Wednesday, March 31, 2010

The Zing Flight into Santa Rosa

This was one of my favourite and most thrilling single engine flight I had taken during my training days through the San Joaquin Valley in the middle of California. An entire night of foggy weather flying in the Californian winters, only to be greeted by a beautiful sunrise almost instantly and magically dispersing the mist that lay ominously beneath us, barring our view of the green dewy ground!

We took off from Castle Airforce Base, Atwater, CA with barely any fuel in our tanks. Cessna 172s are 4 seater, single airplanes capable of flying for about 4 hours exluding the reserve time and can do 500 km at a stretch without breakin' sweat. Taking off from Atwater at 0430 local time, we took a short hop south of Atwater for fuel in the city of Merced, CA to top up our tanks and prepare a flight plan to Santa Rosa, approximately 335 kms North of Merced.
Winds favoured us that morning, with a graceful breeze of about 12 kms/hr from the Northwest. So the the flight plan was made, and it was gonna be a smooth ride to Santa Rosa in about about 2.5 hours. This picture to the left was taken on our way from Merced to Modesto as we climbed to 4,500 feet over Castle Airforce Base with our barracks literally invisible between the criss cross of roads and blocks of houses near it. Outside air temperature grew colder as we climbed to 8,500 feet to make the optimum use of the already dense cold air of the California Valley. The denser the air, the better is the performance, however, to save fuel and increase range, we climbed higher to maintain a lean air and fuel mixture. The climb to 8,500 would not have been necessary had it been summers. For a summer flight to Santa Rosa, a cruise level 4,500 would suffice. The cabin temperature was maintained at about 14*C while the outside was not reported to us yet.

It was pretty chilly in the cabin and it was getting harder to move fingers to cross check instruments and make the fuel calculations every 30 mins into the flight. It was about 0425 hrs in the morning and everything seemed alright except that our airspeed had been continously decreasing while trying to maintain level altitude of 8,500 feet at the trim settings. We had our carb-heat on just in case we didnt have a dead carb at 8,5. The airspeed kept falling further below 80KIAS as we tried to troubleshoot. I made a quick glance at my left wing to check for ICE and there I found the root. The leading edge of my plain was quickly building ice disrupting the airflow above and beneath the wings leading to decrease in airspeed and lift.

We took to manual brain override and decided to enrichen the mixture, gave in full carb heat and began to make a shallow dive on idle engine and keeping the airpseed constant at 90KIAS and began to use deep rudder movements to create turbulent relative wind in and around the wing area and the empennage. We had flown higher then the freezing levels of Californian winters, and the lack of freezing level information led to this error. My friend and I were in sweats at 14*C in the cold cabin! Hearts pounding, adrenaline rushing through our systems, greasing our head connections, so that we could think clearly.

We dived to an altitude way below the freezing level and reached 2,500 feet. The air outside here was relative warmer than up there, and this difference could be felt
even by skin. After this, we decided to remain at this altitude for the rest of the flight. We obviously burnt a whole lot of fuel for this trip, but as Pilots, the safety of our flights is priority one and we maintained that rule until we landed at Santa Rosa early in the morning at about 0715 hrs. The first thing after getting off the plane at KSTS was to get a fuel check and another $300 top up, and a total de-icing of the plane. And what could have been better than brilliant warm sun of the Golden California!

Saturday, February 27, 2010

Battered Battery

MOST of us use our laptops plugged into the wall outlet without ever realizing the effects of the same on the battery being used. Most lappies use the Li-Ion batteries, and for most efficient use, its highly recommended to use the wall outlet only for the purpose of charging the battery. I will explain as to why this is neccessary...

When a battery is connected to an AC source, the electrodes erode as the electric current is passed through the contacts and through the battery in a process called as 'electroplating'. The deposits on the anode and cathode in turn gradually but certainly, increase the internal resistance of the unit. This causes a voltage drop
across the polar caps of the cells as the amperage drawn by our computers remain the same. As this happens continuously over time, the run-time of the battery lowers from 88,000 mh useable (3 hrs) to about 14,000 (35 mins) over a period of 2-3 years.
Li-Ion batteries usually have an efficient age limit of 2-3 years depending on the usage. To best avoid this run-away electro-erosion, I would highly recommend to use your laptop batteries in a constant charging and discharging cycles per use. Li-ion batteries should be charged typically to 100% and discharged to utpo, if not less than 12-15%.

Lot of other tips are available online, but I found most of them redundant and producing negligible results. However, this method has been tried and tested by me over a period of over 6 years. Using this method of charging and discharging, my battery backup time remained in the efficient bracket of upto 3 hrs when new, to 1:10 mins after 3 years.