20 sm in 5 minutes at 465 Knots


#1

There is a Falcon 20 at my airport that was shown on FA as traveling from my airport to another 20 miles away. Thing is, it is shown making the trip at 2000 ft at 465 knots. Is that legal?


#2

not legal… maybe

91.117 unless *otherwise authorized * no person may operate below 10,000 feet MSL at indicated speeds above 250 knots.

That being said i dont know if someone would or would not authorized 450 kts that low. could be an error, maybe it was supposed to say 20,000 ft.


#3

In the U.S. ATC can not authorize speeds above 250KIAS below 10k the only exception is Air Ambulance.

They can approve you to fly faster then 250KIAS in Canada (those crazy kunuks)


#4

I assume that’s just the default speed when they file flight plans. Their other flights all seem to be 465.


#5

Don’t know. The airports are 20 miles apart. I’m trying to wrap my head around getting up to 465 then back down to landing speed in 20 miles, but to do that and climb to 20,000 and then get back down again?

After I posted, I checked the weather and the ceiling was about 500 ft all day so no VFR traffic, maybe that’s why they let him rip at 2000. Would like to have heard that go by.


#6

The filed speed is usually a typical cruising speed. Most operators won’t adjust it before filing on a short segment. I suspect they’ll really hop over town at 200-250 knots.


#7

20 miles in 5 minutes is, um…, 4 miles a minute= 240 on average. Since most jets can get to 250 and 2000 ft. in about a minute and, if the weather cooperates, slow from 250 to landing speed while descending in 6 or 7 miles that means this is a possibility. Rounding would help, maybe it was really 5:29!


#8

I was hoping you would render a decision. At 2000 ft would 465 knot be near Vne?


#9

I mean Vmo


#10

Uhhhhh, yes they can. That’s kind of the point of 91.117 (a). I’ve been told to exceed 250kts arriving into PBI, FLL, FXE, MIA, et al. more times than I can possibly count.


#11

Vne… the mach number is low since the speed of sound is so high at the surface. Indicated airspeeds, OTOH, would be quite high.


#12

465 is the filed TAS, at altitude that would be around .80M or 270IAS, more or less, depending on temp. and altitude.
I don’t know what VMO is on the Falcon but I would imagine it is around 360 IAS, roughly.


#13

You were more then 12 miles off shore when they gave you that clearance.