Bell Helicopter 407
Flight Crew Commercial
Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Landed As Precaution; Flight Crew Landed in Emergency Condition; General Maintenance Action
Aircraft
During a flight back to base after dropping a patient off I noticed that my transmission pressure indication was decreasing rapidly. I contacted Dispatch and let them know that I would be diverting to [a nearby] airport and why. On final to the airport my transmission pressure indication came back to normal and throughout the situation I did not receive a CAS message indication XSM pressure on my MFD. Upon landing I shutdown and contacted [Operations] and informed them what was going on; and then proceeded to contact my maintainer on duty and inform him of the situation. [The mechanic] asked if I had written up the transmission pressure reading and at the time I had not. [He] then proceeded to tell me that all he was going to do was come out and have me do a ground run and see if the transmission pressure would drop again. He then said if I would conduct the ground run and then if no adverse condition arose to fly the aircraft back to base and he would take a look at it in the morning. I conducted the ground run and a hover check and all indications were in the green. En-route back to base my transmission pressure reading began to decrease and I made a [precautionary] landing in a parking lot. I then called the appropriate personnel and made an entry into the aircraft logbook stating a rapid decrease of transmission pressure was observed during cruise flight.I should have made an entry in the logbook at the first incident and not conducted maintenance over the phone.
BHT-407 helicopter pilot reported making a precautionary landing in a parking lot after the transmission pressure dropped.