WANTED: M20J ram air cable

[John Martindale]

Hi folks

Sorry this is not in the classifieds but I can't seem to post there for some reason. Yes, I have donated the $10.00.

I need a ram air cable for my M20J please.

If anyone has one for sale or can otherwise help, please reply to john_martindale@bigpond.com

Regards

John Martindale (Australia)

[ArtVandelay]

You might want to consider if now would be a good time to remove the ram air function, there is a service bulletin describing how to do this.

[John Martindale]

Hi Tom

It was already removed when I bought the aircraft. I want to put it back again but I haven't got it available to do so.

Regards John

[EricJ]

I'll +1 that you're likely far better off without it.   IMHO the minuses far outweigh the pluses, and there are significant downsides.    I definitely wouldn't put one in where one doesn't exist.

That said, I deleted my ram air (77 J) a couple years ago and the cable is still in my hangar.   I can get a pic the next time I'm there, which will likely be within a few days if you really need.

 

[John Martindale]

Hello Eric

I understand the SB and the reasons for deletion of the cable but I would still like to consider the purchase your old one if you wish to sell please.

My Mooney is also a 1977 M20J with the quadrant controls (SN 24-0039).

Email me off line if interested with a price.  john_martindale@bigpond.com

Thanks John

[carusoam]

Message for @Eric J above...

-a-

[Yetti]

Bowden Cable at Aircraft spruce or McFarland

 

[PTK]

3 hours ago, John Martindale said:

I need a ram air cable for my M20J please.

PM sent.

[John Martindale]

Hi Yetti

The problem with the Spruce cable is that it doesn't allow for the microswitch that controls the warning light to be be installed on the stalk behind the knob.

I have contacted McFarlane and they are researching the fabrication but are yet to respond with a quote.

Cheers John

[EricJ]

4 hours ago, John Martindale said:

Hello Eric

I understand the SB and the reasons for deletion of the cable but I would still like to consider the purchase your old one if you wish to sell please.

My Mooney is also a 1977 M20J with the quadrant controls (SN 24-0039).

Email me off line if interested with a price.  john_martindale@bigpond.com

Thanks John

I'll get a pic of it for you in the next few days and if you're still looking by then we can go from there.

[John Martindale]

Thanks Eric

Appreciate your efforts.

John

[Yetti]

6 hours ago, John Martindale said:

Hi Yetti

The problem with the Spruce cable is that it doesn't allow for the microswitch that controls the warning light to be be installed on the stalk behind the knob.

I have contacted McFarlane and they are researching the fabrication but are yet to respond with a quote.

Cheers John

couple of minutes with a file, dremel tool, milling machine and it will work.  Remove innner cable before attempting.

[John Martindale]

Geday above folks

Kelli at McFarlane has kindly responded to me promptly with a quote of US$300 to fabricate a new one.  McFarlane do quality work and have received good reviews on this forum previously. However, I have since managed to track down a good genuine second hand cable down over there for a lot less. It even has a matching knob and relevant attach brackets that I need and I don't have any hassles with approvals over here with its installation in a certified aircraft.

Thank you everyone for your comments.

Regards John

[jbgood11X]

yes john i probably do.  off what year and model.  sorry for late reply but i just now saw this inquiry.  ph 815 210 2675 I live in a bad cell reception area so if I don't answer leave me a text.  If you already found one let me know  thanks John

[John Martindale]

Hi John

Thanks for your offer but I'm in Australia  so not worth trying to phone you over there in the USA at the moment. I think I already have one on the way now provided the virus doesn't interrupt the delivery process unduly. I'll keep you in mind however should it all go pear shaped. I have a 1977 M20J. The later models dispensed with the ram air. Regards John.

 

[jgarrison]

Just my $.02. Sorry if you are trying to sell John your cable and I got in the way. I'll try to make it up to you. Maybe there is something I can do for you one of these days regarding value or something.

Ram air on the 201 typically increases MP by no more than 1/2". Usually closer to 1/4. On the F and E, you will typically see and inch, maybe slightly more. The induction system on the J was better than the predecessors. Thus the gain was less because it was already very efficient and breathing.

The potential for having induction icing is one reason to not reinstall it. I know of one dead stick landing on a plane I currently have that was due to icing through the ram air port. The second reason is it basically does little to no good.

[John Martindale]

Geday there jgarrison

No worries about getting in the way...you haven't at all

 I understand the consensus that ram air is of little value in the J's due to their improved inlet design and that Mooney removed it in later models. I can also appreciate the icing possibility that you mention.

However, given the ram air inlet exits into the same airbox as the filtered air does and that the airbox also has an alternate door on its rear side that is supposed to open automatically if there is an inlet constriction, I find it difficult to see how, even if the ram air inlet was completely occluded by ice, that a dead stick landing would be the inevitable outcome unless the ice forms further down in the injector pump body itself. If this were the case, why hasn't Mooney recommended it be removed from the earlier models also.

I think if icing is a possibility it's pitot heat on and ram air off immediately and either descend to a warmer altitude or climb into clear air or turn back.  Of course, we shouldn't be there in the first place with flight into known icing prohibited. I would be interested to hear from other Mooney pilots about their experiences with ram air icing.

Regards John 

[carusoam]

John,

I’m glad you asked...

I know a guy...

That has an M20J...

a Little bit on the opposite end of the globe from where you are...

Who ran into an icing challenge over the North Sea...

While the plane was relatively new to him...

See if I can find Andrew... he might be able to point to the thread around here...

Andrew has some interesting sailing experience in the same area... lots of hazards available over the North Sea...

@Hyett6420 (got any ram air icing experience to share?)

All I know about alternate air sources... they can get old and not work so well anymore...  you don’t want to be over a tough spot when you find out... The M20C has a stranger system... equally challenged by age and wear...

PP thoughts only, not a. CFII... or mechanic...

Best regards,

-a-

[EricJ]

1 hour ago, John Martindale said:

Geday there jgarrison

No worries about getting in the way...you haven't at all

 I understand the consensus that ram air is of little value in the J's due to their improved inlet design and that Mooney removed it in later models. I can also appreciate the icing possibility that you mention.

However, given the ram air inlet exits into the same airbox as the filtered air does and that the airbox also has an alternate door on its rear side that is supposed to open automatically if there is an inlet constriction, I find it difficult to see how, even if the ram air inlet was completely occluded by ice, that a dead stick landing would be the inevitable outcome unless the ice forms further down in the injector pump body itself. If this were the case, why hasn't Mooney recommended it be removed from the earlier models also.

I think if icing is a possibility it's pitot heat on and ram air off immediately and either descend to a warmer altitude or climb into clear air or turn back.  Of course, we shouldn't be there in the first place with flight into known icing prohibited. I would be interested to hear from other Mooney pilots about their experiences with ram air icing.

Regards John 

With the ram air door open on a J model (or I think an E or an F, but I'm not positive on those), the ram tubes in the fuel servo, and the throttle plate, are both in the direct air path.   This means cold/freezing moisture can accumulate on them just like on any leading edge, but when ice accumulate on the ram tubes the fuel injection gets fubared.    All of that is downstream of the automatic alternate air door, so it won't help.   I don't know whether that has ever happened, but when I look at those systems that is one the potential issues that I see.

Likewise dirt/dust/whatever goes in those tubes other than just air, can accumulate in the servo.    I had an in-flight engine failure not long after I bought my airplane that was due to the servo failing, and the overhaul shop said it was full of "grit".     I deleted the ram air not long after that.

Edited May 1, 2020 by EricJ

[jgarrison]

1 hour ago, John Martindale said:

Geday there jgarrison

No worries about getting in the way...you haven't at all

 

I just sell em... Not a mechanic nor overly mechanically minded. Just know that they are not much good and for some reason Mooney came out with an SB or SI to remove them and sold kits to accomplish so they clearly knew there was either no benefit or there was a potential issue (or both). The plane I have in inventory now, I know, had the kit installed after the owner had an engine failure in IMC due to some blockage in the system. Whether he had Ram Air engaged or if it was because of a leak in the seal, or something completely different, I don't know. I only know he had the ram air removed immediately after it happened.. I fly a turboprop on occasion. First thing you do when encounter with moisture is engage the FOD diverter to keep moisture out of the system (it defects it overboard before it goes into the compressor). Ice in the induction system of any engine is not welcome. And especially when the benefit is almost non-calculable.

[Mooney in Oz]

On 5/1/2020 at 12:42 PM, John Martindale said:

I think if icing is a possibility it's pitot heat on and ram air off immediately and either descend to a warmer altitude or climb into clear air or turn back.  Of course, we shouldn't be there in the first place with flight into known icing prohibited. I would be interested to hear from other Mooney pilots about their experiences with ram air icing.

Hello John, Victor here. Hope you are well.

Back in 87 when I didn't have much experience in Mooneys, I was flying a 201 from Lightning Ridge to Bankstown at 9,000 feet and above cloud with an OAT of +5 degrees C. I was about 5 minutes from over the top of Mudgee flying along fat, dumb and happy when I entered cloud and had not noticed for a few minutes the OAT drop to -2 degrees C.  About to descend, I switched on the pitot heat, but forgot the Ram air was open. After another couple of minutes the engine suddenly stopped when I was directly over the top of Mudgee. I started a shallow spiral descent over the top of Mudgee airport using the NDB as guidance, in cloud with no power and not having a clue what the cloud base was.  The grid LSALT in that area is 5,000 feet.  I was still in cloud and about to declare a mayday when descending through 6,000 feet the engine suddenly came to life with full power restored. I managed to descend below the freezing level.

The experience frightened me so much that I did the VOR approach into Mudgee and landed.  I cannot remember whether the Ram Air light was illuminated on the annunciator panel or whether the light even worked. I was reluctant at first to continue to Bankstown but after regaining my confidence and realising I left the Ram air open as the cause, I departed and later landed at Bankstown without further incident.

Apart from entering cloud in icing conditions, the three lessons I learnt from the experience is, 1 - it is very easy to forget the Ram air is open,  2 - unintentionally having the Ram air open in icing conditions is highly dangerous and 3 -  it is the most useless system on the 201.  It makes not a micro of difference to enroute performance and even if not in icing conditions, with it open dust particles or other contaminants can enter directly into the induction system, so I've been told.

Those days I flew a number of 201's and since that incident the first item I checked before flying any 201 was the Ram air is closed and it was never, ever again opened in flight.

After I bought my own 201 at the first opportunity, I had the Ram air removed in accordance with the SB.

Give my regards to Tim and Warren.  

[N201MKTurbo]

I found in my M20F,  when the injector gets iced, going to full rich will get it going again.

[Mooney in Oz]

11 minutes ago, N201MKTurbo said:

I found in my M20F,  when the injector gets iced, going to full rich will get it going again.

I did that as part of the engine failure procedure, but the engine did not restart until I was out of the freezing level.

[N201MKTurbo]

5 hours ago, Mooney in Oz said:

I did that as part of the engine failure procedure, but the engine did not restart until I was out of the freezing level.

Yea, all iceing is different. It only happened once, and it was barely running. I had the power boost on too. You only do that once.

[John Martindale]

What I am unclear about is that if there is moisture in the air at a temperature conducive to icing in the pump body after the automatic alternate door then why doesn't that same air cause problems after going through the normal air filter. Is that filter really fine enough to remove molecules of water? What makes the ram air entrance so different, it's the same air after all. Also, if it is such an issue why isn't removal of the ram air inlet mandated in all models or a mod available to add hot air if needed like a carburetor engine?  Regards John