NJA KASE apporach question...

[VVJM265]

Actually they do. I posted the definition because whatitdoing? stated that the approach category is defined off of groundspeed; it is not as shown in the bolded text above. tk855, you are correct, however, that is also defined in the AIM:

"For example, an aircraft which falls in Category A, but is circling to land at a speed in excess of 91 knots, must use the approach Category B minimums when circling to land."



​

Another example of this would be if you had to fly a no-flap approach and the no-flap Vref put you over 141 kias; then you would use Cat D mins.

Also, as I stated above, if the wx is VMC, then you can certainly ask for the visual, regardless of the aircraft's approach catergory.

Like I said, I haven't been into Aspen, however, I have been into Sarajevo plenty of times, which has similar geography.

 

[Correcting]

Here's the answer to the original question.

If you are going into ASE on the IFR approach, and you are Cat D, then you can fly all the way to the final approach fix (Allix or Doype). At that point, if you see the airport, you can land. If you don't see the airport, you go miss. You can't legally go beyond the FAF without the airport in sight. Why? Because there are no minimums for you.

There's your answer.

 

[Bandit60]

Your approach category is either the speed at your max landing weight or the speed you are using for the approach, whichever is HIGHER. If your max landing weight speed exceeds 140 kts, then you are a Cat D for every approach you fly. If you are a Cat B but decide to fly the approach at 138 knots, then you are a Cat C for that approach.
Also, the LOC DME 15 (Jeppesen 11-7) and RNAV GPS Z (Jeppesen 18-7) both publish minimums for straight in landings. Both of those approaches are also N/A for Cat D aircraft.

What I said before is correct. Here is my example which applies to ASE.

Since the appoaches are not straight in approaches (due to the angle of decent needed) they are circling appoaches. The airplane I fly is a Certified Cat C aircraft but since it is a circling appoach I cannot use full flaps. With less flaps i have a higher Ref speed and if heavy that would put me into a cat D. Therefore not legal. However if I am light with circling configuation on the aircraft the Ref speeds are now within cat C and I am now legal.

I do agree if an airplane is certified as a cat D you cannot go to a cat C.

 

[gunfyter]

AIN Online August 2002: Aspen crash prompts approach controversy

 

[gunfyter]

Protected Airspace

I believe the TERPS does not reference SPEED in designing protected airspace. So at 10200 ft your TRUE Airspeed will be somewhat higher than at low altitudes and the 1.7 miles radius for CAT C may not be enough.

 

[RTRHD]

My last boss had a house in ASE. We were there once or twice a week the older I got the farther towards DBL my minimums got. I am with the guys that go around at DBL. I wonder what it would be like if an airplane pulled out on the runway and you had to make a low altitude go around. (What if there was a 2500 foot ceiling?) The missed approach criteria start at 2500 feet right? Just food for thought.

 

[Bandit60]

My last boss had a house in ASE. We were there once or twice a week the older I got the farther towards DBL my minimums got. I am with the guys that go around at DBL. I wonder what it would be like if an airplane pulled out on the runway and you had to make a low altitude go around. (What if there was a 2500 foot ceiling?) The missed approach criteria start at 2500 feet right? Just food for thought.

Could not agree more. VMC is the only way into Aspen...

I hear that the Avros or BAC146 that goin to Aspen are now going to be CRJ's. That will be scary.

 

[satpak77]

Guys, the Cat D or C or whatever is based on GROUNDSPEED.

uh, sorry, WRONG. Or maybe I am wrong, I need to start watching my ground speed as my DME ticks down to the runway and divert attention from flying....funny over the years at FlightSafety type rides and recurrent I never did this....better start now

(not)

at your next airline interview, please don't tell them you use groundspeed to determine approach category!

Lets re-quote AIM 5-4-7 (again)

5-4-7. Instrument Approach Procedures

a. Aircraft approach category means a grouping of aircraft based on a speed of VREF, if specified, or if VREF not specified, 1.3 VSO at the maximum certificated landing weight. VREF, VSO, and the maximum certificated landing weight are those values as established for the aircraft by the certification authority of the country of registry. Helicopters are Category A aircraft. An aircraft must fit in only one category. Pilots are responsible for determining and briefing which category minimums will be used for each instrument approach. If a higher approach speed is used on final that places the aircraft in a higher approach category, the minimums for the higher category must be used. Approaches made with inoperative flaps, circling approaches at higher-than normal straight-in approach speeds, and approaches made in icing conditions for some types of airplanes are all examples of situations that can necessitate the use of a higher approach category. See the following category limits:
1. Category A: Speed less than 91 knots.
2. Category B: Speed 91 knots or more but less than 121 knots.
3. Category C: Speed 121 knots or more but less than 141 knots.
4. Category D: Speed 141 knots or more but less than 166 knots.
5. Category E: Speed 166 knots or more.

NOTE-
V[SIZE=-1]REF[/SIZE] is the reference landing approach speed, usually about 1.3 times V[SIZE=-1]SO[/SIZE] plus 50 percent of the wind gust speed in excess of the mean wind speed (See 14 CFR Section 23.73). V[SIZE=-1]SO[/SIZE] is the stalling speed or the minimum steady flight speed in the landing configuration at maximum weight (See 14 CFR Section 23.49).​

Since Approach Category is derived from VREF (or) 1.3 VSO, lets take a look at how VREF and VSO are defined per the FAR Part 23, which certifies the airworthiness of aircraft:

http://www.risingup.com/fars/info/part23-49-FAR.shtml

http://www.risingup.com/fars/info/part23-73-FAR.shtml

Since VSO (and its derivative, VREF), are defined per the FAR's using CALIBRATED AIRSPEED, the "best-est" answer is that Approach Category is based on CAS, which according to FAR Part 1, means

Calibrated airspeed means the indicated airspeed of an aircraft, corrected for position and instrument error. Calibrated airspeed is equal to true airspeed in standard atmosphere at sea level.

So best-est answer is its based on CAS, real-world answer is to use IAS (unless someone has a CAS indicator, my King Air 350 does not...)

 

[GVFlyer]

Sorry guys, this straight from the AIM (PCG):

AIRCRAFT APPROACH CATEGORY- A grouping of aircraft based on a speed of 1.3 times the stall speed in the landing configuration at maximum gross landing weight. An aircraft must fit in only one category. If it is necessary to maneuver at speeds in excess of the upper limit of a speed range for a category, the minimums for the category for that speed must be used. For example, an aircraft which falls in Category A, but is circling to land at a speed in excess of 91 knots, must use the approach Category B minimums when circling to land. The categories are as follows:
a. Category A- Speed less than 91 knots.
b. Category B- Speed 91 knots or more but less than 121 knots.
c. Category C- Speed 121 knots or more but less than 141 knots.
d. Category D- Speed 141 knots or more but less than 166 knots.
e. Category E- Speed 166 knots or more.

(Refer to 14 CFR Part 97.)​

VVJM265 is rigtht...and I'm one of those guys that's going somewhere else if I'm not VMC at Red Table.

GV

 

[Bandit60]

Hey GVflyer...Im just wondering. What is your ref speed at max gross weight in landing config. for the G500 or G400?

I know very little about the Gulfstream but thought it could fly pretty slow on approach.