LOSS OF AIRSPEED INDICATOR on night takeoff with dual GI 275's in a Mooney Ovation!!!
ฝัง
- เผยแพร่เมื่อ 2 ธ.ค. 2020
- After having had several configuration changes done to the top GI 275 unit so that it would drive my KFC 150 autopilot on an ILS I took off at night for a flight and although the airspeed indicator "came alive" on the takeoff roll when I looked back at it as I was up in the air it only read 35 kts!! And then it quickly went to ZERO!! Had to first AVIATE, then navigate and communicate.
Thank you for sharing this. This can help so many people. It sure did help me. It will definitely help me to slow down and not loose focus on what is important and to be super careful about distractions.
Thank you for your comment. Yep, we all need to slow down and be methodical. :)
This was an excellent video Chris. Kudos for sharing and great job getting to a positive outcome. Every one of us makes mistakes in (and out) of the cockpit. Successfully managing these situations and learning how to avoid them again is what matters. A couple of interesting takeaways:
1/ "Airspeed alive" is not sufficient to determine proper ASI operation on the takeoff roll. In addition, the pilot should subsequently verify rotation speed (Vr) prior to initiating rotation.
2/ Know pitch attitude and power settings and regularly practice (with a safety pilot) loss of ASI at a safe altitude.
3/ Even with all the redundancy in your panel, including the iPad, a single point failure existed that rendered 3 out 4 speed sources (two IAS and one GS in the iPad). Ironically it was the oldest piece of avionics that gave you what you needed!
Again, well done!
Great comments and thank you FlightPractitioner! By the time I verified Vr I was already up in the air since I was so light. So no choice but to keep on going. After this event I set up a page in my newly installed GI-275 Standby ADI/MFD to give GS that is sent from the 530W or its internal VFR GPS in case the 530 fails. Next time I lose ASI for any reason (hopefully not a forgotten pitot cover!) I can just turn to that page so don’t need to look at the 530 which is a bit out of direct view.
Way to go Chris, talking about your mistake so others can learn. Nicely flown, too.
Thank you Sharklet320. I believe that it is waaay better to learn from other people's mistakes than from one's own mistakes. So why not put out my own? :)
@@chriskoppel3940 Exactly. Thanks for doing so! All the best to you!
This is why I do the "dummy check" before I get in my plane to start. Its my last chance to see if I left anything obvious (chocks, pitot cover, or heater plugged in). Glad it was something simple yet frustrating.
A "dummy check" is a smart check! Hopefully we are able to catch all of our dummy human errors! Of course, we could also be distracted from the dummy check in case of poor mindset. That's where IMSAFE check also comes in.
Great job managing the situation. Thanks for sharing.
Thank you!
Our flying club airplane has a pitot cover back in the baggage compartment along with a spare quart of oil, the folding stepstool, and the emergency tiedowns.
As a rule, we don't cover the pitot in the hangar. If we ever experienced mud wasps in the hangar, maybe we would. We do have the advantage of being able to see the pitot from the cockpit.
I remember taking off as a student getting dual in a C-150 with a wasp-plugged pitot. When I realized we had no airspeed, there wasn't enough of the 2,700' runway left to abort.
The instructor treated it as a learning experience, and I flew to the destination airport without incident by listening to the air and feeling the controls. (This being in 1987, there was no source of groundspeed information on board).
We would have felt smarter about having handled the situation if we'd thought to inspect the pitot before departure back to home base. Alas, we did not, so I had more no-airspeed practice on the way home.
Great learning experience for you and me!!
It was a first time for me since I started flying. I did forget to close the door once as a student. I now also verify that it's in the "hat" compartment or on my flight bag as part of the pre-start checklist.
Thank you for your comment!!
Wow, thanks for stepping up and sharing. I’ve not done that but have come close a couple of times. I did forget to latch oil door one time and it blew open on take off roll. The interesting thing on that one, was I had a gut feeling prior to take off that I had not inserted the dipstick back in fully. Well it wasn’t the dipstick that was a problem and giving me concerned senses but the oil door itself. Lesson to self; if a question comes up in your mind or gut, check it out. I kept telling myself during the taxi that I was okay and besides I did not want to stop the engine and get out. Laziness. I have one other incident that I’m not ready to share that was far more serious. Distracted in all cases doing the preflight. So, I will walk around 2 to 3 times now, double checking fuel caps, baggage door, pitot cover, tire condition etc. Thanks again for sharing.
Welcome Robert! We are human and will commit mistakes. Hopefully we can learn from others before we have to “learn it” ourselves. ;)
@@chriskoppel3940 Yes, we all do indeed make mistakes. I enjoy reading the NTSB accident synopsis upon occasion. By the way, I’m drooling over the GI275s for my ‘66 Bellanca 260. Looking forward to more of your videos. No need to reply back. Thanks again Chris.
The first thing I thought was icing without turning the pitot heat on. Something I have done. Then I remembered that you live in Florida. I would say that your "learn" was wrong. It's not leaving the cover on It's what caused the problem and that is the distraction. This could have been leaving a tie down on which could have ripped out and caused real damage. I have seen it done when a guy who was distracted with his family. In my opinion the "learn" should be what happened, what caused it, and what procedure would have stopped it from happening.
When I do a preflight there are two things I ALWAYS do. #1- all passengers must be in one area away from the plane and they have to stay there until the preflight is complete. This actually has a bonus because the passengers see just how serious you take being pilot in command is. If I can I try to keep them in the FBO lobby until the preflight is done. #2- If for any reason I am distracted I restart the preflight from the beginning after stopping the preflight for any reason. No matter how many times it happens. I go at the same pace every time and have full attention on the preflight.
Great presentation Chris!
Wow, Airspeed alive! Doesn’t mean the airspeed system is alive anymore.... - a -
Thank you A C! Yep, it "died" shortly thereafter!
Interesting case. Thanks for sharing. Nicely executed "abnormal" landing. Was there any action taken to prevent the same from happening again? Maybe using a larger pitot cover that also covers that drain hole or one with a long flag, that can be thrown over the wing so it can be seen from the cabin? We all have been in that position with distractions etc... aleays nice to have some last line of defense against human errors...
Thank you for your comment Benno!
For me the preventive action was recognizing that a distraction occurred and to go back where I was at the time. My line of work lends itself to the same so I apply the principle to both . I had not heard of a flag that could be thrown over the wing although if the plane were to be outside that flag could be blown off.
Unfortunately human errors are human. There are people who walk into doors etc. Once the brain is focused on something else it can easily ignore audible and visual alarms. It will even not really process a checklist correctly. There have been pilots that have landed gear up even with the gear horn blaring away.
So.... Hopefully we are able to either remove distractions or "reset" after a distraction as someone else commented on this video.
Everyone should practice for this. Power and attitude will give the performance, and if you know exactly what your stall warner / aircraft feels like at slow speed you've got another indication of certain airspeeds. Fortunately I can see my pitot cover from the cockpit, however I like to know I can still comfortably fly and land if for some reason I was to lose airspeed indication.
There are two types of people; those who have done it and those who won’t admit they’ve done it. Nice work on getting home safely. I’m FHB and would like to discuss the 275s with you. I’m going that route as well. I don’t know the guys on the field and would like to bend get your feedback on their side too. I’m having Sarasota avionics upgrade my 430w to the gtn650xi very soon but holding off the 275s for just a bit. Would be super convenient if the guys here could do the work.
Would be Happy to talk with you about the 275’s install and the work done at AATG. I am going to the airport this morning to fly with a friend in his Mooney to do some approaches. Could meet with you at your hangar when we get back around 1230.
@@chriskoppel3940 sounds good. I don’t have a hangar but I’m tied down on the ramp along the fence. Would like to meet some more people around the hangars, I’ve only been here a couple months.
At the airport now and not going flying. You can come out and meet at the quonset hangar, west of you. Saw your plane.
Send email or phone so I can contact you
@@chriskoppel3940 I’m on my way out there.
How come you removed the Traditional airspeed indicator as well as the simple turn and bank indicator? Would make good mechanical backups.
Good question Dilithium. I did not want extra stuff hanging on the pitot-static system and create a point of failure. Also would be distracting and use up space. In addition, in case of pitot tube icing up or another failure in the pitot tube would also affect the mechanical indicator. Only circumstance in which it could help would be in failure of both 275's not showing airspeed. Still have ground speed on 530 and iPad to assist.
True coordinator gyro was getting old because you could hear the gyro whining loudly. Did not want to overhaul and so use up space.
I have a video coming up where I show another pito failure and then turn off other inputs to the 275's to see how they perform. They were flawless.
You mean to tell me the Ki275 will display airspeed live with the pitot tube plugged…. That just made my mind up on garmin.. I am sticking with my king steam gauges.
Seems like when the pitot is covered by the pitot tube cover it is not fully obstructed. Garmin also compares IAS vs GS vs TAS and will blank out display of IAS when there is sufficient diacrepancy. If you notice, I believe the IAS display went blank around 30-40 kt.
Of course GS will always be available as long as GPS is working.
Look at another video I posted where I was able to put the GI275's through "torture" tests.
In my experience Garmin has superb software in their digital equipment.
I carry my pitot tube with me and put it on the glareshield until i pull up to the runway. I didn't leave the ground because someone stopped me but it changed how I do things
That is a good idea. Put it where it is in the initial cockpit flow check. Then put in your flight bag or side pocket. 👍
Most folks leave their pitot tube on the wing. It works better there. :-)
Glad this worked out. We can all get distracted. I suggest reinstalling your traditional ASI. That original item would of helped in this scenario.....another great post. Keep them coming!
The original ASI would have shared the same pitot static plumbing as the dual 275's and therefore not really more helpful than the standby ADI (bottom unit). I never took off with the pitot cover on with the old ASI and so not sure if the needle would have moved up a bit (sufficient to register 23 kts or somewhat less?). The reason I did not keep it installed is that its diaphragm and additional connection can be a point of failure. I like the KISS approach.
Since it always "comes alive" at 23 KIAS under normal conditions what I do now is to not only verify it "comes alive" at 23 but also continues up past 40 KIAS and then focus on the runway. Plane takes off when it's ready based on weight etc, not at an arbitrary number anyway.
Ideally one should have the second unit connected to a separate and redundant pitot-static plumbing system but that is not the custom in GA. Even so one should remember to remove the cover on that one too! A friend of mine who flew B-52's says that they had dual pitot-static systems and when the crew chief forgot to take the covers off the pitot tubes they would use pitot heat to burn them off (they were made of leather) and on they went. No way to abort the bombing mission!!
@@chriskoppel3940 I am a subscriber to KISS as well! I think the needle not moving on a traditional ASI would of helped you clearly abort the takeoff. Your post has made me realize that I need to teach my friends and students with light GA planes with an EFIS to cross-check the ASI indication on the roll like it is done in turbo props and jets with one or two crew.....I remember “50 kts, cross-check” call outs in most of the two pilot turbines I flew back in the day. This is especially try with all the ADAHRS failures and “red-x’s” everyone seems to get at the worst moment in light GA. great B52 story! My wife’s godfather was a B52 driver in Nam. Will see if he ever had to do the procedure:)
I have not had a chance to call Garmin to find out why the ASI goes directly to 23 in normal conditions and why it even moved up to 23-35 with the pitot cover on. Was it porous enough to let through some ram air? Other reason such as their internal algorithm? I will do an experiment where I totally seal it and do a brief takeoff on a looong runway and see if it still "comes alive".
As I mentioned, I have changed my procedure with this unit to verify it continues to move up past 40 kias. By 50 I am too close to takeoff point already and need to be focusing outside the cockpit.
Please thank your wife's godfather for his service and I am curious as to whether his crew chief ever forgot to remove the covers. ;)
I had a similar thing happen on two different night flights in a rental 172 during the summer in San Antonio. I lost airspeed just after takeoff. After I got things sorted out, I got out my flashlight to see if I had inadvertently done something wrong. While turning on the lights I had also turned on the pitot heat. Turned it off and the airspeed came back in seconds. Explain that one to me.
Sounds like the pitot tube may have had some small partial obstruction (bug, spider web,...) and it also had sufficient moisture to clog it up. It cleared up with the pitot heat.
I had a similar issue once about 2-3 nile final after flying through some rain in S. FL when my KIAS stayed at 60 Kts which made me think I was slow. In response I kept on adding power and landed further down the runway than expected. Taxied with KIAS at 60 as well!!! Cleared up after a few min of pitot heat.
Even without rain or moisture the pitot heat obviously burnt away whatever the obstruction was you had. I have a friend who flew B-52's and he told me that the crew chief was in charge of removing the pitot covers that were made of leather. Every once in a while the crew chief would forget to remove the covers and they would burn them off with the pitot heat rather than RTB and possibly scrub the mission. Had they been made of nylon it would not have been a good idea to turn the pitiot heat on....
@@chriskoppel3940 It's the other way around. Turning OFF the heat brought airspeed back. Happened twice, same plane. No moisture in San Antonio.
@@rnordquest Ahhh.... misread your first comment.
Hmmm.... hard to explain. Only thing that comes to mind is that there may have been some plastic debris that would melt in such a way to obstruct the pitot when heated and when back to solid after turning heat off would change shape to make the opening patent. Definitely a head scratcher!!!
I had a similar malfunction, and I noticed the airspeed was incorrect on takeoff. I should have aborted, but didn't. Anyways, the trick is to look at the groundspeed and ignore airspeed, and get it back on the ground as fast as possible.
It had just come from the avionics shop (first clue). It turned out the pitot-static system had been misconnected.
Agree, but once in the air it is difficult to make the decision to land right away. Groundspeed becomes primary and very important either way!
Glad it worked out well for you!!
@@chriskoppel3940 Not even close in difficulty. It was midday with no clouds.
There's such an easy fix for this - will never happen again. Tie a 10ft. string of yarn from the pitot cover and loop it over the prop. There's no way you won't see that from the left seat before you start the engine. Stupid simple.
That sounds like it would work. However, we happen to be human beings and will on occasion develop tunnel vision because our brain is preoccupied with something else and we have read of pilots landing gear up in spite of the gear horn blaring away. If the pilot were to start the engine with the string around the prop I can imagine the string wrapping itself around the prop as well as ripping the pitot tube off the wing. That would be quite expensive to repair and kill the flight completely. Taking off with pitot tube cover just disables the ASI and one can fly the plane with ground speed, power, attitude and come back to the field and land.
According to a friend of mine who flew B-52's, they would have leather pitot tube covers that would melt with pitot heat when the crew chief would forget to remove them. No way to turn around from a time critical mission just to remove them. Just burn them off!!