View Full Version : Non normal Approach category

23rd Sep 2012, 14:41
Hi all !

My plane is a category C aircraft.
In a non-normal condition, for example a No flaps landing, my approach speed will be higher than normal and also higher than maximum speed for cat C.
I have to use cat D (DH/RVR) for landing??

23rd Sep 2012, 16:03
Topper 80,
I don't think so, you're aircraft is Cat C and remain Cat C beside any malfunction.
Nothing tell you to swap for cat D, check AFTM and QRH.
In case of B737 you're speed will be VREF 40 + 55 knots, let's say about 180kts.
The same for a Circling minima and radius...still cat C!

23rd Sep 2012, 17:32
Category is determined by the speed you choose to fly the visual portion of the given approach at the given time. If a no-flap landing raises your approach speed over 140 kias, then you are to use cat d mins while shooting the approach without the use of flaps.

23rd Sep 2012, 19:29
According to Appendix 2 to EU-OPS 1.430 (c),The category defined for a given aeroplane shall be a permanent value and thus independent of the changing con-
ditions of day-to-day operations..

In FAR-land things are different, though. They seem to have a provision requiring the PIC to choose a higher approach category when, as in your example, the approach speed exceeds the respective category.

I remember the question has been covered here before. A search might help.

23rd Sep 2012, 20:06
Category is determined by the speed you choose to fly the visual portion of the given approach at the given time. If a no-flap landing raises your approach speed over 140 kias, then you are to use cat d mins while shooting the approach without the use of flaps.

Sorry man, but the category is choosen by the weigh of aircraft first of all and other parameters...
It's not a game, where you can chose which Cat. Aircraft you are...and which model or series of aircraft will be.;)

23rd Sep 2012, 20:36
Speed at threshold based on 1.3 times stall speed Vso or 1.23 times stall speed Vs1g in the landing configuration at maximum certificated landing mass.

Doc 8168 :ok:

23rd Sep 2012, 20:37
TERPS Category C criteria are different to ICAO which explains the difference between the opinions above. Jepp Text Definitions refer.


23rd Sep 2012, 20:49
I remain C category, but obstacole separation and radius of turn for the procedures are calculated for "C speed" and probably, with no flaps, I will be faster ! like "D speeds"

23rd Sep 2012, 20:53
Yes Topper,
but remember you are in non normal condition, so You will be vectored to final and priority to land with probably the fire brigate waiting for you.:p..but of course in case going around you have to do it at the CAT C DA/MDA.

de facto
24th Sep 2012, 11:02

If you are flying a JAA registered aircraft,as stated above your STRAIGHT IN approach category will be dependent of your Aircraft MAX landing weight VAT(1.23vsr or 1.3vso whichever higher).
As your weight decreases,your cat will remain the SAME and STRAIGHT IN Da/MDA rvrs/vis will be dependent on it.

For CIRCLING,your MDA will be dependent on your IAS,so flapless,refer to uour speed and circling chart.
The higher your actual speed,the higher the MDA.
If your speed is higher than the max circling IAS (ie ICAO 205kts),then you are not allowed to circle or if you have no other choice than to circle , stay within the radius for the max 205 kts,i think 5.3 miles and use greater bank angle.(more than 20 degrees).

Always stay within the protected radius,unless in that case you are visual and you are 100 perc sure visual wil be maintained and all terrain is clearly visible.

So 2 different things: One is AIRCRAFT CATEGORY (a/b/c ect based on VAT) and second is CIRCLING CATEGORY (also named a/b/c which causes the confusion) based on your IAS during circling which will has a specific max radius to it.
If you circle at 170 kts your circling cat will be C.
If you are circling at 185 kts(you will be using minima for circling category D).

Based on your circle category,you will need to check the circling radius that goes with it.((pan ops,terps..which is seen on the jepp charts).

On the b 737 ,standard circle is with flaps 15,so Cat C all time.

25th Sep 2012, 00:38

When your aircraft was certified it met the regulatory requirements to fit into Category C under normal operating conditions.

Airports, their runways, and approaches are built to include protected airspace. It is understood that a Category C aircraft will remain within a fixed distance from the approach end of the runway. Minimums are set with respect to obstacles within that protected airspace.

If the aircraft's ground speed is such that it is unable to remain within the protected airspace and that aircraft flies outside the physically protected airspace then no protection from obstacles or terrain is provided by the published minimums. So your Cetegory C jet at max takeoff weight returning for a landing with no flaps or slats is not going to be able to slow down enough with its clean wing to fit into Category C speeds. In that case one would use Category D minimums to reflect the actual operational speeds. Flying to Category C minims while maneuvering at Category D speeds will take you out of protected airspace.

As an emergency aircraft the regulations allow you to what is necessary to bring your flight to a safe conclusion. Declare the emergency, use all your resources to come up with the best plan fly to whatever minimums you can safely fly to and land. The approach categories, minimums, and speeds were designed for routine operations. With a crippled jet you are no longer in the normal operations regime.

Some companies require operations at the next higher Category minimums under certain conditions as a matter of policy. An example would be requiring crews to use Category D minimums to circle, even though the jet is a Category C aircraft.

25th Sep 2012, 01:19
You guys crack me up....

CAT C for final approach has NOTHING to do with weight, flaps, lack of pilot experience or anything else...

It is plain and very simple. FAS.

CAT C is 140 kts..doesnt matter

1.3 times Vref A380 or DH8

de facto
25th Sep 2012, 02:25
CAT C for final approach has NOTHING to do with weight, flaps

Aircraft category is based on max landing weight VAT and is for STRAIGHT IN ONLY!.
For JAA,it doesnt change depending on flaps,speed changes ....
For FAA,if your speed will be above 140 for example,(flaps up,asymetry)the pilot can increase his minima to CAT D.Flaps do matter for your final approach speed..even pilots with lack of experience know that.

Aircraft circling category is dependent on a MaX IAS used during the maneuver(yes directly dependent of flaps setting),and depending on the max IAS category you fall into before the maneuver,a specific obstacle radius from the runway must be observed.

1.3 times Vref A380 or DH8
An A380 in JAA may fall in C category.(so huuuuuge flap):E
So for planning purposes,the minima for RVR and DA/MDA will be based on CAT C.
If they perform a flapless landing,the cat will remain CAT C!
In FAA lalaland,they may increase their DA to cat D.

Same for Dash 8, maybe cat B.

Such are JAA regs !