CHAPTER 6 - ASSAULT LANDING ZONE OPERATIONS Flashcards
What is considered a “standard operating strip”?
5,000 ft x 60 ft
Define an ALZ
natural, semi-prepared, or prefabricated strip with surface, slope, dimensions, load-bearing capacity, and clearance from obstructions
sufficient to allow suitably-trained crews to takeoff/land in good weather conditions
What AF pub can be used to find ALZ info?
AFI 13-217, Drop Zone and Landing Zone Operations
What 3 categories are airfields generally divided into?
- high-strength
- marginal strength
- substandard
Define High-Strength Airfield
paved runways either Rigid (concrete) or Flexible (asphalt) with a subgrade code indicating strength of soil bearing the runway environment
Define Marginal Strength Airfield
temporary airfields with minimally surfaced or unsurfaced runways such as dirt, grass, gravel, coral, etc
surface/soil strength evaluated in terms of California Bearing Ratio
What is CBR?
California Bearing Ratio
lower numerical values indicate lower subgrade strength - surfacing material is considered to be ineffective and only the subgrade soil is considered in defining the airfield strength
What is the minimum soil strength required for operation on marginal strength airfields?
When should particular consideration be given to operations? (what value?)
CBR value of 3
CBR of 6 or less
What can adverse soil characteristics result in?
poor braking, unpredictable rutting or other surface deterioration, airframe damage from thrown dirt/gravel, engine FOD
What constitutes a “pass”?
1 landing plus 1 takeoff
The number of passes is predicated on what?
aircraft weight and CBR
based on recommended tire pressures corresponding to 39% tire deflection for marginal strength airfields
To prevent excessive tire damage what should you do?
do not exceed 39% tire deflection
To minimize a/c and engine maintenance on marginal strength/substandard what are some things you can do?
- inflate/deflate MLG tires to recommended psi
- empty external fuel tanks
- do not exceed 10 kts while taxiing
- minimize braking if porpoising occurs
- minimize nose gear loads by using elevator during landing rollout and takeoff / load a/c to mid or aft CG
- minimize use of reverse
- shut off FS and cargo AC to prevent clogging of heat exchanger unit
- limit gross weight to 164K
Define Substandard Airfields
may be either paved or unpaved and have unusually rough, undulating, pitted, or rutted runways
visible ruts
most likely not considered for normal/routine operations
Operational feasibility on unsurfaced airfields depend on what?
soil type, soil moisture content, and operational frequency
What do Ground Flotation charts do?
permit matching the loads that the aircraft imposes on an airfield to the strength capability of the airfield
Ground flotation characteristics are correlated for the following 5 methods of evaluating runway strength:
- Footprint Loading (pressure) - same as tire inflation pressure
- Unit Construction Index (UCI) - determine characteristics of comparative a/c, seldom used
- Equivalent Single-Wheel Load (ESWL) - determined from geometry of multiple wheeled landing gears, number and size of tires, a/c weight. Where data are given in terms of ESWL, UCI & LCN values can be calculated
- Load Classification Number (LCN) - when this is used (primarily outside US), data shown on ground flotation charts can be used to estimate the capability of a/c to operate from given airfield
- CBR - represent required surface hardness for operation of a/c in terms of weight and number of passes
Which fields can be evaluated in terms of CBR?
only unpaved surfaces
To compute minimum runway required
unless otherwise specified, compute landing distance or ground roll with what?
4 engines in reverse and full brakes
Minimum Runway Required
land with training crew
3,000 ft
or
ground roll + 1000 ft
whichever is greater
Minimum Runway Required
takeoff with training crew
3,000 ft
or
ground run + 1,000 ft
or
AMFLMETO + 500 ft
whichever is greater
Minimum Runway Required
land with sustainment training/operational crew
Ground roll + 500 ft w/ 4 engine reverse and full brakes
No wind, 150% tailwinds
Minimum Runway Required
takeoff with sustainment training/operational crew
Ground run + 500 ft
or
AMFLEMTO, whichever is greater
No wind, 150% tailwinds
What don’t we use MFLMETO?
does not provide adequate safety margins for engine loss below Vmca
takeoffs with field length between AMFLMETO and MFLEMETO require approval by the appropriate authority
How wide should taxiways be?
for single-direction operations they should be no less than 40 ft but should be made 60 ft wide to increase ease in turning off the runway
What should the dimensions of a parking apron be?
no less than 150 ft long and 150 ft wide
How far do overruns extend?
300 ft outward from the arrival and departure ends of the runway
Which Marine Corps beacon is compatible with the C-130?
PPN-19
What is the primary use of the IR-Cooled Descent?
remain in a sanctuary altitude as long as possible and then descend through threat engagement altitudes with a reduced IR and aural signature
What is the Random High Approach designed to do?
fly outside the effective range of small arms and descend within the protected airspace of the Base Defense Zone (BDZ)
Why should you use the Random Low or Shallow Approaches?
used to counter the threat of enemy aircraft, ADA, or certain types of SAMs
least effective in countering a small arms threat
What are the 5 random low approaches?
Straight-In Teardrop Abeam Spiral Downwind
Advantages of random low approaches
reduced exposure time to ADA and SAMs
minimized overflight time of unsecured areas surrounding the airfield
Disadvantages of random low approaches
places aircraft in small arms envelope
closer to the ground
requires more aircrew proficiency and experience
navigation and ALZ acquisition more difficult
What are the parameters for a good final?
200-300 AGL
0.5 NM (no less than 0.25)
The LM will call Brown Out 3 times. Where is the dust each time he says it?
- when dust cloud obscures trailing edge of horizontal stabilizer
- obscures the leading edge of horizontal stabilizer
- obscures paratroop door windows
Define Takeoff Factor
combines the parameters of field pressure altitude and runway temperature
based on normal bleed air condition
Define Refusal Speed
based on runway available
max speed to which aircraft can accelerate with engines at takeoff power and then stop within the remainder of the runway available with 2 engines in reverse, 1 engine in ground idle, 1 prop fx’d and max anti-skid braking
What should you do if refusal speed is greater than the brake energy limit speed?
set refusal speed equal to brake energy limit speed
Define Critical Field Length
total runway distance required to accelerate on all engines to CEF speed, experience an engine failure, then continue the takeoff or stop within the same distance
Define Critical Engine Failure Speed
speed to which aircraft can accelerate, lose an engine, and then either continue the takeoff with the remaining engines or stop in the same runway distance.
Define Brake Energy Limit Speed
max speed at which anti-skid braking can be applied without exceeding the energy absorption limit of the brake system
Define Minimum Field Length for MAX Effort Takeoff
length of runway required to accelerate to CEF, experience an engine failure, and stop or continue acceleration to max effort takeoff speed within the remaining runway
Define max effort takeoff speed
1.05 Vmu4, 4-engine minimum unstick speed
What is Vmu4
4-engine minimum liftoff speed with aircraft at maximum pitch attitude on the ground
What is Vmu3
3-engine minimum liftoff speed with aircraft at maximum pitch attitude on the ground
Define 3 engine minimum liftoff speed
1.05 Vmu3, 3-engine minimum unstick speed
Define Minimum Field Length for ADJUSTED Max Effort Takeoff
distance required to accelerate on all engines to CEF, experience an engine failure, then in the same distance either stop or accelerate to liftoff at or above Vmca and the 3-engine minimum liftoff speed
On an AMFLMETO takeoff, what should you do if an engine fails after refusal speed?
accelerate to rotation speed and rotate toward the target pitch attitude
once airborne, adjust pitch attitude to accelerate to obstacle clearance speed while maintaining a climb
When should acceleration check time be made?
between brake release and either 60, 70, 80, 90, 100, 110, or 120 kts
use the highest of these speeds which will not exceed refusal -10 (rounded to the nearest 10 kts)