If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
On Tue, 07 Oct 2003 13:46:01 GMT Robert Moore wrote:
Brake temperature is only critical just after landing. That's why the wheels hubs on a Concorde are equipped with fans that run during ground stops. Not exactly a short hop aircraft. From my B-707 Flight Manual: MAXIMUM LGW FOR SHORT TRANSITS Takeoff must not be scheduled less than 40 mimutes after any landing in which the gross weights and operating conditions critical for wheel fusible plug melting energy levels have been exceeded. Well, the 707 is a pre-historic aircraft, and wheel fusible plug melting energy levels are usually not exceeded during a landing. -- _/_/_/ -=jh=- |
#12
|
|||
|
|||
Having flown the B737, and several of its variants, and been an FE on the
727, brake energy is a consideration. Long runways reduce that need, however short runways with heavy load factors can overheat the brakes. The problem can surface in two places. One is on the ground, and the explosion can kill those nearby. The other problem is in the air and happens some 20 mins after takeoff. The accumulated heat can, and has, caused a wheel well explosion. In particular a B727 over Mexico a number of years back. There is a brake energy chart, and for most slow turn arounds, it is usually a non issue. Short runways, heavy loads, and quick turnarounds raises the risk. Additionally, the other points that have been made about parts, weight, and so on are also valid. BTW the A320 et al series also have brake cooling fans, however they are only used over a certain temperature. Leaving the gear down after takeoff is not an option for cooling the brakes. The brake energy chart is what is followed. Leaving the gear down after takeoff (and it is done sometimes) to cools the wheels violates the takeoff criteria. With the gear down the aircraft does not meet the climb gradients on an engine failure. I would suggest that there is probably no one single reason the 737 has exposed main wheels, but many. And probably Boeing has some idea what it is doing. Simon |
#13
|
|||
|
|||
On 2003-10-08 21:41:30 -0700, (null) said:
Well, the 707 is a pre-historic aircraft, and wheel fusible plug melting energy levels are usually not exceeded during a landing. The 500-series Citation is considerably less prehistoric than the 707, but brake energy is a serious consideration. During checkrides, we had to sit for a good 15 minutes or so (consulting the brake energy chart for the exact time) after a full stop landing before we could take off again. The company learned the hard way on that one, one time doing a full stop followed by an abort and then melting the fusible plug. It's not difficult to imagine getting into similar trouble in real life operations. -- Larry Fransson Seattle, WA |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Speech: A Question of Loyalty: Gen. Billy Mitchell | Otis Willie | Military Aviation | 0 | September 25th 04 09:30 PM |
VOR/DME Approach Question | Chip Jones | Instrument Flight Rules | 47 | August 29th 04 05:03 AM |
A question on Airworthiness Inspection | Dave S | Home Built | 1 | August 10th 04 05:07 AM |
Phoenix AIM-54A (QUESTION) | Krztalizer | Naval Aviation | 10 | February 23rd 04 07:22 AM |
Question about Question 4488 | [email protected] | Instrument Flight Rules | 3 | October 27th 03 01:26 AM |