Sunday, September 1, 2013

Scary stuff ...

Happy to finally be on our way, we set off to fly the two scheduled legs for the day. The first leg was to take us to Wick in Scotland for refuelling and the second leg from Wick to Reykjavik in Iceland.

We left Hildesheim with full "normal" fuel and we enjoyed a calm flight to Scotland with mostly pleasant weather. This flight was also the first time we climbed into our immersion suits as we would be over water for a good part of the trip. Not very comfortable at all and we experienced difficulty moving in flight and reaching various things within the aircraft. During the flight, we experienced headwind components of around 40 knots. In Wick, we filled up our Turtle Tank as well. This was planned from the beginning, to test the functionality on a leg that would not normally require it. The forecasted winds however had increased to 70 knots and for that reason too, I would have wanted to use the tank.

There were no performance problems on departure at all and we were happy that all worked well. Soon after departure however, the headwind component kept increasing and the 70 knots forecast was exceeded substantially. First, we saw 80 to 90 knots, and that kept increasing to 100 to 110 knots. For a while, we experienced a headwind of 120 knots! To put things into perspective for the non-flyers amongst us: We typically cruise at 195 knots, burning 23 US Gallons of fuel per hour. At that speed, the 651 nautical miles would have taken 3.3 hours to fly. The forecast headwind of 70 knots would have reduced our groundspeed to 125 knots, resulting in a flight time of 5.2 hours. A constant 120 kn headwind would have reduced our groundspeed to 75 knots (which we saw for some time) and increased the flight time to 8.7 hours. Fortunately, as we moved closer to Iceland, the wind subsided to around 60 knots and we ended up with an overall flight time of 6.2 hours.

Descending to lower flight levels to seek lesser winds wasn't an option as the weather below us was not good with plenty of icing potential. As it was, we picked up some ice, which is somewhat unusual at -20 deg Celsius. Besides, the forecast winds weren't really much better below us. While we are equipped to deal with icing, this is not intended for flight into known icing conditions and it's better to avoid icing conditions wherever possible.

If the winds had been our only problem on that flight, all would have been good. We were however treated to a shock of a different kind: While cruising along in calm non-turbulent conditions, we experienced an engine failure without prior warning. This happened at roughly halfway on our 650 nm leg across the Atlantic. I have experienced other inflight emergencies before, but none quite like this one. Still, I wasn't prepared to test all our survival gear and I tried - as calm as possible - to solve the problem and to get that engine going again. After establishing a stable glide (fly the airplane), I first turned on the "continuous ignition" to ensure that any available fuel could be relit. No effect. Next, I checked the fuel supply to the engine and found no fuel pressure, pointing to a non-working electrical fuel pump. Fortunately, the aircraft is equipped with two of them. Switching from pump 1 to pump 2 with the ignition on, brought the turbine back to live. Within a few seconds, the  engine developed normal power again and I could climb back to our assigned altitude of 18,000 feet. By the time the engine started to develop power again, we had lost around 2,000 feet of altitude.

One needs to realise that when the engine fails, there will be consequential issues. For starters, there is no more air available for cabin pressurisation and within less than a minute, the cabin had climbed to aircraft altitude. At the altitudes we fly, this is not a train smash as the "time of useful consciousness" is 20 to 30 minutes. That's enough time to descend to lower altitudes. Another thing that fails along with the engine is the generator. In an engine fail scenario that is not of major consequence, because the battery will continue to supply power during the glide down. One does however need to realise that when the generator fails while the engine is still working, the battery has limited capacity and while one can turn off all sorts of electrical consumers, our turbine aircraft WILL require electrical power for the fuel pumps to sustain flight.

Upon arrival in Reykjavik, I tested both fuel pumps several times and both pumps were working again. It appears that the pump problem may have been a transient issue. I will nevertheless investigate possible solutions to reduce the risk of the pump failing again in flight.

I am now spending extra time with the aircraft flight manual to better understand potential emergency scenarios. With the type of flying we are doing on this trip, one can never do enough advance planning.


  1. Hallo Ihr Lieben,
    wir sind heilfroh, dass Ihr Gott-sei-Dank trotz Eures beängstigenden Zwischenfalls unbeschadet in Island angekommen seid. Passt bloß gut auf Euch auf, "Ihr Verrückten"!!! Erholt' Euch gut von dem Schreck und "Master" kontrollier' bitte Euren Flieger.
    Wir drücken Euch fest die Daumen, dass es ab jetzt ohne größere Störungen oder Katastrophen weitergeht.
    Ganz liebe Grüße

  2. Lieber Dietmar und Vero,

    Alles Gute und von nun an ganz entspannte Flüge. Mögen die Engel euch weiter beschützen.

    LG Heinz Güntensperger

  3. Hallo Vero & Dietmar,

    es ist schon komisch, aber ich habe an diesem Tag bestimmt 10mal an Euch gedacht. Und dann lese ich Eure - am Ende - doch glückliche Geschichte.

    Wir reisen weiter mit Euch!

    Volker & Petra


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