Flap5,
Not all aircraft have reversers tied into squat switches, by any means. The 737 has a Rad alt ht of 10' as the earliest reverser opportunity. This is to ensure that they are IMMEDIATELY available after landing, especially on slippery runways where they may be the only retarding force.
Without this, If you lose a squat switch and land on a slippery runway which prevents your wheels from spinning up you are in trouble!!
Mutt,
Why are reversers less effective on a dry runway???
Surely you mean they may not be used because the brakes are MORE effective? You cannot change the laws of physics, the same backwards force out of the engine will produce the same retardation, wet or dry?
Try applying your argument to forward thrust, are the engines less effective in the wet? Is that why V1 wet is lower than V1 dry??
I fail to see why using reverse idle in the air would have an instantly catastrophic affect on many aircraft. As long as it is SYMMETRIC!!!!
