Ok probably more than 2kts, not sure about L/D glide of C150 at various speeds, the hard bit is to know what is the strength of thermal without total energy variometer (or maybe maintain ASI and look at altimeter average? normal VSI & ASI are just too unstable for the task)
Ibra wrote:
There is your sink rate on still air at 100kts which differs from the one at 70kts, let say you have 1:7 at 100kts (-1400fpm) and 1:10 at 70kts (-700fpm), so there is 700fpm or 7kts delta between the two speeds that you need to account for with power or thermal strength, if you hit a +3000fpm at 70kts you will get +23kts, if you hit a +3000fpm at 100kts you will get +16kts, there is also more loss from acceleration inertia & control deflection in the latter
Well … I know from experience that in a C172 you get at least +10 kt at 110 kt with thermals weaker than 1000 fpm. The C150 has lower speeds, but I don’t think it differs enough that you would only get +2 kt.
There is your sink rate on still air at 100kts which differs from the one at 70kts, let say you have 1:7 at 100kts (-1400fpm) and 1:10 at 70kts (-700fpm), so there is 700fpm or 7kts delta between the two speeds that you need to account for with power or thermal strength, if you hit a +3000fpm at 70kts you will get +23kts, if you hit a +3000fpm at 100kts you will get +16kts, there is also more loss from acceleration inertia & control deflection in the latter
I am ignoring power for level flight it is the same story, just the numbers may slightly differ depending how thrust changes with speed delta, depending if it is fixed pitch, variable pitch or jet…
Ibra wrote:
For all this you have to fly really slow to notice this, if you fly at 70kts and hit +1000fpm thermal at best you get +10kts speed, if you fly at 100kts you will see +2kts…
You’ll see +10 kt at least at 100 kt. Flying level while in a 1000 fpm thermal will give you the same airspeed as if you where descending at 1000 fpm in still air.
Jujupilote wrote:
Spending 6 hours in one day sitting in a C150 looks brave to me Do you have a specific need to build hours ?
Actually, I am kind of used to long vehicle rides, and with snacks, water, a toilet solution in case of need, and nice weather, I could fly for much longer as long as the plane is comfortable. Since I flew alone, the cosy cabin of the C150 was not a concern.
Regarding the hour building, I bought last year a share in an RV-7 hangared at my home airport, and we have a clause in our society and usage contract that each pilot needs to have at least 150h TT or 100h PIC time, and since I received my PPL in September last year, I was busy getting to that number. So flying slowly was actually quite OK as I did not venture too far from home despite the flight time.
Great report and photos – many thanks for posting it 
I remember Hilversum in a different way: back in Czechoslovakia, my parents had a big valve radio, and it was one of the stations on it, along with Beograd, etc. It was quite illegal to listen to some stations…
Nice to read reports of “simple” flights like these. Thank you..
Spending 6 hours in one day sitting in a C150 looks brave to me Do you have a specific need to build hours ?
I flew some cross-countries like these in a 152 but far shorter. It does about 95 kts and is baddly rigged like yours. Frankly, I let him have the ball uncentered, instead of forcing him by yawing and banking. It made straight flight look weird 
As for the throttle, I had the same impression a couple times. Usually I turned the throttle “brake” (the ring around it) and it was fine.
Nice! Juist looks rather busy. Wonder what’s up, the NOTAM leaves little room for interpretation…
That looks more like flying along a thermal cloud street (strong thermals & flying into strong wind) otherwise you will be flying in +600fpm lift & -600fpm patches randomly, no? Also, effect of depends if you maintain height or speed when flying, if you hit termals while maintaining height you get a speed increase as well as rpm increase
For all this you have to fly really slow to notice this, if you fly at 70kts and hit +1000fpm thermal at best you get +10kts speed, if you fly at 100kts you will see +2kts…
NinerEchoPapa wrote:
The skies certainly were busy yesterday, A look on flightradar24 in the afternoon showed more GA activity than I’ve seen in a long time. Mostly gliders.
Not surprising with the holiday and good weather coinciding. The Langen Information controller running the nortwestern sector was also having fun it seemed, keeping us little guys out of each other’s way :) With my little experience, I enjoy most the German FIS (but as it’s my mother tongue, I’m biased of course) as they seem to have a very, very proactive “can do” attitude. Amsterdam Information is good as well, as were the French controllers on my trips along the Channel coastline.
Maybe the experienced pilots here can weigh in: I noticed during the last half hour that I had to gradually pull the throttle back to maintain 2400 RPM in level flight about 1200-1300 ft AGL, and I would have thought that it’s due to the heavy thermals in the later half of the day which gave me more and more “free” lift so that the engine had to work less and less hard … Does that make sense?
