Follow up on accident from 2006

I saw via another thread the NTSB report DFW07LA032. It involved a three ship Cessna 172, RV9A and the accident airplane RV7A. This excerpt from it would seem to explain most of it:

"After the flight of three airplanes departed 2OK2, they lined up abreast with the accident airplane on the left, a Cessna 172 in the middle, and an RV-9A on the right side. The pilot of the RV-9A reported that as they approached OUN, the other two airplanes slowed to 65 mph, in order for him to land first, followed by the 172, and then finally the RV-7A (N216RV). The pilot of the 172 reported that as they approached the airport they slowed to 70 mph, and then to 65 mph for spacing, and the last time he observed the RV-7A, it was at the 7 o'clock position "about quarter to half mile" behind."

According to this, they agreed to slow to essentially the stall speed of the 7A. 65 mph is 56 knots, right at the stall speed, depending on weight and other variables. I have no interest in judging what all went on that terrible day, but, we need to be vigilant...

Even in RV's, the stall speeds are different, and should be understood by all in the formation.

Formation is a learned skill which should not be taken casually. Although all you need IAW FARs is brief the flight to fly in formation, it is insane for three aircraft to fly in formation without some prior training, a thorough briefing, and a qualified formation flight lead who is familiar with the various procedures used during various phases of formation flight.