Re: LBA Jet proceudres
A departure where the track is 15deg or less from the runway centerline is considered to be a straight departure. Thus the first "turn" in the procedure is at 2.1 DME ILF.
If one looks at a simple version of the numbers for obstacle clearance.
Climbing at 3.2% (there is no higher gradient specified for obstacle clearance) would take about 2.6nm from the DER to reach 500ft above DER.
Thus I understand the restriction is not to make the turn at 2.1dme unless at or above 500ft above DER.
Regards,
DFC