Zero-Zero Takeoff
There are no accident figures that preclude zero-zero takeoffs as being dangerous. The acceleration of the aircraft can cause a somatogravic illusion that you are more nose up than it seems. Pilots who habitually make zero-zero Part 91 departures tend to be confident of their abilities and the maintenance of their aircraft.

The risk in a low-visibility takeoff lies in loss of control. Control can be lost during ground acceleration or in the transition from seeing the ground and entering MIC. You do not have any prep-period for the instantaneous change. Acceleration is a vertigo producer and the pilot must know that illusions will occur and gauges must be believed.

The next immediate risk is loss of power. Even if you know the area, low-visibility blinds you and trusting to blind luck is not a good choice. It is for these reasons that the airline minimums of one mile visibility are good minimums for the Part 91 pilot, too.

Low visibility takeoffs and departures have as an inherent factor flight close to the ground and unseen obstacles. The hazard of the takeoff is the abrupt transition to a full IFR workload. Part 91 has no minimums for takeoff but as with any other IFR takeoff it has four phases:Preparation;
This is where you taxi into position, align with the centerline, check and set compass to HI, hold brakes while you use power to give you rudder control before brake release, and go to takeoff power.

(2) Roll;
You use rudder rather than brakes to control rolling heading. If you can set a localizer frequency the CDI has a one dot range of 70 feet to each side. Keep the CDI centered. Acceleration can fool the AI into a nose-high indication so be smooth.

(3)Liftoff;
Rotation speed should be slightly faster than usual and relatively positive and smooth. Let the plane fly off and get on the gauges. Apply right rudder. Get at least 100' before changing gear or flaps. Waiting longer is usually better.

(4) Initial climb.
Maintain two bars on the AI and confirm airspeed and VSI both of which may lag due to static error.

Climb Minimums
FAA climbs and climbs to minimum altitudes are predicated on crossing the departure threshold at 35'. You are required to report to ATC anytime you are unable to climb 500 feet per minute.

Non-Standard Minimums
An airport that meets the weather forecast may not be legal if it has non-standard minimums. (Jepp on airport diagram sheet). A NOS chart may show an A for an airport where Jepp charts may not because Jepp does not chart for Category E aircraft.

Sidestep Minimums
Sidestep landings to parallel runways have higher minimums than straight in approaches. Sidestep should be done as soon as runway is in sight.

Obstacle Clearance Minimums
Obstacle free zone (OFZ) May be used in specific region near airport.
From end of runway away from MAP you have 1/2 nautical mile obstacle clearance area. This area extends in an ever widening angle to 13.5 NM. At 13.5 NM the primary safe area extends 4 nm to each side of center line and the secondary safety area is an additional 2 nm to each side. MOCAs insure obstacle clearance by 2000' lateral and 1000' vertical and navigational signal within 22 nautical of Navaid. In some instances as over the hills of Vallejo and Hayward the proximity of the terrain is much closer.

--Every airport with an instrument approach procedure also have a departure procedure if obstructions are present in the terminal area.
--An IFR departure is available for safety when terminal area obstructions cannot be seen or avoided.
--Obstacle clearance is assured if the departure end of the runway is crossed above 35’ and climbs to 400’ before turning.
--At this point a climb of 200 fpm will clear obstacles up to the enroute airways.
--This and any published rate of climb will clear obstacles by 35’.
--NOS charts have a T to advise of non-standard requirements.
--90 knots per nautical mile gives a climb rate per minute of 300 where only 200 fpm may be required.
--If 350 fpm is required you should climb at 525 fpm.
--If terrain is above runway elevation the obstacle clearance may be a little as 120’ even though the DH is at 200’.
--The further away from the runway the greater the obstacle clearance.
--Laterally the protected airspace is 1000’ wide when 200’ from the threshold.
--At ten miles the lateral dimension is five miles to each side of the centerline with the outside mile tapered upward.
--Your obstacle clearance may be as little as 70 feet.

VOR/DME with FAF, Straight-in 250 250
VOR/DME, radial or arc final 500 500
NDB on airport, no FAF, straight-in 350 350
NDB obstacle clearances become wider toward the runway. This accounts for the higher minimum descent altitudes
NDB w/FAF, straight in 300 300
Localizer, LDA, SDF 250 250
GPS approaches usually become narrower toward the runway. Therefore, the MDAs are lower. Cannot be used to track courses unless there is an overlay. It is o.k. to fly the missed or a transition but not the approach.

Circling 300 Tapers to 0

Holding 1,000 500DF Approach 500

In the secondary area the obstacle clearance tapers to zero at the outer edge. The greatest clearance is on the centerline.

Approaches with 500’ minimums will have higher obstacles. Check the circling area.

If you intend to land, you must at some point descend below the MDA and DH. The closer you get to the runway the less your obstacle clearance becomes. The non-precision minimum is 250’. The visibility minimums of all approaches are determined by the slope to the runway. It is possible to have an obstacle intrude into the glide path inside the DH if visibility minimums are over one mile.

Minimum Vector Altitudes
Controllers are required to issue an altitude to maintain that provides obstacle clearance until on a published segment of the approach. MVAs are used by radar controllers depending on radar quality and the distance from the antenna. Controllers often put in their personal fudge factor to protect themselves.

Minimum En route Altitude (MEA)
The MEA provides at least 2000' of clearance above enroute obstacles when the route is over mountainous terrain and 1000' otherwise.
--An MEA assures reception of VOR signals. VHF communications are usually but not always possible.
--MEA guarantees radio communication on airways. Communication is guaranteed at FAF and at missed approach point.
There is no assurance of communications anywhere else during the approach.
--Don’t accept as gospel the MEA altitude during very cold conditions.
--Request or fly at least a thousand above MEA.

Minimum IFR Altitude
The MIA is on unpublished direct ATC routes established by the facility. Any ATC clearance will give restriction to keep pilot above MIA.

Minimum Safe Altitude
If there is no nav facility within 30 nm of the airport, there will be no MSA. MSA provides 1000' clearance above the highest obstacle in a defined sector. Be sure to check plates to see facility used to determine MSA distances.

Minimums Off Airways Altitude (Jepp MORA /FAA OROCA
IFR pilots operating on an IFR flight plan off a designated airway must ensure they operate at a safe altitude based upon the requirement of FAR 91.177. Actual flight information can only be determined by use of sectional plus any NOTAMed new obstacles.

The pilot is responsible when operating off-airways on a direct routing for determining the minimum en route altitude. In mountainous terrain the minimum IFR altitude for off-airway operations is 2000' above the highest obstruction within 4 miles either side of your course.

Minimum off route altitude. On Jepp shown at 6000' or lower gives obstacle clearance of 1,000'. Above 7000' there is 2000' clearance. This is only obstacle clearance no reception or navigation included.  The acronym MORA stands for minimum off-route altitude. It's a Jeppesen term, found only on Jeppesen charts and defined in the company's chart glossary as "An altitude derived by Jeppesen...it provides known obstruction clearance within 10 nm of the route centerline."

NOS Off-Route Obstruction Clearance Altitude (OROCA) and Jepp's Minimum Off-Route altitude (MORA) are supposed to provide obstruction free direct routes. These altitudes are the same as appear in each quadrant of the sectional charts.

 

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