Flight Log: Gran Canaria GCLP -- Dakar GOOY 26.11.2015

Distance: 820 NM
scheduled Flying time: 7:35 hrs
Filed Route:
ATIS Gran Canaria:
Clearance:
Take Off Time: 09:40h
ATIS Dakar:
Landing Time: 17:15h
28.11.2015 Dakar:
After taking breakfast in the Radisson the promised taxi came at last to take us to the airfield.

Martin was busy changing the flight plan because the route initially took us to the African coast, before turning to the west towards Dakar. This entailed a detour of almost 100 miles. So Martin came up with another flight plan. After arriving at the airport he asked our handling agent whether he could submit the new flight plan which would save us a good 90 miles. The handling agent did so immediately, but to start with we had an invalid plan with the wrong call sign, i.e. not DEMCA but DEMCR. This flight plan was of course inacceptable, so a third flight plan had to be submitted with the right call sign. That all took up so much time that instead of 9.30 a.m. we weren't able to take off until 10 o'clock half an hour later. And this flight plan also specified the detour. Radio contact with the tower then indicated that this detour was deliberate because military exercises were taking place at the time on the sea. However, to be on the safe side we had filled up the plane with an extra 150 litres, i.e. in our extra tank in the passenger cabin. We also wanted to try out the pumps for this tank and avoid having to make an emergency landing on the African coast before Dakar.

After about 30 minutes flying, Martin was able to obtain permission by radio to make the planned leg shorter. The air-traffic controller informed us that the military exercise had finished and we could follow the course directly for Dakar. The section we had to fly over the sea was a lot longer, but the route was shorter overall.

I didn't just put on my survival suit for this flight, but also attached the lifeboat the whole time. That was quite an experiment to find out how long you could put up with flying with all this equipment on. I managed it until Dakar, in other words for 7 ½ hours. Shortly before we reached the Mauritanian border, the controller suddenly asked for a 20-digit approval code which we had dug out a few minutes beforehand from our flight documents because a French pilot in front of us had also been asked for the same thing. In the end the flight was uneventful and after about seven hours we reached Dakar-Radar.

As the African air-traffic controllers don’t usually have any radar, pilots or radio operators have to report their positions so that they know exactly where each plane is. The purpose of these precise reports is to ensure air safety and to avoid collisions in the air.

About 100 miles from Dakar, we noticed slight irregularities in the way the engine was running and weren’t really sure where these were coming from. Once we had taken off our headphones to listen more closely, we couldn’t hear anything anymore. When approaching Dakar airfield, the engine was clearly spluttering. We couldn’t explain where this was coming from. We did of course plan to do a trial run on the ground. After all, it was obvious we couldn’t fly over the Atlantic with a faulty engine. However, after landing the engine sounded completely normal. Martin's idea was to phone someone at Aerowest to find out what the cause might be. They gave us a good tip. They said that while the plane was flying for a long time in relatively warm air and due to the descent to even warmer air in Dakar very hot air might have built up in the engine. This hot air could in turn have an impact on the fuel lines where small air bubbles might have formed which the engine then took note of with a slight splutter. It’s quite easy to counteract this behaviour. The external fuel pump has to be switched on so that the pressure on the infeed fuel line is increased, the bubbles are compressed or they don’t form in the first place. This explanation seemed very logical to us because we’d already experienced something similar on a flight in Namibia and switching on the fuel pump got rid of the problem. But this time, we didn’t come up with the solution ourselves but needed the help of the fitter at Aerowest. However, we then decided to carry out a test flight in Dakar on 27 November and put the plane through its paces. The Aerowest fitter had suggested this course of action.