I have declared an emergency once when I got dual ECU fails on both engines and could not maintain altitude over the Jura. I recovered power but the ECU messages were still displayed, so canceled the emergency and landed at the airport I was diverting to. Met by Gendarmerie, fire brigade and a medic. The latter inquired about our mental health. The fire brigade made sure the airplane was not about to catch fire, and the gendarmes asked for documents and interviewed both myself and my wife about the circumstances of our emergency. Then I was asked to call the BEA. Departed a few hours later after having done several engine run-ups and had lengthy discussions with mechanics. End of story.
Prior to that, in my very early flying days, I had an episode in Norway where I had smoke coming up from the electrical switches. I was in the pattern (holding) and requested immediate landing which was immediately granted. In the meantime I had turned off all electrical switches and smoke disappeared. Landed and was escorted to parking by fire brigade. They asked me what had happened. End of story.
More recently, coming back from the Braç fly-in, I had the engine miss a couple of beats during climb-out from Poitiers on an IFR flight into IMC at nightfall. I rapidly decided to call it a night, turned around, notified ATC that I might have an engine problem and landed on the opposite runway. During my approach to land I heard tower’s communication with the fire brigade they scrambled. I would rather not have heard that because the fireman asked how many “potential victims” there were onboard. Needless to say my wife was not amused, but she’s a tough cookie. End of story.
I had the fire brigade scrambled three times, twice in France and once in Norway, although I only declared an emergency once. And not once did it have any aftermath or unpleasantness.
So the morale of the story is: Declare early, declare often.
I had only one moment that scred me pretty much for a couple of minutes. After takeoff in my PA-28 Warrior I climbed to FL80 when all of a sudden I saw smoke rising from below the panel … it wasn’t very much, but really enough to catch my attention. I pulled the power, fully extended the flaps and made an emergency descent. In 1000 ft AGL i levelled off and flew back to my airfield … and made a small recording.
On the ground I found out that brake fluid from the master brake cylinder was dripping into the heating where it burned and produced the white smoke. That was fixed quickly. I am sure though that this is not the most healthy stuff to inhale …