{"action":"created","issue":{"url":"https://api.github.com/repos/PX4/Firmware/issues/10185","repository_url":"https://api.github.com/repos/PX4/Firmware","labels_url":"https://api.github.com/repos/PX4/Firmware/issues/10185/labels{/name}","comments_url":"https://api.github.com/repos/PX4/Firmware/issues/10185/comments","events_url":"https://api.github.com/repos/PX4/Firmware/issues/10185/events","html_url":"https://github.com/PX4/Firmware/issues/10185","id":348474327,"node_id":"MDU6SXNzdWUzNDg0NzQzMjc=","number":10185,"title":"VTOL: Return behaves dangerously in some situations.","user":{"login":"tubeme","id":12617619,"node_id":"MDQ6VXNlcjEyNjE3NjE5","avatar_url":"https://avatars1.githubusercontent.com/u/12617619?v=4","gravatar_id":"","url":"https://api.github.com/users/tubeme","html_url":"https://github.com/tubeme","followers_url":"https://api.github.com/users/tubeme/followers","following_url":"https://api.github.com/users/tubeme/following{/other_user}","gists_url":"https://api.github.com/users/tubeme/gists{/gist_id}","starred_url":"https://api.github.com/users/tubeme/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/tubeme/subscriptions","organizations_url":"https://api.github.com/users/tubeme/orgs","repos_url":"https://api.github.com/users/tubeme/repos","events_url":"https://api.github.com/users/tubeme/events{/privacy}","received_events_url":"https://api.github.com/users/tubeme/received_events","type":"User","site_admin":false},"labels":[{"id":10884838,"node_id":"MDU6TGFiZWwxMDg4NDgzOA==","url":"https://api.github.com/repos/PX4/Firmware/labels/bug","name":"bug","color":"fc2929","default":true},{"id":249514594,"node_id":"MDU6TGFiZWwyNDk1MTQ1OTQ=","url":"https://api.github.com/repos/PX4/Firmware/labels/vtol","name":"vtol","color":"bfe5bf","default":false}],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":9,"created_at":"2018-08-07T20:26:11Z","updated_at":"2018-10-27T21:52:43Z","closed_at":null,"author_association":"NONE","body":"Hello guys,\n\nI define it as feature request although it has bug connotation to it.\n\nWe've had this discussion on the git before about how should the VTOL Return function be implemented.\n\nFour days ago we had a total crash of our plane fully loaded ~10k US.\n\nThis was a case where the Return original behavior though consistent somehow crashed the plane.\n\nWe had to perform a mission flight at 1000 m height. So we prefer to gain the altitude by hand or in big loiter and when the altitude is gained we activate the mission.\nEverything went ok at first. The pilot gained altitude but at that height you barely see the VTOL. He climbed to 1000m and activated the mission. But there was something wrong with the mission. So he decided to abort the mission. During this moments the plane was gone in Position for 30 seconds in one direction. The pilot could not find the vtol in the sky so by telemetry in the QGC he saw where the plane is and decided to activate Return. He told me \"I could not see the plane but I heard the motors of the quad ramping and the plane obviously transitioning to MC.\" \n\nSo imagine in this moment if you want to perform RTL. 1000m descending in MC with 1.5m/s... If it is emergency landing there is no way the battery could hold 1000m.\n\nThe pilot then decided to make a transition back to FW flight.  He is not sure what he had done with the controls in this situation, either he removed the Return mode and continued on POS or just flipped the transition switch while in Return mode... The result is that the moment he saw the VTOL it was nosediving in FW flight 80 degrees down to the lake without any control what so ever.\n\nWe try to retrieve the plane with divers to recover the SD card with LOGS if possible and SD card with video. No luck so far...\n\nWe have the auto-saved .tlog files but the qgroundcontrol is somehow broken and does not want to replay the .tlog files.\n\nThe main point is we want to have RTL or Return for the VTOL to behave exactly like an airplane up to the moment it reaches the RTL_DESCEND_ALT altitude. Then it will loiter for the wait period then transition and land. \n\nIf this was the implemented behavior,  in our situation the pilot could activate Return mode the VTOL could have spiraled down to 30 meters probably, make a loiter for the waiting period and then transition to MC and land.\n\nAlso in missions if we want to use the Return command at the end of the mission to return the vtol it will perform the return at current altitude and transition, and then start in MC to descend. This makes us to have to program the return with descending points before we land at the end of the mission. If the return is implemented correctly the end of the mission could be just using the RTL point in the route planner.\n\nBecause there are people that would like to have the current behavior it might be enabled or disabled with parameter.\n\nAt least this is a 10k US lesson learned."},"comment":{"url":"https://api.github.com/repos/PX4/Firmware/issues/comments/433657942","html_url":"https://github.com/PX4/Firmware/issues/10185#issuecomment-433657942","issue_url":"https://api.github.com/repos/PX4/Firmware/issues/10185","id":433657942,"node_id":"MDEyOklzc3VlQ29tbWVudDQzMzY1Nzk0Mg==","user":{"login":"LorenzMeier","id":1208119,"node_id":"MDQ6VXNlcjEyMDgxMTk=","avatar_url":"https://avatars3.githubusercontent.com/u/1208119?v=4","gravatar_id":"","url":"https://api.github.com/users/LorenzMeier","html_url":"https://github.com/LorenzMeier","followers_url":"https://api.github.com/users/LorenzMeier/followers","following_url":"https://api.github.com/users/LorenzMeier/following{/other_user}","gists_url":"https://api.github.com/users/LorenzMeier/gists{/gist_id}","starred_url":"https://api.github.com/users/LorenzMeier/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/LorenzMeier/subscriptions","organizations_url":"https://api.github.com/users/LorenzMeier/orgs","repos_url":"https://api.github.com/users/LorenzMeier/repos","events_url":"https://api.github.com/users/LorenzMeier/events{/privacy}","received_events_url":"https://api.github.com/users/LorenzMeier/received_events","type":"User","site_admin":false},"created_at":"2018-10-27T21:52:43Z","updated_at":"2018-10-27T21:52:43Z","author_association":"MEMBER","body":"@tubeme There are different use cases with different priorities. What you are describing is not really a software fault but something that in your (very particular) operating configuration is understandably an issue. You're more than welcome to contribute the required change or, alternatively, engage with one of the organizations offering commercial support for PX4 to get it added at a faster pace.\r\n\r\nThere are many other things that need to get done for PX4, many of them affecting a far larger user base. Other companies I know of solve this by having their own developers or by contracting a consultant to contribute it. Just raising it in the issue tracker repeatedly won't get it implemented.\r\n\r\nOpen source is about collaboratively solving a problem. I'm happy to discuss offline how to best get there. Thanks!"}}
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