Flight Log: Khartoum HSSS -- Addis Abeba HAAB 07.11.2010

Distance: 588 NM
scheduled Flying time: 4h 55min
Filed Route: KTM EMITA TIKAT
ATIS Khartoum: 0440 rwy 36 wind 020 09kts CAVOK temp 29 QNH 1009
Clearance: Right turn climb 090
Take Off Time: 04:50 (UTC)
ATIS Addis Abeba: 0950 rwy 07R wind 060/12kts CAVOK temp. 27 QNH1024
Landing Time: 10:15 (UTC)
07.11.2010 Khartoum/Addis Abeba: According to the flight plan, we were originally to take off at 9.00 a.m. local time. Martin took another glance at the NOTAMs. This is information about airports. The NOTAMs showed that Khartoum Airport was closed for construction work from 9.00 a.m. to 12.00 p.m. As a result, we had to ask our handling agent to change our flight plan in order to start before this juncture. We agreed on changing the flight plan to 7.30 a.m. local time.

After we'd gone through passport control, paid the handling agent and the plane was ready for take-off, a second pretty big problem emerged. After requesting permission for take-off, the tower answered: 'You're in 11th place'. That meant a lot of planes were still in front of us that also wanted to take off before 9.00 a.m. We had to wait more than 55 minutes in total. Then we were allowed to taxi and move to the runway behind a UN plane.

We eventually took off at 8.20 a.m. This time it was a slightly more demanding task, as we had 300 litres of avgas in our additional tank in the cabin. The plane behaved like a duck taking ascent - it took quite a time - we ascended to 200 or 300 feet max. At some point, we then reached flight level 090 - our cruising altitude. We had to constantly state our position and altitude because the Khartoum tower has no radar and cannot follow the position on the radar screen. This is no easy task if air traffic is heavy. After we had reached cruising level, we had a mini breakfast of two muffins. They were vital motivation. After a further approximately 1.5 hours, we left the Nile area and flew on towards Ethiopia. The scenery changed to become greener with more fields. We now had no radio contact any more to the authorities in Khartoum and none yet with Ethiopia. This was to continue for the next three hours. We were able to send a message when we flew over the border to Ethiopia. The Ethiopian uplands were very attractive: scattered settlements, waterfalls and similar highlights - but turbulence was heavier than previously. You have to remember that the plateau is located at 6,000 and 8,000 feet and we were flying at flight level 090. Later we selected flight level 110, or 11,000 feet.

About an hour before reaching Addis Ababa airfield, Martin felt like a second breakfast. He grabbed the plastic bag from behind his seat and took out the second piece of cake to eat it. A few minutes later, slight panic struck on board. Martin thought it smelt strongly of avgas. He asked if possibly a tube or something similar had burst. He suggested interrupting the pumping process from the additional tank into the main tank and asked to open the window on the left immediately. I hadn't noticed any smell of avgas and couldn't really understand Martin's request. Nevertheless, I opened the window and ceased the pumping process after about two to three minutes. Once we had flown for about a quarter of an hour with the window open, Martin said the avgas smell had lessened. In addition to the avgas smell in Martin's nose, we then had heavy turbulence as we had to fly closely over the mountain slopes. Martin became increasingly paler, almost chalky white.

On the approach to Addis Ababa, we were told to use runway 07 and make a visual approach. This was not particularly difficult. We landed with about 170 litres of avgas still in our additional tank. After we taxied to our position, both doors were opened to air the cabin. Martin got out to recover from the shock. He said he was still belching avgas. We thought the whole thing was so strange that we now pulled out all the stops to find the answer. Why had Martin noticed a strong smell of avgas and I hadn't noticed any? After a while we found the cause: Martin had put his bag with the piece of cake in the back on the extra tank. This always diffuses a certain amount of avgas. It must have accumulated in Martin's bag and the cake. When he ate the cake he unavoidably inhaled some avgas fumes as well. This is what made him feel unwell. What's the lesson? Don't put any bags with food at the back on the full avgas tank. It makes you feel queasy.

After a few phone calls on the ground, we were welcomed by the handling agent and led through the entrance area to a Sheraton hotel stand without any major complications. After a while, we were told that a car was ready to take us to the hotel.