Speed during holds and IA

[Oliver]

All

I've asked Dojo about this and he gave a clear reasoning but also said we don't have any formal guidelines or even procedures yet.

What speed should we in an A-10 maintain when holding for an Instrument Approach, and what speed envelope should we maintain during the IA up until the point where we start changing throttle settings, speed, and air brakes for the landing?

Dojo suggested 300 GS during the hold and between 230-250 IAS during the IA with the most important aspect maintaining a 2-3 NM trail distance. Are there perhaps real world IFR procedures that we can adopt without running into the issue of not always having ATC?

[Noodle]

The 3-3 provides guidance on recommended airspeeds to be flown during holding and descent/penetration for an instrument approach.

[Oliver]

Hmm you're right. It says 200-250 IAS in the hold and 200-250 IAS under TACAN peneration. Didn't notice that at first.

[Dojo]

Dojo suggested 300 GS during the hold and between 230-250 IAS during the IA with the most important aspect maintaining a 2-3 NM trail distance. Are there perhaps real world IFR procedures that we can adopt without running into the issue of not always having ATC?

Slightly misquoted me, but that's OK, I understand the spirit of what you were asking. My point about the separation being important (2-3NM was my recommendation) was in regards to us currently not having a defined way to maintain separation between two aircraft in the same flight without a human controller during the procedure, unlike the Instrument Trail Departure contract, which provides that.

e.g. if you're at 250 and the guy ahead of you is at 200, with 1nm separation, good chance you'll overtake him during the initial approach, while you're heads down. It's happened here several times.

I brought this up recently, and Tex responded with his findings. From there, I believe the process is for Energy/Roto to work to define this further for training process, hopefully soliciting Noodle/Tex for their input. In fairness, items like this tend to be underdeveloped because they're not common scenarios we have outside of training. Still, it should be polished.

[Isimus]

Also bare in mind than any time you are going to a holding pattern, except for training reasons it's because you can't continue at that moment in time, being airport closed or low visibility procedures in force, rush hour, waiting for other elements at a marshal point.

So you as a pilot no longer need to worry about speed but in fuel. A tank of fuel is a tank of time, so more options are open for you.

Therefore, best holding speed is the one that gives you the lowest fuel consumption. And on a holding pattern, you are separated by flight levels, so different aircraft types with different speeds can hold together without a problem.

A different story is speed for the approach. As Dojo said, one needs to be agreed/issued in order to keep brief/required separation between traffics.

But regardless of your aircraft type, always adhere to minimum and maximum published speeds on instrument charts.

[Tex]

Are we talking about instrument procedures as a flight or separate flights? What I posted in the Instrument Trail thread address separation between aircraft in the same flight and it's as simple as briefing speeds and configuration changes. If you talking separation between seperate flights, there aren't procedures. You wouldn't be flying approaches IMC without some sort of controlling agency like AWACS, ATC, or CRC. The reason these things keep coming up is we are inserting procedures that are designed for controlled airspace into an uncontrolled environment. In this case of separate flights flying instrument procedures, I'd suggest using 1000' altitude separation in holding and 2 min seperatation on the approach. For A-10s, that's about 8 miles at enroute airspeed and 4.5 NM at final approach speed. It may seem excessive but they preceding aircraft has to land and clear the runway before you can land.

[Dojo]

I don't think anyone is confused about what you were referring to. The issue is it's not defined, so it can't be taught. We've got to get this somewhere better than a thread.