Why is a standard hold right turns?

Greg Esres wrote:

On Sat, 26 Jun 2004 17:43:15 -0700, "Bob Gardner"
wrote:

Minimum holding altitude is 2000 agl, according to FAAO 7130.3...hard to
conflict with traffic in the pattern at that altitude.

My copy says "MHA's are determined by the National Flight Procedures
Office." It also says

2-11. ALTITUDE LEVELS.
...Holding at 2,000' and below requires use of the appropriate pattern
for 2,000'....

Anyway, a local approach has a hold at 2,000 MSL, which is about 1,500
AGL.

You're right; there is no 2,000' floor. It's policy to have controlled
airspace at least 300 feet below the MHA. That is normally accomplished with
Class E 700 AGL airspace. That means, in theory, the MHA could be as low as
1,000 AGL, except no one would design to that assumption. But, 1,200 AGL is
certainly possible because 200 feet is the assumed adverse obstacle height
where no higher obstacles are recorded in the digital obstacle file.