Sunday, March 20, 2011

Holding Speeds

In a faster airplane, I suddenly have to start thinking about things that never were an issue in slower ones. Suddenly stuff I skimmed over, like noise abatement rules, advisories to remain below 165 knots in the climb until above a certain altitude and engine-specific rules become relevant. For some reason I loved the 250 and 200 knot speed restrictions when I learned them in private pilot groundschool, but I've never needed to care. Here are the rules from the CARs:

602.32 (1) Subject to subsection (2), no person shall

(a) operate an aircraft at an indicated airspeed of more than 250 knots if the aircraft is below 10,000 feet ASL; or

(b) operate an aircraft at an indicated airspeed of more than 200 knots if the aircraft is below 3,000 feet AGL within 10 nautical miles of a controlled aerodrome unless authorized to do so in an air traffic control clearance.

(2) A person may operate an aircraft at an indicated airspeed greater than the airspeeds referred to in subsection (1) if the aircraft is being operated in accordance with a special flight operations certificate - special aviation event issued pursuant to section 603.02.

(3) If the minimum safe airspeed for the flight configuration of an aircraft is greater than the airspeed referred to in subsection (1), the aircraft shall be operated at the minimum safe airspeed.

602.33 No person shall operate an aircraft at a true Mach number of 1 or greater.

Okay, that last one isn't an issue just yet, but who knows, eh?

It's also the first time I'll be legally required, as opposed to just being sensible, to slow down in a hold.

10.7 Speed Limitations

Holding patterns must be entered and flown at or below the following airspeeds:
(a) Propeller Aircraft (including turboprop)

(i) MHA to 30 000 feet 175 KT IAS

(b) Civil Turbojet

(i) MHA to 14 000 feet 230 KT IAS

(ii) above 14 000 feet 265 KT IAS

(c) Military Turbojet

(i) all except those aircraft listed below 265 KT IAS

(ii) CF-5 310 KT IAS

(iii) CT-114 175 KT IAS

(d) Climbing while in the holding pattern

(i) turboprop aircraft normal climb speed

(ii) jet aircraft 310 KT IAS or less

Minimum Holding Altitude (MHA) – The lowest altitude prescribed for a holding pattern which assures navigational signal coverage, communications and meets obstacle clearance requirements.

I love how all the military section says reduces to, "Look, unless you're a CF-5 Freedom Fighter, you're just a jet. And Snowbirds? You're not really a jet."

So that's holds. Airplanes are so fast, but just when you think you're going somewhere, you find out that you have to slow down and circle back. For the approximately two people who still remember what this post means: yeah, I'm serious.


Anonymous said...

does (b) mean that you cannot increase to speeds over 200 knots under 3000 feet during climb from any airport?

Love these posts btw!

J said...


Ed said...

Subtle differences in air law between countries: if I recall correctly in the UK the 250 kts below 10,000 (FL100, actually, I think) can also be exempted by an air traffic control clearance. There was some discussion as to whether the phrase "no ATC speed restriction" constituted such a clearance. (Anonymous, anybody who wanted over 200 knots in the climb would just get a clearance. Is it specified on the departure plates?)

About a decade ago we spent a wet Sunday afternoon at my then-local gliding club with the books out trying to work out how a non-instrument rated member could legally fly the Jet Provost he had a share in at maximum speed at low level. Some class D airspace over the Bristol Channel looked like the best bet as I remember it.

GPS_Direct said...

Two comments...

First: I'd be curious to hear from somebody that's flown the Big iron about subsection 3 - minimum safe airspeed. I haven't seen the POHs, but I'm guessing that a 747 or A380, and certainly the Concored, have (had) minimum speeds above 250 kts with no flaps. So, do you guys bomb along at Flaps 10 until above 10K, or does subsection 3 exempt you?

Second: Poop!

Anonymous said...


majroj said...

Yeah, congrats!

The F-116 (aka CF5, aka F5 Talon fighter, aka T-38 astronaut killer) does NOT like to go slow, so they need that extra speed to remain optimal (controllably airborne).

Anoynmous said...

It's a win-win, right? Having noticed a telling comment elsewhere, I was wondering about the time delay. Sounds like it's about two weeks.

mattheww50 said...

Actually I doubt that either the A380 or the 747 has any real problem with 250kt. I've actually been on the flight deck of a 747 at MGTOW during departure from LAX where we were limited to 250kt due to traffic in front of us. The only issue with 250kt is at MGTOW: the climb rate is pretty anemic.

Comparted to most Airbus Aircraft, the A380 has a relaively lightly loaded wing, so I would be very surprised if 250kt was an issue.

Concorde could be operated at 250kt at MGTOW, but it was something they tried to avoid. In an engine out situation, 250kt would be 'unsafe'. Most tried to make it a priority to get to a more desireable part of the flight enevelope ASAP after departure.

Concorde just didn't handle or behave very well at low speed and hight TOW (Delta wings have poor L/D performance at low speeds).

Minimum drag speed on Concorde at MGTOW was reported to be about 370kt. By contrast on most aircraft, Minimum drag speed is somewhere near V2.

D.B. said...

Empathetic nods here. I'm transitioning from a fixed gear 4 seater to a very clean high powered retractable with 5 or 6 seats. Everything is happening much faster, and I have to think well ahead of the plane. At least I don't have to be concerned about speed regulations - it's not quite THAT fast.

Traveller said...