Alternator/Generator
On a multiengine aircraft, each engine has an alternator or generator installed. Alternator or generator paralleling circuitry matches
the output of each engine’s alternator/generator so that the electrical system load is shared equally between them. In the event of an
alternator/generator failure, the inoperative unit can be isolated and the entire electrical system powered from the remaining one.
Depending upon the electrical capacity of the alternator/generator, the pilot may need to reduce the electrical load (referred to as load
shedding) when operating on a single unit. The AFM/POH contains system description and limitations.
Nose Baggage Compartment
Nose baggage compartments are common on multiengine airplanes (and are even found on a few single-engine airplanes). There is
nothing strange or exotic about a nose baggage compartment, and the usual guidance concerning observation of load limits applies.
Pilots occasionally neglect to secure the latches properly. When improperly secured, the door may open and the contents may b e
drawn out, usually into the propeller arc and just after takeoff. Even when the nose baggage compartment is empty, airplanes have
been lost when the pilot became distracted by the open door. Security of the nose baggage compartment latches and locks is a vital
preflight item.
Most airplanes continue to fly with a nose baggage door open. There may be some buffeting from the disturbed airflow, and there is
an increase in noise. Pilots should never become so preoccupied with an open door (of any kind) that they fail to fly the airplane.
Inspection of the compartment interior is another important preflight item. More than one pilot has been surprised to find a
supposedly empty compartment packed to capacity or loaded with ballast. The tow bars, engine inlet covers, windshield sun screens,
oil containers, spare chocks, and miscellaneous small hand tools that find their way into baggage compartments should be secured to
prevent damage from shifting in flight.
Anti-Icing/Deicing Equipment
Anti-icing/deicing equipment is frequently installed on multiengine airplanes and may consist of a combination of different systems.
These may be classified as either anti-icing or deicing, depending upon function. The presence of anti-icing and deicing equipment,
even though it may appear elaborate and complete, does not necessarily mean that the airplane is approved for flight in icing
conditions. The AFM/POH, placards, and even the manufacturer should be consulted for specific determination of approvals and
limitations. Anti-icing equipment is provided to prevent ice from forming on certain protected surfaces. Examples of anti-icing
equipment include heated pitot tubes, heated or non-icing static ports and fuel vents, propeller blades with electrothermal boots or
alcohol slingers, windshields with alcohol spray or electrical resistance heating, windshield defoggers, and heated stall warning lift
detectors. On many turboprop engines, the “lip” surrounding the air intake is heated either electrically or with bleed air. In the
absence of AFM/POH guidance to the contrary, anti-icing equipment should be actuated prior to flight into known or suspected icing
conditions.
Deicing equipment is generally limited to pneumatic boots on wing and tail leading edges. Deicing equipment is installed to remove
ice that has already formed on protected surfaces. Upon pilot actuation, the boots inflate with air from the pneumatic pumps to break
off accumulated ice. After a few seconds of inflation, they are deflated back to their normal position with the assistance of a vacuum.
The pilot monitors the buildup of ice and cycles the boots as directed in the AFM/POH. An ice light on the left engine nacelle allows
the pilot to monitor wing ice accumulation at night.
Other airframe equipment necessary for flight in icing conditions includes an alternate induction air source and an alternate static
system source. Ice tolerant antennas are also installed.
In the event of impact ice accumulating over normal engine air induction sources, carburetor heat (carbureted engines) or alternate air
(fuel-injected engines) should be selected. Ice buildup on normal induction sources can be detected by a loss of engine rpm with
fixed-pitch propellers and a loss of manifold pressure with constant-speed propellers. On some fuel-injected engines, an alternate air
source is automatically activated with blockage of the normal air source.
An alternate static system provides an alternate source of static air for the pitot-static system in the unlikely event that the primary
static source becomes blocked. In non-pressurized airplanes, most alternate static sources are plumbed to the cabin. On pressurized
airplanes, they are usually plumbed to a non-pressurized baggage compartment. The pilot may activate the alternate static source by
opening a valve or a fitting in the flight deck. Activation may create airspeed indicator, altimeter, or vertical speed indicator (VSI)
errors. A correction table is frequently provided in the AFM/POH.
Anti-icing/deicing equipment only eliminates ice from the protected surfaces. Significant ice accumulations may form on unprotected
areas, even with proper use of anti-ice and deice systems. Flight at high angles of attack (AOA) or even normal climb speeds permit
significant ice accumulations on lower wing surfaces, which are unprotected. Many AFM/POHs provide minimum speeds to be
maintained in icing conditions. Degradation of all flight characteristics and large performance losses can be expected with ice
accumulations. Pilots should not rely upon the stall warning devices for adequate stall warning with ice accumulations.
Ice accumulates unevenly on the airplane. It adds weight and drag (primarily drag) and decreases thrust and lift. Even wing
shape affects ice accumulation; thin airfoil sections are more prone to ice accumulation than thick, highly-cambered sections.
For this reason, certain surfaces, such as the horizontal stabilizer, are more prone to icing than the wing. With ice
accumulations, landing approaches should be made with a minimum wing flap setting (flap extension increases the AOA of the
horizontal stabilizer) and with an added margin of airspeed. Sudden and large configuration and airspeed changes should be avoided.
Unless otherwise recommended in the AFM/POH, the autopilot should not be used in icing conditions. Continuous use of
the autopilot masks trim and handling changes that occur with ice accumulation. Without this control feedback, the pilot may
not be aware of ice accumulation building to hazardous levels. The autopilot suddenly disconnects when it reaches design limits,
and the pilot may find the airplane has assumed unsatisfactory handling characteristics.
The installation of anti-ice/deice equipment on airplanes without AFM/POH approval for flight into icing conditions is to
facilitate escape when such conditions are inadvertently encountered. Even with AFM/POH approval, the prudent pilot avoids icing
conditions to the maximum extent practicable and avoids extended flight in any icing conditions. No multiengine airplane is approved
for flight into severe icing conditions and none are intended for indefinite flight in continuous icing conditions.
Performance and Limitations
Discussion of performance and limitations requires the definition of the following terms.
⦁ Accelerate-stop distance is the runway length required to accelerate to a specified speed (either VR
or VLOF, as specified by the manufacturer), experience an engine failure, and bring the airplane to a
complete stop. [Figure 13-5A]
⦁ Accelerate-go distance is the horizontal distance required to continue the takeoff and climb to 50
feet, assuming an engine failure at VR or VLOF, as specified by the manufacturer. [Figure 13-5A]
⦁ Climb gradient is a slope most frequently expressed in terms of altitude gain per 100 feet of
horizontal distance, whereupon it is stated as a percentage. A 1.5 percent climb gradient is an
altitude gain of one and one-half feet per 100 feet of horizontal travel. Climb gradient may also be
expressed as a function of altitude gain per nautical mile (NM), or as a ratio of the horizontal
distance to the vertical distance (10:1, for example). [Figure 13-5B] Unlike rate of climb, climb
gradient is affected by wind. Climb gradient is improved with a headwind component and reduced
with a tailwind component.
Figure 13-5A. Accelerate-stop distance and accelerate-go distance.
Figure 13-5B. Climb gradient.
⦁ The all-engine service ceiling of multiengine airplanes is the highest altitude at which the airplane can
maintain a steady rate of climb of 100 fpm with both engines operating. The airplane has reached its
absolute ceiling when climb is no longer possible.
⦁ The single-engine service ceiling is reached when the multiengine airplane can no longer maintain a 50 fpm
rate of climb with OEI, and its single-engine absolute ceiling when climb is no longer possible.
The takeoff in a multiengine airplane should be planned in sufficient detail so that the appropriate action is taken in the event of an
engine failure. The pilot should be thoroughly familiar with the airplane’s performance capabilities and limitations in order to make
an informed takeoff decision as part of the preflight planning. That decision should be reviewed as the last item of the “bef ore
takeoff” checklist.
In the event of an engine failure shortly after takeoff, the decision is basically one of continuing flight or landing, even off-airport. If
single-engine climb performance is adequate for continued flight, and the airplane has been promptly and correctly configured, the
climb after takeoff may be continued. If single-engine climb performance is such that climb is unlikely or impossible, a landing has to
be made in the most suitable area. To be avoided above all is attempting to continue flight when it is not within the airplan e’s
performance capability to do so. [Figure 13-6]
Figure 13-6. Area of decision for engine failure after lift-off.
Takeoff planning factors include weight and balance, airplane performance (both single and multiengine), runway length, slope and
contamination, terrain and obstacles in the area, weather conditions, and pilot proficiency. Most multiengine airplanes have
AFM/POH performance charts and the pilot should be proficient in their use. Prior to takeoff, the multiengine pilot should ensure that
the weight and balance limitations have been observed, the runway length is adequate, and the normal flightpath clears obstacles and
terrain. The pilot should also consider the appropriate actions expected in the event of an engine failure at any point during the
takeoff.
The regulations do not specifically require that the runway length be equal to or greater than the accelerate-stop distance. Most
AFM/POHs publish accelerate-stop distances only as an advisory. It becomes a limitation only when published in the limitations
section of the AFM/POH. Experienced multiengine pilots, however, recognize the safety margin of runway lengths in excess of the
bare minimum required for normal takeoff, and they insist on runway lengths of at least accelerate-stop distance as a matter of safety
and good operating practice.
The multiengine pilot considers that under ideal circumstances, the accelerate-go distance only brings the airplane to a point a mere
50 feet above the takeoff elevation. To achieve even this meager climb, the pilot had to instantaneously recognize and react to an
unanticipated engine failure, retract the landing gear, identify and feather the correct engine, all the while maintaining precise
airspeed control and bank angle as the airspeed is nursed to VYSE. Assuming flawless airmanship thus far, the airplane has now
arrived at a point little more than one wingspan above the terrain, assuming it was absolutely level and without obstructions.
For the purpose of illustration, with a near 150 fpm rate of climb at a 90-knot VYSE, it takes approximately 3 minutes to climb an
additional 450 feet to reach 500 feet AGL. In doing so, the airplane has traveled an additional 5 NM beyond the original accelerate-
go distance, with a climb gradient of about 1.6 percent. Any turn, such as to return to the airport, seriously degrades the already
marginal climb performance of the airplane.
Not all multiengine airplanes have published accelerate-go distances in their AFM/POH and fewer still publish climb gradients. When
such information is published, the figures have been determined under ideal flight testing conditions. It is unlikely that this
performance is duplicated in service conditions.
The point of the previous discussion is to illustrate the marginal climb performance of a multiengine airplane that suffers an engine
failure shortly after takeoff, even under ideal conditions. The prudent multiengine pilot should pick a decision point in the takeoff and
climb sequence in advance. If an engine fails before this point, the takeoff should be rejected, even if airborne, for a landing on
whatever runway or surface lies essentially ahead. If an engine fails after this point, the pilot should promptly execute the appropriate
engine failure procedure and continue the climb, assuming the performance capability exists. As a general recommendation, if the
landing gear has not been selected up, the takeoff should be rejected, even if airborne.
As a practical matter for planning purposes, the option of continuing the takeoff probably does not exist unless the published single-
engine rate-o f-climb performance is at least 100 to 200 fpm. Thermal turbulence, wind gusts, engine and propeller wear, or poor
technique in airspeed, bank angle, and rudder control can easily negate even a 200 fpm rate of climb.
A pre-takeoff safety brief clearly defines all pre-planned emergency actions to all crewmembers. Even if operating the aircraft alone,
the pilot should review and be familiar with takeoff emergency considerations. Indecision at the moment an emergency occurs
degrades reaction time and the ability to make a proper response.
Weight and Balance
The weight and balance concept is no different than that of a single-engine airplane. The actual execution, however, is almost
invariably more complex due to a number of new loading areas, including nose and aft baggage compartments, nacelle lockers, main
fuel tanks, auxiliary fuel tanks, nacelle fuel tanks, and numerous seating options in a variety of interior configurations. The flexibility in
loading offered by the multiengine airplane places a responsibility on the pilot to address weight and balance prior to each flight.
The terms empty weight, licensed empty weight, standard empty weight, and basic empty weight as they appear on the manufacturer’s
original weight and balance documents are sometimes confused by pilots.
In 1975, the General Aviation Manufacturers Association (GAMA) adopted a standardized format for AFM/POHs. It was
implemented by most manufacturers in model year 1976. Airplanes whose manufacturers conform to the GAMA standards utilize the
following terminology for weight and balance:
standard empty weight + optional equipment = basic empty weight
Standard empty weight is the weight of the standard airplane, full hydraulic fluid, unusable fuel, and full oil. Optional equipment
includes the weight of all equipment installed beyond standard. Basic empty weight is the standard empty weight plus optional
equipment. Note that basic empty weight includes no usable fuel, but full oil.
Airplanes manufactured prior to the GAMA format generally utilize the following terminology for weight and balance, although the
exact terms may vary somewhat:
empty weight + unusable fuel = standard empty weight
standard empty weight + optional equipment = licensed empty weight
Empty weight is the weight of the standard airplane, full hydraulic fluid, and undrainable oil. Unusable fuel is the fuel remaining in
the airplane not available to the engines. Standard empty weight is the empty weight plus unusable fuel. When optional equipment is
added to the standard empty weight, the result is licensed empty weight. Licensed empty weight, therefore, includes the standard
airplane, optional equipment, full hydraulic fluid, unusable fuel, and undrainable oil.
The major difference between the two formats (GAMA and the old) is that basic empty weight includes full oil and licensed empty
weight does not. Oil should always be added to any weight and balance utilizing a licensed empty weight.
When the airplane is placed in service, amended weight and balance documents are prepared by appropriately-rated maintenance
personnel to reflect changes in installed equipment. The old weight and balance documents are customarily marked “superseded” and
retained in the AFM/POH. Maintenance personnel are under no regulatory obligation to utilize the GAMA terminology, so weight
and balance documents subsequent to the original may use a variety of terms. Pilots should use care to determine whether or not oil
has to be added to the weight and balance calculations or if it is already included in the figures provided.
The multiengine airplane is where most pilots encounter the term “zero fuel weight” for the first time. Not all multiengine a irplanes
have a zero fuel weight limitation published in their AFM/POH, but many do. Zero fuel weight is simply the maximum allowable
weight of the airplane and payload, assuming there is no usable fuel on board. The actual airplane is not devoid of fuel at the time of
loading, of course. This is merely a calculation that assumes it was. If a zero fuel weight limitation is published, then all weight in
excess of that figure should consist of usable fuel. The purpose of a zero fuel weight is to limit load forces on the wing spars with
heavy fuselage loads.
Assume a hypothetical multiengine airplane with the following weights and capacities:
Basic empty weight 3,200 lbs
Zero fuel weight 4,400 lbs
Maximum takeoff weight 5,200 lbs
Maximum usable fuel 180 gal
1. Calculate the useful load:
Maximum takeoff weight 5,200 lbs
Basic empty weight –3,200 lbs
Useful load 2,000 lbs
The useful load is the maximum combination of usable fuel, passengers, baggage, and cargo that the airplane is capable of carrying.
2. Calculate the payload:
Zero fuel weight 4,400 lbs
Basic empty weight –3,200 lbs
Payload 1,200 lbs
The payload is the maximum combination of passengers, baggage, and cargo that the airplane is capable of carrying. A zero fue l
weight, if published, is the limiting weight.
3. Calculate the fuel capacity at maximum payload (1,200 lb):
Maximum takeoff weight 5,200 lbs
Zero fuel weight –4,400 lbs
Fuel allowed 800 lbs
Assuming maximum payload, the only weight permitted in excess of the zero fuel weight should consist of usable fuel. In this case,
133.3 gallons (gal).
4. Calculate the payload at maximum fuel capacity (180 gal):
Basic empty weight 3,200 lbs
Maximum usable fuel +1,080 lbs
Weight with max. fuel 4,280 lbs
Maximum takeoff weight 5,200 lbs
Weight with max. fuel –4 ,280 lbs
Payload allowed 920 lbs
Assuming maximum fuel, the payload is the difference between the weight of the fueled airplane and the maximum takeoff weight.
Some multiengine airplanes have a ramp weight, which is in excess of the maximum takeoff weight. The ramp weight allows for fuel
that would be burned during taxi and run-up, permitting a takeoff at full maximum takeoff weight. The airplane should weigh no more
than maximum takeoff weight at the beginning of the takeoff roll.
A maximum landing weight is a limitation against landing at a weight in excess of the published value. This requires prefligh t
planning of fuel burn to ensure that the airplane weight upon arrival at destination is at or below the maximum landing weight. In the
event of an emergency requiring an immediate landing, the pilot should recognize that the structural margins designed into th e
airplane are not fully available when over landing weight. An overweight landing inspection may be advisable—the service manual or
manufacturer should be consulted.
Although the foregoing problems only dealt with weight, the balance portion of weight and balance is equally vital. The fligh t
characteristics of the multiengine airplane vary significantly with shifts of the center of gravity (CG) within the approved envelope.
At forward CG, the airplane is more stable, with a slightly higher stalling speed, a slightly slower cruising speed, and favorable stall
characteristics. At aft CG, the airplane is less stable, with a slightly lower stalling speed, a slightly faster cruising speed, and less
desirable stall characteristics. Forward CG limits are usually determined in certification by elevator/stabilator authority in the landing
round out. Aft CG limits are determined by the minimum acceptable longitudinal stability. It is contrary to the airplane’s operating
limitations and 14 CFR to exceed any weight and balance parameter.
Some multiengine airplanes may require ballast to remain within CG limits under certain loading conditions. Several models require
ballast in the aft baggage compartment with only a learner and instructor on board to avoid exceeding the forward CG limit. When
passengers are seated in the aft-most seats of some models, ballast or baggage may be required in the nose baggage compartment to
avoid exceeding the aft CG limit. The pilot should direct the seating of passengers and placement of baggage and cargo to achieve a
CG within the approved envelope. Most multiengine airplanes have general loading recommendations in the weight and balance
section of the AFM/POH. When ballast is added, it should be securely tied down, and it should not exceed the maximum allowabl e
floor loading.
Some airplanes make use of a special weight and balance plotter. It consists of several movable parts that can be adjusted over a
plotting board on which the CG envelope is printed. The reverse side of the typical plotter contains general loading recommendations
for the particular airplane. A pencil line plot can be made directly on the CG envelope imprinted on the working side of the plotting
board. This plot can easily be erased and recalculated anew for each flight. This plotter is to be used only for the make and model
airplane for which it was designed.
Ground Operation
Good habits learned with single-engine airplanes are directly applicable to multiengine airplanes for preflight and engine start. Upon
placing the airplane in motion to taxi, the new multiengine pilot may notice several differences. The most obvious is the increased
wingspan and the need for even greater vigilance while taxiing in close quarters. Ground handling may seem somewhat ponderous
and the multiengine airplane is not as nimble as the typical two- or four-place single-engine airplane. As always, the pilot should use
care not to ride the brakes by keeping engine power to a minimum. One ground handling advantage of the multiengine airplane over
single-engine airplanes is the differential power capability. Turning with an assist from differential power minimizes both the need for
brakes during turns and the turning radius.
The pilot should be aware, however, that making a sharp turn assisted by brakes and differential power can cause the airplane to pivot
about a stationary inboard wheel and landing gear. The airplane was not designed for this action, and the pilot should not allow it to
occur. Unless otherwise directed by the AFM/POH, all ground operations should be conducted with the cowl flaps fully open. Th e
use of strobe lights is normally deferred until taxiing onto the active runway.
Normal and Crosswind Takeoff and Climb
After completing the before takeoff checklist and pre-takeoff safety brief, and after receiving an air traffic control (ATC) clearance (if
applicable), the pilot should check for approaching aircraft and line up on the runway centerline. If departing from an airport without
an operating control tower, the pilot should listen on the appropriate frequency, make a careful check for traffic, and transmit a radio
advisory before entering the runway. Sharp turns onto the runway combined with a rolling takeoff are not a good operating practice
and may be prohibited by the AFM/POH due to the possibility of “unporting” a fuel tank pickup. The takeoff itself may be prohibited
by the AFM/POH under any circumstances below certain fuel levels. The flight controls should be positioned for a
crosswind, if present. Exterior lights, such as landing and taxi lights, and wingtip strobes should be illuminated immediately prior to
initiating the takeoff roll, day or night. If holding in takeoff position for any length of time, particularly at night, the pilot
should activate all exterior lights upon taxiing into position.
Takeoff power should
be set as recommended in the AFM/POH. With normally aspirated (non-turbocharged) engines, this is
full throttle. Full throttle is also used in most turbocharged engines. There are some turbocharged engines, however, that require the
pilot to set a specific power setting, usually just below red line manifold pressure. This yields takeoff power with less than full
throttle travel. Turbocharged engines often require special consideration. Throttle motion with turbocharged engines should be
exceptionally smooth and deliberate. It is acceptable, and may even be desirable, to hold the airplane in position with brakes as
the throttles are advanced. Brake release customarily occurs after significant boost from the turbocharger is established. This
prevents utilizing the available runway with slow, partial throttle acceleration as the engine power is increased. If runway length
or obstacle clearance is critical, full power should be set before brake release as specified in the performance charts. Note that for all
airplanes equipped with constant speed propellers, the engines can turn at maximum rpm and can develop maximum engine
power before brake release. Although the mass of air per revolution is small, the number of rpm is high and propeller thrust is
maximized. Thrust is at a maximum at the beginning of the takeoff roll and then decreases as the airplane gains speed. The
high slipstream velocity during takeoff increases the effective lift of the wing behind the propeller(s).
As takeoff power is established, initial attention should be divided between tracking the runway centerline and monitoring the engine
gauges. Many novice multiengine pilots tend to fixate on the airspeed indicator just as soon as the airplane begins its takeoff
roll. Instead, the pilot should confirm that both engines are developing full-rated manifold pressure and rpm, and that as the fuel
flows, fuel pressures, exhaust gas temperatures (EGTs), and oil pressures are matched in their normal ranges. A directed and
purposeful scan of the engine gauges can be accomplished well before the airplane approaches rotation speed. If a crosswind is
present, the aileron displacement in the direction of the crosswind may be reduced as the airplane accelerates. The elevator/
stabilator control should be held neutral throughout.
Full rated takeoff power should be used for every takeoff. Partial power takeoffs are not recommended. There is no evidence
to suggest that the life of modern reciprocating engines is prolonged by partial power takeoffs. In actuality, excessive heat and
engine wear can occur with partial power as the fuel metering system fails to deliver the slightly over-rich mixture vital for engine
cooling during takeoff.
There are several key airspeeds to be noted during the takeoff and climb sequence in any twin. The first speed to consider is V MC. If
an engine fails below V MC while the airplane is on the ground, the takeoff needs to be rejected. Directional control can only be
maintained by promptly closing both throttles and using rudder and brakes as required. If an engine fails below V MC while airborne,
directional control is not possible with the remaining engine producing takeoff power. On takeoffs, therefore, the airplane
should never be airborne before the airspeed exceeds V MC. Pilots should use the manufacturer’s recommended rotation speed (V R) or
lift-off speed (VLOF). If no such speeds are published, a minimum of VMC plus 5 knots should be used for VR.
The rotation to a takeoff pitch attitude is performed with smooth control inputs. With a crosswind, the pilot should ensure that
the landing gear does not momentarily touch the runway after the airplane has lifted off, as a side drift is present. The rotation
may be accomplished more positively and/or at a higher speed under these conditions. However, the pilot should keep in mind
that the AFM/POH performance figures for accelerate-stop distance, takeoff ground roll, and distance to clear an obstacle were
calculated at the recommended VR and/or VLOF speed.
After lift-off, the next consideration is to gain altitude as rapidly as possible. To assist the pilot in takeoff and initial climb
profile, some AFM/POHs give a “50-foot” or “50-foot barrier” speed to use as a target during rotation, lift -off, and acceleration to
VY. Prior to takeoff, pilots should review the takeoff distance to 50 feet above ground level (AGL) and the stopping distance from 50
feet AGL and add the distance together. If the runway is no longer than the total value, the odds are very good that if anything fails, it
will be an off-runway landing at the least. After leaving the ground, altitude gain is more important than achieving an excess
of airspeed. Experience has shown that excessive speed cannot be effectively converted into altitude in the event of an engine failure.
Additional altitude increases the time available to recognize and respond to any aircraft abnormality or emergency during the climb
segment.
Excessive climb attitudes can be just as dangerous as excessive airspeed. Steep climb attitudes limit forward visibility and impede the
pilot’s ability to detect and avoid other traffic. The airplane should be allowed to accelerate in a shallow climb to attain VY, the best
all-engine rate-o f-climb speed. V Y should then be maintained until achieving a safe single-engine maneuvering altitude, which
considers terrain and obstructions. Any speed above or below V Y reduces the performance of the airplane. Even with all engines
operating normally, terrain and obstruction clearance during the initial climb after takeoff is an important preflight consideration.
Most airliners and most turbine-powered airplanes climb out at an attitude that yields best rate of climb (V Y) usually utilizing a flight
management system (FMS).
When to raise the landing gear after takeoff depends on several factors. Normally, the gear should be retracted when there is
insufficient runway available for landing and after a positive rate of climb is established as indicated on the altimeter. If an excessive
amount of runway is available, it would not be prudent to leave the landing gear down for an extended period of time and sac rifice
climb performance and acceleration. Leaving the gear extended after the point at which a landing cannot be accomplished on th e
runway is a hazard. In some multiengine airplanes, operating in a high-density altitude environment, a positive rate of climb with the
landing gear down is not possible. Waiting for a positive rate of climb under these conditions is not practicable. An important point to
remember is that raising the landing gear as early as possible after liftoff drastically decreases the drag profile and significantly
increases climb performance should an engine failure occur. An equally important point to remember is that leaving the gear down to
land on sufficient runway or overrun is a much better option than landing with the gear retracted. A general recommendation is to
raise the landing gear not later than V YSE airspeed, and once the gear is up, consider it a GO commitment if climb performance is
available. Some AFM/POHs direct the pilot to apply the wheel brakes momentarily after lift-off to stop wheel rotation prior to
landing gear retraction. If flaps were extended for takeoff, they should be retracted as recommended in the AFM/POH.
Once a safe, single-engine maneuvering altitude has been reached, typically a minimum of 400—500 feet AGL, the transition to an en
route climb speed should be made. This speed is higher than V Y and is usually maintained to cruising altitude. En route climb speed
gives better visibility, increased engine cooling, and a higher groundspeed. Takeoff power can be reduced, if desired, as the transition
to en route climb speed is made.
Some airplanes have a climb power setting published in the AFM/POH as a recommendation (or sometimes as a limitation), which
should then be set for en route climb. If there is no climb power setting published, it is customary, but not a requirement, to reduce
manifold pressure and rpm somewhat for en route climb. The propellers are usually synchronized after the first power reducti on and
the yaw damper, if installed, engaged. The AFM/POH may also recommend leaning the mixtures during climb. The climb checklist
should be accomplished as traffic and work load allow. [Figure 13-7]
Figure 13-7. Takeoff and climb profile.