“How often do planes crash?”/“Just once.”

An airplane riddle is often given as a passenger question to a flight attendant:
 
Q (passenger): How often does a plane crash?
A (flight attendant): Only once.

 
Or:
 
Q (passenger): How often do planes crash?
A (flight attendant): Just once.

 
“Isn’t that like the ‘how often do planes crash?’ question? Just the once, usually” was posted on the newsgroup uk.comp.sys.mac on June 21, 2002. The joke has been printed on several images.
           
   
Google Groups: uk.comp.sys.mac
Mac OS 10.1.5 ate my iMac
Rowland McDonnell
6/21/02
(...)
> Isn’t that like the “how often do planes crash?” question? Just the once,
> usually :(
 
Google Groups: alt.religion.christian.roman-catholic
Sign From God: Pilots’ Prayers for Safe Landing Are Answered  
Christopher A. Lee
5/22/08
(...)
How often do planes crash?
Once.
 
Google Groups: rec.travel.air
Mid-air panic as plane plunges 26,000 feet  
Rog’
8/27/08
(...)
Pilot humor:
Question… “How often does a plane crash?”
Answer is… “Once.”
 
Twitter
Roberto Is Magic
@RobertoIsMagic
Whenever someone asks the question ‘How often do planes crash?’ the answer is “Once.”
10:52 AM · Mar 7, 2013·Twitter for iPhone
   
Twitter
Thomas Dodson Lives In Nashville Now
@shockthomas
how often do planes crash like that?
just once.
4:31 PM · Jul 6, 2013·Sprout Social
   
Twitter
Carly Milverton
@FewerMorals
How often do planes crash? Only once. #HappyThoughts
11:12 AM · Mar 31, 2014·Twitter Web Client
 
Reddit—Jokes   
Posted by u/captain_cup June 29, 2019
How often do planes crash?
Just once.
 
Twitter
Villi Wilson❌
@Conservative_VW
The old lady next to me on the plane asked me, “how often do planes crash?”
I replied to her, “just once”
12:38 PM · Jul 1, 2019·Twitter for iPhone
   
Reddit—Jokes
Posted by u/JP-Seven September 24, 2019
Passenger asked a flight attended “How often do planes crash?”
Flight attended “Just once.”
 
Twitter
Mike the Italian Lion 🇮🇹 🇮🇹
@Italianmike
It’s time again for ......Friday Funnies !!! 😂😂
A nervous 1st time flyer stopped the Flight attendant and asked
How often does a plane crash
The attendant said with a straight face
Only once !! 😳
4:02 PM · Oct 18, 2019·Twitter Web App
 
Twitter
Ralph Nelson Willett
@NorthernOvation
Q:  How often does a plane crash?
A: Only once.
#Joke
10:55 PM · Nov 21, 2019·NorthernOvationMediaBot
   
Twitter 
Buck Woody
@BuckWoodyMSFT
The lady in the seat next to me was nervous about flying. She said “How often do planes crash?” So I told her “Just the one time, normally.”
7:46 PM · Dec 8, 2019 from Safety Harbor, FL·Twitter for Android
 
Reddit—Jokes
Posted by u/31moreyears January 11, 2020
Passenger: How often do planes crash?
Flight attendant: Just once