Wish there was a way to simualate Vacuum Failur

[121Dispatch]

Wish there was a way to simulate Vacuum Failure

I finished up my required training for my instrument checkride last week...I got lots of good information from this board, but unfortunately, never had anything too exciting to post about on here......until today.

I went up with my instructor to "finalize" a few things prior to my checkride, which is scheduled next week. We went over to the local uncontrolled field to shoot an NDB approach, missed, then hold at the NDB. Other than a quick brushup on outbound timing due to winds, all went well. We headed back to LZU, and I started verbally going over "what if" scenarios, and then giving the answers. I talked about pitot blockage, static blockage, and then vacuum pump failure. Then I pointed to the stand-by vacuum system, and went over my thoughts on how it worked just to make sure I completely understood. As we were getting vectored for the ILS, I noticed the AI was indicating a descending left turn. I thought, man, that is weird...but that's it. As I continued with the scan, I got back to the AI, which was now showing a steep descending turn. At this point, I would have ideally checked the vacuum guage. Unfortunately, I tilted my head back, and confirmed that we were straight and level with the actual horizon. THEN I looked at the suction guage, which was pegged to the bottom left. I knew there was no way to simulate actual vacuum failure other than covering up the AI/DG, but I questioned my CFII anyways...he said he was not messing with anything. I said, well then, I guess we have a real vacuum failure!

After all our partial panel training, I am bummed that I didn't catch it right away, and do the cross scan to identify. It was a perfect training opportunity, and I blew it by transitioning to visual to confirm. I guess it was a good opportunity to get me thinking more about a possible failure, and how I will react next time.

I sure wish there was a way to simulate vacuum failure other than just covering up the instruments...that is a definite sign they have failed. It would be much more realistic to do partial panel with the "slow death" that actually occurs.

 

[gismo]

Re: Wish there was a way to simulate Vacuum Failure

I finished up my required training for my instrument checkride last week...I got lots of good information from this board, but unfortunately, never had anything too exciting to post about on here......until today.

I went up with my instructor to "finalize" a few things prior to my checkride, which is scheduled next week. We went over to the local uncontrolled field to shoot an NDB approach, missed, then hold at the NDB. Other than a quick brushup on outbound timing due to winds, all went well. We headed back to LZU, and I started verbally going over "what if" scenarios, and then giving the answers. I talked about pitot blockage, static blockage, and then vacuum pump failure. Then I pointed to the stand-by vacuum system, and went over my thoughts on how it worked just to make sure I completely understood. As we were getting vectored for the ILS, I noticed the AI was indicating a descending left turn. I thought, man, that is weird...but that's it. As I continued with the scan, I got back to the AI, which was now showing a steep descending turn. At this point, I would have ideally checked the vacuum guage. Unfortunately, I tilted my head back, and confirmed that we were straight and level with the actual horizon. THEN I looked at the suction guage, which was pegged to the bottom left. I knew there was no way to simulate actual vacuum failure other than covering up the AI/DG, but I questioned my CFII anyways...he said he was not messing with anything. I said, well then, I guess we have a real vacuum failure!

After all our partial panel training, I am bummed that I didn't catch it right away, and do the cross scan to identify. It was a perfect training opportunity, and I blew it by transitioning to visual to confirm. I guess it was a good opportunity to get me thinking more about a possible failure, and how I will react next time.

I sure wish there was a way to simulate vacuum failure other than just covering up the instruments...that is a definite sign they have failed. It would be much more realistic to do partial panel with the "slow death" that actually occurs.

One way you can experience this is with a PC instrument procedures trainer like OnTop or Elite. I know OnTop allows you to set yourself up for a failure at a random point in your session and believe that Elite offers the same capability.

 

[Let'sgoflying!]

There is a way and it would be a real good idea. It would involve messing with the system and installing tubing and an out of sight valve for the cfi to twist surrepetitiously. I have heard of planes with them. There is some risk (legal and safety matters) to doing this to an airplane.

 

[Lance F]

Re: Wish there was a way to simulate Vacuum Failure

One way you can experience this is with a PC instrument procedures trainer like OnTop or Elite. I know OnTop allows you to set yourself up for a failure at a random point in your session and believe that Elite offers the same capability.

I have On Top and typically set it for a random failure. Even though I set the vacuum to fail and therefore KNOW it will fail, it still amazes me how long it can take to catch a very gradual loss of the AI. One must keep the TC in the scan (or use the TC as the primary instument for maintaining a constant heading as certain schools and certain highly regarded instructors teach).

 

[poadeleted20]

Re: Wish there was a way to simulate Vacuum Failure

I sure wish there was a way to simulate vacuum failure other than just covering up the instruments...that is a definite sign they have failed. It would be much more realistic to do partial panel with the "slow death" that actually occurs.

While that is all true, regrettably, the FAA has already considered and rejected that idea on the grounds that a vacuum shutoff device might be inadvertantly actuated in flight in IMC and cause a fatal accident. The best thing to do is find a flight training center with something like a Frasca 141/142, which allows a very realistic simulation of a vacuum failure. My instructional experience is that most students are badly burned the first time they see it in the sim, but learn fast, and are not as perplexed by it after that. My operational experience is that the sim sessions in the Frasca made all the difference in the world when I had my vacuum pump failure in IMC about 15 years ago -- piece of cake, it was, being the nth rather than 1st time I'd seen it happen.

 

[gibbons]

The guys at SimCom got me with a vacuum failure in the sim. I lost one engine soon after takeoff. We flew back around for an approach to minimums and a missed, then back around for another approach. During the whole thing the instructor failed the vacuum pump on the good engine. Yes, the Baron sim will fly inverted for a very short while.

 

[Bill]

Re: Wish there was a way to simulate Vacuum Failure

After all our partial panel training, I am bummed that I didn't catch it right away, and do the cross scan to identify.

In addition to scan, all of our club aircraft have bright red "low vacuum" lights up high on the panel, hard to miss. We also have bright red "low voltage" lights as well.

 

[EdFred]

I've had a failure in VMC. Interesting to see it happen. What? I'm not in a 70º banked dive, the horizon is right there!

 

[mikea]

Like you, I had the vacuum pump go bad while I was under the hood. It was during my PPL training and <b>I</b> didn't cheat by looking outside. I did wonder after a while why the DG was turning when I wasn't. Then my cheat was my CFI saying, "Look here." and pointing to the vacuum gauge. He told me how to fly using the TC and altimeter we continued the approach.

Like you I suspected he had failed it some way. I'm thinking it was like pulling a circuit breaker although I knew that wouldn't do it and I couldn't think of how you could fail it.

I asked, "How did you you do that?" He said, "I didn't."

$400 or so later my instruments were "unfailed."

 

[EdFred]

I wasn't under the hood. I was solo in a 152 before I had done any instrument training. I saw the AI start to tilt on me even though I was straight and level.