Helipad Lighting 1

[richanton]

We just built a helipad and installed Flight Light HL-392 LED perimeter lights. We have been having a lot of intermittent trouble with the lights, either the remote signal not working from the approaching helicopter, or the lights coming on when they are not supposed to. Has anyone had any experience with controlling these type of lights.

 

[VEBill]

Your problem description points to the "radio control option", not the LEDs.

 

[IRstuff]

"the lights coming on when they are not supposed to"

suggests that it's an RF interference or EMI problem.

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[VEBill]

The radio receiver for this sort of application should be intentionally designed or adjusted to be quite low sensitivity. It needs to pick up a roughly 5 watt signal from an aircraft at most just a few miles away. If it proves to be too sensitive, approach the manufacturer with the suggestion of installing an attenuator in the antenna lead. They should already be ahead of the curve on this.

The webpage mentions that the radio controller can be adjusted to 3, 5, or 7 microphone clicks. I'd set it to 3 (plenty tricky enough). You might want to borrow a VHF-AM Aircraft walkie-talkie to use for troubleshooting the system; beware violating FCC rules. I assume that the system has been programmed to an appropriate frequency so that it doesn't cause interference to nearby airports, etc.

There's a possibility that the issue is further down the signal path. But there's plenty to check at the receiver side first. If it's new, enlist tech support from the OEM.

 

[richanton]

Thanks for the info. The attenuation info is interesting. Some of the prior troubleshooting involved getting a better antenna and repositioning it.

 

[VEBill]

Older radio designs tended to be quite simple and thus 'quick on the draw' for application of the PTT button. One could send 3 quick, short 'mic clicks' very easily. Some (many? most?) more modern radios sometimes run the PTT through a microcontroller, and it might even be programmed to filter out short PTT presses. Or it would have enough latency to accomplish the same thing as a side effect. Some of my VHF-FM (not airband) radios have a good half-second latency on the PTT, to the point where one must not start speaking too quickly else the first word would be cut-off. I'm not positive this necessarily applies to VHF-AM Airband radios.

So if some users are having problems, then check to make sure that they're actually sending 3 mic clicks (by listening on a nearby radio).

The helipad lighting company should already be on top of this by now. They might have had to slow down their mic click detector over the years, to allow for periods of at least a 1 second.

If they offer tech support, then I'd recommend getting them involved.

 

[SceneryDriver]

As a private pilot, I can attest to the mic-click receivers being a bit, well... temperamental. The runway lighting at small uncontrolled airports is often controlled this way.

3 clicks: lights up at Low
5 clicks: lights at Medium
7 clicks: lights at HIGH
Auto-off after some predetermined length of time; usually around 15 minutes.

Whether it was a finicky PTT switch in the 1977 Cessna I was flying, or a finicky receiver, I don't quite know. I do know it seemed to take forever to get any runway lights to come up at that tiny airport when I was landing in that snow squall that night. Ugh.

Airports are often set up like this so that bringing up the lights doesn't blind the pilot with the brightest light setting; their vision has presumably adjusted to flying in the dark. If the receiver isn't responding correctly, please, as a pilot, get it fixed immediately. Your manufacturer should be able to help. Where are you located in the world? I'm not certain, but the FAA may have things to say about this system, especially if it's not working correctly. Read the regs... carefully. To not get this working correctly could jeopardize the lives of the people on a helicopter that needs to land immediately; weather, mechanical issues, and low fuel come to mind as reasons.


SceneryDriver

 

[VEBill]

These days, the manufacturers of such systems should be looking at switching over to voice recognition of specific keywords (not user-specific). Such technology seems to be working quite well for various automated telephone call center applications.