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-   -   qiz about "circling approach" (https://www.pprune.org/tech-log/416658-qiz-about-circling-approach.html)

clunckdriver 7th Jun 2010 15:29

Aterpster, one of the reasons its so damned expensive is the its farmed out to "contractors" and a bloody great RJ is used for the certification flights, there is a ground unit used by the military which can do it for about 10% of the cost, in the mean time we will continue with our "in house" straight in.

BOAC 7th Jun 2010 15:35


Approach flaps should be used until turning CTL base or final, in the "slot," and final descent has begun.
- so what do you say to

Originally Posted by eagle737
Q1. For TERPS, max allowable circling IAS for CAT D is 165kt(738 with gear down/F15 at max landing weight, actual circling IAS will be 161kt), radii for CAT D is 2.3nm, bank angle for CAT D is 20°. Let's say it's a sea-level airport, our TAS at 1000ft will be 173kt, and the radius of the turn will be 1.2nm——more than half of 2.3nm!! that means we can not make a 180° turn within the protective area while we start our continuous turn to the final!

How should it be flown to stay in the terps zone?

aterpster 7th Jun 2010 16:27

BOAC:

How should it be flown to stay in the terps zone?
In those circumstances it is not possible to remain within the inadequate TERPS circling airspace. That's why those of us who are honest brokers have tried so hard for at least 15 years to get far better CTL criteria in TERPs. But, thus far, the special interests are prevailing.

There are a couple of work-arounds that work at some locations.

1. Get a copy of the FAA approach chart to determine if the airport has Approach Category E CTL minimums. (Jeppesen doesn't chart them). If the location does, then use the CAT E MDA and accept any weather minimum penalty that results.

2. At locations without CAT E CTL minimums an operator using aircraft that bump up against the CAT D limits are well-advised to conduct their own flight-track analysis as to whether it is safe to breach the 2.3 mile containment area. Often, there are no obstacles where it could bite. But, "often" is far from always.

The option to slow the airplane down to a potentially unsafe airspeed is simply not worth the risk.

And, circling is a very high risk option at night or in precip without a thorough airport assessment by the operator and without meaningful training in all aspects of the CTL maneuver.

Then, there are the even worse traps at high elevation airports, and especially those with CTL MDAs well above standard.

For-hire performance engineering vendors could provide some great services in this area. So far as I know, none of them do that.

aterpster 7th Jun 2010 16:31

c_driver:


Aterpster, one of the reasons its so damned expensive is the its farmed out to "contractors" and a bloody great RJ is used for the certification flights, there is a ground unit used by the military which can do it for about 10% of the cost, in the mean time we will continue with our "in house" straight in.
I've never heard of a ground unit that can do as well as flight inspection.

A lot of the costs, particulary for procedures with Decision Altitudes, is the cost of on-site surveys.

eagle737 8th Jun 2010 03:18

we are so lucky to have a TERPSTER here, I think he has background of goverment working and lots of people here can learn sth from him!(or her:})
So here are some qiz for Aterpster:
1)what's the difference between TERPS1/2/3 when we have them on the left bottom of Jeppesen chart?
2) When to descend from MDA? For my understanding, we can only descend from MDA when A)we are close to the final course; B)as well as on the proper landing profile. Reason A)we can have a obstacle clearance only when we are close to the final course; B) for stable approach purpose.
But what is "close to the final course"? 10° each sides of final course when we have a PAPI? somebody told me that, but i don't know where it comes from.

Again, thanks for everyone's reply!

aterpster 9th Jun 2010 20:13

eagle737:


So here are some qiz for Aterpster:
1)what's the difference between TERPS1/2/3 when we have them on the left bottom of Jeppesen chart?
Jeppesen will have "TERPS" if that is known as the criteria used; "PANS-OPS" if that is known as the criteri used. And, nothing for "criteria unknown or uncertain." Any number should be the IAP amendment number.


2) When to descend from MDA? For my understanding, we can only descend from MDA when A)we are close to the final course; B)as well as on the proper landing profile. Reason A)we can have a obstacle clearance only when we are close to the final course; B) for stable approach purpose.
But what is "close to the final course"? 10° each sides of final course when we have a PAPI? somebody told me that, but i don't know where it comes from.
I can only speak to the U.S. In the U.S. a PAPI or VASI is good to 4 miles unless further limited in the airport facility directory (FAA publication). And, unless limited they are good 10 degrees each side of runway centerline, extended, not necessarily the final approach course.


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