Summary
We propose to adopt a new airworthiness directive (AD) for certain Gulfstream Aerospace LP Model Gulfstream G150 airplanes. This proposed AD was prompted by a report that the main entrance door (MED) opened during flight, and by the determination that the ``CABIN DOOR UNLOCK'' crew alerting system (CAS) message may extinguish before the handle latch pin is fully engaged. This proposed AD would require accomplishing an updated rigging procedure for the adjustment of the MED microswitch. We are proposing this AD to address the unsafe condition on these products.