FAA Liaison

by Mike Manes, W5VSI

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You will find some redundancy on this page but, it is in a good cause.

Sent 10-Mar-04

Question about Payloads in excess of 6 LBs.

Well, you are precisely correct about FAR 101 provisions and the need for filing an FAA Form 7711-2 Request for Waiver and getting a Form 7711-1 Certificate of Waiver where you conform 100% to FAR 101 for an unmanned balloon.

As you may have perceived, FAR 101 is subject to interpretation, and EOSS's policy of keeping the FAA notified of our operations in an effort to avoid midair collisions has perhaps raised the bar a bit. Since EOSS can do nothing to avoid a midair, the only means to mitigate that risk is to let FAA flight controllers know where we are in flight so that they can vector aircraft around us.

Although the historical risk of a balloon-aircraft midair is vanishingly small, and the damage to an aircraft from an "exempt" payload is expected to be minimal, such a collision would nonetheless have a devastating impact on EOSS's ability to recover our payloads intact. Thus our agreement with the FAA is to a large extent a pursuit of self interest.

The I-25 corridor thru Denver and the area to the east carries some of the heaviest air traffic corridors in the country, and the DIA approach and departure traffic exacerbates that traffic. Thus EOSS and Denver Center have an informal understanding that we will file an FAR 101 HiBal Notice for all of our flights, even those which are exempt, and that we will pass on balloon position reports often enough to enable controllers keep aircraft away from us.

Having thus established an expectation for full FAR 101 notification for exempt payloads, the FAA now expects that an even more intense notification accompany our heavier "non-exempt" payloads. The FAA has defined next highest level of notification to be an Application for Certificate of Waiver (Form 7711-2) filed 45 days in advance with the NW Mountain Region office in Renton WA. This application is expected to request a waiver from para 101.1(a)(4) - payload weight, which I must admit doesn't make great deal of sense. But in the interest of maintaining a long-standing working relationship with Denver Center and DIA Tracon, we accede to this expectation. While we're going through that trouble, we also add waivers to 101.33(b)(c) - (vis and cloud cover) and 101.35(a)(3) - (radar reflector), which do confer some nice operational benefits.

Although this paperwork does take some time to prepare, NW Region has never shot us down, and they have even taken steps to ease this task by OKing filing via email and cutting their approval processing time to about a week. Most recently, Region has even granted EOSS a blanket Certificate of Waiver for 12 heavy launches for Colo Space Grant during 2004, similar to the SHOT flight that you participated in.

Now, so far as I know, this protocol is unique to EOSS and flights in Denver ARTCC's airspace. Thus it is not surprising that San Antonio ARTCC may not have a clue about waivers, etc. And I apologize if I may have led you to believe this process to be SOP nation-wide. Further, since your expected flight trajectory lies well clear of the kind of heavy air traffic corridor that EOSS penetrates, going beyond the letter of FAR 101 requirements is not likely to make any sense.

Thus if your payload is indeed non-exempt, then I'd recommend that you simply file a HiBal notice with San Antonio Center's Airways and Procedures Office. If they require further, they will get back to you.

I've attached the HiBal for EOSS's most recent exempt flight which you may find helpful in preparing your own. Of course, you should delete the reference to "non-exempt", among the other more obvious changes.

Sent 15-Mar-04

Aviation Speak, how do I talk to these people

Your present questions relate to "aviation-speak", and if you have a licensed pilot in your group, he/she can probably bring you to a reasonable level of fluency in that lingo in a few minutes. But I'll get you a head start:

All altitudes between 18,000 and 60,000 ft are known as the "high altitude structure". Aircraft altitudes in that region are measured in terms of barometric elevation above mean sea level (MSL) with the altimeter barometric pressure adjustment (Kollsman window) set to a uniform 29.92"Hg, regardless of what the local baro pressure might be. This eliminates the burden of constantly updating the adjustment to local baro pressure over long flights, while still ensuring that all aircraft are using the same setting so altitude separation doesn't degrade. To distinguish over properly adjusted altitudes below 18,000 ft, these altitudes are labelled Flight Levels (FL), and are experessed in units of 100 ft. Thus if the baro altimeter reads 35,000 ft with 29.92 set, the pilot reports "Flight Level Three Five Zero" (FL350) to FAA controllers.

Horizontal positions are expressed in polar coordinates with respect to a known reference location. The angular reference is MAGNETIC north rather than true north, since earlier aircraft carried only magnetic compasses for navigation, and in Nautical Miles (NM) rather than statute miles, since any map (aka "chart") that shows latitude in minutes has a built-in distance scale (1 NM = 1 minute of latitude anywhere on the planet).

Reference locations are usually standardized as those of VOR (VHF Omnirange) beacon sites used for air navigation. Each VOR bears a 3-letter identification, just like airports. And the polar position relative to a given VOR is specified as a magnetic bearing or "radial" in degrees followed by a distance ("range") in NM.

Finally, time of day is expressed in terms of Universal Coordinated Time (UTC) which is coded as global time zone Z (Zulu) in order to prevent confusion as an aircraft travels from one time zone to the next. And 4-digit 24-hour time in the form hhmm is used to prevent AM/PM confusion (note that the US is one of the few countries left that have not adopted 24-hr time for everyday use, which ties in nicely with our persistence in use of English measures and Farenheit temperatures - the US and Liberia, that is.)

Note that in the HiBal, we showed the launch site location as GLL 250 019. This is spoken "Gill Two Five Zero at Zero One Niner" and means that the location is on a radial of 250 degrees CW from magnetic north and a range of 19 NM from the Gill (GLL) VOR. This lets the FAA controllers plot the launch site location easily on a standard aviation map (chart) using an aviation plotter. Then the forecast balloon position can be plotted just as easily from the launch site.

So, the forecast postion of "FL600: 1654Z 090/040 NM re launch site" translates to "The balloon is expected to ascent through 60,000 ft above mean sea level with a standard barometric reference at 4:45 PM Universal Coordinated Time at a position of 90 degrees magnetic and 40 nautical miles from the launch site".

Thus ends aviation-speak 101. Once you master it, you can talk to FAA folks with an air of confidence and authority (even if you're clueless!)

I'll recommend that you pick up a set of Sectional aviation charts covering your expected flight area and a Jeppeson plotter from the pilot shop at your local general aviation airport. These charts show latitude and longitude and every VOR and airport, plus resticted areas where you ought not be flying thru lest you draw the Wrath of Tom Ridge. Major roads and towns and topo lines are also shown, making translation to regular road and rec maps easy.

More generically ...

Sent 19-Oct-03

If you haven't got a copy of 14 CFR Part 101, you can download an annotated version from the EOSS web site, focused on unmanned balloons with some interpretive comments. Basically, if you're biggest payload box is under 6 lb and total payload weight is under 12 lb, and lateral density is under 3 oz/in^2, then you're exempt and aren't required to notify the FAA at all - it's like you're a party balloon that escaped its tether. See 14 CFR 101.1(a)(4).

EOSS takes a step beyond the FAR 101 requirements and files an FAR 101 SubPart D HiBal Notice for every flight. Our rationale is that even though an aircraft would come out of a midair with our exempt payload string unscathed, it'd ruin our whole day. Since we can do nothing to avoid a midair, we rely on the FAA to do it for us; and they can do that only if they know where we're at.

We also take another step when we're flying "heavy" (non-exempt); we file for a Waiver with FAA Regional in Seattle. Although we do fully conform to SubPart D, we request a waiver from 101.1(a)(4), plus some other stuff, like the radar reflector. The reflector is an obsolete requirement, since the FAA doesn't even see primary radar any more, and NORAD radars can track a golf ball over Cuba. One of NORAD's sites is just E of Denver, so they see everything we fly.

EOSS has a pretty solid working relationship with Denver Center Airways and Procedures Office, with whom we file our HiBals. After you've got solid with the FAR 101 requirements and know you're exempt, you might refer LA Center to Michelle Smith, our contact at DEN ARTCC. It would also help if you'd arrange to get your APRS beacons reflected to the internet - Den Center controllers have used findu.com for tracking EOSS balloons with 60-sec updates for a year now.

Sent 15-Sep-03

Although EOSS doesn't have a written policy regarding the risk of an air-to-air collision, here's what EOSS has done to mitigate that risk:

1. 14 CFR Part 101 is the FAA's rules regarding unmanned balloons, among other things. Para 101.1(a)(4) describes the physical parameters below which balloon-borne payloads are assumed to present negligible risk to air traffic. In general, payload packages under 6 lbs and payload strings under 12 lb are treated no differently from a party balloon which has escaped the grasp of its owner; EOSS tags such payload strings as "exempt". Note that EOSS also assumes a definition of "payload" to be that part of the flight string that does the work, regardless of how it gets to altitude; accordingly, we don't include the weight of the balloon envelope, parachute or cutdown towards that limit.

2. EOSS strives to keep EVERY flight string "exempt" and goes "heavy" only when a client payload cannot be held under those limits. Never- theless, EOSS is quite aware that in the unlikely event of a mid-air, the balloon flight string will come up 2nd-best, even though the aircraft may suffer no damage (per FAA's presumed regulatory rationale). Accordingly, it's in EOSS best interest to avoid mid-airs. The only practical means to that end is keep aircraft away from our flight string, since even if we were aware of an impending mid-air, which we are not, we can't maneuver to avoid it. However, the FAA air traffic controllers are quite aware of where all the aircraft are, except for those outside controlled airspace, and thus if those contollers know where our flight string is, they can divert aircraft around us. Thus EOSS conforms to FAR 101 Subpart D to the greatest extent possible for ALL of its balloon flights, even though it's not required.


a) We file a "HiBal Notice" (para 101.35(d)) describing the launch site and time, balloon, parachute and payload appearance and expected flight trajectory; this is filed with three FAA offices:

  • The affected Ait Traffic Control Center (Center)
  • The Ops office of the nearest airport (TRACON)
  • The nearest Flight Service Station, which publishes a NOTAM for VFR traffic

b) We phone in a refined trajectory to Center and TRACON about 30 minutes prior to launch

c) An additional call immediately upon launch.

In addition, EOSS passes the current location and altitude on to the cognizant FAA controllers during the flight, plus "on deck" calls to all three offices immediately after landing. EOSS has recently pioneered a means to get minute-by-minute position reports onto the FAA control floor by relaying the GPS-based position downlink directly to an internet site which translated the lat/lon data into the VOR radial/DME format preferred by the controllers.

So EOSS has bent over backwards to mitigate the risk of a midair. Now, earlier I used the term "unlikely" - this bears on the fact that, insofar as EOSS has been able to learn after in-depth inquiries with the FAA, there are no records of any mid-air collisions between aircraft and unmanned balloons, nor or course any which have damaged aircraft. Thus we judge the risk of this hazard to be vanishingly small.

A more probable hazard could be the risk of a traffic accident should the payload string land on a busy road or highway. We mitigate this by another policy that scrubs any launch if the forecast landing is near a populated area. Fortunately, the eastern plains of Colorado is a pretty wide open space, but not so desolate as Arizona! And we pick our launch sites with that policy in mind. Thus although some EOSS payloads have landed within several hundred yards of 2-lane blacktop, none of the 71 flown to date has created a traffic hazard.

As an aside, EOSS and other balloon groups have sought out liability insurance to cover any damage or injury which our operations might cause. Except for Lloyd's of London, which quoted an absurd premium, no underwriters have responded with any interest. I guess the cost of developing an actuarial basis was deemed excessive in light of a reasonable net premium income.