Sunday, December 27, 2009

Keep it on the runway


The recent AA faux pas in Jamaica, almost going for a bath rather than a simple landing, reminded me of an early flight of mine that ended in a bad way. I was trying to land a Cessna 172 at NY38, Nedrow Air Park, a 2100 ft. paved runway with 50 ft trees at the north end. The field is no longer there ( I wish it hadn't been there then). Anyway I came in too high and fast and couldn't stop on the runway even by standing on the brakes. Unfortunately no reverse thrust available on the 172. However forward momentum was arrested by a well placed tree at the south end of the runway. I was lucky then to learn several lessons about landing. Lessons that stayed with me for the rest of my flying career.


So what were those pilots thinking as they tried to land a 737-800 with a questionable strong tailwind and a wet runway? Both of these factors: tailwind and water on the runway can significantly increase stopping distance of a landing airplane. These factors become much more critical if you are too high and too fast. In fact every 2 knots of tailwind will increase the landing distance (over no wind) by 10%. Standing water on the runway can increase the stoppping distance required by as much as 15%. So adding these things together makes for a challenging landing requiring speeds to be precise and touchdown as close to the threshold numbers as possible (not halfway down the runway).


According to Blake & Elliot in commercial aviation there is only one overrun per 3.6 million flights. They also state that 42% of commercial aviation accidents occur during final approach and landing.


So to avoid being a statistic when landing a pilot must plan his/her approach carefully keeping the following in mind. Fly the proper approach speed for plane configuration( no flaps to full flaps), wind conditions on the runway (allowing for gusts, head or tailwind etc), runway condition( dry,wet or icy). And of course length of runway including obstructions.


May your next landing be smooth and uneventful.

Tuesday, December 1, 2009

Are you ready to go?


Preflighting the plane isn't something pilots talk about much, not unless they are discussing some of the potentially disasterous things that may have happened to them. Things like forgetting to take the tow bar off the nose wheel before taxiing, or checking the fuel level in the tanks, or peeking around in the engine compartment when checking the oil level and finding an oily mechanics rag or a wrench. You get the idea now. An ounce of prevention may eliminate many pounds of pain later.
So what is a good plan for preflighting most singles and light twins? I used to start mine at the entrance to the cabin or cockpit. Then do a counter clockwise walk around the plane. starting out looking at the flaps(first lowering them) and ailerons, actually moving them and checking the hinge pins etc. Next, as you walk around the wingtip, check the lights and then the leading edge including the stall warning. If the master is on, when you flick the stall warning lever it should sound in the cockpit. Sounds like a lot, but if you move steadily and do it regularly it should only heve taken you less then a minute so far. Next of course is checking the fuel, both looking in the fill port to verify level of gas and to go under the wing and drain the sump. Don't just drain and dump, but actually look at what drains out into the cup (not just drain it onto the tarmac). You might have all water in the cup rather than fuel or a mixture. If in doubt, drain it again. Also when under the wing check the tires for inflation and tread. Look at the brakes-rotor and brake pads, or for leaking brake fluid. You never know when you might just badly need those brakes.
Next is a biggie, checking the engine compartment(s). Oil level is primary, but while the cowl or access port is open give the whole compartment the once over as possible. I know some models only have an opening to check the oil level. But if you can look for oil splatter or leaks, loose ignition cables and foreign objects as rags etc. During the spring check for bird nests, a real fire hazard.

Now as you round the nose look over the pitot and any other probe, radome etc. The nose wheel should be looked over and if there are gear doors check them too. Checking the left side of the plane is a repeat of the right. Walking back to the tail look over the fuselage, verifying that the static ports are clear. At the tail, remove all gust locks and move the elevator and rudder to see if they are free and that the hinges are intact. At some point check all the external lights.
Getting into the cockpit now you should be ready to start your before engine start check, to be discussed in another blog.

Enjoy another fun, safe flight. Those 5 to 10 minutes you just spent on exterior preflight may have saved your plane, life or both!
Incidentally I ran across an excellent preflight article at :firstflight.com