#4b: Takeoff, Circuit and Landing

Aim: 

To determine your ability to complete a takeoff, circuit and landing using correct procedure for actual surface, wind and runway conditions.

If possible, this exercise will be completed in a crosswind condition; look for the Examiner to specify a touchdown zone—likely to be the first one-third of the runway.

Assessment is based on the following:

  • ability to maintain runway centre line;
  • adherence to specified speeds;
  • correct positioning and separation in the circuit.

Discussion

Begin with a solid briefing on normal and emergency procedures governing the takeoff.

Be sure to demonstrate the proper power confirmation technique when the takeoff roll is initiated.

The Examiner will be looking for the development of symmetrical power when the roll is initiated, so use some care to bring both engines up to power at the same rate (remember that the accurate indications for power are RPM when the power is below approximately 2000 RPM).

If you develop power smoothly, then your feet will have the opportunity to keep the nose wheel precisely on the centre line.

Don’t forget that you must ensure the proper crosswind input with respect to aileron positioning.

Remember all your checks and verbal calls during the takeoff roll.1

The target speed on a takeoff below 400’ AAE is the blue line and power changes are not instituted until the aircraft climbs above that altitude.  Be sure to maintain this speed and it is equally important to climb to that altitude as soon as possible.

Through 400’ AAE, reduce the pitch first from 10° to 5°, then set climb power smoothly and accurately, using peripheral vision to control pitch (relative to the natural horizon).  For the circuit, leave all of the systems set for landing—e.g., fuel pumps, landing lights, and mixtures—so that the only work load during the circuit levelling procedure will be setting the throttles, setting the flaps, closing the cowl flaps and getting the trim organized.

Keep the circuit normal—i.e., get the crosswind turn started after climbing through 500’2 and the downwind turn started through 800’ or so.  Watch your tracking and keep the circuit square.

Once you begin to pitch forward to the cruise attitude in the downwind leg, bring the power right back to 15”MP and add 10° flaps;3 this will keep your speed down to a manageable 115 MPH (approximately)4 —a speed that will make any conflict with slower aircraft in the circuit less likely.  Be sure you don’t let the aircraft accelerate beyond 115 MPH—if you do, you will simply be making more trim and pitch work for yourself.  Target the SOP speeds published in the PA-34 Checklists:

 

   Circuit Speeds
Proximity    120 MPH
Downwind     115 MPH
Base   110 MPH
Final (40° Flaps)     90 MPH

 

Proximity Speed, by the way, is the speed you should fly in proximity to the departure or destination airports; you should slow to this speed within 3 miles of an airport.  If you have a pressing need to get slower faster, don’t forget to make effective use of 10° flap extension, bearing in mind the limit speeds which of course insure that you will not exceed aerodynamic loading limits of the flap surfaces:

 Limiting Speeds
10° Flaps  160 MPH
Gear Extension  150 MPH
25° Flaps   140 MPH
40° Flaps     125 MPH

  

Begin your approach at the point at which you normally do in a single-engine aircraft—when the threshold appears behind the trailing edge of the wing.  Rather that beginning the approach with a reduction of power, start the approach with the lowering of the gear.  The extended gear is an effective drag mechanism and will add a degree of smoothness to your transition onto the base leg.  Under normal wind conditions, you will likely be required to follow the lowering of the gear with a slight reduction of power—approximately 1”MP, which can be obtained with just a slight tug on the throttles.  Now smoothly select 25° flap5 —as this is being done, be sure to let the nose of the aircraft pitch forward, as it will be inclined to naturally do so (don’t inadvertently hold back-pressure).  Now that you are properly configured, adjust your pitch smoothly to target the base leg speed as indicated above—make sure the trim setting is always updated as the speed settles on target.  From this point on, adjust the throttles as you would for any aircraft—smoothly reducing power if you are too high, or increasing power if you are too low.6  Anticipate the projected altitude at which you are planning to turn onto final—you should arrive at the turn point for final approach slightly above 500’ AAE.7

A good time to complete the GUMP check is when the turn onto base leg has be completed—there is a brief yet adequate time-span here where the workload has temporarily eased.  Never defer the GUMP check until you are far too busy on the final approach leg.8  The risks of failing to do the GUMP Check cannot be overemphasized—a very expensive and very hazardous gear-up landing.  This GUMP Check must be completed verbally prior to descending below 500’ AAE during an approach for landing.

   FINAL APPROACH
G (Gas)    Fuel pumps and Selectors On
U (Undercarriage)  Fuel pumps and Selectors On
M (Mixtures) Mixtures full Forward
P (Propellers)    Propellers full Forward

 

Stability of the aircraft is critical when landing the twin, especially at Langley Airport where there isn’t a lot of room for error, and, as you know, a nicely flown base leg sets up for a nicely flown final approach and landing.  Stability in the approach, of course, refers to constant speed and constant glide path and centreline tracking.  The airspeed is a constant function of pitch, leaving power inputs as the variable which controls altitude.  The Seneca is twice as heavy as a Cherokee or C-172 so you must be conscious of the momentum of the PA-34; if the aircraft begins to slip below the desired glidepath and the momentum of the undesired descent becomes established, it will require an ever-increasing amount of power to produce a correction.  Excessive power changes to correct deviations from the glidepath will, of course, have the undesirable effect of disrupting pitch stability.  The short of it is that you want to correct any deviation up or down with as little power as necessary and as early as possible, and, if you follow this rule, your speed control will be less taxing.  I found it surprising, though, that most students don’t have a problem with the approach and landing of the PA-34, especially students with previous experience in Cherokees.  As with so much of flying, good aircraft handling is a strange combination of aggressiveness and smoothness.

The “bottom end” of the approach, as it were, is of course the most important.  Speed accuracy must be established early after turning final.  Full flaps are always selected for Langley Airport landings, with the only possible exception being crosswind landings—here the POH calls for Flaps 25°.  The target speed is 90 MPH, and your instructor will caution you if there is any deviation.  Remember that on short final the key to airspeed stability is pitch control—as long as the pitch does not change, the airspeed will not change.  In saying this, however, I must add that you must watch for significant changes in power, which will of course require compensating pitch adjustments.  A significant reduction in power will require a dropping of the nose slightly if you are to maintain constant airspeed, and the reverse is true for the same type of power increase.  More than ever, if you are not comfortable with the approach, go around and try again.  Otherwise, as soon as you are ready to initiate the flare, close the throttles smoothly—and make sure they are fully closed as you flare (any residual power—e.g., just 1000 RPM—will quickly create “white knuckles”).

The flare of the PA-34 is again a combination of smoothness and aggression—get ready to yank on that stick with considerable force.  Remember our job is to protect that tiny nose gear by ensuring that the touchdown force is exerted on the robust main gear.  If you do it correctly during training flights (two persons on board), the touchdown of the main gear will be quickly followed by the touchdown of the nose gear, and you will find that it is quite difficult to get the nose gear nice and high.  When you load up the PA-34 with passengers, however, there is still lots of pitch control at touchdown, and the touchdown of the nose gear can be delayed considerably with skill and practice.  You will quickly learn that the full rearward extension of the control column will be required, especially with only two passengers and the corresponding forward Centre of Gravity—be ready to use lots of muscle. 9   If you do not use the full control column during the final second of a flare, the Seneca will “clunk,” and this, of course, places unnecessary stress on the landing gear.  Watch out also for the misguided attempt to contact the surface at too fast a speed; with excess speed you are setting yourself up for a porpoise, as you attempt to “probe” for the runway with the nose gear.  Should the nose gear contact before the main gear, porpoising oscillations are inevitable.  As a simple rule, always be sure the “stick is back” at touch down.

You should also be cautioned against applying aggressive forward pressure on the control column when attempting to correct a flare that appears too high.  Just before landing, the lift demands on the wings are at their highest—attempting to support 4000 lbs. just above the stall—any sudden forward pressure on the control column will almost instantaneously erode all of this lift, leaving only gravity to force the 4000 lbs. onto the runway.  Owing to the pervasive influence of momentum, the 4000 lbs. of lift required to re-establish the flare cannot be spontaneously regenerated, and a “clunk” will result.  The proper thing to do is to plan the flare so that only a constant pulling back of the control column is required—you can do this by starting your fairing movement at a greater height above the runway surface, and simultaneously reduce the rate at which back pressure is applied.  Instead of a “jerking” flare, you “ease” into the flare.  (Get used to this flare technique, by the way, as this is how you will land the aircraft when your hair gets grey and your reflexes have slowed!)

There is, of course, no excuse for allowing the longitudinal axis of the aircraft to deviate from the runway centreline at any point during the flare and at the point of touchdown, so stay alert to this, and keep your feet working during landings.

With respect to crosswind landings, Piper has specific comments in the POH:

Crosswind or High-wind Landing

Approach with higher than normal speed and with zero to 25° of flaps.  Immediately after touchdown, raise the flaps.  During a crosswind approach hold a crab angle into the wind until ready to flare out for the landing.  Then lower the wing that is into the wind, to eliminate the crab angle without drifting, and use the rudder to keep the wheels aligned with the runway.  Avoid prolonged sideslips with a low fuel indication.

The maximum crosswind component for landing is 15 MPH.  (p. 7-11)

 

Clearly, Piper wants us to avoid prolonged slips during landing as a means of adjusting for the crosswind.  If you do slip at final approach speeds, the aircraft does indeed have a “dead duck” feeling about it, as there is a tremendous amount of change in drag and lift forces during a slip, which have the effect of complicating the bottom end of the approach.  By the way, watch that low crosswind limitation.  The engine nacelles and larger fuselage has the effect of shading the tail surfaces from the crosswind, and there is a noticeable loss of rudder effectiveness, so be sure to respect the low number that is published by the manufacturer.

It is important to lead into a crosswind flare with a slight wing-down attitude—less then 5° is quite adequate.10

Make sure you maintain the centreline throughout the landing roll and if there is a deviation be sure you immediately but smoothly migrate the aircraft back to the centreline position.11

With respect to the touch and go, the prime consideration is that when applying takeoff power, you must first place the throttle in the half-power position (only for a brief instant) prior to applying full power; this will allow the engines and governors time to catch up to maximum power.  There is nothing more dangerous than one of the engines failing to respond to your command for maximum power after the landing is completed12 —this could happen if you inadvertently “jam” the throttles from idle to the firewall.  Otherwise, as soon as the engines respond to half-power, the throttles should then be smoothly placed into the maximum power setting.  The only other thing to mention is that you want to ensure the cowl flaps are opened during the departure from a touch and go, but this is a distant priority, undertaken only after you have safely established the aircraft in the departure climb with the gear retracted;13 there is no time to do this during the rolling sequence at Langley (while there will be lots of time to do this during the roll on longer runways).

In the event of an overshoot, the same procedures—half-throttles, slight delay, then full-throttles—must be strictly adhered to.  If the overshoot is initiated from the flare, the aircraft should be held level in ground effect until full-throttles have been set.  Of course, there must be no change in the flap or gear configuration until the aircraft is established in the proper climb pitch.  If the overshoot is initiated before the flare, the aircraft should be held in a slight nose-down attitude while the “throttle-up” procedures are completed.

Safety

Traffic conflict is a major safety concern to flying circuits, so be especially alert during all circuit legs.14   Don’t hesitate to smoothly drop a nacelle to have a look.  Be sure that you establish the aircraft in a level climb in the crosswind leg so that you can check for traffic coming straight in along the downwind leg.

Braking is critical, especially at Langley, so you must always check your brake pressure as part of the downwind checks.  The key to minimum braking is, of course, the correct speed on final approach.

As part of the pre-landing checks be sure that you smoothly reduce the power on one of the engines to ensure that the gear-up warning system is properly functioning.

The 50% rule is sacred when conducting landings in the twin at Langley Airport—if the aircraft does not touched-down by the time the aircraft has reached the ½-way mark of the runway length, an overshoot must be initiated.

References

1. If you are not verbal, the Examiner may not pick-up on your checks and actions.

2. Or as required by noise abatement procedures.

3. See p. 45 for a summary of the levelling procedures in the downwind leg.

4. Be sure you do not become overly concerned with precise airspeed control; instead, we know that approximately 16”MP with Flaps 10° will get use close to 115 MPH, and this is good enough—priority should, therefore, be given to power setting, rather than airspeed.

5. It goes without saying that you must be below the Flaps 25° limiting speed.

6. Fine-tuned throttle adjustments should be made with the arm, rather than the hands or fingers—the wrist should be held rigid, with the throttles knobs buried in the palm of a firm hand, insuring that the arm pressure is transferred evenly to both throttle levers.  You will note that the left throttle lever on GURW is always slightly ahead of the right throttle lever—perhaps only an eighth of an inch.  Attempt to maintain this slight difference whenever you make subtle throttle changes.

7. It cannot be overemphasized that the key to a smooth and therefore effortless final approach is getting the aircraft to the correct glideslop altitude when the turn onto final from base is initiated.  An experienced pilot has a good “mental image” of the planned glideslop, and can visualize this at the top of the approach, way back when the initial turn is made onto the base leg.

8. The same applies to radio calls.  When MFA procedures are in effect at Langley Airport, get the “final” position report done just prior to turning final— “Langley Traffic, URW is turning final, Runway 19, Touch and go.”

9. The heavy force that is required to pull back the control column has the effect of encouraging some to try two-handed landings—both hands on the control column.  Never do this, as the throttles must always be guarded during the flare, just in case an immediate application of power is required—a sudden wind gust, for example.

10. The reference here is to the up-wind wing being down, of course.

11. Just as a policeman never gives up his or her gun, a pilot never gives up the centreline in a crosswind landing.

12. Remember that when the decision to initiate an overshoot is made, the aircraft is quite likely well below Vmc, and the risks of a engine that “hiccups” is readily apparent.

13. Especially don’t try to do this with just-departing aircraft hovering near the tree tops.

14. Just a quick note on pilot-controller communication regarding traffic advisories.  Pilot must be very careful how they respond to traffic information passed by a controller.  Although the pilot is never relieved of the responsibility to maintain safe separation from other aircraft, the controller also has responsibility for separation within his or her controlled airspace.  The controller essentially ends all responsibility for separation once traffic information is acknowledged by the pilot—for example:

                C:            “ABC  there is traffic at your 2 o’clock position, west-bound at one thousand five hundred.”

                P:            “ABC, Roger.”

                C:            “ABC you are number two, following traffic on left base.”

                P:            “ABC.”

 

So often pilots respond to traffic advisories without relaying back to the controller whether or not they have the target aircraft in sight—simple acknowledgement of this sort technically relieves the controller of further responsibility.  If, on the other hand, you advise the controller “Negative Contact”—meaning that you do not see the target—the controller is “kept in the play” and must provide additional separation information; additionally, the pilot of the target aircraft becomes aware of the continued risk caused by the lack of visual contact.

 

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