Minimum Safe Altitude during the GAAR 2010

[Les Smith]

As you know the minimum safe altitude for an area is published on charts and planning software. FS9 and FSX suggests this flight height when "finding the route". FSNav has markers on the map for high terrain. FS Commander, which I have just started to use, prints the minimum safe altitude on its map in sectors. So, if we fly above 5000' in Australia we should fly according to the "hemispherical level": Aircraft flying a magnetic track from North [000 deg M] through East [090deg M] to [359 deg M] should fly at ODD THOUSANDS + 500 FEET. Flying a magnetic track from South [180 deg M] through West [270 deg M] to 359 deg M should fly at EVEN THOUSANDS + 500 FEET. (From my real world flight training manual, now 10 years old).
During the second leg of the GAAR 2010 from YPID to YWSL the flight travelled through two minimum flight levels: 4900' and 5700'. Hence I attempted to follow the "hemispherical levels" and flew at 5500' and 7500'.
My question to GAAR director Andrew is: "Has the target time for each leg been calculated to include the "hemispherical levels" along the way?

Phew!

Les

[Andrew Godden]

Les,

Without trying to over-complicate the whole GAAR process, the Target Time factors in all aspects of the flight profile including the climb to cruise. But this is an average and across the performance factors for a myriad of different aircraft at both ends of the performance spectrum.

The GAAR is a rally, and as such, is not prescriptive about flight planning, rather it aims to focus participants on good, solid flight planning in order to achieve the Target Time for the Flight Legs. You are given the route, Target Time and weather conditions. Your flight planning should take into account all aspects in order to achieve as close as possible to the Target Time.

To your point more specifically, the additional climb can be compensated for, to a degree, by a higher ground speed at altitude or could be compensated for with a faster cruise or a longer / faster descent profile.

I will be providing more detailed weather information, as a download on the GAAR Downloads page in the next few days.

The flight planning is all up to you.

P.S. I trust I answered your earlier question regarding all the Flight Legs satisfactorily.

[Les Smith]

Thanks Andrew, just what I needed to know.

And, yes I jumped the gun with my reference to the schedule on an earlier email. Now I understand with the release of the detailed flight plans.

Les

[Tom Goodrick]

I have now completed Leg 6 on my second pass through the GAAR. After YPID, I fly all legs IFR. No need to add 500 ft. I use the minimums given in FS9's Flight Planner. I have found that the target times do give ample allowance for climbs to the minimums.

[Allan_Lowson]

Tom, you obviously were too smart to try Leg 4 in an asthmatic 85 year old biplane. Damp in places too. At least the downhill run from the top of climb and a straight in approach minimised the damage.

Leg 2 needed 2,000rpm for the last half to make it in too. A breezy corner of the globe.

Did we use YMCO in a previous GAAR, the approach seemed familiar?

[rattler1]

Tom,
You say that FltSim's Flight Planner gives you minimum altitudes for each portion of the route. I find it only suggests an altitude for the whole route, once you set dep. and arr. airfields. Is there something I'm missing here that I can do to make it more accurate? The other option which I sometimes use is to go over the route in Google Earth and note the highest ground en-route. That way you know you're safe (assuming FS has the correct height data)

Rattler

[pterodactyl (George)]

I guess I fly a bit different. I consider my safe altitude as the height where I ain't kicking up dust with my props while enroute.

[Tom Goodrick]

You can make the flight plan as simple or as complex as you wish in FS9. If you only pick a departure airport and a destination airport, you will get a great circle route and one minimum safe altitude. But if you pick waypoints as noted in the flight description that are published waypoints (ie- navaids, airports and published intersections - the little triangles), then look at the navlog and you will find times, distances and altitudes for each segment of the flight. You use the map and zoom in to find all the features you need to select waypoints.

With all the ridge-hugging clouds I saw along the routes, you would not be able to tell the gravel kicked up by props.

Anyone planning on flying by pilotage had better stay home.