This a developing issue, check back for updates!

UPDATE 21 Oct. 0800: The NPRM was revised this morning to reduce the active times of R-2511 to much more reasonable terms. The text of this post has been updated to reflect that.

A dramatic change of airspace has been proposed for the “Trona Gap” region of Southern California airspace. The Trona Gap has been a key transit route for General Aviation pilots, both powered and un-powered, for decades, providing an efficient and safe route for traffic transiting between the Mojave and Death Valley regions. Presently it is formed by a space (“gap”) between several large restricted area complexes, offering a clear path for civilian aircraft to transit at altitude between the surface and FL200.

The change proposed (as officially presented here in a Notice of Proposed Rule Making) would create a new restricted area called R-2511 that would bridge across the Trona Gap connecting the R-2505 and R-2524 restricted areas. The floor of R-2511 would be 6,000 ft MSL, allowing civil traffic the ability to always transit the area below 6000 ft MSL. The area would extend up to but not including FL200 which, practically speaking, means it would extend up to the floor of R-2508 preventing any possible overflights. R-2511 would be used no more than 36 times per year, between the hours of 0700-1700 local time, Monday-Friday, and activated by NOTAM at least 7 days in advance. Each day would consist of no more than two 2-hour blocks when activated.*

A graphic depiction of the proposed R-2511 is below:

Graphical depiction (blue shaded region) of proposed R-2511

Were R-2511 to become more active than currently stated, many general aviation users are expressing concerns about this change. For the transient aircraft, the need to descend down to below 6,000 ft in this region is not just inconvenient, but also poses additional hazard to safe transit of the area. A quick look at the VFR Sectional Chart’s Maximum Elevation Figures (MEF) shows that all quadrants surrounding the Trona Gap region contain obstructions that are either within 500 ft of the 6000 ft floor or well in excess of 6000 ft. Given the frequent strong winds in this region, flying at altitudes below or coincident with nearby terrain features presents a high likelihood of encountering significant mechanical turbulence, rotor, and wave activity.

MEFs (circled in red) show obstructions that could be hazardous to aircraft restricted to below 6000 ft MSL

The glider community has also expressed concern with this change as the Trona Gap is an important corridor for cross-country glider flights to transit to and from the Panamint Range, a key geographical feature for cross-country glider routes in this area. In order for gliders to transit through the Trona Gap they need altitude well in excess of the proposed 6000 ft floor of R-2511.

The origins of this proposal come from US Navy’s weapons development needs. For many years the Navy has used what is called a Controlled Firing Area (CFA) for conducting live ordinance firings across the Trona Gap. When the CFA is active civilian traffic can still transit the area and the Navy must immediately suspend activity if a non-participating aircraft is approaching the area. With the new weapons systems that the Navy intends to test, such immediate suspension capability can not be accommodated. As such, they are proposing that a new restricted area (R-2511) be established thus replacing the use of the CFA and removing the immediate suspension capability requirement. Historically the CFA has not been activated frequently, which bring into question why the Navy would needs an essentially permanent block of airspace.

Presently in the proposed rule, no provision is made regarding the ability for civil aircraft to transition the proposed restricted area. However, if as-stated the area is only activated for 2 hours windows (at a maximum of 36 times per year), the likelihood of needing to transition is very low. For the neighboring restricted areas (R-2505, R-2515, and R-2524), local procedures have historically allowed some civilian aircraft to transition the areas when they are not in use by the military. There are two options potentially available to a civilian aircraft wishing to transition these restricted areas:

  1. Transition as approved by FAA ATC Joshua Control Facility (JCF)
  2. Transition as approved by respective military control entity (China Control or SPORT)

These options are generally only available on an as-able basis. JCF has agreements with the military that allow JCF to grant transitions of the restricted areas to civilian aircraft (but with strict minimum altitude restrictions) when the airspace is not in use by the military. The military controls can grant transition at any altitude at any time, but are far less likely to do so and often require the pilot/operator to have additional credentials and prior coordination. With the typical limitations on transitions of the restricted areas by civil aircraft, it is of concern that similar difficulty will be found when asking for transition of R-2511 should it become active more frequently than currently stated in the NPRM.

The question is also posed then as to if a restricted area is the correct tool for addressing the problem that the Navy has presented, namely, an effective means by which to restrict civil aircraft from flying in the weapons test area when testing is occurring. Certainly a restricted area will do that, but it does so at a cost of designating airspace as a restricted area that is only very infrequently used as such. I would argue that the odds of a pilot mistakenly transitioning an active R-2511 after being accustomed to it being inactive the majority of the time is increased by the current approach. A TFR of the same dimensions as the proposed R-2511 would be more effective, and provide civilian pilots far more awareness to the importance of the airspace they are being made to avoid. The advantage of the TFR being that at times when testing is not being conducted, civilian traffic will have the same flexibility as today for flying through the gap without the burden of having to verify that R-2511 is indeed inactive.

If R-2511 does become established as currently proposed, additional notations on the VFR Section Chart would be welcomed as a means of informing unfamiliar pilots of their options for flight planning through the Trona Gap. At present the airspace is only a MOA, giving the transient pilot the ability to freely plan a flight through the area. Charting it as a restricted area without clarifying notations will cause confusion and potentially discourage efficient flight planning via the Trona Gap.

Based on the proposal and stated concerns, the author makes the following recommendations:

Recommendation A

  1. Do not establish a new restricted area
  2. Do require the use of a TFR when testing is to be conducted
  3. Add notations to the VFR sectional chart for pilots to be aware of potential TFRs in that vicinity

Recommendation B

  1. Continue with the establishment of R-2511 as proposed
  2. Add notations to VFR Sectional Chart to clarify infrequent nature of R-2511 and the means by which to be aware of its status


What can you do?

Be informed: Read about this issue by reviewing the Notice of Proposed Rule Making (NPRM). Specifically see what nature of comments are desired by the FAA:

Interested parties are invited to participate in this proposed rulemaking by submitting such written data, views, or arguments as they may desire. Comments that provide the factual basis supporting the views and suggestions presented are particularly helpful in developing reasoned regulatory decisions on the proposal. Comments are specifically invited on the overall regulatory, aeronautical, economic, environmental, and energy-related aspects of the proposal.

Submit a comment: You may do so using the comment button at top of the NPRM webpage. You can also mail-in a comment and receive an acknowledgment of receipt from the FAA following the steps explained in the NPRM.

Spread the Word: Share the link to the NPRM. Discuss this with others in the aviation community. Share this post.

*An earlier revision of the NPRM stated that the area would be active always Monday through Friday 0700 to 1700. This was a much more severe scenario than currently stated.


Some thoughtful remarks from the comment submitted by an operator familiar with Trona Gap operations:

“As a Part 91 and Part 135 operator regularly flying between California, Nevada, and Arizona, I strongly oppose the creation of the new restricted airspace blocking the so called “Trona Gap”. VFR flights through this corridor between the altitudes of 9,500 and 17,500 allow efficient transit of an otherwise large airspace constraint presented by the Edwards and China Lake complexes. The proposed available altitude of 6,000 feet or less is insufficient for aircraft such as the single engine and multi engine piston aircraft we operate such as Cessna 206, Cessna 210, Cessna 414A, Cessna 180, Vans RV6/8, and Lancair ES, as well as even turboprops such as our King Airs and Pilatus PC12s which often we need to transit westbound at lower altitudes to avoid headwinds or for passenger or medical patient comfort at lower cabin altitudes. These aircraft operate between 9,500 and 17,500 feet through the Trona Gap regularly. Significant cost, time delay, and passenger discomfort will result in closing this corridor and would not meet the FAA’s mandate of promoting aviation nor increasing safety. A better alternative as discussed is using as needed TFRs or other temporary but easily noticed airspace restrictions. Having the restricted area “not hot” is not an effective solution because the routing choices for navigating through this corridor versus going all the way around these airspace complexes have to be made prior to talking to the controlling sector to avoid backtracking or large deviations. Often preceding sector controllers do not know or do not have the bandwidth to request status from the controlling sector and pass that information along ahead of time. A TFR is easily seen on EFBs and made aware during preflight briefings in order to facilitate route planning prior to arriving at the corridor and being turned back. Please consider this high use VFR corridor for a variety of GA and Commerical aircraft as a critical resource and do not block it. Thank you.”

Published by theflyingfiddler

General Aviation pilot trying to make the world of flying a better experience for all.

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  1. Use a TFR serves both interests well. No education needed general aviation understands the TFR system.


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