Honeywell 660 Radar on 139 specific, and helicopters in general
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Honeywell 660 Radar on 139 specific, and helicopters in general
So a questions for the experts. We are having a friendly argument about WHY we have the radar on at the least standby when operating the helicopters.
From my own "common wisdom" which isn't very wise I'll admit, we have always left them on because of vibrations damaging the gimbal mounts, and obviously because if you need it, it won't take ages to warm up.
I've searched the books, Honeywell 660 manual, Primus Epic manual, Flight Safety and Leonardo training books, company SOP. Only guidance is company and Flight Safety says ON on checklists...
So to the panel of experts, anybody have a good reference for WHY?
Cheers
Winnie
From my own "common wisdom" which isn't very wise I'll admit, we have always left them on because of vibrations damaging the gimbal mounts, and obviously because if you need it, it won't take ages to warm up.
I've searched the books, Honeywell 660 manual, Primus Epic manual, Flight Safety and Leonardo training books, company SOP. Only guidance is company and Flight Safety says ON on checklists...
So to the panel of experts, anybody have a good reference for WHY?
Cheers
Winnie
On a gin clear day never saw reason to turn it on, interested to see what knowledgeable folk have to say, does the practice cause problems with the system? Didn't seem to in as much as we never had radar problems, iron gyros were another matter which were replaced with solid state.
Unknowledgeable folk here... just experienced with complex systems those many components have convoluted interactions.
Sometime its interesting what a sub-system those functionality is far removed can create such an unforeseable implication.
it would be likely that the aircraft is tested and qualified with all system on. testing with partial system off is probably an area that receive less attention.
Sometime its interesting what a sub-system those functionality is far removed can create such an unforeseable implication.
it would be likely that the aircraft is tested and qualified with all system on. testing with partial system off is probably an area that receive less attention.
no expert but my impression would be in SOP is to have an ON/OFF option you’d then have to give further consideration to what equals ON or OFF, serviceability and if OFF when it becomes ON. If there is no life limit issues then I suspect easier to leave on.
Scanner stability would be my suggestion - keep it powered up to stop it flopping around and getting damaged.
Agree. If the system is powered, the antenna is kept in place and stable so no risk of damage to components, which there might be is the system was unpowered. Also, why go to the bother of having a radar and not using it?
You might be looking in the wrong location.
Does the fire department only test hydrants just before a fire?
My guess would be that the aircraft was tested and certified in that configuration. And it’s an installed system, so why wouldn’t be on?
FWIW, FAR part 135.175 (for large transports) requires it to be operational when detectable weather is reported. If it's not on, how does one know it's operational?
Does the fire department only test hydrants just before a fire?
My guess would be that the aircraft was tested and certified in that configuration. And it’s an installed system, so why wouldn’t be on?
FWIW, FAR part 135.175 (for large transports) requires it to be operational when detectable weather is reported. If it's not on, how does one know it's operational?
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why go to the bother of having a radar and not using it
Honeywell specifies it is s stabilised antenna on this family of radars so without power, there is no stabilisation of the antenna and it will flop around on its gimbals.
Honeywell specifies it is s stabilised antenna on this family of radars so without power, there is no stabilisation of the antenna and it will flop around on its gimbals.
Honeywell Primus 880/660/440, Bendix King RDR-2000/2060/2100 and the Honeywell RDR-4000 and RDR-7000 systems. All of the radars just listed “except the RDR-4000” use stepper motors and it is safe to turn power off during taxi or any other phase of flight.
Test Pilot, Flight Technical Services
Honeywell Aerospace Technologies
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Avoid imitations
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I got into the habit of leaving the radar on STBY so it came on as the relevant bus bar came on line. I was advised that ground taxying could be quite harmful if the unit was left unpowered.
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Maybe? According to an article from the manufacturer - The Use, And Misuse Of Weather Radar – Part 4
Stephen D. Hammack
Test Pilot, Flight Technical Services
Honeywell Aerospace Technologies
Stephen D. Hammack
Test Pilot, Flight Technical Services
Honeywell Aerospace Technologies
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