Large Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Training / Qualification
Deviation / Discrepancy - Procedural Hazardous Material Violation; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Overcame Equipment Problem
Human Factors
We loaded two pallets of hazmat (propane bottles) on as part of our [cargo load]. All propane bottles had screw-in type plugs installed; and no smell of propane [was] present at the time of loading. After departure and as altitude and pressure increased; we smelled propane fumes in the aircraft cockpit/cabin. I sent the cargo load handler into the main cabin to check the propane bottles. I understand he was able tighten some valves closed further. This diminished the fumes somewhat. At the top of climb (FL270) the fumes were not increasing any longer but they were also not decreasing. We elected to perform the 'smoke removal' checklist. Even though there was no smoke or fire; this was the most logical choice to clear the cabin of fumes.The initial portion of the checklist diminished the fumes; but not well enough. We requested and received from Center a descent to lower than 14;000 ft so that we could continue the checklist by depressurization of the aircraft. This cleared the fumes to our satisfaction. After calculating fuel left on board and our ground speed compared to our fuel consumption; it was decided that we were safe to continue to our destination. The rest of the flight passed uneventfully.I'd like to suggest a safety bulletin to all flight crew and outstations; highlighting the necessity for more consistent vigilance on matters such as 'propane bottle preparation for shipment'. This information could also be included in all future recurrent training.
Captain reported noticing odor and fumes from propane bottles loaded as hazmat. The fumes were cleared by descending and depressurizing the aircraft.