reducing "Crew-caused"
approach and landing
accidents 

Pilot-in-charge Monitored Approach

2013 Gulfstream 550 short touchdown Stansted UK

Brief account : 

The aircraft was vectored for a CAT I, ILS DME approach with the autopilot (AP) and autothrust (AT) engaged. Conditions at the time were below the CAT I approach minima. With the aircraft fully established on the approach, the AP and AT were disengaged at 1,600 ft aal and the aircraft was hand flown by the commander for the remainder of the approach and landing. The localiser was maintained, but the aircraft flew above the glidepath before descending through it. For reasons that could not be established, go-around mode was selected, which would have inhibited the EGPWS glideslope warnings. 

In the final stages of the approach the aircraft was well below the glideslope, causing it to strike the ILS localiser monitor aerial and the opposite runway localiser aerial array, before touching down short of the threshold causing minor damage to the gear and wing underside.

Crew-related factors : 

Personal Information on the crew is not available, nor is a CVR transcript.  The crew apparently conducted a briefing, and the Captain started an automatic approach with an RVR of 250 m increasing to 300m (both of which were below hte 550m minimum for the operation), and broken cloud at 100ft. 

The autopilot initially captured the ILS, but at about 5 miles the flaps were selected to full down above the limit speed. Shortly after, the autopilot and autothrust were disconnected with the aircraft significantly high on the glideslope. It was unstable throughout the approach being both high and fast until about 1 mle out when it passed through the glideslope as the pilot corrected. "The aircraft continued to decelerate and then descended below the glideslope, reaching 4 dots deviation as the aircraft collided with the localiser antenna at 19 ft agl.  

The pilots commented that they had been able to see approach and runway lights (but not the VASI) from several miles out. However this appeared to have been a textbook shallow fog - the Captain of an aircraft making a Cat 3 autoland 6 minutes earlier commented on entering the fog bank at around 100ft.  

This near-disaster appears to be a classic example of the reasons why the NTSB Special Study in 1974 emphasised the need for continuous monitoring of the instruments to touchdown. Instead as the report commented "The fact that the pilots could see the runway and approach lighting caused them to believe that, as long as they remained visual with these landing references, they would comply with their company procedures and thus could continue their approach."

If PicMA had been in use 

1) the approach would likely have been conducted more in accordance with SOPs, and not become unstable

2) the descent below the glideslope starting at 300 ft would have been noted.  

Type: 
Gulfstream 550
Where: 
Stansted UK
Expected weather: 
Instrument
Pilot in charge: 
Capt
Early transition: 
Yes
Go-around : 
No
Damage: 
Minor or none
PicMA potential: 
Major
Year: 
2013
Time: 
Night
Deterioration: 
No
Vert Guidance: 
G/S
Both Head Up: 
Yes
LoC: 
No
Operator: 
CHarter
Fully prepared: 
Yes
Actual Weather: 
Fog
Autopilot : 
N
CCAG: 
Normal