Updrafts...first time I noticed

[larrynimmo]

I have got over 600 hours and IFR rating...until yesterday, I never really felt what an updraft was all about....there were several large dark cumulus clouds in the area, but nothing really towering.  I was flying at 2,000 ft, perfectly trimmed on the autopilot 125 ias, in a headwind...flying lop at 7 gph.  All of a sudden my nose dipped down and my ias went up to 140.  All three altimeters held at exactly 2,000 ft. My ground speed went up a little but less than 5...this went on for a couple of minutes.

[ragedracer1977]

I hit a good one 2 weeks ago.  Here's the graphs.  Speed went from just over 100 kts to over 170kts.  While I was pitching down, power at idle, and climbing.  It was a good ride for a few minutes.

 

[carusoam]

Any terrain features to go with that?  Nearby mountains?

We have a weather guy that has great insight to these sort of things.... @Scott Dennstaedt

Just remember... the associated downdrafts can be more narrow, but much stronger...

It helps to have a plan for escape when the down drafts occur...

I ran into a downdraft during IR training.... in a C172...  can’t outclimb the downdraft.... 
 

PP thoughts only, not a CFI...

Best regards,

-a-

[Ibra]

You need to install a total energy vario VSI that links altimeter ALT & speed ASI changes to get the exact reading of updraft strength , as you kept same altitude +15kts on ASI means that updraft is way higher than +1500fpm (could by way more than that depending on L/D glide ratios at 125kts & 140kts) 
 

Near cloud base the trigger is likely thermals, if it is windy you get cloud lift street, I think you were flying along the wind direction near that grey cloud and the patch of sink sits on a parallel track?

In clear sky away from fluffy grey clouds the lift is more likely from terrain & wind and is generated by hill ridges & mountain waves, the sink patches of these are to be avoided at any cost: dragons & sirens live there (waves are better flown with engine at idle and slow speeds to avoid losing propeller or wings with an escape route from rotors & lenticular dips)

[MooneyMitch]

I love roller coasters too!!! 

Keep your belts fastened and keep your arms and legs inside at all times during the ride! 

[Unit74]

I was between Freeport and Eleuthera At 15.5ft, pitched 10 deg nose down and doing 150kts climbing at 900fps. First time I really had that feeling I was in trouble. About 4 min later I came out the other side.  I don’t know what alt I ended up as I was too focused on flying at the time, but I did tell ATC I was in an uncontrolled climb. 
 

also got into mtn wave eastbound between TN and NC. That was smooth as butter and less startling. Got very turbulent on the backside of it though. 

[larrynimmo]

3 hours ago, Ibra said:

You need to install a total energy vario VSI that links altimeter ALT & speed ASI changes to get the exact reading of updraft strength , as you kept same altitude +15kts on ASI means that updraft is way higher than +1500fpm (could by way more than that depending on L/D glide ratios at 125kts & 140kts) 
 

Near cloud base the trigger is likely thermals, if it is windy you get cloud lift street, I think you were flying along the wind direction near that grey cloud and the patch of sink sits on a parallel track?

In clear sky away from fluffy grey clouds the lift is more likely from terrain & wind and is generated by hill ridges & mountain waves, the sink patches of these are to be avoided at any cost: dragons & sirens live there (waves are better flown with engine at idle and slow speeds to avoid losing propeller or wings with an escape route from rotors & lenticular dips)

Eastern shore of Maryland (no terrain), direct 13knot head wind cloud bases looked to be 3,500 - 4,000’ Msl&agl

[N201MKTurbo]

I was out at the stack this morning. To hold 90 KTS and 4500 ft in the hold took 14 inches at the eastern end and 23 inches at the western end. This held for two approaches over about 1/2 an hour.

If this was easy, they would let anybody do It!

[bonal]

47 minutes ago, N201MKTurbo said:

I was out at the stack this morning. To hold 90 KTS and 4500 ft in the hold took 14 inches at the eastern end and 23 inches at the western end. This held for two approaches over about 1/2 an hour.

If this was easy, they would let anybody do It!

Can't be too hard,. They let me do it.  My first instructor used to call it free avgas and when we flew he would teach me how to find the updrafts and how to understand and avoid the resulting down draft.  He'd say show me where the free gas is today.  His long term lesson was about extending range in the event of an engine out emergency.  Flying out west provides lots of crazy air currents.  

[Hank]

11 hours ago, larrynimmo said:

I have got over 600 hours and IFR rating...until yesterday, I never really felt what an updraft was all about....there were several large dark cumulus clouds in the area, but nothing really towering.  I was flying at 2,000 ft, perfectly trimmed on the autopilot 125 ias, in a headwind...flying lop at 7 gph.  All of a sudden my nose dipped down and my ias went up to 140.  All three altimeters held at exactly 2,000 ft. My ground speed went up a little but less than 5...this went on for a couple of minutes.

My very first XC with my rating, outbound was severe clear (I41 --> KSAV). Going home (KSAV --> KHTW), ran into IMC over central SC. Center held me at 7000 versus my filed 10,000. Next thing I knew, I had no control over altitude and ATC gave me a block, 7-9. With throttle reduced and 10° nose down, I was showing 1500fpm climb . . . From 9000, I could see scattered bits of blue and asked for 10. Had to agree to routing around CLT, a whole 10° deviation. To avoid that, ATC kept me in the shaker almost a half hour!

[larryb]

The other side is no fun. I think it was somewhere over Arizona my IAS started dropping. When it got down to 95 I took action and added full throttle. It took full throttle just to maintain altitude for about 5 minutes. This was at 15,000 feet. There was a good tailwind though.

[kortopates]

I live out west and see lots of mountain wave activity flying the Owens Valley on the eastern side of the Sierra Nevadas; especially in winter time.

Some things I’ve learned is to disconnect the AP and not to attempt to maintain altitude but to maintain level pitch and airspeed. You could use pitch mode rather than altitude hold but I also want to be prepared for turbulence and I can do far better hand flying in turbulence. Invisible rotors is an additional hazard. Most severe are not far downwind on leeward side at the top of a wave and something to really avoid for its severe turbulence.

There is a fairly well know fatal accident of a turbine powered C210 that was believed to be on AP in alt hold mode enroute to Las Vegas from LA area while it experienced strong mountain waves and stalled in a downdraft. The pilot had some small children in the back that may have helped distract the pilot.

Taking an elevator ride in a building CU can be a different kind of interesting updraft experience- but this is something entirely predictable and seen well in advance. Too many thousands of feet of vertical development though will yield a much larger ride up than one may care for; including some icing at the tops.

 

 

Sent from my iPhone using Tapatalk