Jet blast when landing

I don’t think so. This is airflow after the engine.

Also, relevant engines are high bypass so most of the air mass is from what is basically a propeller.

An Air France pilot said in the old days they would have old jet turbines pointed at the runway on zero-zero days to disperse and evaporate fog before landing. Apparently it worked ok, but the turbulence was horrific.

I found mention of it in this American study from 1970. The quick summary: it works, but fog returns about 1 minute after engine shutdown; it’s an expensive system, but cheaper than diverting.

local copy

That’s an interesting paper, especially in the way they calculated the required energy to clear both the fog and the water produced by burning jet fuel to clear the fog.

I guess CAT3 has eliminated the fog problem for commercial traffic, and few people care about the remainder.

Capitaine wrote:

An Air France pilot said in the old days they would have old jet turbines pointed at the runway on zero-zero days to disperse and evaporate fog before landing. Apparently it worked ok, but the turbulence was horrific.

In his book “Glide path”, Arthur C. Clarke describes similar experiments done by the RAF during WWII, including mention of the horrific turbulence. The book is a semiautobiographical account of the development of the Precision Approach Radar (PAR) system which he was involved in. Highly recommended.

Thanks for the recommendation, Airborne_Again, that sounds interesting; I’ve just ordered a copy on ebay.

There’s a Wikipedia page on FIDO (Fog Investigation and Dispersal Operation), pipes parallel to the runway burning avgas. I’m sure Don Bennett’s Pathfinder also mentioned the turbulence. One bit I found interesting on pea-soupers or smog:

It is difficult for the modern (2008) UK resident to comprehend what World War II fogs were like. It was not uncommon for a person to be unable to see the hand at the end of an outstretched arm. The post-war Clean Air Act hugely ameliorated UK fogs.