Descent Planning Includes Slowing Down for a Bumpy Ride

Hi Mark. Good advice from Bob Buck about managing descents in turbulent air. Here are a few of my best tips for safe flying and improving technique.

Here are some of my favorite aviation maxims: Aviate; Navigate; Communicate. GUMPS is a good, all-purpose reminder when changing attitudes, leveling off and passing beacons in IFR: Gas; Undercarriage; Mixture; Prop(s), Switches. UPS is similar: Undercarriage; Prop(s) fine; Switches. Another classic is the Five 'T's: Time; Turn; Throttle; Tune (radios); Talk.

When flying circuits (aka the pattern) don't always use the same technique. Try a soft field or short field takeoff the first time. Try taking off with 0, 10 degrees or even 25 degrees flaps and see how the aircraft operates in different configurations. Try landing with no flaps occasionally and observe the difference in distance required. Don't just do touch and gos. Try takeoffs without flaps, with ten, 25 and full flaps. Consult the POH for correct trim settings and rotation speeds. If you can talk a few friends into flying with you, try doing the above techniques at weights near the MTOW, to observe how the aircraft performs and handles at higher weights.

To practice short field landings more safely use the five-hundred foot markers as your aiming point on most approaches, not the numbers. There is NO pressing need to hit the button every time on a practice flight. Save that for when you need to get into short (less than 2000 foot strips. For most normal VFR flying the 500 foot markers are also a good general aiming point and make it much harder to come up short and bend metal. This neatly jives with a basic design criteria at many airports, where the first available taxiway is sited about 2000 feet (600 meters) beyond the threshold. This reduces the average 'time on runway' to about 40-45 seconds.

Feel free to fly your approach faster than normal into big airports, but use the higher of the Vle or Vfe as your upper limit. It can be difficult to slow a fast moving object that is traveling down hill. For example, the Cessna 172 has can have the first 10 degrees of flaps deployed at 110 knots, an effect speed brake. Th B-58P Baron has the same number, 156 knots I think, for both Vle and extending the first notch of flaps. Practice this at a fairly long runway before trying it for real. Don't be surprised if ATC asks you to make the first taxiway, either, so make sure you can get the airplane down to final approach speed at about one mile to touchdown.

My IFR course was a real eye opener, in terms of flying more precisely. To capture altitudes accurately and consistently begin your level off at 10 % of your rate of climb/descent above/below your target , and do the level off in this order: direction, attitude, power. To level off at 2,000 feet when climbing/ descending at 1000 fpm, begin the level off 100 feet above/below your target altitude. Descent rates on an ILS may be quickly calculated by taking your speed in knots and multiplying by five. Example: an aircraft approaching at 120 knots on a 3 degree glideslope would multiply 120 X 6 = 600 fpm. Rate one turns are usually done by watching the turn and bank (turn coordinator) but may also be determined by taking 10% of your speed and adding five for knots and seven for miles per hour. Not sure what the conversion is for furlongs per fortnight...

On high winged aircraft, ALWAYS visually inspect the fuel tanks during walk around. Don't be lazy. There are a remarkably high number of easily preventable accidents caused by inadequate pre-flight inspection. When considering passing available runways when the fuel gauges read less than 1/4 tanks, imaging what you'd have to say to the aircraft owner, your wife, the policeman and the reporters who will want answers after you've put it into a field or a lake somewhere. Always be suspicious of an aircraft that has sat, especially outside, for more than a a few weeks or so. Look for birds nest, ice/frost accumulation on the wing and tail surfaces. Another bromide is to ALWAYS set the pitch trim to the takeoff setting. This seems rather basic but, as you kn ow, s@#t happens and people make mistakes.

Finally, here's one my first instructor offered: What are the three most useless things in aviation? Answer: Ceiling above you; Runway behind you; and Air in the gas tanks!

-Doug McIntyre
Surrey BC

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