Gulfstream G450 Instrument Procedures
Approach categories seem to cause a lot of confusion in the corporate pilot world for some reason. The rules are pretty simple and are linked below. The confusion in the Gulfstream world was caused by magical two-sided plastic placards in the cockpit which pilots used to move at will from one category to another. The FAA ended all that with an emphatic statement that pilots could not do that, in fact only mechanics could do it with log book write ups. (The placards now only have one side, they are either installed or they aren't.)
Photo: from Haskel's jet
|Max Landing Weight||Category|
More on this in the Approach Categories section.
GV / G550
The GV and G550 are almost always Category C aircraft since they circle at VREF+5 with 39° flaps and that speed is almost always below 141 knots. (You would have to be close to max landing weight and well above sea level to exceed 141 knots.)
The answer "it depends" applies to the GIV when it comes to approach categories:
- If you don't have ASC 61, your certified maximum landing weight is 66,000 lbs. and your lowest possible VREF is 149 knots; you are in Category D, end of discussion.
- If you do have ASC 61, your certified maximum landing weight is 58,5000 lbs. You could, on a sea level day with full flaps say you have a VREF (just) under 141 knots and you are therefore a Category C airplane. That is true, but there is an exception. If your actual VREF + 10 knots or whatever additive you are required to add keeps you below 141 knots everything is okay. But if your actual VREF and additives take you to 141 knots or greater, you are "bumped" into the next category. You could end up at Cat D minimums, even on a circling approach.
Note: I am almost always in the same situation in my G450, except my minimum additive is 5 knots, not 10 knots.
The G450 is better off since it circles at VREF+5 with 39° flaps and weighs a little less than a GIV, but it still sometimes ends up above 141 knots. ASC 007 reduces the aircraft's maximum landing weight, thereby reducing the aircraft's approach category, as detailed below.
Remember, the pilot can always raise the category. (More on this: Circling Approaches.)
G450 Specifics - ASC 007C
Here is what ASC 007C says on Category C:
Figure: Maximum Landing Weight, from ASC 007.
And about moving back to Category D:
Bottom Line? If you have ASC 007C installed, you are flying a Category C airplane with a 58,500 landing limit. You can change either of those facts thusly:
- If you find yourself needing to circle faster than 140 knots you as a pilot deem yourself to be flying at Category D minimums.
- If you want to land heavier:
- An authorized mechanic must remove the placard and AFM supplement from the aircraft.
- The mechanic must then make a logbook entry stating the ASC had been removed.
- At this point the aircraft returns to Approach Category D, and there is nothing you as a pilot can do to return it to Approach Category C.
14 CFR 97, Title 14: Aeronautics and Space, Standard Instrument Procedures, Federal Aviation Administration, Department of Transportation
Gulfstream G450 Aircraft Service Change 007C, Maximum Landing Gross Weight, 58,500 pounds, Category C, Provisions, October 26, 2011
ICAO Doc 8168 - Aircraft Operations - Vol I - Flight Procedures, Procedures for Air Navigation Services, International Civil Aviation Organization, 2006