Ruling on passing the meeqaat without entering ihraam
Question

I passed the meeqaat when I was on board the plane. What should I do?.
Praise be to Allah.Entering ihraam from the meeqaat is one of the obligatory actions of Hajj and ‘Umrah. It is not permissible for anyone to pass the meeqaat without entering ihraam if he intends to do either Hajj or ‘Umrah, whether he comes by land, sea or air. 
Shaykh Muhammad ibn Saalih ibn ‘Uthaymeen (may Allaah have mercy on him) was asked about the ruling on passing the meeqaat without entering ihraam, and he replied as follows: If a person passes the meeqaat without entering ihraam, one of two scenarios must apply:  
Either he is intending to perform Hajj or ‘Umrah, in which case he must go back to it and enter ihraam for the ritual he intends to perform, Hajj or ‘Umrah; if he does not do that then he has omitted one of the obligatory actions of the pilgrimage and according to the scholars he must offer a ransom, a sacrifice to be slaughtered in Makkah and its meat distributed to the poor there; 
Or he passed it and does not intend to perform Hajj or ‘Umrah, in which case he does not have to do anything, regardless of whether he was away from Makkah for a long time or a short time. That is because if we say that he has to enter ihraam from the meeqaat, that would mean that it was obligatory for him to do Hajj or ‘Umrah more than once, but it was proven from the Prophet (peace and blessings of Allaah be upon him) that Hajj is obligatory only once in a lifetime, and if a person does more than that then it is a voluntary act of worship. This is the most correct scholarly view concerning the one who passes the meeqaat without entering ihraam, i.e., if he does not intend to do Hajj or ‘Umrah then he does not have to do anything, and he does not have to enter ihraam from the meeqaat. 
Fiqh al-‘Ibaadaat, 283; Fataawa Arkaan al-Islam, p. 513. 
Based on this, then what you should have done is to go back to the meeqaat after the plane landed and entered ihraam from there. If you did not go back and you entered ihraam after passing the meeqaat, then according to the scholars you have to slaughter a sheep and distribute its meat to the poor in Makkah. 
And Allaah knows best.