Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Emergency: When To Land Gear Up Or Not  
User currently offlineNorthwest727 From United States of America, joined Jul 2005, 491 posts, RR: 0
Posted (3 years 6 months 2 days 14 hours ago) and read 5555 times:

Lets say an aircraft has an emergency. When would a pilot decide to land with the gear up vs. gear down if a partial main landing gear extension has occurred (one of the gear is up while the others are down?

In addition, what about ditching the aircraft, other than water? Example, if a pilot of a PA28R should need to ditch the airplane, is there any terrain that would affect this choice of gear up vs. gear down? Example, corn fields vs. soybean fields, marshland vs. grass (prairie or a golf course),. pine trees vs. hardwood trees, rugged terrain vs. swamp vs. beach?

12 replies: All unread, jump to last
 
User currently offlineunattendedbag From United States of America, joined Oct 2003, 2325 posts, RR: 1
Reply 1, posted (3 years 6 months 2 days 14 hours ago) and read 5555 times:

Quoting Northwest727 (Thread starter):
When would a pilot decide to land with the gear up vs. gear down if a partial main landing gear extension has occurred (one of the gear is up while the others are down?

I would say, he/she should make that decision at least 3 minutes before touchdown.



Slower traffic, keep right
User currently offlineNorthwest727 From United States of America, joined Jul 2005, 491 posts, RR: 0
Reply 2, posted (3 years 6 months 2 days 14 hours ago) and read 5542 times:

Quoting unattendedbag (Reply 1):

I would say, he/she should make that decision at least 3 minutes before touchdown.

Appreciate the response, however, I was looking more for along the lines of short runway vs. long runway, runway material, weather, etc. Anything that would effect control-ability upon touchdown and survivability for the passengers. Maybe factor in airframe survivability as well, although that always takes back seat to passengers' lives.


User currently offlineWilco737 From Greenland, joined Jun 2004, 8991 posts, RR: 76
Reply 3, posted (3 years 6 months 2 days 13 hours ago) and read 5541 times:
AIRLINERS.NET CREW
HEAD MODERATOR

Quoting Northwest727 (Thread starter):

There are many many different opinions about that out there. Even in our manuals we only have guidelines what to do.
For a water landing it would be better to have gear up to achieve a smooth touchdown with the aft fuselage. Partial gear would make sense on a normal runway. Keep it 'in the air' as long as possible until some parts of the airplane touches the runway. A full gear up landing on a runway can be bad as well if the belly touches down and you basically cannot control the airplane to weer off to the left or right...
But this is all very theoretical and I hope I never have to make that decision.

wilco737
  



It it's not Boeing, I am not going.
User currently offlineViscount724 From Switzerland, joined Oct 2006, 25117 posts, RR: 22
Reply 4, posted (3 years 6 months 2 days 6 hours ago) and read 5342 times:

Quoting Wilco737 (Reply 3):
A full gear up landing on a runway can be bad as well if the belly touches down and you basically cannot control the airplane to veer off to the left or right...

Reminds me of the PIA 742 that landed gear up at ISB in 1986 (crew forgot to lower the gear). It stayed on the runway. Aircraft was repaired and returned to service.



User currently offlinemusang From United Kingdom, joined Apr 2001, 864 posts, RR: 7
Reply 5, posted (3 years 6 months 1 day 15 hours ago) and read 5141 times:

I would add to Wilco737's post by saying the guideline on the 737 is basically that you land with whatever gear combination you have. I would think the worst case scenario is only one main leg, but one main plus the nose didn't look too dramatic in the USAir landing at Greensboro.

The other basic philosophy is that even if landing on rough ground, use the gear because it will act as an initial shock absorber. The gear will either survive and help protect the fuselage from damage, or if the stresses are too high, it will rip off with minimal colateral damage.

As far as I'm aware, the only emergency landing 737s would be advised to do with the gear UP is on water.

Regards - musang


User currently offlineSEPilot From United States of America, joined Dec 2006, 6875 posts, RR: 46
Reply 6, posted (3 years 6 months 1 day 13 hours ago) and read 5016 times:

Landing gear up very seldom causes serious injury to passengers; every gear up accident I have read about that had serious consequences happened because the pilot did something stupid. If the pilot just treats it as a normal landing until the actual impact it almost always comes out OK.


The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineHaveBlue From United States of America, joined Jan 2004, 2104 posts, RR: 1
Reply 7, posted (3 years 6 months 1 day 5 hours ago) and read 4882 times:

An example of the decision your talking about happened a few miles from my house at New Smyrna Beach (EVB) airport. An F-4U Corsair, owned by Collins Foundation and newly restored was being test flown by veteran airshow pilot Dale Snodgrass. The right main gear refused to extend. Dale tried maneuvers in the air and additionally bouncing the plane off of the left gear to try to get the gear to extend. After exhausting all options, he retracted the left gear and opted for a belly landing. Because he shut down the engine prior to touchdown, and because of the Corsairs unique gull wing, little damage was done to the aircraft and it was repaired.

As a side note, and ironically, a pilot was forced to ditch that same F-4U back in '97 after running out of fuel. It was after years of restoration that Dale was taking it up for its first flights when the gear incident happened.



Here Here for Severe Clear!
User currently offlineInbound From Trinidad and Tobago, joined Sep 2001, 851 posts, RR: 2
Reply 8, posted (3 years 6 months 1 day 3 hours ago) and read 4855 times:

practiced partial gear up landing in 738 sim recently with right main not extended.

approach on one engine. good engine had to be shut down prior to touchdown. no speed brake or reversers available.

worked out fine. held off on left main, then eventually rested on right pod.
even with 15Kt xwind, was able to hold centre line and stop within reason....dry conditions this time.



Maintain own separation with terrain!
User currently offlinebjorn14 From Norway, joined Feb 2010, 3411 posts, RR: 2
Reply 9, posted (3 years 6 months 23 hours ago) and read 4793 times:

I was told its always best to try to land on a solid suface because what can happen is that the plane will dig into the ground and possibly flip over.


"I want to know the voice of God the rest is just details" --A. Einstein
User currently offlineKlaus From Germany, joined Jul 2001, 21442 posts, RR: 54
Reply 10, posted (3 years 6 months 18 hours ago) and read 4748 times:

I would guess that landing with whatever gear legs you manage to extend has to do with being able to slow down as far as possible before the unsupported wing ultimately loses too much lift and scrapes the ground. But by that point you should already be well below touchdown speed and the damage should be reduced that way, right?

It would seem plausible that spoilers might not be deployed to keep the unsupported wing afloat as long as possible.

And do I remember correctly that both the 747 and A380 should be able to land safely with at least one main landing gear leg per side extended (and the nose landing gear, of course) provided it is light enough (minimal fuel)?

[Edited 2011-02-23 06:11:02]

User currently offlineSEPilot From United States of America, joined Dec 2006, 6875 posts, RR: 46
Reply 11, posted (3 years 6 months 18 hours ago) and read 4743 times:

Quoting bjorn14 (Reply 9):
I was told its always best to try to land on a solid suface because what can happen is that the plane will dig into the ground and possibly flip over.

Correct. Also, even if the plane doesn't flip the irregular soft surface and chance of rocks are likely to do more damage to the plane than a hard, smooth runway does. I have seen a couple of aftermaths of belly landings on small planes; it's really surprising how little damage it does (except to the prop and engine.)



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offline113312 From United States of America, joined Apr 2005, 571 posts, RR: 1
Reply 12, posted (3 years 5 months 4 weeks 1 day 6 hours ago) and read 4542 times:

I would say that there isn't a cut and dry set of rules for this. In some cases, attempts to lower landing gear may make it impossible to raise it again. So landing with partial gear results and is not an option. It is almost always suggested that landing on water should be done with the landing gear retracted. Landing on a solid surface should be done with landing gear extended. The thought behind this is to absorb energy even if this means the landing gear will be sheared off. However, the aircraft has to be able to get to the point of the intended landing. When making an emergency landing off airport or on a runway, the pilot has to determine if the plane will reach the intended and safest point of touchdown with the landing gear extended. If that cannot be achieved, the only option might be to make the approach with the landing gear retracted and land in that state.

I was once faced with an engine failure, in a single engine plane, at night over mountainous terrain. I made a successful forced landing with the landing gear retracted and am convinced that the outcome would have been different had I attempted to land with the gear extended.


Top Of Page
Forum Index

Reply To This Topic Emergency: When To Land Gear Up Or Not
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
When To Land With The Lights? posted Sun Dec 7 2003 17:11:55 by Tarzanboy
To Backtrack Or Not To Backtrack? posted Sat Jan 16 2010 07:49:55 by BeakerLTN
To NAT Or Not To NAT? posted Tue Jul 14 2009 10:46:14 by Meristem
Opposite To "Positive Climb, Gear Up"? posted Wed May 6 2009 09:27:48 by RichM
F/As Told When To Prepare To Land? posted Tue Apr 10 2007 00:53:35 by CanadianNorth
To Soap Or Not To Soap? posted Tue Nov 28 2006 08:04:19 by Turbonytro
Flare Or Not To Flare? posted Mon Oct 30 2006 09:58:37 by GlobalVillage
When Committed To Land? posted Sun Feb 19 2006 09:35:35 by Nudelhirsch
When To Deploy Landing Gear? posted Fri Jul 8 2005 20:35:22 by Goinv
Best Place To Land In An Emergency? posted Thu Apr 28 2005 07:21:23 by Goinv
F/As Told When To Prepare To Land? posted Tue Apr 10 2007 00:53:35 by CanadianNorth
To Soap Or Not To Soap? posted Tue Nov 28 2006 08:04:19 by Turbonytro
Flare Or Not To Flare? posted Mon Oct 30 2006 09:58:37 by GlobalVillage
When Committed To Land? posted Sun Feb 19 2006 09:35:35 by Nudelhirsch
When To Deploy Landing Gear? posted Fri Jul 8 2005 20:35:22 by Goinv

Sponsor Message:
Printer friendly format