Ground School: How to taxi the DC-3 or “Gooneybird feet”

Ground School: How to taxi the DC-3 or “Gooneybird feet”

No matter how many times we have flown the airlines in real life, we would be hard pressed to recall the last time that we boarded an aircraft at the end of the runway. It’s time to expose the mystery of taxiing the flightsim DC-3, and begin or end the flights properly… at the terminal!

Initially, one is baffled. What’s the big deal about turning a DC-3 while departing from a gate or entering a runway? turn left, left rudder; turn right, right rudder.
It’s not that simple, for two reasons:

  • At slow speeds, insufficient air flows past the rudder for it to be effective.
  • The DC-3’s rudder is small for the size of the aircraft.

This unhappy situation leaves us with two controls to steer the aircraft: the engines and the brakes. Effective use of them, however, especially together, can give us a much sharper turning radius than with a tricycle gear aircraft. So let’s mount our trusty DC-3 and find out whether a mortal truly can taxi her.

Before we taxi out to the tarmac to give it a go, understand two basic principles:

  • Use the inside brake, the one nearest the center of the circle, to turn.
  • Use the outside engine, the one farthest from the center of the circle, to turn.

Not a bit of that information is useful, though, until we solve the visibility problem while taxiing the DC-3. All we can see is the sky. Trust me, nothing will quite ruin our day so much as taxing into a fuel truck. Well, taxiing into the boss’ office is a close second.

So, change that viewpoint! Dedicate one for taxi and make sure it has good side to side vision as well.

Ok, send all the gigglers away and we’ll get started. First, though, be aware that taxiing is ever so much simpler and more enjoyable if you have rudder pedals. Plus pedals greatly add to the realism of flight (and you’ll finally discover what that ball in the Turn and Bank indicator is present for.) But be certain that the pedals can operate the aircraft’s brakes, too.

Satisfactory ground steering is impossible unless the Rudder Auto-coordination is off, in X-Plane this means binding your rudder controls.

 

Brakes-Only steering.

Let’s begin with brakes-only steering. To clear the airport of all other aircraft, we affix a “Student Pilot” sign to each side of our fuselage, in such a position to cover the AKV logo. Next, we move the aircraft to a runway. Adjust your view and set the props to the High RPM position. For this situation, leave the engine controls locked so that both throttles advance together, etc. Now advance the throttles sufficiently to taxi down the runway at 15 to 20 kts. Easy on the speed, though … nothing quite so embarrassing as lifting off while taxiing.

NOTE: Flightsim brakes differ from those on a real aircraft or from those in your car … they are digital, either fully on or fully off. However, if you use rudder pedals, or a script (and in certain aircraft) proportional braking is available.

Follow this routine

Taxi to the turn-off, and tap the left brake to turn left. If you have rudder pedals, also apply the left rudder pedal. Proceed down the taxiway and again tap the left brake, and apply the left rudder pedal, to turn left toward the beginning of the runway. Using the sims “slew” command, Rotate the aircraft 180 degrees and repeat the above taxi maneuver but in the opposite direction, which requires right turns.

 

Power-Only steering.

We’ll repeat the procedures we just did for brakes-only steering, but this time we will control the aircraft’s direction with its engines. Again move the aircraft to the runway and verify that the power controls are able to move independently.
Increase the throttles to begin your straight-ahead taxi up the runway, about 10 to 12 knots is a good speed. As you near the turn off, slowly increase the power on the right engine to navigate the turn. You can synch the two throttles together again for the straight portion of the taxi if you wish, as you near the runway, unsynch the power controls, and control the left turn by adjusting power to the right engine, and taxi to the end of the runway.

Again rotate the aircraft by “slewing” it to the runway and repeat this procedure in the opposite direction, controlling the left engine for the right turns.
If you have rudder pedals, apply left rudder when turning left, and right rudder when turning right. The newer versions of the DC-3 have steerable tail wheels to assist in steering.

 

Brakes and power-control for steering.

This method gives the most control to turn the DC-3. Move the aircraft to the runway, synch the power controls, then taxi up the runway until near the turn off. unsynch the power controls, tap the left brake and carefully apply power to the right engine to accurately control the turn onto the taxiway. Repeat that procedure for entering the runway with another left turn.
Lastly, move the aircraft to the runway and repeat this procedure rotated, making right turns by tapping the right brake, and increasing power to the left engine.

 

Homework

1) Taxi twice in each direction using Brakes-Only steering.
2) Taxi twice in each direction using Power-Only steering.
3) Taxi four times in each direction using Differential steering.

ICAO flight plans will be mandatory for both VFR and IFR flight plans starting August 27th.

ICAO flight plans will be mandatory for both VFR and IFR flight plans starting August 27th.

The FAA will transition to mandatory use of the international flight plan format for all IFR and VFR domestic and international civil flights on August 27, 2019. The change is part of an effort to modernize and streamline flight planning and supports the FAA’s NextGen initiatives. Several improvements to the international form make it easier and more intuitive for pilots to use and will increase safety, including an increase in the size of the departure and destination fields to allow a greater variety of entry types, including Special Flight Rules Area (SFRA) flight plans.

Many resources and videos are available to help you setup your preferred flight planning tools. See the links below:

Help with an ICAO Flight Plan (FAA document)

The ICAO Flight Plan (AOPA video)

Setting up ICAO Flight Plans – ForeFlight app (video)

Setting up ICAO Flight Plans – Garmin Pilot app (video)

Setting up ICAO Flight Plans – Leidos (video)

Setting up ICAO Flight Plans –

ForeFlight, Garmn Pillot and FltPlan.com (iPad News)

Setting up ICAO Data at FltPlan.com (video)

AKV Blog Returns!

We are not dead yet, sorry for the long absence but we had a few bugs and quirks to work out before the blog could return to us.

Watch this space 😀

Ground School: Seaplanes: Taxi & Takeoff, or “Get your floaties on”

Ground School: Seaplanes: Taxi & Takeoff, or “Get your floaties on”

Seaplanes and X-Plane 
Originally by Chuck Bodeen with edits for XP11 by yours truely 😉

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PECULIARITIES OF SEAPLANES
Once a seaplane is in the water and released from contact with a dock it is subject to weathervaning which is the tendency of the plane to face the wind. Its the same physical principle that keeps an arrow going straight ahead. The strength of this effect depends upon how much of the plane is behind the center of buoyancy.

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WEATHERVANING

Wheeled airplanes tend to pivot on the main landing gear wheels. Tail wheel planes have more side area exposed to the wind behind the main gear and are more subject to weathervaning than planes with tricycle gear. For seaplanes, the pivot is around the center of buoyancy which varies according to the pitch attitude in the water. At rest in the water a seaplane acts like a tail dragger. As it starts to move forward you must hold the yoke full back to counter the moment produced by the engine thrust. This raises the nose of the floats and there may be just as much wind-exposed side area ahead as there is behind producing virtually no weathervane effect. If this progresses into a deep plow the weathervaning can even be reversed! Finally, when the floats are moving fast enough to plane or up on-the-step, the effect of side winds can be almost the same as a taildragger again. Because of weathervaning there are only two practical taxiing speeds: slow and on-step although plowing is sometimes useful in turning.

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Getting on the step requires the nose to be lowered and staying there is no easy task. You must use just the right amount of back pressure on the stick. Too much or too little will increase the drag and reduce speed. For taxiing, the throttle has to be reduced after you are on the step. Continuing on step with full power you will eventually reach the speed where the plane will lift itself off the water and then fly like a regular airplane. Lack of proper elevator control on a step taxi or takeoff run can result in porpoising which is a pitch oscillating condition that can increase in magnitude if you do not reduce elevator back pressure. Otherwise you may need to reduce power and abort the takeoff.

You may think that smooth water would be the best. Actually the rough water associated with a nice headwind allows you to takeoff at a lower waterspeed which reduces the drag on the floats. The fact that you are cutting along across the tops of the waves also reduces water drag. Depending upon the design of the floats, it is usually not recommended that you rotate as the plane lifts off the water.

Landing is made difficult by lack of visual contact with features on the ground and is particularly troublesome when coming in on glassy, smooth water. On the other hand, hitting rough waves at high speed can damage the floats, so you should always use the slowest possible water speed. Usually the waves will be caused by the wind, so even without a windsock you should be able to determine the proper heading for final approach. Never land parallel to the wave fronts rocking the boat is not a good idea.
So after landing what do you do? Once again you are at the mercy of the wind and with no ground-gear friction or brakes to help you steer. Sailing is a technique that allows you to take advantage of weathervaning and get where you want to dock, even by going backward in the water! After landing in a wind of, say, 20 knots you can set the engine to idle, and use the flight controls to turn the nose toward the dock. Go past the dock and then use power and control to finish.

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SAILING

Docking can be rather tricky because in a real plane you will be out of the cockpit standing on one of the floats. With the engine off, you may need a paddle (standard equipment on seaplanes) if you need just a bit more propulsion, or you might have to use your foot to keep the floats from hitting the dock too hard. There is a lot more to learn including the combined effects of currents and wind.

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TAKEOFF

Here is how the takeoff goes. Once in the water, water rudders are lowered (more about that later) and gear is raised followed by a slow taxi out to the end of the takeoff area and a turn into the correct heading. At this point be sure the brakes are off. In the water, the brakes activate an anchor that will tie you to the spot you drop it. Now raise the water rudders, lower the flaps one notch, set the elevator trim for takeoff, and advance to full pitch and throttle. Pull back on the yoke to reduce drag by raising the leading edge of the pontoons. At about 40 knots, push the yoke forward to get the tail of the pontoons out of the water and have the ship plane on-the-step. At 60 knots the plane will lift off the water by itself. Come to think of it, this is quite a bit like a takeoff for a tail dragger, X-Plane has a default wave height which causes the ripples in the altitude, but I made the takeoff tests with little wind and wave height set to 0.3

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TAKEOFF FROM THE WATER HAS FOUR CRITICAL STAGES

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START TAXI, UP ELEVATOR FOR PLOWING, DOWN ELEVATOR FOR ON-THE-STEP, AND THEN LIFT OFF

MODELING WATER RUDDERS
Real water rudders are usually placed at the rear of the pontoons or hull and are retractable so as not to be damaged or cause excessive drag during high speed operation. X-Plane has only one way to handle a water rudder. On the landing gear page, you can specify the longitudinal position, the area of the rudder, and the maximum angular movement. You have no control over the vertical position and X-Plane assumes that the water rudder is completely submerged if any part of the fuselage or floats is in the water.

LANDING HELP COMING SOON.

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Still having trouble? Duct Tape can help! no seriously check this out:

https://forums.x-plane.org/index.php?/files/file/20632-duct-tape-10/

VATSIM Event PAJN – PAWG VFR Helper

VATSIM Event PAJN – PAWG VFR Helper

This flight is fairly straightforward, starting out in Juneau,

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out the Gastineau Channel,

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Flying south along Stephens Passage

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into Frederick Sound,

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Humpback whales bubble net feeding in the waters off Pinta Point, Frederick Sound, Inside Passage, Southeast Alaska

Humpback whales bubble net feeding in the waters off Pinta Point, Frederick Sound, Inside Passage, Southeast Alaska

then turning southeast past Farragut Bay,

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then flying south past Petersburg,

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then following Mitkof Island

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to Wrangell.

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