CoolP asked: Re: Lou - STORIES
Reply #146 - Today at 10:58:50   Hey, Lou, I'd like to drop two small items to trigger a story.  

First, the use of reverse thrust after touchdown together with the problem to maintain a "stable" airflow over the rudder. Problem with the 727 or a thing to disregard? I've read both versions so far, so we need a lourification on this.  

Second, and also focused on the rear engine mounts of some planes, is the icing problem when all the "air suck up arrangements" are in the back of the plane.
I've read that Boeing was very anxious about the whole icing thingy since "dropped" ice may enter the engines, unlike on planes where the engines are wing mounted.
I've read that, because of this awareness, even some roof mounted antennas were de-iced by active heating to protect the No 2 engine.

Answer to first question: The best answer is the school house answer - Delay reverse until nose wheel is on the ground.

Now what happened in the real world was that most pilots would select reverse detent (idle) as the nose was coming down, then apply desired reverse with nose wheel contact. I don't ever remember this being a big deal on the 727. Remember the center engine cascade vanes are horizontal and the pod engines are vertical. This tends to keep the effect of reverse on the rudder to a minimum. The 707 and other planes, where the outboard engines are far out on the wing, did make a big difference if one of the outboard engines did not go into reverse. I remember that the flight engineer would monitor the reverser lights and holler like a stuck pig if one did not go into reverse.  :o

Second question: The 727 was not as prone to ice FOD (foreign object damage) as was the MD-80. The nose wheel on the 727 had a "chine" molded into the tire to keep spray down. The Roof antennas were heated to avoid chunks of ice breaking off and going into the center engine. The MD-80 was just a mess. The nose wheel was a bigger problem than the 727 and had a "mud flap" to keep the spray from going over the wing into the engine, which was a NO GO item if it was missing. They also had a few gliders from large chunks of ice shedding off the inboard wing root and going right into the fan. SAS comes to mind!

The solution was to put a heating blanket at that section of the upper wing surface, or de-ice the wing almost every flight. Some planes had short string tufts in this critical area so the pilot, on walk around, could check if ice had formed. This was not just a cold weather problem, but even on warm days ice would form because of the cold fuel in the tank.