine.

Now the Perlan project is trying to fly to 100,000 feet using stratospheric wave (Steve Fosset is one of the principle pilots).

I learned to soar out of Inyokern. One of the senior members of the club flew his Cessna 170 as a motor-glider to over 28,000 feet (rigged with a barograph and everything to make it a legal Gold Badge flight for altitude gained with the SSA). Another member of the club flew a Mooney from Reno to Inyokern on only 5 gallons of fuel.
Here is a link to IYK's history: http://www.inyokernairport.com/soaring_at_iyk/soaring_at_iyk.html

The reason so many power pilots don't like wave is they don't think to climb out of the rotor and low level turbulence. Climb above the rotor to get into the wave (usually 9-10k around the Sierras in the winter; if it is a wave day), and you can pull the power to idle and still accelerate and climb.

 

[urflyingme?!]

Crazy.
But one question, does it ever come down?(As in force you down)

 

[414Flyer]

Sometimes coming around that same part of the Big Island, I would get downward winds, and get pushed down and out to sea. Luckily around 1000AGL it would start to die out, but until then, I would just be at Vy, and just along for the ride.

 

[HMR]

Going IFR was out of the question until south of IYK, as the MEA's were far too high for the normally aspirated Lance.

I've said it before: you AmFlight guys doing that MMH run have my respect. I used to do that same route in a BE20. I was amazed airplane wings could flap like that. It was always humbling to pull into MMH after 45 minutes of bronco busting turbulence and see you guys loading up the Lance.

 

[Crimson03]

Unsolicited, unwarrenteed advice. Someone previously mentioned flying in descending air at Vy. My advice if it is really bad fly at Va, as you are not going to be able to out climb strong sink so the faster you fly out of it the better. As for what direction to fly to get out of down rotor/sink ...
Basically flying gliders the faster the air is sinking the faster you fly, the idea is to get out of the sinking airmass as quick as possible, even though the altitude loss flying at higher speed is greater. HTH

 

[FearlessFreep]

I was flying westbound around the eastern portion of Mammoth area delivering a C-172XP. I was around 12,500' - 14,500' when I started going up. Pulled the power all the way back, nose down 20 degrees and still going up. I was getting flight following and needed get an IFR clearance as I was going through 18,000'. Of course on the other side started the downward slide, where I was down to <1000' AGL over the Sierras. Fun!

 

[Swass]

Nice stories, thanks.

 

[TurboS7]

You guys are great story tellers enjoyed reading your post. I have run into all kinds of mountain waves high and low, I flew with some great pilots in the Andes when I was 17 which gave me a great basis to learn. Dispite learning though once in a while you run into some real severe stuff, two times come to mind. I was flying from ANC to KET in a PA-32-350. I will loaded to the gills and had the airplane full of my family as we were leaving Alaska and returning to the lower 48. I was flying VFR, took off from ANC and we were making our way up Turn A gan arm to go through Whitier(sp) pass. It got real smooth when all of the sudden we hit severe turbulence dropping from 2500 feet to 1500 feet right now. All the kids let out a big yell as we fell. I did a 180 when around the Chiugacks and went up Chicaloon Pass. We then climbed to 12000 cut across the mountains and landed at YAK for fuel instead. Other than the turbulence the weather was CAVOK that was late October 1982. Long time ago.