2 Mile Base

9 Answers

1. 
   

   
   

   MaggotCFII on Feb 11, 2011

   As explained a million years ago by our tower chief:
   “A base leg that will intercept the final 2 miles from the end of the runway”
   I make this a “visual” distance, not a DME or GPS distance, because where is the DME on the airport and/or what waypoint is where. 
   Besides at his point, VFR, your head needs to be outside the airplane, looking for the guy that wants to run you over.
    

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2. 
   

   
   

   Thomas Vaillencourt on Feb 13, 2011

   I am based out of a towered field, and am very frequently issued similar pattern entry instructions. In my experience it is understood that in an instance like this, you would use your best judgement and estimates of distance, and is not expected to be exact. Usually using the intended touchdown point as your reference point for distance will adequately satisfy any tower and is usually a close enough proximity to runway centerline and threshold. This particular entry instruction expects that you would directly proceed to the base leg, and make your call at two miles, but in many cases, if the frequency is in use when you reach the call point you may have to wait, and adjust your distance report as needed. Also in many cases, when traffic is light, you may be contacted by the tower prior to your assigned reporting point, with a clearance to land. ~ Just a note of etiquette on this, for pilots new to towered fields… In the instance you have been asked to contact the tower at two miles (example) and you are still, say, three or more miles out when the tower contacts you, and issues you a landing clearance, it is then not expected that you make the two mile call. By issuing you the landing clearance, the tower has basically said, “we know where you are, and the runway is yours”, and they will not expect to hear from you again untill you are on rollout, or in the instance you need to go-around for another approach.

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3. 
   

   
   

   Kent Shook on Feb 14, 2011

   Ugh… This debate again! (The FAA needs to add this to one of their publications to clarify it.)
    
   When they say “report 2 mile right base” they want you to make a right base that will result in a normal-length final (as if you were in the pattern), and call them 2 miles from the field. Or the centerline – It doesn’t really matter, because if you start the call 2 miles from the centerline, you’ll probably be 2 miles from the field by the time you finish it. So do that.
    
   They are NOT telling you to make a base that’s going to intercept final 2 miles out from the field – Sorry Maggot – If that’s what they were telling you, then when on that base would you call them? 10 miles out from your 2-mile final? And in that situation, if you’re 2 miles out, you’re turning final, not on base.
    
   So – Make a “normal” base, and call about 2 miles from the field. It doesn’t have to be super-exact – The reason the controller is doing this is that he is not able to clear you to land at this time, but by the time you’re 2 miles from the field on that right base he should be able to give you the clearance. He’s telling you to “report 2 mile right base” so that a) you know what kind of route to fly to the runway, and b) he’s going to get a reminder that you’re there at a time that he’ll probably be able to clear you to land. It’s as simple as that. 🙂
    

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4. 
   

   
   

   MaggotCFII on Feb 14, 2011

   The response I provided was “sourced”.  So “sorry Maggot” was not appropriate.
   FAA Order JO 7110.65T in Chapter 3, section 10, 3-10-1 Landing Information does not appear to address the “2 mile right base” issue.
   Further noted is the following from 3-10-1, at “g”:
   g. Requests for additional position reports. Useprominent geographical fixes which can be easilyrecognized from the air, preferably those depicted onsectional charts. This does not preclude the use of thelegs of the traffic pattern as reporting points.
   So, perhaps this is where the “2 mile right base” gets it roots.
    
   The Pilot/Controller for “Traffic Pattern” definitions for the following legs
    
    
   d. Base Leg- A flight path at right angles to thelanding runway off its approach end. The base legnormally extends from the downwind leg to theintersection of the extended runway centerline.
   e. Final Approach. A flight path in the direction oflanding along the extended runway centerline. Thefinal approach normally extends from the base leg tothe runway. An aircraft making a straight‐in approachVFR is also considered to be on final approach.
   The definitions are specific.
   So when to advise the tower you are on the 2 mile base?  At the point your base leg intersects the downwind.
   The contoller wants you away from other close in traffic or traffic on an opposite base leg.
   I further note that other forums have discussed this issue.  And, yes opinions are split.
   If there is a controller out there that can add to this please do.
   Absent a cited source/professional opinion, I’m done with this thread.
    
    

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5. 
   

   
   

   Kent Shook on Feb 15, 2011

   “Sourced” by hearsay – And the official documentation, including what you quoted, does not address it.
    
   It doesn’t make sense to make a base that goes to a 2-mile final and report crossing downwind – At that point, you are VERY close to final, and by the time you make the call to remind the controller you’re there, you may find yourself *very* close to an airplane on a long, straight-in final, without a whole lot of maneuvering options. If you call on a base to a normal 1/2 mile VFR final when you’re 2 miles from the field/centerline, that gives the controller some options for where to put you before you run into that traffic he had on final in the first place.
    
   I’ve had this conversation many times, and it has never once resolved to the “make a two mile final and report when you’re almost on top of it” version. I’ll have to ask my ATC/CFII buddy to chime in here… Not that that’s any more definitive than yours, but if anything it’ll show that there can even (apparently) be a difference of opinion among controllers.
    
   Personally, since this isn’t defined in the official documentation and is thus obviously somewhat ambiguous – I think from now on whenever any of us get this clearance, we should ask for a clarification of what that particular controller really wants. Maybe then they’ll either stop using it or the FAA will decide to actually define it. Either would be better than the current situation…
    

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6. 
   

   
   

   David Eberhardt on Dec 18, 2011

   this is an old thread but let me try …
   tower is looking for a heads up that you are two miles from landing. In a Cessna or Piper Cherokee, that means roughly 2 minutes from the runway. They would likely hold short a departing aircraft if they call ready for takeoff …. 

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7. 
   

   
   

   GCRicker on Jan 29, 2012

   I just read in, “Say Again, Pleease Guide to Radio Communications” by Bob Gardner, on page 6-21 for those that have the book, that it means your base leg should be 2 miles long, and your final should be a normal distance.

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8. 
   

   
   

   David Eberhardt on Feb 01, 2012

   GCRicker: I’ve been searching regs, ACs, other aviation sources for a definitive answer and so far no luck. A “normal distance” for final approach is undefined. A rectangular traffic pattern can result in a 1 mile final approach or longer and sometimes it can be as short as 1/8 or 1/4 mile final if you’re practicing engine out patterns.
    
   Perhaps Gardner is correct, but I wonder what his reference is for that answer.

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9. 
   

   
   

   Christopher Ian on Mar 21, 2013

   I agree with author Gardner: post by GCRicker.

   1st note: at “2-mile . . “, the tower has a visual on you.
   2nd note: tower reference to a pattern “leg” when you are expected to report means you are ON that leg, so
   ‘report 2-mile base’ does not mean you are on a base leg 2 miles from the end of the runway 1/2 mile from the centerline.

   Thus; ‘ report ‘ . . .
   – ‘4-mile final runway 36’, means you are on final leg 4 miles from runway threshold (not touchdown point). A straight-in approach.

   – ‘5-mile left downwind Runway 36’, means you are 5 miles from the pattern on downwind leg.
   You are approaching from the upwind side of the field on extended downwind leg.

   – ‘3-mile base, right-hand traffic, Runway 36’, means 3 miles from the runway centerline on extended base leg, turning right onto final leg.

   – You reported your position on your initial call so the Tower expects you to fly somewhat directly from your position to the point they instructed you to report again.
   -The standard traffic pattern and its size/ dimension is discarded w/ tower instructions.
   – You may have reported your position from 8 miles SE or 10 miles NW or 9 miles NE of the field for these examples, respectively.
   – Not likely tower will have you cross the field to the downwind leg unless they have you cross midfield for left downwind, Runway 36 or possibly have you enter the pattern onto left crosswind leg to turn left onto base leg.

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