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Saturday, May 7, 2011

Life's Little Annoyances

The first 95% of yesterday's flight from KBDR down to KVKX in the DC area was uneventful. I like uneventful. Then, as N631S and I got within about seven miles of home plate it got a little bit interesting. I don't care for interesting.

It pleased me no end, that one of the control sectors as I worked my way through Potomac Approach's airspace was being minded by my friend Sarah. We did, "Washington altimeter is 29.82, hi, Frank," and "29.82, 31 Sierra, hi Sarah!" And I felt so very comfortable and at home with that familiar voice on the frequency. In due course I was handed off to one of Sarah's colleagues who gave me a descent to 1,500 feet MSL, turned me toward KVKX, and asked me to report the field in sight. That's when it got interesting.

I acknowledged the transmission, turned toward KVKX, and soon reported that "31 Sierra has the field in sight." I then heard the controller say, "Skylane 31 Sierra, cleared for the visual approach to VKX." I acknowledged that transmission..."31 Sierra, cleared for the visual at VKX."

Then, I heard, "Skylane 631 Sierra, cleared for the visual approach, VKX." Umm...already heard and acknowledged. Whazzup? "31 Sierra, cleared visual at VKX," got me "Skylane 31 Sierra, if you can hear me, IDENT."

Oh, crap. Here I am in the most secure airspace in the western hemisphere and, while I'm not "NORDO" I seem to be "no-transmit". I hit the IDENT button on the transponder.

My controller came back with, "31 Sierra, IDENT observed; you are cleared visual approach to KVKX, keep your squawk code until on the ground then cancel IFR with Potomac Approach as soon as possible."

I switched to the #2 radio, no joy. That's when I noticed (finally!) that pressing the Push-to-Talk (PTT) switch on the yoke was not producing the distinctive "click" in the headset. OK, bad PTT switch. I reached down and grabbed the handheld mike.

By this time I'm turning onto the right downwind for runway 24 at KVKX. Using the handheld mike I transmitted, "Approach, 631 Sierra." The response: "Ah, there you are! I think I must have stepped on you." (Not!) "Change to advisory frequency approved, keep your squawk until on the ground."

I quickly responded, "31 Sierra, over to CTAF, cancel IFR at this time," and got, "IFR cancellation received..." Phew!

The landing at KVKX was uneventful. Sarah, if you're checking this out, let your colleague know that he did not step on me. It was an equipment issue and he was BRILLIANT! He can be my final controller any time!

There at left is the little bastard that I think failed (unless it turns out that it's a wiring issue).

That little guy is a Mason 611-4302 momentary contact switch. If you want to buy it under the Mason part number, it's just about $200.00. Cessna assigns their own part number to the Mason switch. It's Cessna p/n S1985-1 and they want about $156.00 for it.

Now, it seems that Rob-Air Repair LLC in Silverdale, WA, offers a part numbered RA S1985-1 as a direct replacement for this silly little switch, for $17.99 each. I have an e-mail in to the Rob of Rob-Air, asking him to provide the approval basis for his switch so I can convince Dave at Three Wing to install the low cost option.

Meanwhile I trust you have one of these (left), and it works, and you can fetch it up without looking down to where it's stowed. Better if you can slip it back in it's holder without looking down. I couldn't, and just dropped it on my lap. Rest assured, stowing the handheld mike will now be practiced until I get it right.

As for Monday morning, I have one of these (left) left over from my Student Pilot days 17 years ago. A portable PTT switch, that can be secured to the yoke with Velcro strips and is able to bypass the yoke-mounted PTT switch. Should be good to go.

Never a dull moment, eh? Well, that's what makes it fun.

6 comments:

carlsonj said...

Let me know what you find out! My PTT in my '78 172 Hawk XP gave out yesterday while talking to Boston Approach, and I'm disappointed with the $155 Cessna answer as well. $20 sounds much better ... though the "not pma'd" note on the web site sounds like a possible hassle.

carlsonj said...

Well, just in case anyone else stumbles over this blog, I did order that switch, and it doesn't appear to be a direct replacement. It's a different size and doesn't fit in the hole left by the Mason 611-4302. The search continues.

navspex said...

the Mason switch is a double pole momentary switch. Cessna audio engineers thought it would be a great idea to not only provide a ground to the radio to key it, but to run the microphone return through the PTT switch so the mic wasn't hot all the time. A real pain in the arse for us avionics types! I wire around it whenever possible because intercoms need a hot microphone (DUH!).

JOSEPH SWANSON said...

Do you have a part that might replace this expensive factory switch.. My PTT on my 182r seems to work fine when at idle, but will not transmit at normal RPM,s. It may be something besides the switch. Any suggestions? Thanks, Joey

Frank Van Haste said...

Joey, it sure doesn't sound like the switch is the problem. It's just a momentary contact make-break switch and if it works at one RPM it should work at any. Your mechanic ought to be able to verify that the switch is functioning in a few minutes with an ohmmeter.

That said, if it isn't the switch I have no idea what else might be causing the trouble.

Good luck.

JOSEPH SWANSON said...

Frank, thanks for your help. If you have any ideas on where to check, they will be greatly appreciated! Joey