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 23rd Sep 2011, 11:50 #1 (permalink) Thread Starter   Join Date: Jan 2008 Location: Reading, UK Posts: 7,722 Rate One Turn I've just made the mistake of consulting Wikipedia to check that my understanding of what a Rate 1 turn (which I'd always thought was 3 degrees per second) is correct. "The aviation term ROT stands for rate one turn, also known as a standard rate turn. All aircraft must be able to perform a standard rate turn. A standard rate turn for (light) airplanes is defined as a 3° per second turn, which completes a 360° turn in 2 minutes. This is known as a 2-minute turn, or rate one (= 180°/minute). For heavy airplanes a standard rate turn is a 4-minute turn." http://en.wikipedia.org/wiki/ROT_(aviation) Any comments ? Am I expecting too much of Wikipedia ?
23rd Sep 2011, 13:14   #2 (permalink)

Join Date: Aug 2002
Location: Up north
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From (FAR) AIM:

Quote:
 STANDARD RATE TURN− A turn of three degrees per second.

 23rd Sep 2011, 22:56 #3 (permalink) Join Date: Jun 2010 Location: Canada Age: 31 Posts: 382 While Wikipedia is typically a great reference, it's wrong on that one. ROT stands for "rate of turn". There is not only rate 1 turns but rate 2 and 3 and I guess you could continue past that. Rate 2 is a 6 degree/sec turn and rate 3 would be a 9 degree/sec turn. Half rate turns are sometimes used as well; 1.5 degree/sec. imgur: the simple image sharer Also of note, if you search just ROT in wikipedia it comes up correctly. ROT - Wikipedia, the free encyclopedia
 25th Sep 2011, 10:07 #4 (permalink) Join Date: Mar 2005 Location: Uh... Where was I? Posts: 1,345 And not every airplane has to be able to do it! Can you imagine a Concorde flying a holding at FL 370 with one rate turn? How many gs would that be?
 26th Sep 2011, 02:33 #5 (permalink) Join Date: Jun 2010 Location: Canada Age: 31 Posts: 382 The speed limit for holding is typically 265 kts or Mach 0.83. The bank is limited to turn rate of 3 degrees/sec or a bank angle of 25 degrees, whichever is less. So no matter what speed you were flying, you'd never be pulling more than 1.1G. But just for the sake of fun... I calculated the Concorde (any airplane for that matter) would be pulling 3.32G if it was in a steady, level 3 degree/sec turn at a speed of 1150 KTAS (~Mach 2). The angle of bank required is 72.45 degrees.
 26th Sep 2011, 03:31 #6 (permalink) Join Date: Nov 1999 Location: The Land Downunder Posts: 767 Yea, I seem to remember the angle of bank for a rate one turn is approx. your TAS / 10 + 7. So once you get a tas of 380 kts plus then you are over 45 degrees angle of bank to maintain a rate one turn, so not possible to achieve on most jet aircraft except in the hold on on approach.
 26th Sep 2011, 03:54 #7 (permalink) Join Date: Jun 2010 Location: Canada Age: 31 Posts: 382 That's why ICAO says to maintain a maximum of 25 degrees bank in the hold. It's unadvisable to go beyond 30 degrees bank while flying with reference to the instruments. It's very easy to get into a spiral dive or at least experience some difficulty maintaining speed and altitude beyond 30 degrees.
26th Sep 2011, 11:50   #8 (permalink)

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Location: UK
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Quote:
 It's very easy to get into a spiral dive or at least experience some difficulty maintaining speed and altitude beyond 30 degrees.
Which is why, at an early stage of their training, military pilots spend a lot of time doing just that

 26th Sep 2011, 20:14 #9 (permalink) Join Date: Mar 2005 Location: Uh... Where was I? Posts: 1,345 Any of you guys have flown "B figures" during training? I'm not sure it they are a "local" thing where I trained or if it is universal
 26th Sep 2011, 21:22 #10 (permalink) Join Date: Dec 2006 Location: The No Trangression Zone Posts: 1,877 I wonder if Concorde got a pass on limit holding speeds
26th Sep 2011, 23:24   #11 (permalink)

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Location: France
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Quote:
 Originally Posted by Pugilistic Animus I wonder if Concorde got a pass on limit holding speeds
PG, Concorde would 'hold' at the usual 250 to 300 kts, like everybody else.... not Mach 2 as an earlier poster suggested....
CJ

27th Sep 2011, 04:21   #12 (permalink)

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Age: 31
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Quote:
 PG, Concorde would 'hold' at the usual 250 to 300 kts, like everybody else.... not Mach 2 as an earlier poster suggested.... CJ
You must have skimmed my post extraordinarily fast...

 27th Sep 2011, 09:47 #13 (permalink) Join Date: Sep 2009 Location: South Wales Age: 41 Posts: 3 I remember reading in Brian Trubshaw's book on Concorde that although the holding speed was higher its handling characteristics were such that it's rate of turn allowed it to follow the same holding pattern as normal aircraft. Is this turning into another Concord thread?
 27th Sep 2011, 10:12 #14 (permalink) Join Date: Mar 2011 Location: Somewhere over the rainbow Posts: 28 that rule really falls apart quickly at higher TAS
 27th Sep 2011, 10:18 #15 (permalink) Join Date: Jan 2006 Location: In a far better place Posts: 2,476 Oh my... how about the SR-71??
 27th Sep 2011, 11:15 #16 (permalink) Join Date: Jun 2005 Location: USA Posts: 896 It's been said the Blackbird would start a 180 turn over Dallas, Texas and complete it over Wichita, Kansas, completely missing the state of Oklahoma. Checking an online turn calculator, that seems plausible too. 1,750 KTAS (~mach 3.0) 15 deg of bank 335 NM turn diameter 18 minutes to complete the 180 deg. turn (10 deg. per min.) 525 NM flown Straight line distance between Dallas and Wichita = 310 Nm So yeah!