The Gemara (Brachot 54b) lists four types of experiences when one should recite Birkat Hagomel upon emerging in good health from these situations. The four cases are: “those who have traveled on the sea, those who have traveled in the desert, those who have recovered from illness, and those who were released from prison.” The Rishonim disagree if the Gemara limits the requirement of reciting Birkat Hagomel specifically to those four cases. However, we are accustomed to recite Hagomel after emerging in good health from any dangerous situation, as the Magen Avraham notes (Orach Chaim 219:10).
Furthermore, the Rishonim disagree about the circumstances in which one is required to say the blessing on Hagomel. On one hand, the Ramban (commenting on Brachot 54b) asserts that one must say Hagomel after traveling regardless as to whether there was any element of danger involved. His contention is predicated on the statement that appears in the Gemara Yerushalmi (Brachot 4:4) “all roads are assumed to be dangerous.” On the other hand, the Meiri (also commenting on Brachot 54b) cites an opinion which contends that Hagomel is required only if one had encountered serious danger while traveling. For example, if one was lost and later found his way, he would be required to bless Hagomel.
However, the Talmidei Rabbeniu Yona (43a in the pages of the Rif) offer a compromise between the Ramban and the opinion quoted in the Meiri. They cite the opinion of the French Ravs that say that one should recite Hagomel only when one has traveled on a dangerous road. Hence, the custom of French Jews was not to bless Hagomel after intercity travel because they did not consider travel on the roads of France to be dangerous.
The French Ravs interpret the aforementioned quote from the Gemara Yerushalmi to be referring to Tefilat Haderech, where one is required to say this Tefila regardless of the degree of danger in the journey. However, this opinion disagrees with the opinion quoted by the Meiri, in that if one has traveled on a dangerous road he must recite Hagomel whether a serious incident has occurred or not. The Shulchan Aruch cites this view as the practice of German and French Jews (Orach Chaim 219:7).
Accordingly, it is the practice of Ashkenazic Jews to recite Hagomel only after traveling on a dangerous road. Hence, the question posed to us as to whether one should recite Hagomel after airplane travel, is contingent upon whether one considers airplane travel to be dangerous. Rav Lichtenstein Shlita has informed me that it is Rav Yosef Dov Soloveitchick zt”l’s practice not to recite Birkat Hagomel after airplane travel, unless a serious incident had occurred. Nevertheless, Rav Lichtenstein recalls the Rav saying that if an individual perceives airplane travel to be dangerous, he should recite Hagomel.
Rav Moshe Feinstien zt”l (Igrot Moshe Orach Chaim 2:50), however, has an entirely different approach to our question. He believes that the degree of danger involved in airplane travel is irrelevant to our question. Rav Moshe asserts that the Machloket Rishonim we have discussed pertains only to the category of traveling on land. Airplane travel, though, is in the category of one who travels on the sea. Everyone who travels on the sea by definition is in a dangerous situation and therefore should recite Hagomel when he arrives on land.
Rav Moshe explains that traveling on the sea puts on in a position on tremendous vulnerability. He explains that if a boat malfunctions and sinks, the passengers will be forced into the sea, where they could survive for only a few minutes. Similarly, if an airplane, Chas Vishalom (G-d Forbid), should malfunction, the passengers would be doomed. However, if one’s car seized to function properly, he merely drives the car to the side of the road and is reasonably safe.
Therefore, despite the fact that airplane travel may be safer then traveling on land from a statistic perspective, in the former case one is required to recite Hagomel, whereas in the latter case he is not. Accordingly, the question as to whether one should recite Hagomel after airplane travel is a matter of controversy between the two Torah giants of the past generation, Rav Feinstein and Rav Soloveitchik. It should be noted, however, that each Rabbi maintains his perspective irrespective of whether a plane flies over land or sea.