Sareval & cell phones

[Paradoc]

Howdy,

A heads up... on our recent Sareval, our Wing had only one "unsuccessful" in communications because a crew used their cell phone from the air to send text messages.  The air force folks emphasized this is an FCC not an FAA law, but it is a law.  Cell phones (including iPad's and other devices that use the cell network for data) need to be off or in "airplane mode" when airborne.  They should not be used from the air for calls or text messages, except in an "emergency".  "Emergency" was left to the mission pilot to define.  It was asked "what if radio comms are out and we need to make a check-in" and the answer was "unless there is an 'emergency', you should land and call from the ground".

Ironically, the crew that used the cellphone from the air was from a neighboring state that was helping us out with the Sareval.  So it wasn't even one of our local aircrews.  But our communications people (who did an EXCELLENT job) were still held accountable on the final grade.  On a different flight, a "VIP" we were tasked with transporting also tested this by pulling out his cell phone during taxi and trying to make a call.  He was told by the mission pilot he had to "turn it off and maintain sterile cockpit", so we got kudos for that.

We were told this has been a problem nationally, and that the airforce is specifically looking for this at Sarex and Sarevals.  You may want to brief this with your aircrews.

Good luck!

[RADIOMAN015]

That is correct about uncertified airborne cellphones that operate in the 800-900 mhz range.   My understanding via the comm channels is that those used (air cards) with the new GIIEP systems which ONLY operate in the 1800-1900 mhz band, which is not off limits for voice/data use for aircraft in flight.  You can ask your wing DC about this since they all recently got an email reaffirming the guidance on NOT using cellphones.

I know in my state the State Police Air Wing helicopters all have INMARSAT satphones installed, BUT most of the time they used passive text message pager/receivers for getting enroute instructions (sort of like a poor man's encrypted radio system) from dispatch just acknowledges they got the page.  (Usually it's the coordinates for response to a lost person search).   Perhaps CAP could look into these passive paging digital receivers and add one to each aircraft in each wing.  The radio callsign list would have an added column for aircraft text message pager number.

RM     

[PHall]

That is correct about uncertified airborne cellphones that operate in the 800-900 mhz range.   My understanding via the comm channels is that those used (air cards) with the new GIIEP systems which ONLY operate in the 1800-1900 mhz band, which is not off limits for voice/data use for aircraft in flight.  You can ask your wing DC about this since they all recently got an email reaffirming the guidance on NOT using cellphones.

I know in my state the State Police Air Wing helicopters all have INMARSAT satphones installed, BUT most of the time they used passive text message pager/receivers for getting enroute instructions (sort of like a poor man's encrypted radio system) from dispatch just acknowledges they got the page.  (Usually it's the coordinates for response to a lost person search).   Perhaps CAP could look into these passive paging digital receivers and add one to each aircraft in each wing.  The radio callsign list would have an added column for aircraft text message pager number.

RM     

How about following the rules and not always looking for a loophole?

YOU could do some research yourself and contact the FCC and see if the Air Cards and such are really authorized for use in-flight.

[Paradoc]

Here is what the FCC says on their website:
http://www.fcc.gov/guides/wireless-devices-airplanes

The problem isn't interference with navigation equipment.  Although that is theoretically possible, it hasn't been shown to be a real issue.  And as others have pointed out here, at least half the people on any commercial flight ignore (or don't know how) to turn off their phones.  If interference with navigation equipment was really a problem, commercial planes would be crashing all the time.  It just doesn't happen.  Although I will say that if you forget to turn off your 3G phone in a CAP plane, you will get digital interference crossing into the intercom system that doesn't sound very nice in your headphones.  Your crew may not appreciate the loud buzzing in their ears!

The bigger issue from the FCC standpoint is interference with cell phone towers on the ground.  Since cell signals are mostly line of sight, one cell phone on the ground might hit 10-20 cell phone towers.  The cell network then determines which signal is the best, and uses that one for your call.  As you travel down the road, it is constantly switching to the next tower.  The problem with a cell phone in an airplane is it can literally hit HUNDREDS of cell towers, tieing up those frequencies and creating bandwidth problems.  The cell antennas on the ground are directed in a mostly horizontal direction.  Once you are in a commercial airliner at flight level 360 going 400 knots you probably won't get a cell signal at all.  But... in our cessnas at 1000 ft AGL over an urban area, your cell can tie up a lot of bandwidth, even if you are not using it to make a call.  Cell phone based data-cards, iPads, etc still use the cell network, and can NOT be used to send/receive data in flight.  It is the same thing as using your cell phone, you are just sending data instead of voice.

We do have FCC/FAA certified satellite phones installed in some of our CAP aircraft.  Not very reliable in my experience... they are "busy" at least 50% of the time.  It is fine to use these for checkins if radio coms are down since they are installed in the airplane and certified for use in the aircraft.

One interesting question I have is the SPOT transmitters that are now used by many CAP wings to track aircraft.  These use satellites to send the GPS coordinates.  Since they are on satellite, using it doesn't cause the same issues with the cell network as using a cell phone does.  The Air Force and CAP seem to be smitten with them, and I think it is a great tool to have for operational awareness.  But... I've never seen anything in writing that definitively says they are approved for use in aircraft.  Does anyone have a link to FAA and/or FCC that specifically permits the use of SPOT in aircraft??

Jim

[Thom]

That is correct about uncertified airborne cellphones that operate in the 800-900 mhz range.   My understanding via the comm channels is that those used (air cards) with the new GIIEP systems which ONLY operate in the 1800-1900 mhz band, which is not off limits for voice/data use for aircraft in flight.  You can ask your wing DC about this since they all recently got an email reaffirming the guidance on NOT using cellphones.

How about following the rules and not always looking for a loophole?

YOU could do some research yourself and contact the FCC and see if the Air Cards and such are really authorized for use in-flight.

I'm not sure why you think this isn't a well-documented fact. The entire reason the GIIEP system uses the Sprint Aircards is because they only transmit on the 1800-1900 MHz PCS band, which is not covered by the FCC rules preventing the use of cellular telephones on airborne aircraft.

To add to this, the prohibition on use of cellular telephones in the 800-900 MHz range is in 47 C.F.R. § 22.925   Prohibition on airborne operation of cellular telephones. This is found in Subpart H of Part 22 of CFR 47. Subpart H sets out rules ONLY for the 800-900 MHz spectrum.

The FCC has no rules, and therefore is silent, on the subject of use of cellular data devices in the 1800-1900-2100-etc. bands on airborne aircraft. Since the services are authorized to use that spectrum, and no specific prohibition is in place regarding airborne usage, it is legal.

Anything else?


Thom

[Thom]

Here is what the FCC says on their website:
http://www.fcc.gov/guides/wireless-devices-airplanes

<snip>

The bigger issue from the FCC standpoint is interference with cell phone towers on the ground.  Since cell signals are mostly line of sight, one cell phone on the ground might hit 10-20 cell phone towers.  The cell network then determines which signal is the best, and uses that one for your call.  As you travel down the road, it is constantly switching to the next tower.  The problem with a cell phone in an airplane is it can literally hit HUNDREDS of cell towers, tieing up those frequencies and creating bandwidth problems.  The cell antennas on the ground are directed in a mostly horizontal direction.  Once you are in a commercial airliner at flight level 360 going 400 knots you probably won't get a cell signal at all.  But... in our cessnas at 1000 ft AGL over an urban area, your cell can tie up a lot of bandwidth, even if you are not using it to make a call.  Cell phone based data-cards, iPads, etc still use the cell network, and can NOT be used to send/receive data in flight.  It is the same thing as using your cell phone, you are just sending data instead of voice.

<snip>

One interesting question I have is the SPOT transmitters that are now used by many CAP wings to track aircraft.  These use satellites to send the GPS coordinates.  Since they are on satellite, using it doesn't cause the same issues with the cell network as using a cell phone does.  The Air Force and CAP seem to be smitten with them, and I think it is a great tool to have for operational awareness.  But... I've never seen anything in writing that definitively says they are approved for use in aircraft.  Does anyone have a link to FAA and/or FCC that specifically permits the use of SPOT in aircraft??

Jim

The first thing, the quote about using Aircards is only partially correct. Devices which transmit on the 800-900 MHz spectrum bands are prohibited by the FCC from operation on airborne aircraft, and although the exact interpretation is up to the FCC and the Courts, generally most people take that to include pure Data as well as CDMA or TDMA/GSM Voice. HOWEVER, there are now a number of devices which only transmit on the higher bands, typically 1800-1900-2100-etc. These are NOT currently prohibited from airborne operation by the FCC, since the prohibition on airborne usage appears ONLY in the section dealing with 800-900 MHz devices.

It is true that if anyone at the FCC stopped and thought about it, they might add some new restrictions to prohibit airborne usage of the upper bands, but currently they are not restricted.

Secondly, you might not find a specific passage allowing the usage of the SPOT transmitters while airborne, because the normal rulemaking at the FCC results in approved uses of spectrum. The SPOT folks have an approved service for talking to and from a satellite network. It is actually the same Globalstar satellite network that the (useless...) phones in the CAP SDIS/ADIS aircraft use, the SPOTs simply don't depend nearly as much on the downlink channel. Unless the FCC specifically (as in the case of 800-900 MHz cellular telephones) prohibits a particular type of use, any use that fits within the overall approval is de facto approved and does not need specific language. I haven't dug up the Globalstar approvals, but it seems likely that they either include use on airborne aircraft, or at least have no prohibition on use while airborne.

Finally, while it isn't an ironclad guarantee of legality, the long conversation I had with the SPOT sales manager about how well the units were working for Louisiana Wing and how he could best appeal to other wings leads me to believe that the SPOT folks think it is a legal use of their devices.


Thom

[Paradoc]

Thom, thanks for the info.  Couple of thoughts/clarifications:

The first thing, the quote about using Aircards is only partially correct. Devices which transmit on the 800-900 MHz spectrum bands are prohibited by the FCC from operation on airborne aircraft, and although the exact interpretation is up to the FCC and the Courts, generally most people take that to include pure Data as well as CDMA or TDMA/GSM Voice. HOWEVER, there are now a number of devices which only transmit on the higher bands, typically 1800-1900-2100-etc. These are NOT currently prohibited from airborne operation by the FCC, since the prohibition on airborne usage appears ONLY in the section dealing with 800-900 MHz devices.

Reading between the lines... it appears that the FCC originally passed this law in the 80's/90's when cell phones only operated on the 800-900 MHz frequencies.  In 2004 they considered removing this law entirely, but they bent to industry pressure and dropped that proposed rule change in 2007.  So the existing rule prohibiting cell phone use in flight applies only to 800-900 MHz, but the rationale for the law certainly applies to ANY type of cellular device.  I'll leave it to the bureaucrats to sort out if there really is a reason for this rule!  But in the meantime... When I'm acting as mission pilot I intend to turn off my cell phone, and instruct my crew to do the same.  I certainly wouldn't want to get into an argument with FCC and/or Air Force about what frequency band my cell phone was using to transmit a text message while in flight.

Secondly, you might not find a specific passage allowing the usage of the SPOT transmitters while airborne, because the normal rulemaking at the FCC results in approved uses of spectrum. The SPOT folks have an approved service for talking to and from a satellite network. It is actually the same Globalstar satellite network that the (useless...) phones in the CAP SDIS/ADIS aircraft use, the SPOTs simply don't depend nearly as much on the downlink channel. Unless the FCC specifically (as in the case of 800-900 MHz cellular telephones) prohibits a particular type of use, any use that fits within the overall approval is de facto approved and does not need specific language.

My question about use of SPOT in flight relates to FAA, not FCC rules.  I seem to remember reading somewhere in the FAR's that use of portable transmitters was prohibited in flight unless specifically approved for aircraft use, such as a portable airband radio.  I can't find that in the FAR's at the moment and it very well might be an old FAR, but maybe you or someone else here knows?

I did find FAA Circular 91.21-1B which regulates use of "Personal Electronic Devices" in flight.  http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/B5C85AE8E38DF676862571DA00529DA4?OpenDocument.  Paragraph 5a states:

The determination of an interfering effect caused by a particular device on the navigation and communication system of the aircraft on which it is to be used or operated must, in case of an aircraft operated by the holder of an air carrier certificate or other operating certificate, be made by that operator (i.e., certificate holder). In all other cases, a determination must be made by the operator and/or by the pilot-in-command (PIC).

So... it would look to me like as long as CAP (the operator) and the PIC have determined that the SPOT is OK in flight... the FAA does not specifically prohibit it.  The next paragraphs goes on to say:

b. When safely at cruise altitude, the pilot could allow the devices to be operated. If interference is experienced, the types of devices causing interference could be isolated, along with the applicable conditions recorded. The device responsible for the interference should then be turned off.

Sounds like good advice to me!

Cheers!

[dbaran]

Folks - I already went through this exercise about a year and a half ago for CAP, and confirmed the info below with the deputy of the bureau that handles mobile phones.

Operating below 1 GHz with a cell phone is illegal under FCC rules.  This is because the original rules for the frequencies prohibited airborne use, and those rules were not changed when the usage switched from analog cellular to PCS data.

Operating above 1 GHz is fine.  This is because there is no restriction on airborne use in the rules that granted those as PCS frequencies.

From discussions with AT&T and Verizon (who have frequencies below and above 1 GHz), neither was able to offer a way to restrict the frequencies to the airborne-legal ones only.  Thus, you cannot use devices from these carriers  in the air.

Sprint, on the other hand, operates above 1 GHz as their < 1 GHz frequencies are used by NEXTEL, which requries different hardware.  HOWEVER, the air cards come from a supplier that makes equipment for Verizon, so you MUST disable roaming on the air cards for them to be legal (otherwise, they will roam onto the 800-900 MHz frequencies for Verizon).

The FAA specifically prohibits use of devices on an IFR flight plan (note: FLIGHT PLAN.  Not IMC) unless the testing has been done to ensure that they don't interfere with the aircraft ssytems  and requires PIC approval for Part 91 operators for non-IFR operations. 

I also confirmed that SPRINT is OK with airborne operations, but their techincal group told me that we were largely wasting our time.  The cell site antennas are angled down to the ground for better coverage there, and he correctly said that we'd have trouble getting a signal much above 1000 AGL...which is exactly what we found in testing on both coasts.

I did obtain confirmation from several local agencies (fire, not CAP) that they use the data cards in helicopters all the time and just ignore the FCC rules.

There was a 20+ page report on this that I wrote for ATG that never emerged from the morass; it even included the FCC letters, etc.

[Thom]

Folks - I already went through this exercise about a year and a half ago for CAP, and confirmed the info below with the deputy of the bureau that handles mobile phones.
Operating below 1 GHz with a cell phone is illegal under FCC rules.  This is because the original rules for the frequencies prohibited airborne use, and those rules were not changed when the usage switched from analog cellular to PCS data.
Operating above 1 GHz is fine.  This is because there is no restriction on airborne use in the rules that granted those as PCS frequencies.
From discussions with AT&T and Verizon (who have frequencies below and above 1 GHz), neither was able to offer a way to restrict the frequencies to the airborne-legal ones only.  Thus, you cannot use devices from these carriers  in the air.
Sprint, on the other hand, operates above 1 GHz as their < 1 GHz frequencies are used by NEXTEL, which requries different hardware.  HOWEVER, the air cards come from a supplier that makes equipment for Verizon, so you MUST disable roaming on the air cards for them to be legal (otherwise, they will roam onto the 800-900 MHz frequencies for Verizon).
The FAA specifically prohibits use of devices on an IFR flight plan (note: FLIGHT PLAN.  Not IMC) unless the testing has been done to ensure that they don't interfere with the aircraft ssytems  and requires PIC approval for Part 91 operators for non-IFR operations. 
I also confirmed that SPRINT is OK with airborne operations, but their techincal group told me that we were largely wasting our time.  The cell site antennas are angled down to the ground for better coverage there, and he correctly said that we'd have trouble getting a signal much above 1000 AGL...which is exactly what we found in testing on both coasts.
I did obtain confirmation from several local agencies (fire, not CAP) that they use the data cards in helicopters all the time and just ignore the FCC rules.
There was a 20+ page report on this that I wrote for ATG that never emerged from the morass; it even included the FCC letters, etc.

That's all excellent info. I only have a couple of things to add:

1. There are a handful of devices available now which work on AT&T or Verizon that allow you to limit operation to the upper frequencies. Given the issues of making sure you are using only those devices and staying legal, it is probably easier to simply avoid those carriers completely. But, if someone wants to put in the work, it is theoretically possible now...

2. Having used the GIIEP system with its Sprint Aircards during our recent Mississippi River Flooding Mission, I can add a big DITTO to your comments about wasting time trying to use them airborne. If you limit yourself to particular places and altitudes, the system can work marginally, but it is not at all the 'data anywhere' solution we need.


Thom

[Thom]

Thom, thanks for the info.  Couple of thoughts/clarifications:

Secondly, you might not find a specific passage allowing the usage of the SPOT transmitters while airborne, because the normal rulemaking at the FCC results in approved uses of spectrum. The SPOT folks have an approved service for talking to and from a satellite network. It is actually the same Globalstar satellite network that the (useless...) phones in the CAP SDIS/ADIS aircraft use, the SPOTs simply don't depend nearly as much on the downlink channel. Unless the FCC specifically (as in the case of 800-900 MHz cellular telephones) prohibits a particular type of use, any use that fits within the overall approval is de facto approved and does not need specific language.

My question about use of SPOT in flight relates to FAA, not FCC rules.  I seem to remember reading somewhere in the FAR's that use of portable transmitters was prohibited in flight unless specifically approved for aircraft use, such as a portable airband radio.  I can't find that in the FAR's at the moment and it very well might be an old FAR, but maybe you or someone else here knows?

I did find FAA Circular 91.21-1B which regulates use of "Personal Electronic Devices" in flight.  http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/B5C85AE8E38DF676862571DA00529DA4?OpenDocument.  Paragraph 5a states:

The determination of an interfering effect caused by a particular device on the navigation and communication system of the aircraft on which it is to be used or operated must, in case of an aircraft operated by the holder of an air carrier certificate or other operating certificate, be made by that operator (i.e., certificate holder). In all other cases, a determination must be made by the operator and/or by the pilot-in-command (PIC).

So... it would look to me like as long as CAP (the operator) and the PIC have determined that the SPOT is OK in flight... the FAA does not specifically prohibit it.  The next paragraphs goes on to say:

b. When safely at cruise altitude, the pilot could allow the devices to be operated. If interference is experienced, the types of devices causing interference could be isolated, along with the applicable conditions recorded. The device responsible for the interference should then be turned off.

Sounds like good advice to me!

Cheers!

Here is the FAR in question:
Sec. 91.21

Portable electronic devices.

(a) Except as provided in paragraph (b) of this section, no person may operate, nor may any operator or pilot in command of an aircraft allow the operation of, any portable electronic device on any of the following U.S.-registered civil aircraft:
(1) Aircraft operated by a holder of an air carrier operating certificate or an operating certificate; or
(2) Any other aircraft while it is operated under IFR.
(b) Paragraph (a) of this section does not apply to--
(1) Portable voice recorders;
(2) Hearing aids;
(3) Heart pacemakers;
(4) Electric shavers; or
(5) Any other portable electronic device that the operator of the aircraft has determined will not cause interference with the navigation or communication system of the aircraft on which it is to be used.
(c) In the case of an aircraft operated by a holder of an air carrier operating certificate or an operating certificate, the determination required by paragraph (b)(5) of this section shall be made by that operator of the aircraft on which the particular device is to be used. In the case of other
aircraft, the determination may be made by the pilot in command or other operator of the aircraft.

That says it all right there. The PIC of an airplane operating IFR (and not on an operating certificate) may determine (using the guidance of the AC you already listed...) that any particular Portable Electronic Device does not interfere with the aircraft. If you are flying VFR, there is no requirement at all.

NOTE: You need to do this the same for a Garmin Aera 796 as for a SPOT Tracker or an iPad. This FAR has no exemption for portable Aviation GPS devices. (If this has been superseded elsewhere I'd like to know the FAR number for that...)

So, when VFR you can turn on pretty much anything you like according to the FAA. And, IFR, you only need to determine to your satisfaction that a particular device causes no problems.


Thom

[Eclipse]

CAP's official answer, off the press of the EX's Open Cockpit:
http://www.capmembers.com/emergency_services/operations_support/cellphone__data_card_use.cfm

The bottom line is, other than the special equipment used in the GIIEP system, we are not allowed to use cell phones or cellular cards in flight. No text messages, no phone calls, no emails, etc.  That may change in the future as technology advances, but members should be careful not to take it upon themselves to test the rules as fines can be steep CAP does not condone personnel operating illegally.

[Al Sayre]

Guess we'll have to switch to our Satelite phones...

[Eclipse]

Guess we'll have to switch to our Satelite phones...

Or have the MO turn switch the radio on his side from ATC to CAP frequencies (I know radical...)

[Al Sayre]

Have to have a ground station or repeater within range (a problem in our area).

[Spaceman3750]

Have to have a ground station or repeater within range (a problem in our area).

At a mission you don't have a ground station or repeater you can talk to from 1500AGL?

Climb really high then.

[a2capt]

LOL.. and on one SAR Eval where I was MO, the base knew we were in the air, as our communications were spotty due to a repeater that was not repeating very well, and just decided to dial my phone.

So I shoved it into the headset and answered, "CAP Flight fower ate niner"...  Took down our tasking and completed the objective, RTB'ed and they were thrilled. We were the only ones that did, in light of a repeater failure. No one else thought about it. This was a while back..  and with terrain as such as it is out west, and having worked in the tower industry, knowing that there are at least a few higher than the average low level GA flight in altitude, the whole bit about lighting up 27 towers from altitude just doesn't fly anymore. Antenna's are optimized for terrestrial use where optimum, otherwise - it is what it is.

[jks19714]

Guess we'll have to start installing some Collins HF ALE radios in the aircraft, along with an extra alternator to power them. 

[N Harmon]

Guess we'll have to start installing some Collins HF ALE radios in the aircraft, along with an extra alternator to power them. 

Hey hey hey. Let's get the ground teams outfitted with HF radios first.

[disamuel]

All my comms training has taught me that it is forbidden to use repeaters from the air. Is this incorrect, or is it just my Wing's policy? I also don't think that our aircraft are programmed for repeater usage. If someone has different information, or if other wings allow repeater usage from the air I would like to know that. (I am of course referring to ground based repeaters, not high-bird usage)

Thanks-

[N Harmon]

All my comms training has taught me that it is forbidden to use repeaters from the air. Is this incorrect, or is it just my Wing's policy? I also don't think that our aircraft are programmed for repeater usage. If someone has different information, or if other wings allow repeater usage from the air I would like to know that. (I am of course referring to ground based repeaters, not high-bird usage)

Thanks-

It used to be a no-no to use the universal repeater access tone from the air, but AFAIK our repeaters don't operate like that any more. I might be wrong though.

[Eclipse]

All my comms training has taught me that it is forbidden to use repeaters from the air. Is this incorrect, or is it just my Wing's policy? I also don't think that our aircraft are programmed for repeater usage. If someone has different information, or if other wings allow repeater usage from the air I would like to know that. (I am of course referring to ground based repeaters, not high-bird usage)

First I've ever heard of it.  My wing has no issue and routinely briefs using repeaters from the air.

I personally keyed them up from 10K during Ardent Sentry, and we had all of our aircrews using them as necessary during our last eval.

[EMT-83]

CTWG does not allow use of repeaters from aircraft, due to potential interference to adjacent Wings. It's not unusual to hear simplex traffic from 2 or 3 different states without lighting up repeaters.

The repeaters are programmed in the aircraft radios, for use if they're really needed. Otherwise, it's climb up and establish communications. We had to do that several times during a photo mission for Irene, where we couldn't contact mission base at 1,000 feet. Fortunately, the state is small enough that you can pretty much talk from one end to the other at 3,500 feet.

[SarDragon]

The standard channel plan for the A/C radios has all the repeaters programmed in. I don't think the 100 Hz tone is in use any more, so using a repeater while airborne in most areas is no big deal.

[JeffDG]

All my comms training has taught me that it is forbidden to use repeaters from the air. Is this incorrect, or is it just my Wing's policy? I also don't think that our aircraft are programmed for repeater usage. If someone has different information, or if other wings allow repeater usage from the air I would like to know that. (I am of course referring to ground based repeaters, not high-bird usage)

First I've ever heard of it.  My wing has no issue and routinely briefs using repeaters from the air.

I personally keyed them up from 10K during Ardent Sentry, and we had all of our aircrews using them as necessary during our last eval.

Pretty common here.  One of our route surveys for the New Madrid scenario was about 120 miles from the base I operated out of and another 60 from our ICP.  At 1,000' AGL flying the route, not a lot of chance of comms back to base without an airborne repeater.  Even with the airborne repeater, we had some comms gaps.

[argentip]

Before the latest change in CAPR 100-1 (28AUG09) and the introduction of the new repeaters and channel plans, airborne use of ground-based repeaters was not allowed.  This was because of a couple factors.  One was that every repeater was programmed with a universal PL access tone (100Hz), and the second was that the distinct PL tones were often re-used within close proximity to other repeaters with the same tone.  Re-using these tones was not an issue for ground-based radios, but because the coverage area is much greater when airborne, it could cause an issue there.

With the change in regulation and channel plan, the PL tones are now more diverse, and planning took place to make sure that repeaters with the same tone were placed far enough apart to not cause a problem.  The 100Hz tone was also eliminated (much to the dismay of many operators).

Aircraft are now authorized to use any CAP-assigned frequency (with the exception of Wings with Border Zone Restrictions), including ground-based repeaters..

If your specific Wing still does not allow aircraft to utilize the repeaters, that is a question you would need to ask them individually.  There is nothing in the regulations that prohibits it anymore.