Nothing “Standard” About Takeoff Minimums

Nothing “Standard” About Takeoff Minimums

  • September
  • 06
  • 2023
  • Advanced Aircrew Academy

Maybe it's to be ironic, but there is nothing "standard" about figuring out what weather requirements must exist for you to legally depart a specific runway. It's not often you even have to contemplate this, but Murphy's Law states that when your brain is the rustiest is when the weather is the worst.

The first thing to remember is that despite the rules, you should always consider the need to come back to the airport. Even if the rules say you can, it doesn't mean you should.

Second, all this filtering of information relates to your aircraft performance if you lose an engine at V1. With very few exceptions, all modern corporate jets meet the climb gradients for departure limitations with all engines operating, but that's not the issue. It's the obstacles in the area that are the concern should you lose an engine.

When calculating takeoff minimums, you're trying to do two things: find out what the takeoff minimums are, and then figure out how to comply with them, so let's run the information through your thought process filters.

Thought Process Filters

Filter One: Which "Part" are you operating under according to Federal Aviation Regulations, Titles 14 and 49 of the Code of Federal Regulations?


This is easy. If you have the risk tolerance of a Red Bull Rampage Mountain Biker, you have the aviation right to depart in zero visibility conditions and cloud ceiling of on the ground. If you filed or are assigned a Standard Instrument Departure (SID), then you are required to follow the altitude and heading requirements only (not the takeoff minimums), but why would you accept that level of risk? Part 91 pilots have the right to decline a SID, but then your requirements default to a Diverse Departure or an Obstacle Departure Procedure (ODP). If you cannot meet the climb gradients, then you should wait to climb in VMC conditions.

PART 135

Sorry three-engine Falcon and rotor pilots, we're going to ease the pain for everyone else here by narrowing this down to two-engine, Part 135 airplane operations to keep this simple.

The Standard Takeoff Minimum for Part 135 operators is one-mile visibility (1 mile). That's it. No cloud ceiling minimums on standard takeoffs because visibility is the controlling factor.


Filter Two: The airport now gets to tell you if its takeoff minimums are anything other than "standard."

For most of you, your software apps will help you click to where you need to be.

On FAA charts, you must look for the "Trouble T" symbol. It won't give you any information but if you see it, there is something troubling your departure safety, so find out what it is in the terminal procedures publication (TPPs) in the front of the book.

On Jeppesen charts, just go to the second page of the Airport Diagram called the "10-9A" to find out departure information.


Filter Three: If you're assigned a SID, just go to the departure plate and look for TAKEOFF MINIMUMS.

Even if you're Part 91, you must meet the climb gradient listed in your Airplane Flight Manual (AFM). In most cases, the final segment ends at 1500' AGL. That's typically easy, but if your aircraft can't climb it if/when you lose an engine, why would you try to do this in the clouds?

OPERATING SPECIFICATIONS – So forget everything you just read

Filter Four: IF you're operating under Part 135 regulations, most operators have Operation Specifications (Ops Specs) C079.

Now that you understand all of that, IF you're operating under Part 135 regulations, most operators have Operation Specifications (Ops Specs) C079 issued which lets you take off with LOWER than standard takeoff minimums! Ops Spec C079 will list your authorized lower than standard takeoff minimum and you'll train for that specifically at your Part 142 sim provider training center. Operators not authorized for lower than standard takeoff minimums will be issued only Ops Spec C057.

HOWEVER, just because your Ops Specs allow for lower than standard takeoff minimums, it does not mean the airport will allow you to do it. Airport rules trump Ops Specs.

DEPARTURES: Bet you didn’t know...

There are four broad categories of how you safely depart an airport.

  1. Follow Obstacle Departure Procedures (ODP).
  2. Follow a Standard Instrument Departure (SID).
  3. Follow a Radar Departure – the adage; When the pilot screws up the pilot dies. When the controller screws up, the pilot dies – might come from this
  4. Diverse Departures.

That last one made you look twice, right? When an airport has an instrument approach, it is assessed for obstacles. If an aircraft may turn in any direction from a runway within the limits of the assessment area and can remain clear of obstacles, that specific runway passes what is called a Diverse Departure Assessment and an ODP may not be published.

For example, let's look at Heber Valley Airport, UT (KHCR) Runway 4/22 through the eyes of Dr. Dan Boedigheimer, CEO of Advanced Aircrew Academy:

"With the statement in the Chart Supplement for Takeoff Minimums, a diverse departure in instrument conditions is not authorized. From Runway 22, the Visual Climb Over Airport (VOCA) with minimum weather of 5800-5, no standard or lower takeoff minimums authorized.

Off Runway 4, you can fly the COOLI SIX DP which then Standard (or lower when authorized – in C079) Takeoff Minimums apply IF you can meet the minimum climb requirement of 655' per NM to 8700 with both engines operating. To comply with FAR Part 135.379, you would need to show you can clear obstacles with one engine inoperative, but that could be a separate calculation using a special departure procedure in case of an engine failure."

Here's your last conundrum for discussion at your next pilot meeting. This conundrum has compliance consequences for Part 135 operators. Here is the set up:

The Instrument Procedures Handbook (IPH), in Chapter 1, Departure Procedures, states the following: "The FAA establishes takeoff minimums for every airport that has published Standard Instrument Approaches. These minimums are used by commercially operated aircraft, namely Part 121 and Part 135 operators. At airports where minimums are not established, carriers must use FAA designated standard minimums. These are 1 statute mile visibility or 5000 RVR for single and twin-engine aircraft."

On the other hand, Ops Spec C057, contains the following: "When a takeoff minimum is not published, the certificate holder may use the applicable standard takeoff minimum and any lower than standard takeoff minimums authorized by these operations specifications.", meaning Ops Spec C079, when issued. Which is correct? Are lower than standard takeoff minimums authorized at airports that do not publish any takeoff minimums?

On the face of it, an Ops Spec would trump the IPH; however, to add to the fun, here is a selection from C079, the Ops Spec which authorizes lower than standard takeoff minimums: "Lower Than Standard Takeoff Minima. When takeoff minima are equal to or less than the applicable standard takeoff minima, and the operation is conducted in compliance with the provisions and limitations of this operations specification, the certificate holder is authorized to use the lower than standard minima described herein."

This one is not as clear as the IPH, but it could be read to mean that if you can only use lower than standard when there are takeoff minima, then when there are not any minima published, you must use standard.

Instrument Procedures Training

Clear as mud? Instrument Procedures is among the 120+ module topics Advanced Aircrew Academy can customize for you. Our Instrument Procedures module is intended for Airline Transport Pilot (ATP) rated pilots flying transport category jet or equivalent high performance turboprop aircraft. The module includes a review of navigation basics and instrument procedures including departures, arrivals, and approaches. Training on the use of approach VNAV is provided.

This module also includes information on the following documents: FAA Safety Alert for Operators (SAFO) 09011-Using Constant Angle of Descents Techniques for Nonprecision Approaches and 12005-Aircraft Approach Category; Information for Operators (InFO) 08027-Backing Up Visual Approaches, 11003-Visual Approaches, 11009-ILS Stepdowns, 12002-Reduced ILS Landing Minima, and 12018-Flight Plans.

Part 135

This Instrument Procedures module provides ground training in preparation for the testing requirements of Federal Aviation Regulation (FAR) 135.293 (a)(4) and (5), and in response to the training requirements of FAR 135.345 (Initial) and 135.351 (Recurrent). After customization, this module satisfies your Training Program Airman Specific Basic Indoctrination curriculum on Aircraft Performance and Airport Analysis, Navigation, Airspace and Air Traffic Control (ATC) Procedures, and Concepts of Instrument Procedures. Separate Initial and Recurrent versions of the module are available. The module is customized based on your Ops Specs, General Operations Manual (GOM), and/or Flight Operations Manual (FOM) requirements, and any special curriculum requirements in your FAA-approved Training Program.

Part 91

Using Aeronautical Information Manual (AIM) and Instrument Procedures Handbook materials, this module supports Part 91 pilot knowledge and proficiency requirements for navigation and instrument procedure flight operations in the U.S. National Airspace System. The module is not required by the International Standard for Business Aircraft Operations (IS-BAO) or Business Aviation Safety Consortium (BASC) standard.

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