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BlueJays
1st Jul 2015, 21:17
Evening!

As a very low hour PPL, I wanted to ask a few of you who probably have superior knowledge when it comes to aviation.

My question: is it safe to fly after a thunderstorm has passed, say an hour later? Would there still be severe updraft and downdrafts around?

Sorry if this is a silly question.

Sam.

TheSkiingPilot
2nd Jul 2015, 10:55
For an ordinary thunderstorm, the dissipation stage lasts around an hour. Any time after then, the downdrafts would be too weak to create any hazard or discomfort to safety.

TheSkiingPilot

Luke SkyToddler
2nd Jul 2015, 11:42
There's no simple answer to that one. It depends on severity of storm, how fast it's moving, time of day, knowledge of local conditions, etc.

A UK thunderstorm is often part of a relatively fast moving cold front so an hour later it might be 30 miles away, whereas a tropical one in Singapore might not have moved an inch.

Also depends on what you're flying, VFR in a light single might get into trouble whereas a Boeing or a 'bus will not.

Assuming that you are VFR in a low performance light single that can't outclimb a downdraft, and you don't have any cool stuff like weather radar on board, then the best advice is stay VMC and avoid it by at least 5 or 10 miles.

Transsonic2000
2nd Jul 2015, 13:03
Check-out the following link, it offers a lot of interesting articles to read. If you scroll all the way down to the bottom you'll find an article about weather which is particularly interesting to pilots at the early stage (PPL) called "Weather Wise" I highly recommend it.

Safety Advisors - AOPA (http://www.aopa.org/Pilot-Resources/Air-Safety-Institute/Safety-Publications/Safety-Advisors.aspx)

You can also go to Youtube and search for "thunderstorm hazards / avoidance aviation" you'll find some interesting videos.

Have fun and fly safe, always :ok:

Romeo Tango
4th Jul 2015, 08:52
For other opinion on this subject see:
http://www.pprune.org/private-flying/553745-flying-rough-weather.html

http://www.pprune.org/private-flying/532739-precautionary-landing-during-thunderstorm.html

Pull what
4th Jul 2015, 09:17
Sam its not a silly question. After one hour there will not be severe turbulence from the thunderstorm that has passed through however you may well be still under the influence of the unstable air mass or cold front that has produced that thunderstorm so it could still be turbulent and there still could be other large CBs around.

Read this

http://www.ead.eurocontrol.int/eadbasic/pamslight-ABD2BD849CA8FB10D40952530518A49E/7FE5QZZF3FXUS/EN/AIC/P/056-2010/EG_Circ_2010_P_056_en_2010-08-12.pdf

Pace
4th Jul 2015, 16:22
Ten years ago I was flying a non pilot owner to Malaga in his almost new Seneca Five. I was cruising along in the Madrid area at FL120 and faced with two large cells a distance apart took the clear air in between.

the aircraft was on auto and the air smooth.

It was weird as in front of my eyes the IAS dropped in seconds from 160 IAS to 60 KTS IAS. The auto would not hold altitude, I pushed the nose over disconnected and added power to no avail

I sat there watching the VSI showing a fast rate of descent and the aircraft dropped like an elevator from FL120 to FL090.

The controls frankly felt as if I had flown into a vacuum and were ineffective.
strangely the whole thing was not scary but sedate and I just sat there waiting for everything to come alive again which it did.

It was then just a matter of apologising to ATC and explaining and climbing back to FL120.

I had never experienced this before and must have been a good 10 K in clear air between the cells. Temperature at MADRID WAS 44 deg C

To add a bit more to this flight I was single pilot and we routed to Malaga from the UK VIA a refuel stop in San Sebastian going to San Sebastian I felt really ill. We landed and i told the owner I could not go on as it was not safe. He recognised dehydration and made me drink what felt like a gallon of water. It was like magic as I came back to normal within minutes.

Past Madrid still drinking water I was bursting and was even thinking of dangling it out of the pilot side window but managed to find an empty oil bottle so a number of lessons here }} not just the earth bound Seneca

Pace