I’ve never been one of those guys who lands right at sunset, for various reasons, but recently have become one… I’ve noticed on my little A-65 powered plane #1 that as the engine comes down the last few hundred rpm to its very low idle speed, 600 rpm or so, the strobe effect associated with landing into the sun gets dramatically worse. For me and this plane it’s to the point where it is seriously disorienting and I won’t do it again. You guessed it, I almost ground looped my tailwheel plane today. A little gust yawed the plane just as the very strange and disorienting strobe effect hit me, half way between landing and roll out… No damage and I didn’t (quite) leave the runway but very close.
Any comments other than ’don’t do that again’? Thanks!
PS with the two blade prop I think it works out to about 20 or 25 Hz.
When I did my PPL, my instructor demoed the effect on a night flight in IMC (we were climbing out of the L.A. basin to do some night x-country work) by momentarily turning on the strobes. Scary stuff!
The only remedy I can think of for @Silvaire is to look out the side of the airplane during landing. I tend to do this at night as I find it easier to judge he height above the rwy. That way you avoid looking through the prop disk.
It’s a 74 inch propeller, and its close to the cockpit so almost impossible to visually avoid. As it drops to idle the blade pass frequency drops into the relevant frequency range and when landing a tail wheel plane that’s right when you need good control.
I think I just learned something the (almost) hard way…
It is one of the reasons why I prefer to land with the sun in my back.
I certainly won’t be landing this particular aircraft to the west at sunset again
The most interesting thing about the phenomenon to me was how much worse it got as the frequency dropped below about 25 Hz, and that this matches the published info. Other planes I’ve flown in the same circumstance have more propeller blades and/or higher rpm idle speed.
Maybe this is why single blade propellers never caught on 
I have gotten heat on a French forum for claiming I preferred to land downwind with the sun in my back rather than into the wind with the sun in my eyes. And I once did a go-around at Bergerac LFBE and landed on the opposite runway when during the first flare I realised I was too high due to the sun in my eyes and the strobe effect.
Some people are convinced you always should take off and land upwind no matter what.
I’ve not had the strobe effect, but certainly had the sun one.
Many years ago, I was returing from a nice flight. The wind was reported as calm, and in those conditions the airport prefers runway 25 for noise abaitment, so runway 25 was in use.
A summer shower had just passed through so the runway was wet. As I’m about 10 feet above the runway, suddenly the angle was correct for the sun (in what was not a cloudless sky) to reflect perfectly off the wet runway, and I was pretty much blinded.
As everything had been prefectly stable and I felt no further significant control input was required, I continued.
I had a big bounce, and now always think about the runway direction when landing in the evening!
ATC obviously saw my big bounce and realise what had happened, because for the next aircraft, they changed the runway direction!
Agree that landing right into the setting sun can be very tricky. I’ve gone away and just bored holes in the sky waiting for the sun to set on a couple of occasions – I simply couldn’t see the rwy anymore on short final.
Is this the same issue as seeing strobes on TV etc?
