Talk:Rejected takeoff

Wind shear
In April 2018, the lead was amended to add “environmental conditions such as windshear” as an example of one of the usual causes of rejected takeoffs. See the diff. On 29 October 2022 I noticed this, and deleted mention of windshear. My edit summary said “It is inconceivable that a takeoff might be aborted due to wind shear. Wind shear might become evident while climbing or descending but it couldn’t become evident while accelerating along a runway.” See my diff.

On 19 November 2022 reverted my edit. His edit summary said “Windshear is a reason to reject a takeoff, see https://www.aeroinside.com/15888/tui-nederland-b38m-at-groningen-on-jul-5th-2021-rejected-takeoff-due-to-windshear-alert or https://www.michiganradio.org/offbeat/2011-04-04/aborted-takeoff-attributed-to-wind-shear-fears or https://www.skybrary.aero/accidents-and-incidents/b738-east-midlands-uk-2020 “. See the diff

I have looked at the three sources mentioned by Cagliost. I can make the following comments:
 * 1) www.aeroinside.com - “rejected takeoff at low speed after receiving a wind shear alert.” This was not a takeoff rejected due to wind shear. The pilots received a cockpit alert and responded correctly by rejecting the takeoff. The alert happened to be for predicted wind shear.
 * 2) www.michiganradio.org - “taxiing down the runway when the wind shear signal went off … A dangerous wind shear was not confirmed, but could have been caused by thunderstorms in the area”. This takeoff was rejected when the pilots received a wind shear signal. Whenever a crew detects a warning or an alert at a speed below V1, the correct response is to reject the takeoff, not assess the details of the warning and decide how important it is.
 * 3) www.skybrary.aero - “as the speed approached V1, the aircraft deviated dramatically from the centreline to the right – he estimated the deviation was 20/30 degrees – and saw a downward trend on his airspeed indication. He stated that he had felt that the SFO’s attempts to control the heading were ineffective and perceiving that the indicated airspeed was reducing and the aircraft was still below V1, he had taken control, called “Stop” and commenced a RTO.” This takeoff was rejected following significant deviation from the centreline, and the SFO’s inability to control the heading. It is incorrect to imagine this RTO was related to wind shear or a warning of predicted wind shear.

Mentioning wind shear in the opening paragraph in the lead is inappropriate. MOS:OPEN is relevant. The opening paragraph should introduce the topic but without being too specific.

I will revise the opening paragraph to make it more consistent with MOS:OPEN. Dolphin ( t ) 12:23, 20 November 2022 (UTC)


 * I don't agree with your summaries of those sources. For sources 1 and 2, you try to draw a distinction between rejecting a takeoff because of a warning or alert, versus rejecting a takeoff because of windshear. But this is a distinction without a difference. If a takeoff is rejected because of a windshear alert, it is rejected because of windshear. Source 3 plainly states in the first sentence "a Boeing 737-800 rejected its takeoff from East Midlands from a speed above V1 after encountering windshear". Other editors who read the article will find the focus of the article is entirely on windshear. We should go by what the source says, not your personal interpretation of the accident.


 * Predictive windshear alerts are a reason to reject the takeoff, so I have amended the article to make this clear. If you remove detail from the opening paragraph, you should try to include it elsewhere in the article. If you want to expunge the detail entirely, MOS:OPEN is not sufficient reason to do so. I have restored the detail in a separate paragraph. cagliost (talk) 12:45, 20 November 2022 (UTC)

By the way, actual ("reactive") windshear can be detected on the ground, even though "reactive windshear warnings are not active until the aircraft is airborne." Windshear is any change in wind velocity, which can happen on the ground just as in the air. Symptoms include significant fluctuations in airspeed during the takeoff ground roll, as described in the Skybrary source. Other situations in which windshear could lead to an RTO include windshear being reported by other aircraft ahead in the climb, or by ATC (who have Doppler radar to detect windshear). cagliost (talk) 14:52, 20 November 2022 (UTC)