Tech Log: 8.33 ra­dios

The re­quire­ment to have an 8.33 ra­dio comes into force on 1 Jan­uary 2018, mak­ing 2017 ra­dio re­fit year

Pilot - - CONTENTS - Words Philip White­man

By 1 Jan­uary 2018 all air­craft are go­ing to have to be fit­ted with ‘8.33’ (8.33khz chan­nel spac­ing) ra­dios. This should come as no sur­prise, as Jon Roper of lead­ing UK man­u­fac­turer Trig points out; “Com­mer­cial air­craft have been op­er­at­ing across Europe with 8.33 for over twenty years, so the roll out to GA was per­haps in­evitable. Lim­ited chan­nel ca­pac­ity and lack of VHF band­width are gen­uine is­sues in many parts of Europe and 8.33 spac­ing is the way Euro­con­trol and EASA are fix­ing these prob­lems. This tran­si­tion has been com­ing for some time−for ex­am­ple it has been il­le­gal to sell non 8.33 equip­ment for two years.”

The trou­ble is that, as with so many other things in GA, “there is far too much ru­mour go­ing around”−an ob­ser­va­tion from Mike Pet­ti­can of LX Avion­ics, who goes on to say; “It seems that many sim­ply be­lieve that there will be a last minute change in the rules. The is­sue here is that this is EU law, not na­tional reg­u­la­tion and it can­not be changed by EASA mem­ber states. There is a huge void in com­mu­ni­ca­tions be­tween the au­thor­i­ties and air­craft own­ers and op­er­a­tors.”

Light Air­craft As­so­ci­a­tion CEO Steve Slater has been in­volved in dis­cus­sions with the CAA and is well placed to give chapter and verse on the sit­u­a­tion: “The fact is that all ra­dios used in air­craft from 1 Jan­uary 2018 must be 8.33khz and the only ex­emp­tions will be seven or so fre­quen­cies, such as 121.5, safety, glid­ing and bal­loon fre­quen­cies, which will be avail­able for a fur­ther tran­si­tion pe­riod. No other 720/760 chan­nel 25khz ra­dio use af­ter that time is le­gal.”

How many air­craft will have to be re­fit­ted? Mike Pet­ti­can, LX Avion­ics Ltd says “There are 12,000 or so light GA air­craft on the UK regis­ter and we think that around 8,000 still need to change to 8.33”. It is not just Bri­tish air­craft that are af­fected. “Across Europe there are reck­oned to be around 50,000 GA air­craft, glid­ers and un­tra­lights that need to equip with 8.33 ra­dios,” adds Jon Roper.

Some equip­ment may al­ready be ca­pa­ble of 8.33 op­er­a­tion with­out users know­ing it. “Be­fore go­ing off and re­plac­ing avion­ics, check first that what you have is not able to be re­set,” ad­vises Kevin Churchill of air­craft main­te­nance spe­cial­ists Air­time. “Many peo­ple think that equip­ment such as the Garmin GNS430 needs to be re-chipped. Even older mod­els of Garmin GNS430 can be 8.33 ca­pa­ble and just need a change in set­tings.”

How­ever, a large num­ber of air­craft will have to be fit­ted with new units and we asked man­u­fac­tur­ers, main­te­nance or­gan­i­sa­tions and avion­ics spe­cial­ists what kind of costs own­ers of the most com­mon sin­gle-en­gined GA types would be fac­ing.

“This de­pends on the equip­ment se­lected,” says Trig’s Jon Roper. “Our TY91 com­pact ra­dio sells for around £1,075, ex­clud­ing tax and our TY96 stack ra­dio is around £ 1,750, ex­clud­ing tax. In­stal­la­tion costs are al­ways hard to pin down as the con­di­tion of the ex­ist­ing an­tenna, wiring and rack are fac­tors.”

“For LAA Per­mit air­craft and Glid­ers we es­ti­mate change to cost be­tween £1,200 and £1,300,” says Mike Pet­ti­can. “For cer­ti­fied EASA air­craft,

where a li­cenced avion­ics en­gi­neer needs to carry out in­stal­la­tion, we would sug­gest a fig­ure of be­tween £1,600 and £2,500 for ba­sic comm re­place­ment, £5,000 for Nav/ Comm re­place­ment.”

Brian Cook of Bournemout­h Avion­ics says that costs vary, and for cer­ti­fied air­craft would start from about £2,000 plus VAT for the panel mounted Trig TY96 VHF, fit­ted. “But it could be a Nav/comm set is more ap­pro­pri­ate to the cus­tomer” (adding to the cost).

“The ba­sic labour cost to swap out an old ra­dio and re­place it with an 8.33khz ca­pa­ble unit could be as low as £300 to £400,” says Kevin Churchill, “but it de­pends on what is be­ing re­placed and other fac­tors. For ex­am­ple, is the old VOR/ILS in­di­ca­tor com­pat­i­ble with the new unit?”

Fund­ing avail­able

Hap­pily, the CAA is work­ing on Tran­si­tion Cost Fund­ing re­demp­tion scheme, the first phase of which is due to be an­nounced in De­cem­ber. Up to twenty per cent of the cost of ra­dio equip­ment and fit­ting will be avail­able (see ‘El­i­gi­ble for the Tran­si­tion Cost Fund?’ op­po­site)−and ‘as­so­ci­ated costs’ are still un­der dis­cus­sion.

Of course 25khz chan­nel spac­ing is not go­ing away−the new 8.33khz chan­nels are threaded in be­tween the ex­ist­ing 25khz ones. All new 8.33 ra­dios sup­port both 8.33 and 25khz chan­nels, and they au­to­mat­i­cally switch be­tween them de­pend­ing on the chan­nel num­ber that the pilot di­als in. “There are sev­eral ap­pli­ca­tions, such as multi-site trans­mis­sion sys­tems us­ing off­set fre­quen­cies, where 25khz chan­nels con­tinue to be the best choice,” says Jon Roper. “The air­band VHF en­vi­ron­ment will there­fore al­ways have a mix­ture of 8.33 khz and 25 khz chan­nels. If you only ever wanted to speak to 25khz sta­tions, you might hang onto an old 720/760 chan­nel ra­dio. The prob­lem is that only those multi-car­rier ser­vices and a few in­ter­na­tion­ally agreed safety chan­nels (like 121.5) are likely to re­main on 25khz chan­nels, and many ATC and Air/ground sta­tions will move over to 8.33−a lot of changes are pend­ing, wait­ing for the man­date deadline. If you don’t have an 8.33 ra­dio you will not be able to com­mu­ni­cate with them.”

“Be­cause the 8.33khz chan­nels are in the same spec­trum as the old 25khz chan­nels, you can still pick them up on a 720/760 chan­nel re­ceiver tuned to the near­est 25khz chan­nel. Of course if you are lucky (or un­lucky, de­pend­ing on what you were try­ing to do) you will be able to hear two or three chan­nels at once! The prob­lem is that you won’t be able to speak back to them re­li­ably, be­cause there is no ex­pec­ta­tion that your trans­mit­ter is aligned to their re­ceiver−even for those chan­nels where the nom­i­nal fre­quency is the same, since 25khz ra­dios are al­lowed a much wider trans­mit fre­quency tol­er­ance than 8.33 khz ra­dios. Re­mem­ber that this af­fects not only the ground sta­tion, but also other pi­lots on the 8.33 khz chan­nel who will not hear your trans­mis­sions – whilst those on an ad­ja­cent chan­nel might hear them un­ex­pect­edly. You re­ally do need an 8.33 khz ra­dio!”

Many ATC and Air/ground sta­tions will move over to 8.33... If you don’t have an 8.33 ra­dio you will not be able to com­mu­ni­cate

Many own­ers will be re­plac­ing their ra­dios with mod­ern 8.33 units like the Trig TY91 (left in photo). 720/760 chan­nel 25khz ra­dios like the Edi­tor’s an­cient IC-A2 handheld (be­low) will be re­stricted to emer­gency use

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