Seaeye Falcon NAV pod

[Ray Shields]

Having just come back from my first Falcon job (aint these things cute n compact!) we had a few problems with the nav pod.

Firstly, shouldnt the pitch read positive for nose up? this one read negative for nose up.

The Gyro seemed more lile a random number generator. Trying it on deck, you had to move the sub through 120 degrees to get the numbers to change by 90. Tried a calibration but didnt seem to make any difference. Is this pod a gyr with a fluxgate, can you calibrate on a metal deck ok?

In water you could sit and look at something and teh heading would vary by 60 odd degrees. We had a spare pod, tried fitting it and it was exactly the same.

[Anonymous]

Ray,

Been a while since I used a Falcon (S/N 003 which was a rented bucket of bolts), however. . .

Recommended practice for the compass calibration is to suspend the ROV from a crane etc preferably using non-ferrous lifting gear e.g. soft sling / rope and then manually to slowly turn the sub while performing the system compass calibration as per Surveyor / Panther manuals. Obviously this is a procedure best performed on / above terra firma as you want the rotation of the sub’s actual heading to be in a clockwise direction from north without regressing for 1 1/2 (?) turns.

Did the depth report correctly? There can be a fault with the NAV ROM if both compass and depth are out of kilter.

Cheers
🙂

[Ray Shields]

No, depth was fine. Although Auto depth didnt work, tried it and it just sank and kept on going!

What about the Tilt? Shouldnt it be positive for nose up (as per normal convention?) The book didnt say definatly. I also checked the pod wasnt mounted back to front.

Was my forst time out with a Falcon, its nippy!

[Anonymous]

OK I’m afraid that I’ve never seen the manual for the Falcon but…

The standard convention is pitch up = nose up = +ve.

I’m wondering that the sensor is not mounted correctly or there is this Nav ROM problem.

When you say that in auto depth it sank, can you confirm that it sank and didn’t fly down?

I can send you the procedure later on for performing a reset of the ROM if you need it, just PM me.

Cheers 🙂

[Alex Kerr]

Ray,
Just seen this thread, are you still having problems? we’ve held a couple of Falcon’s for a few years now and come across most faults. 💡
Oz,
where did you come across S/N 003? – that’s one of ours! 😕

[Ray Shields]

Nah we downmanned and demobbed the gear. it was no. 136 so a bit newer than 003!

I mentioned it to the base, so nothing will get done 🙂 Never got to the bottom of it, but that was my first time with a Falcon.

[Anonymous]

Spark,

I believe it was S/N 003 but actually it may have been S/N 001 as several of the pcbs were Id’ed as 001.

Coming from a former electronics OEM I was dismayed when I saw the serial numbers!

Location was Cliff Head offshore Western Australia for Roc Oil.

A lot of problems due to surface mount components either falling off completely or forming intermittent contact leading to a nightmare when fault-finding!

I believe that the unit was leased via Seatronics in Singas, could be wrong there as I wasn’t involved in the procurement process and was at the wrong end of the food chain.

Give me a Panther Plus anytime!

Cheers 😉

[Alex Kerr]

Aah!, the old food chain wheeze, I hear we are now referred to in some quarters as "gash hands"!– 😉 😉

Remember!- you can’t do enough for a good company, or is it that you can’t do a good company for enough- I always forget which way round that goes! 😆

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