Pearson Climb Gradients

[ezconfused]

Anyone know when/why the Pearson clb gradients increased so drastically? ATC only? The numbers don't make sense. The East runways used to be a benign climb to 1100 now they're 400'/NM to 2700.

V0042/19 NOTAMN
Q) CZYZ/QPICH/I/BO/A/000/999/4340N07937W005 A) CYYZ B) 1901141729 C) 1903310500
E) [US DOD PROCEDURAL NOTAM] IFR TAKE-OFF MINIMUMS AND (OBSTACLE)
DEPARTURE PROCEDURES CHANGED C. RWY 05: ADD “REQUIRES A MINIMUM
CLIMB GRADIENT OF 360 FT/NM TO 2700 OR SPECIFIED TAKE-OFF MINIMUM
VISIBILITY (SPEC VIS) CORRESPONDING TO AIRCRAFT CATEGORY AS
FOLLOWS: 1 SM (CAT A); 1 1/2 SM (CAT B); 2 SM (CAT C/D) IN VISUAL
CONDITIONS .” RWY 15L: ADD “REQUIRES A MINIMUM CLIMB GRADIENT OF
390 FT/NM TO 3000 OR SPECIFIED TAKE-OFF MINIMUM VISIBILITY (SPEC
VIS) CORRESPONDING TO AIRCRAFT CATEGORY AS FOLLOWS: 1 SM (CAT A); 1
1/2 SM (CAT B); 2 SM (CAT C/D) IN VISUAL CONDITIONS .” RWY 15R: ADD
“REQUIRES A MINIMUM CLIMB GRADIENT OF 380 FT/NM TO 3000 OR
SPECIFIED TAKE-OFF MINIMUM VISIBILITY (SPEC VIS) CORRESPONDING TO
AIRCRAFT CATEGORY AS FOLLOWS: 1 SM (CAT A); 1 1/2 SM (CAT B); 2 SM
(CAT C/D) IN VISUAL CONDITIONS .” RWY 33R: ADD “CLIMB TO 2100 ON
HEADING 327° BEFORE PROCEEDING ON COURSE.” DELETE, “RWY 06L, 06R,
33L: SPECIFIED TAKE-OFF MINIMUM VISIBILITY TO CLIMB VISUAL OVER THE
AIRPORT TO 1500 BEFORE PROCEEDING ON COURSE.”
CREATED: 14 Jan 2019 17:29:00

[cossack]

I don't know for sure but my guess would be noise abatement and that is GTAA driven, not ATC.

[altiplano]

Published climb gradients for noise don't make sense... or the spec vis option. Must be an obstacle.

[digits_]

Published climb gradients for noise don't make sense... or the spec vis option. Must be an obstacle.

Why not? Make sure you are above XXXX ft before you are flying over the neighbourhood with the most complaints?

[Gino Under]

Climb gradients are for obstacles. Noise Abatement departure procedures are for noise restrictions. Don’t mix the two.
TC could have reassessed the local obstacles and adjusted the departure gradients to meet the new obstacle clearance.

Gino Under

[altiplano]

Published climb gradients for noise don't make sense... or the spec vis option. Must be an obstacle.

Why not? Make sure you are above XXXX ft before you are flying over the neighbourhood with the most complaints?

What Gino said.

They publish noise abatement seperately. Climb gradients are for obstacles. Unless published otherwise they are 200'/nm to a minimum IFR altitude... Maybe 200'/nm southeast bound would put you low over downtown TO.

Another way to look at this scenario - if you can still do the departure without meeting the published gradient under spec vis how does that meet a noise restriction? It's make the gradient or have enough visibility to see the obstacle and assure your clearance to a minimum IFR altitude.

[tired of the ground]

I also agree that it is Obstacle clearance.

That poses some questions however. Is it possible that the obstacles are future planned obstacles and required by the surrounding municipalities? Can obstacle clearance be proactive vs retroactive? Is it possible for the surrounding areas to affect Federally governed airspace? Are there currently any jet aircraft that have trouble making a 400 '/nm climb gradient to 3000ft with 10,000+ft of runway?

[JohnnyHotRocks]

Climb gradients are not always due to obstacles, sometimes they are used for ATC procedures. In this case with spec vis I would say it is obstacle based. So what has changed?

[Gino Under]

Climb Gradients aren’t “proactive”. Meeting gradients based on what-will-be could mean unnecessarily decreasing your Max. allowable takeoff weight today. Airlines don’t like that.
TC publish updates to their obstacle database every 28 days in revision to the AIP. This obstacle database is also used in Runway Analysis software to generate takeoff performance for Max. allowable takeoff weight with today’s actual obstacles.

An ATC gradient looks at a crossing restriction on departure. From the start of your departure climb to the crossing restriction (say it’s AT or ABV 5000 at a waypoint or nav aid on the SID) from the departure end of the runway (DER) to the crossing restriction requires a minimum climb gradient which may or may not be waived by ATC.

With an engine failure on takeoff, climb gradients are practically irrelevant and don’t necessarily apply, because you may or may not be able to meet them. It’s your job to be aware of the obstacles on departure and to not run into them. Runway analysis will, if obstacles dictate, provide a single engine procedure that may or may not follow the SID.

Municipalities and their residents who move closer and closer to an international airport boundary fence don’t have much clout when flight safety rears it’s ugly head. They might bitch and moan about noise, but PET hauls in beaucoup d’argent in tax dollars too. Besides, jet noise is simply getting quieter and quieter. Jet exhaust cleaner and cleaner.

Gino Under

[55+]

Climb gradients are for obstacles. Noise Abatement departure procedures are for noise restrictions. Don’t mix the two.
TC could have reassessed the local obstacles and adjusted the departure gradients to meet the new obstacle clearance.

Gino Under

Yes, you are correct in that published climb gradients are for obstacle clearance only. It is part of the design of IAPs and a specific chapter on Departures is devoted to exactly that in TP-308. An obstacle penetration of the 40:1 slope in either of the departure zones(1,2 or 3)requires a calculated climb gradient above the standard 200ft/NM. Nav Canada Aeronautical Information and Flight Inspection does the IAP design work as I was with them until retirement few years ago, TC doesn’t assess nor publish just the overseeing of regulatory framework.

[Eric Janson]

E) [US DOD PROCEDURAL NOTAM]

This NOTAM only applies to DoD aircraft - not to civilian operators

[linecrew]

E) [US DOD PROCEDURAL NOTAM]

This NOTAM only applies to DoD aircraft - not to civilian operators

That would explain why when i pulled up the CYYZ NOTAMs on the NAV CANADA AWWS site,I couldn't find it.

[altiplano]

I couldn't find the notam either, but the gradients are on the Jeppesen 10-9A page already.

image1.png (581.87 KiB) Viewed 2165 times

[Gannet167]

DOD use their own version of the CapGen, the "FLIPs", Flight Information Publications, produced by the US National Oceanic and Atmospheric Administration. My understanding is the FLIPS are not just a reprint of host nation procedures, but are independently designed, checked and in some cases flight tested to ensure obstacle clearance and compliance with TERPS criteria. In some cases they'll have more restrictive minimums and climb gradients than the pubs produced by Transport Dirka-Dirkastan, etc. They're produced for the entire world so military operators have a trustworthy and standardized product to go anywhere with and not have to interpret PANS-OPS differences etc. Canadian military operators are supposed to use the US DOD FLIP anytime operating outside of Canada (although many use Jeppesen quasi-illegally.)

Sometimes NOAA doesn't update their pubs right away, perhaps they're checking the obstacle climb gradient against their own terrain database? So a DOD Procedural notam is issued to ensure crews using FLIPs have the right numbers. NAVCAN and Jeppesen likely already had the update. Next FLIP pub cycle will likely have the new numbers and the notam can dissapear.

I have seen steep climb gradients in Europe on SIDs published by Jeppesen that I couldn't do single engine, but upon checking the DOD, only 3.3% was required for obstacles. I believe Shannon is an example. A few years later the SID was updated with a note "12% climb required for ATC only" or something to that effect.

[ezconfused]

The gradients are in Canadian (navcan) charts as well. You won't see the notam above in awws because the change has already been incorporated in the canadian pubs. The notation for Obstacle vs ATC Requirement varies from nation to nation. Canadian charts are normally very clear. This appears or reads like it's due obstacles. The only thing that seems to be missing is actual obstacles. Compare it to KLGA or KJFK or other big city (building & tower) obstacles and Toronto's new gradients are way steeper.

CYYZ_VERDO_SIX_DEP_VERDO6.pdf

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CYYZ_VERDO_SIX_DEP_VERDO6.pdf

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[linecrew]

I would suspect that the climb gradients have to do with getting above the protected airspace associated to the IFR procedures at YTZ, YZD and YKZ airports.

[Gino Under]

Aircraft certification requires an aircraft to be able to maintain various positive climb gradients to the end of the takeoff path, which is 1,500 feet above the takeoff surface or at which the transition from the takeoff to the en route configuration is completed, whichever is higher. One item to note is that the climb gradient clear all obstacles. Commercial operators of large transport category, turbine-powered transport category, or commuter category airplanes departing an airport under IFR must have a procedure for avoiding obstacles in the event of an engine failure on takeoff, and ensures compliance with the applicable airplane performance operating limitations. Methods of complying with this rule include either developing your own procedure or using a contract company to develop avoidance procedures.
No one expects you to meet the minimum published climb gradient on one engine. Besides, for most modern twin engine jets, the OEI climb gradient usually isn’t a problem.

Gino

[bradley]

Canadian military operators are supposed to use the US DOD FLIP anytime operating outside of Canada (although many use Jeppesen quasi-illegally.)

There is a hierarchy of procedures we use. DODs can always be used, since all the procedures are reviewed to a standard we consider safe (and modified, if unsafe). The number of airports that have DODs is very limited though, and most only include a small number of the available procedures.

Since Jepps are just a copy/paste of host nation data, whether we can use them depends entirely on the country. Some countries are considered trustworthy, and host nation or Jepp procedures can be used without restriction. Some countries are not trusted, and require review before their procedures (or any Jepps based on them) can used. Often, these reviews will include amendments like higher minimums, MSAs or climb gradients. There’s no questionable legality of any approaches we fly.